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Bibliography on: Microbiome

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ESP: PubMed Auto Bibliography 21 May 2019 at 01:44 Created: 

Microbiome

It has long been known that every multicellular organism coexists with large prokaryotic ecosystems — microbiomes — that completely cover its surfaces, external and internal. Recent studies have shown that these associated microbiomes are not mere contamination, but instead have profound effects upon the function and fitness of the multicellular organism. We now know that all MCEs are actually functional composites, holobionts, composed of more prokaryotic cells than eukaryotic cells and expressing more prokaryotic genes than eukaryotic genes. A full understanding of the biology of "individual" eukaryotes will now depend on an understanding of their associated microbiomes.

Created with PubMed® Query: microbiome[tiab] NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

RevDate: 2019-05-20

Regar RK, Gaur VK, Bajaj A, et al (2019)

Comparative microbiome analysis of two different long-term pesticide contaminated soils revealed the anthropogenic influence on functional potential of microbial communities.

The Science of the total environment, 681:413-423 pii:S0048-9697(19)32108-4 [Epub ahead of print].

Microbial communities play a crucial role in bioremediation of pollutants in contaminated ecosystem. In addition to pure culture isolation and bacterial 16S rRNA based community studies, the focus has now shifted employing the omics technologies enormously for understanding the microbial diversity and functional potential of soil samples. Our previous report on two pesticide-contaminated sites revealed the diversity of both culturable and unculturable bacteria. In the present study, we have observed distinct taxonomic and functional communities in contaminated soil with respect to an uncontaminated soil as control by using shotgun metagenomic sequencing method. Our data demonstrated that Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, and Acidobacteria significantly dominated the microbial diversity with their cumulative abundance percentage in the range of 98.61, 87.38, and 80.52 for Hindustan Insecticides Limited (HIL), India Pesticides Limited (IPL), and control respectively. Functional gene analysis demonstrated the presence of large number of both substrate specific upper pathway and common lower pathway degradative genes. Relatively lower number of genes was found encoding the degradation of styrene, atrazine, bisphenol, dioxin, and naphthalene. When three bacteria were augumentated with rhamnolipid (20-100 μM) and Triton X-100 (84-417 μM) surfactants in HIL soil, an enhanced degradation to 76%, 70%, and 58% of HCH, Endosulfan, and DDT respectively was achieved. The overall data obtained from two heavily contaminated soil suggest the versatility of the microbial communities for the xenobiotic pollutant degradation which may help in exploiting their potential applications in bioremediation.

RevDate: 2019-05-20

Zeng Q, Junli Gong , Liu X, et al (2019)

Gut dysbiosis and lack of short chain fatty acids in a Chinese cohort of patients with multiple sclerosis.

Neurochemistry international pii:S0197-0186(18)30616-8 [Epub ahead of print].

BACKGROUND: Recent studies, mostly conducted in Western countries, showed that gut microbes are involved in the pathogenesis of multiple sclerosis (MS).

OBJECTIVE: The aim of this study was to investigate whether gut dysbiosis is relevant to the initiation and progression of MS in a Chinese population.

METHODS: Next-generation sequencing (NGS) and gas chromatography (GC) were integrated and used to compare the fecal bacterial communities and the short-chain fatty acid (SCFA) levels among relapsing-remitting MS (RRMS) patients (n = 34), neuromyelitis optica spectrum disorder (NMOSD) patients (n = 34), and healthy controls (HCs) (n = 34). T-cell profile analyses were performed by flow cytometry for MS patients and matched controls (n = 12).

RESULTS: (1) The gut microbiome of MS patients was characterized by an increase of Streptococcus and a decrease of Prevotella_9; additionally, compared to NMOSD patients, Prevotella_9 was found to be much more abundant in MS patients. (2) A striking depletion of fecal acetate, propionate, and butyrate was observed in MS patients compared to HCs. (3) The abundance of Streptococcus was negatively correlated with the proportion of pTregs (P < 0.05) and positively correlated with Th17 cells (P < 0.05) in the peripheral blood, while the abundance of Prevotella_9 was negatively correlated with the Th17 cell frequency (P < 0.01), and the fecal SCFA level was positively correlated with pTreg frequency (P < 0.05).

CONCLUSIONS: Gut dysbiosis and a lack of SCFAs exist in Chinese MS patients, which might be related to an aberrant immune response of MS; this relationship may have a diagnostic and therapeutic value for patients with MS.

RevDate: 2019-05-20

Herbert RA, Eng T, Martinez U, et al (2019)

Rhizobacteria mediate the phytotoxicity of a range of biorefinery-relevant compounds.

Environmental toxicology and chemistry [Epub ahead of print].

Advances in engineering biology have expanded the list of renewable compounds that can be produced at scale via biological routes from plant biomass. In most cases, these chemical products have not been evaluated for effects on biological systems, defined here as bioactivity, that may be relevant to their manufacture. For sustainable chemical and fuel production, the industry needs to transition from fossil to renewable carbon sources, resulting in unprecedented expansion in the production and environmental distribution of chemicals used in biomanufacturing. Further, while some chemicals have been assessed for mammalian toxicity, environmental and agricultural hazards are largely unknown. We assessed six compounds that are representative of the emerging biofuel and bioproduct manufacturing process for their effect on model plants (Arabidopsis thaliana, Sorghum bicolor) and show that several alter plant seedling physiology at sub-millimolar concentrations. However, these responses change in the presence of individual bacterial species from the A. thaliana root microbiome. We identified two individual microbes that change the effect of chemical treatment on root architecture, and a pooled microbial community with different effects relative to its constituents individually. Our findings indicate that screening industrial chemicals for bioactivity on model organisms in the presence of their microbiomes is important for biologically and ecologically relevant risk analyses. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-20

Duvallet C, Larson K, Snapper S, et al (2019)

Aerodigestive sampling reveals altered microbial exchange between lung, oropharyngeal, and gastric microbiomes in children with impaired swallow function.

PloS one, 14(5):e0216453 pii:PONE-D-18-20128.

BACKGROUND: Children with oropharyngeal dysphagia have impaired airway protection mechanisms and are at higher risk for pneumonia and other pulmonary complications. Aspiration of gastric contents is often implicated as a cause for these pulmonary complications, despite being supported by little evidence. The goal of this study is to determine the relative contribution of oropharyngeal and gastric microbial communities to perturbations in the lung microbiome of children with and without oropharyngeal dysphagia and aspiration.

METHODS: We conducted a prospective cohort study of 220 patients consecutively recruited from a tertiary aerodigestive center undergoing simultaneous esophagogastroduodenoscopy and flexible bronchoscopy. Bronchoalveolar lavage, gastric and oropharyngeal samples were collected from all recruited patients and 16S sequencing was performed. A subset of 104 patients also underwent video fluoroscopic swallow studies to assess swallow function and were categorized as aspiration/no aspiration. To ensure the validity of the results, we compared the microbiome of these aerodigestive patients to the microbiome of pediatric patients recruited to a longitudinal cohort study of children with suspected GERD; patients recruited to this study had oropharyngeal, gastric and/or stool samples available. The relationships between microbial communities across the aerodigestive tract were described by analyzing within- and between-patient beta diversities and identifying taxa which are exchanged between aerodigestive sites within patients. These relationships were then compared in patients with and without aspiration to evaluate the effect of aspiration on the aerodigestive microbiome.

RESULTS: Within all patients, lung, oropharyngeal and gastric microbiomes overlap. The degree of similarity is the lowest between the oropharynx and lungs (median Jensen-Shannon distance (JSD) = 0.90), and as high between the stomach and lungs as between the oropharynx and stomach (median JSD = 0.56 for both; p = 0.6). Unlike the oropharyngeal microbiome, lung and gastric communities are highly variable across people and driven primarily by person rather than body site. In patients with aspiration, the lung microbiome more closely resembles oropharyngeal rather than gastric communities and there is greater prevalence of microbial exchange between the lung and oropharynx than between gastric and lung sites (p = 0.04 and 4x10-5, respectively).

CONCLUSIONS: The gastric and lung microbiomes display significant overlap in patients with intact airway protective mechanisms while the lung and oropharynx remain distinct. In patients with impaired swallow function and aspiration, the lung microbiome shifts towards oropharyngeal rather than gastric communities. This finding may explain why antireflux surgeries fail to show benefit in pediatric pulmonary outcomes.

RevDate: 2019-05-20

Mainali K, Bewick S, Vecchio-Pagan B, et al (2019)

Detecting interaction networks in the human microbiome with conditional Granger causality.

PLoS computational biology, 15(5):e1007037 pii:PCOMPBIOL-D-18-00900 [Epub ahead of print].

Human microbiome research is rife with studies attempting to deduce microbial correlation networks from sequencing data. Standard correlation and/or network analyses may be misleading when taken as an indication of taxon interactions because "correlation is neither necessary nor sufficient to establish causation"; environmental filtering can lead to correlation between non-interacting taxa. Unfortunately, microbial ecologists have generally used correlation as a proxy for causality although there is a general consensus about what constitutes a causal relationship: causes both precede and predict effects. We apply one of the first causal models for detecting interactions in human microbiome samples. Specifically, we analyze a long duration, high resolution time series of the human microbiome to decipher the networks of correlation and causation of human-associated microbial genera. We show that correlation is not a good proxy for biological interaction; we observed a weak negative relationship between correlation and causality. Strong interspecific interactions are disproportionately positive, whereas almost all strong intraspecific interactions are negative. Interestingly, intraspecific interactions also appear to act at a short time-scale causing vast majority of the effects within 1-3 days. We report how different taxa are involved in causal relationships with others, and show that strong interspecific interactions are rarely conserved across two body sites whereas strong intraspecific interactions are much more conserved, ranging from 33% between the gut and right-hand to 70% between the two hands. Therefore, in the absence of guiding assumptions about ecological interactions, Granger causality and related techniques may be particularly helpful for understanding the driving factors governing microbiome composition and structure.

RevDate: 2019-05-20

Rendina DN, Lubach GR, Phillips GJ, et al (2019)

Maternal and Breast Milk Influences on the Infant Gut Microbiome, Enteric Health and Growth Outcomes of Rhesus Monkeys.

Journal of pediatric gastroenterology and nutrition [Epub ahead of print].

OBJECTIVES: Gut bacteria play an essential role during infancy and are strongly influenced by the mode of birth and feeding. A primate model was used to investigate the benefits of exposure to the mother or conversely the negative impact of early nursery rearing on microbial colonization.

METHOD: Rectal swabs were obtained from rhesus macaques born vaginally and mother-reared (MR, N = 35) or delivered primarily via cesarean-section and human-reared (HR, N = 19). Microbiome composition was determined by rRNA gene amplicon sequencing at 2, 4 and 8 weeks of age and KEGG orthologs used to assess influences on functional metabolic pathways in the gut. Growth trajectories and incidence of diarrheic symptoms were evaluated.

RESULTS: The microbial community structure was different between MR and HR infants with respect to phylogeny and abundance at all 3 ages. When examining dominant phyla, HR infants had a higher Firmicutes-to-Bacteroidetes ratio. At the genus level, breast milk-dependent commensal taxa and adult-typical genera were more abundant in MR infants. This difference resulted in a corresponding shift in the predicted metabolic effects, specifically for microbial genes associated with metabolism and immune function. HR infants had faster growth trajectories (p < 0.001), but more diarrheic symptoms by 6 months postnatal (p = 0.008).

CONCLUSIONS: MR infants acquired adult-typical microbiota more quickly, and had higher levels of several beneficial commensal taxa. Cesarean-delivered and formula-fed infants had different developmental trajectories of bacterial colonization. Establishment of the gut microbiome was associated with an infant's growth trajectory, and implicated in the subsequent vulnerability to Campylobacter infections associated with diarrhea in infant monkeys.

RevDate: 2019-05-20

Hiremath G, Shilts MH, Boone HH, et al (2019)

The Salivary Microbiome Is Altered in Children With Eosinophilic Esophagitis and Correlates With Disease Activity.

Clinical and translational gastroenterology [Epub ahead of print].

OBJECTIVES: Eosinophilic esophagitis (EoE) is an allergen-mediated inflammatory disease affecting the esophagus. Although microbial communities may affect the host immune responses, little is known about the role of the microbiome in EoE. We compared the composition of the salivary microbiome in children with EoE with that of non-EoE controls to test the hypotheses that the salivary microbiome is altered in children with EoE and is associated with disease activity.

METHODS: Saliva samples were collected from 26 children with EoE and 19 non-EoE controls comparable for age and ethnicity. The salivary microbiome was profiled using 16S rRNA gene sequencing. Disease activity was assessed using the Eosinophilic Esophagitis Endoscopic Reference Score and the Eosinophilic Esophagitis Histologic Scoring System (EoEHSS).

RESULTS: A trend toward lower microbial richness and alpha diversity was noted in children with EoE. Although the overall salivary microbiome composition was similar between children with and without EoE, specific taxa such as Streptococcus (q value = 0.06) tended to be abundant in children with active EoE compared with non-EoE controls. Haemophilus was significantly abundant in children with active EoE compared with inactive EoE (q value = 0.0008) and increased with the increasing EoEHSS and Eosinophilic Esophagitis Histology Scoring System (q value = 5e-10). In addition, 4 broad salivary microbial communities correlated with the EoEHSS.

DISCUSSION: The composition of the salivary microbiome community structure can be altered in children with EoE. A relative abundance of Haemophilus positively correlates with the disease activity. These findings indicate that perturbations in the salivary microbiome may have a role in EoE pathobiology and could serve as a noninvasive marker of disease activity.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

RevDate: 2019-05-20

Lunjani N, Hlela C, L O'Mahony (2019)

Microbiome and skin biology.

Current opinion in allergy and clinical immunology [Epub ahead of print].

PURPOSE OF REVIEW: The skin is home to a diverse milieu of bacteria, fungi, viruses, bacteriophages, and archaeal communities. The application of culture-independent approaches has revolutionized the characterization of the skin microbiome and have revealed a previously underappreciated phylogenetic and functional granularity of skin-associated microbes in both health and disease states.

RECENT FINDINGS: The physiology of a given skin-niche drives the site-specific differences in bacterial phyla composition of healthy skin. Changes in the skin microbiome have consistently been associated with atopic dermatitis. In particular, Staphylococcus aureus overgrowth with concomitant decline in Staphylococcus epidermidis is a general feature associated with atopic dermatitis and is not restricted to eczematous lesions. Changes in fungal species are now also being described. Changes in the composition and metabolic activity of the gut microbiota are associated with skin health.

SUMMARY: We are now beginning to appreciate the intimate and intricate interactions between microbes and skin health. Multiple studies are currently focused on the manipulation of the skin or gut microbiome to explore their therapeutic potential in the prevention and treatment of skin inflammation.

RevDate: 2019-05-20

Ogunrinde E, Zhou Z, Luo Z, et al (2019)

A link between plasma microbial translocation, microbiome, and autoantibody development in first-degree relatives of systemic lupus erythematosus patients.

Arthritis & rheumatology (Hoboken, N.J.) [Epub ahead of print].

OBJECTIVE: Systemic lupus erythematosus (SLE) is characterized by antibody production against self-antigens. However, the events underlying autoantibody formation in SLE remains unclear. This study investigated the role of plasma autoantibody levels, microbial translocation, and the microbiome in SLE.

METHODS: Plasma samples from two cohorts, one with 18 unrelated healthy controls (UHCs) and 18 first-degree relatives (FDRs) and the other with 19 healthy controls and 21 SLE patients were assessed for autoantibody levels by autoantigen microarrays, lipopolysaccharide (LPS) levels by limulus amebocyte assay and microbiome composition by microbial 16S rDNA sequencing.

RESULTS: FDRs and SLE patients exhibited increased plasma autoantibodies compared to their control groups. Parents and children of lupus patients exhibited elevated plasma LPS levels in comparison to controls (p = 0.02). Plasma LPS levels positively correlated with plasma anti-dsDNA IgG levels in FDRs (r=0.51, p=0.03) but not in SLE patients. Circulating microbiome analysis revealed that FDRs (Observed species, p=0.004; Chao1 index, p=0.005) but not patients had significantly reduced microbiome diversity compared to their controls. The majority of differentially abundant bacteria identified between UHCs and FDRs were in the Firmicutes phylum, while bacteria from several different phyla were identified between HCs and SLE patients. Bacteria in the Paenibacillus genus was the only overlapping differentially abundant bacteria in both cohorts, and it was reduced in FDRs (p.adj = 2.13 x 10-12) and SLE patients (p.adj = 0.008) but elevated in controls.

CONCLUSIONS: These results indicate a possible role for plasma microbial translocation and microbiome composition in influencing autoantibody development in SLE. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-20

Petrullo L, Jorgensen MJ, Snyder-Mackler N, et al (2019)

Composition and stability of the vervet monkey milk microbiome.

American journal of primatology [Epub ahead of print].

The human milk microbiome is vertically transmitted to offspring during the postnatal period and has emerged as a critical driver of infant immune and metabolic development. Despite this importance in humans, the milk microbiome of nonhuman primates remains largely unexplored. This dearth of comparative work precludes our ability to understand how species-specific differences in the milk microbiome may differentially drive maternal effects and limits how translational models can be used to understand the role of vertically transmitted milk microbes in human development. Here, we present the first culture-independent data on the milk microbiome of a nonhuman primate. We collected milk and matched fecal microbiome samples at early and late lactation from a cohort of captive lactating vervet monkeys (N = 15). We found that, similar to humans, the vervet monkey milk microbiome comprises a shared community of taxa that are universally present across individuals. However, unlike in humans, this shared community is dominated by the genera Lactobacillus, Bacteroides, and Prevotella. We also found that, in contrast to previous culture-dependent studies in humans, the vervet milk microbiome exhibits greater alpha-diversity than the gut microbiome across lactation. Finally, we did not find support for the translocation of microbes from the gut to the mammary gland within females (i.e., "entero-mammary pathway"). Taken together, our results show that the vervet monkey milk microbiome is taxonomically diverse, distinct from the gut microbiome, and largely stable. These findings demonstrate that the milk microbiome is a unique substrate that may selectively favor the establishment and persistence of particular microbes across lactation and highlights the need for future experimental studies on the origin of microbes in milk.

RevDate: 2019-05-20

Zhong S, Zhou Z, Liang Y, et al (2019)

Targeting strategies for chemotherapy-induced peripheral neuropathy: does gut microbiota play a role?.

Critical reviews in microbiology [Epub ahead of print].

Chemotherapy-induced peripheral neuropathy (CIPN) is a progressive, often irreversible condition that produces severe neurological deficits. Emerging data suggest that chemotherapy also exerts detrimental effects on gut microbiota composition and intestinal permeability, contributing to dysbiosis and inflammation. Compared with other complications associated with chemotherapy, such as diarrhoea and mucositis, CIPN is of particular concern because it is the most common reason for terminating or suspending treatment. However, specific and effective curative treatment strategies are lacking. In this review, we provide an update on current preclinical and clinical understandings about the role of gut microbiota in CIPN. The gut microbiota serves as an intersection between the microbiome-gut-brain and the neuroimmune-endocrine axis, forming a complex network that can directly or indirectly affect key components involved in the manifestations of CIPN. Herein, we discuss several potential mechanisms within the context of the networks and summarize alterations in gut microbiome induced by chemotherapeutic drugs, providing great potential for researchers to target pathways associated with the gut microbiome and overcome CIPN.

RevDate: 2019-05-20

Montironi R, Santoni M, Cimadamore A, et al (2019)

Editorial: Emerging Biomarkers in Genitourinary Tumors.

Frontiers in oncology, 9:326.

RevDate: 2019-05-20

Sakai Y, Seki N, Hamano H, et al (2019)

A study of the prebiotic effect of lactulose at low dosages in healthy Japanese women.

Bioscience of microbiota, food and health, 38(2):69-72.

To investigate the prebiotic effect of lactulose at low dosages, we assessed changes in defaecation frequency following ingestion of 1, 2, or 3 g/day of lactulose for 2 weeks. Each test was carried out after a 2-week washout period. This was an open-label, before-after trial that enrolled 26 healthy Japanese women. The defaecation frequency, number of defaecation days, and number of faecal bifidobacteria increased significantly compared with before ingestion of 1, 2, and 3 g/day of lactulose. These results suggest that even 1 g/day of lactulose could have a prebiotic effect.

RevDate: 2019-05-20

Xiao Y, Xiao G, Liu H, et al (2019)

Captivity causes taxonomic and functional convergence of gut microbial communities in bats.

PeerJ, 7:e6844 pii:6844.

Background: Diet plays a crucial role in sculpting microbial communities. Similar diets appear to drive convergence of gut microbial communities between host species. Captivity usually provides an identical diet and environment to different animal species that normally have similar diets. Whether different species' microbial gut communities can be homogenized by a uniform diet in captivity remains unclear.

Methods: In this study, we compared gut microbial communities of three insectivorous bat species (Rhinolophus ferrumequinum, Vespertilio sinensis, and Hipposideros armiger) in captivity and in the wild using 16S rDNA sequencing. In captivity, R. ferrumequinum and V. sinensis were fed yellow mealworms, while H. armiger was fed giant mealworms to rule out the impact of an identical environment on the species' gut microbial communities.

Results: We found that the microbial communities of the bat species we studied clustered by species in the wild, while the microbial communities of R. ferrumequinum and V. sinensis in captivity clustered together. All microbial functions found in captive V. sinensis were shared by R. ferrumequinum. Moreover, the relative abundances of all metabolism related KEGG pathways did not significantly differ between captive R. ferrumequinum and V. sinensis; however, the relative abundance of "Glycan Biosynthesis and Metabolism" differed significantly between wild R. ferrumequinum and V. sinensis.

Conclusion: Our results suggest that consuming identical diets while in captivity tends to homogenize the gut microbial communities among bat species. This study further highlights the importance of diet in shaping animal gut microbiotas.

RevDate: 2019-05-20

Cicatelli A, Ferrol N, Rozpadek P, et al (2019)

Editorial: Effects of Plant-Microbiome Interactions on Phyto- and Bio-Remediation Capacity.

Frontiers in plant science, 10:533.

RevDate: 2019-05-20

Wang J, Lang T, Shen J, et al (2019)

Core Gut Bacteria Analysis of Healthy Mice.

Frontiers in microbiology, 10:887.

Previous studies revealed that there existed great individual variations of gut microbiota in mice, and the gut bacteria of mice were changed with the occurrence and development of diseases. To identify the core gut bacteria in healthy mice and explore their relationships with the host phenotypes would help to understand the underlying mechanisms. In this study, we identified 37 genus-level core bacteria from feces of 101 healthy mice with different ages, sexes, and mouse strains in three previous studies. They collectively represented nearly half of the total sequences, and predominantly included carbohydrate- and amino acids-metabolizing bacteria and immunomodulatory bacteria. Among them, Anaerostipes indwelt the gut of all healthy mice. Co-abundance analysis showed that these core genera were clustered into five groups (Group C1-C5), which were ecologically related. For example, the abundances of Group C2 including probiotics Bifidobacterium and Lactobacillus slightly positively correlated with those of Group C1. Principal component analysis (PCA) and multivariate analysis of variance test revealed that these core gut genera were distinguished with age and sex, and also associated with their health/disease state. Linear discriminant analysis effect size (LEfSe) method showed that bacteria in Group C1 and C2/C3 increased with the age in infancy and early adulthood, and were more abundant in female mice than in male ones. The metabolic syndrome (MS) induced by high fat diet (HFD) and accelerated postnatal growth would decrease Group C2 genera, whereas probiotics intervention would reverse HFD-induced reduction of Group C2. Spearman correlation analysis indicated that the principal components based on the abundance of the 37 core genera were significantly correlated with host characteristic parameters of MS. These results demonstrated that the 37 core genera in five co-abundance groups from healthy mice were related to host phenotypes. It was indicated that these prevalent gut bacterial genera could be representative of the healthy gut microbiome in gnotobiotic animal models, and might also be candidates of probiotics and fecal microbiota transplantation.

RevDate: 2019-05-20

Fuertes A, Pérez-Burillo S, Apaolaza I, et al (2019)

Adaptation of the Human Gut Microbiota Metabolic Network During the First Year After Birth.

Frontiers in microbiology, 10:848.

Predicting the metabolic behavior of the human gut microbiota in different contexts is one of the most promising areas of constraint-based modeling. Recently, we presented a supra-organismal approach to build context-specific metabolic networks of bacterial communities using functional and taxonomic assignments of meta-omics data. In this work, this algorithm is applied to elucidate the metabolic changes induced over the first year after birth in the gut microbiota of a cohort of Spanish infants. We used metagenomics data of fecal samples and nutritional data of 13 infants at five time points. The resulting networks for each time point were analyzed, finding significant alterations once solid food is introduced in the diet. Our work shows that solid food leads to a different pattern of output metabolites that can be potentially released from the gut microbiota to the host. Experimental validation is presented for ferulate, a neuroprotective metabolite involved in the gut-brain axis.

RevDate: 2019-05-20

Calon TGA, Trobos M, Johansson ML, et al (2019)

Microbiome on the Bone-Anchored Hearing System: A Prospective Study.

Frontiers in microbiology, 10:799.

The bone-anchored hearing system (BAHS) has evolved to a common treatment option for various types of hearing revalidation. The BAHS consists of an implant in the skull that breeches the skin. Soft tissue reactions are a common complication associated with BAHS and are generally poorly understood. This study aims to investigate the influence of BAHS and associated skin reactions around the implant. A total of 45 patients were prospectively followed from implantation up to at least 1 year. Swabs were obtained at baseline, 12 weeks follow-up and during cases of inflammation (Holgers score ≥2). The microbiota was assessed using IS-proTM, a bacterial profiling method based on the interspace region between the 16S-23S rRNA genes. Detection of operational taxonomic units, the Shannon Diversity Index, sample similarity analyses and Partial Least Squares Discriminant Analysis (PLS-DA) were employed. Staphylococcus epidermidis, Streptococcus pneumoniae/mitis, Propionibacterium acnes, Staphylococcus capitis, Staphylococcus hominis, Bifidobacterium longum, Haemophilus parainfluenzae, Lactobacillus rhamnosus, Bordetella spp., Streptococcus sanguinis, Peptostreptococcus anaerobius, Staphylococcus aureus, Lactococcus lactis, Enterobacter cloacae, and Citrobacter koseri were the most commonly found bacterial species. S. pneumoniae/mitis was significantly more often observed after implantation, whereas P. acnes was significantly less observed after implantation compared with baseline. The relative abundance of S. epidermidis (17%) and S. aureus (19.4%) was the highest for the group of patients with inflammation. The Shannon Diversity Index was significantly increased after implantation compared with pre-surgical swabs for Firmicutes, Actinobacteria, Fusobacteria, Verrucomicrobia (FAFV), but not for other phyla. When combining all phyla, there was no significant increase in the Shannon Diversity Index. The diversity index was similar post-surgically for patients experiencing inflammation and for patients without inflammation. With a supervised classifier (PLS-DA), patients prone to inflammation could be identified at baseline with an accuracy of 91.7%. In addition, PLS-DA could classify post-surgical abutments as non-inflamed or inflamed with an accuracy of 97.7%. This study shows the potential of using IS-proTM to describe and quantify the microbiota associated with the percutaneous BAHS. Furthermore, the results indicate the possibility of an early identification of patients susceptible to adverse skin reaction following implantation. Both S. aureus and S. epidermidis should be considered as relevant bacteria for BAHS-associated inflammation.

RevDate: 2019-05-20

Shurney D (2019)

The Gut Microbiome: Unleashing the Doctor Within.

American journal of lifestyle medicine, 13(3):265-268 pii:10.1177_1559827619826551.

RevDate: 2019-05-20

Gyongyosi B, Cho Y, Lowe P, et al (2019)

Alcohol-induced IL-17A production in Paneth cells amplifies endoplasmic reticulum stress, apoptosis, and inflammasome-IL-18 activation in the proximal small intestine in mice.

Mucosal immunology pii:10.1038/s41385-019-0170-4 [Epub ahead of print].

Gut microbial translocation contributes to alcoholic hepatitis. Using a mouse model of alcoholic hepatitis, we investigated the effects of chronic alcohol plus binge and found increased abundance of Paneth cells and IL-17A in the proximal small intestine (PSI). Alcohol increased IL-17A production and pro-apoptotic signaling evidenced by Bax, Bim, caspase-3, and caspase-8 increases via endoplasmic reticulum (ER) stress indicated by C/EBP homologous protein (CHOP) upregulation; this was prevented by the ER stress inhibitor, 4-PBA, in isolated crypts in vitro and in vivo. Mechanistically, IL-17 augmented alcohol-induced ER stress in isolated crypts. In vivo IL-17A blocking antibody administration in alcohol-treated mice attenuated ER stress-mediated apoptosis and IL-18 induction and prevented alcohol-induced impairment of tight junctions in the PSI and LPS translocation to the liver. Acute-on-chronic alcohol resulted in inflammasome activation, caspase-1 cleavage, and IL-18 production in the PSI. In vivo treatment with antibiotics or 4-PBA prevented CHOP upregulation and inflammasome activation. Our data suggest that alcohol upregulates innate immune mechanisms by increasing Paneth cell numbers and IL-17A release contributing to apoptosis amplification, inflammasome activation, and gut leakiness in the PSI. Binge alcohol-induced Paneth cell expansion, ER stress, and inflammasome activation in the PSI are modulated by the gut microbiome.

RevDate: 2019-05-20

Zeineldin M, Lowe J, B Aldridge (2019)

Contribution of the Mucosal Microbiota to Bovine Respiratory Health.

Trends in microbiology pii:S0966-842X(19)30098-8 [Epub ahead of print].

Recognizing the respiratory tract as a dynamic and complex ecosystem has enhanced our understanding of the pathophysiology of bovine respiratory disease (BRD). There is widespread evidence showing that disease-predisposing factors often disrupt the respiratory microbial ecosystem, provoking atypical colonization patterns and a progressive dysbiosis. The ecological factors that shape the respiratory microbiota, and the influence of these complex communities on bovine respiratory health, are a rich area for research exploration. Here, we review the current status of understanding of the bovine respiratory microbiota, the factors that influence its development and stability, its role in maintaining mucosal homeostasis, and ultimately its contribution to bovine health and disease. Finally, we explore the limitations of current research approaches to the microbiome and discuss potential directions for future research that can help us better understand the role of the respiratory microbiota in the health, welfare, and productivity of livestock.

RevDate: 2019-05-19

Gottlieb A, Bechmann L, A Canbay (2018)

The Presence and Severity of Nonalcoholic Steatohepatitis Is Associated with Specific Changes in Circulating Bile Acids.

Annals of hepatology, 17(3):341-342.

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease nowadays with currently no approved therapies for the disease. The liver plays a pivotal role in lipid and glucose metabolism. The interactions of molecular mechanisms on the gut for example influences the development still needs to be understood. Bile acids (BA) have been shown to impact metabolic homeostasis and insulin sensitivity. Here, we comment on a study analyzing BA profiles in NAFLD patients addressing novel pathways involved in NAFLD progression.

RevDate: 2019-05-19

Li P, Wu H, Jin Y, et al (2019)

Exploring the diversity and dynamic of bacterial community vertically distributed in Tongguling National Nature Reserve in Hainan Island, China.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] pii:10.1007/s42770-019-00078-2 [Epub ahead of print].

National nature reserves are important for preserving ecological resources and constructing national ecological security barriers. Tongguling National Nature Reserve (TNNR) is known for its unique tropical island ecosystem and abundant biological resources. This study was conducted to characterize and compare its bacterial community diversity and composition in soils from 10, 20, and 30 cm in depth using high-throughput sequencing of 16S rDNA genes. We found that soils from 20 cm had the highest diversity and might serve as a "middle bridge" to the dynamic distribution between the 10- and 30-cm soil samples. The diversity pattern indicated that the main abundant groups varied distinctly and significantly among soils of different depths. Moreover, Chloroflexi was the most dynamic group in TNNR soils, together with another abundant but rarely reported group, Verrucomicrobia, which greatly enhanced the microbial diversity of TNNR soils. Overall, the results of this study emphasize the urgent need for greater understanding of bacterial community variations in response to human activities and climate change.

RevDate: 2019-05-19

Bajic P, Dornbier RA, Doshi CP, et al (2019)

Implications of the Genitourinary Microbiota in Prostatic Disease.

Current urology reports, 20(7):34 pii:10.1007/s11934-019-0904-6.

PURPOSE OF REVIEW: To summarize recent investigation into associations between the genitourinary microbiota and prostatic disease.

RECENT FINDINGS: The genitourinary tract is not sterile. There are microbial communities (microbiota) in each niche of the genitourinary tract including the bladder, prostate, and urethra, which have been the subject of increasing scientific interest. Investigators have utilized several unique methods to study them, resulting in a highly heterogeneous body of literature. To characterize these genitourinary microbiota, diverse clinical specimens have been analyzed, including urine obtained by various techniques, seminal fluid, expressed prostatic secretions, and prostatic tissue. Recent studies have attempted to associate the microbiota detected from these samples with urologic disease and have implicated the genitourinary microbiota in many common conditions, including benign prostatic hyperplasia (BPH), prostate cancer, and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). In this review, we summarize the recent literature pertaining to the genitourinary microbiota and its relationship to the pathophysiology and management of three common prostatic conditions: BPH, prostate cancer, and CP/CPPS.

RevDate: 2019-05-19

Mukhtar I, Anwar H, Hussain G, et al (2019)

Detection of Paracetamol as substrate of the gut microbiome.

Pakistan journal of pharmaceutical sciences, 32(2 (Supplementary)):751-757.

Gut microbiome, a new organ; represent targets to alter pharmacokinetics of orally administered drugs. Recently, in vitro trials endorsed the idea that orally administered drugs interact and some of their quantity may be taken up by normal microbiome during transit through gut. Such transport mechanisms in microbiome may compete for drug with the host itself. Currently, no data confirms specific transport system for paracetamol uptake by gut microbiome. In vivo trial was conducted in normal healthy male rats (n=36). Paracetamol was administered orally in a single dose of 75mg/kg to isolate microbial mass after transit of 2, 3, 4, 5 and 6 hours post drug administration. Paracetamol absorbance by microbiome was pursued by injecting extracted microbial lysate in RP-HPLC-UV with C18 column under isocratic conditions at 207nm using acetonitrile and water (25:75 v/v) pH 2.50 as mobile phase. Paracetamol absorbance (14.10±0.75μg/mg of microbial mass) and percent dose recovery (13.16±0.55%) seen at transit of 4 hours was significantly higher (P<0.05) compared to other groups. Study confirms the hypothesis of homology between membrane transporters of the gut microbiome and intestinal epithelium. Orally administered drugs can be absorbed by gut microbes competitively during transit in small intestine and it varies at various transit times.

RevDate: 2019-05-19

Veach AM, Morris R, Yip DZ, et al (2019)

Rhizosphere microbiomes diverge among Populus trichocarpa plant-host genotypes and chemotypes, but it depends on soil origin.

Microbiome, 7(1):76 pii:10.1186/s40168-019-0668-8.

BACKGROUND: Plants have developed defense strategies for phytopathogen and herbivore protection via coordinated metabolic mechanisms. Low-molecular weight metabolites produced within plant tissues, such as salicylic acid, represent one such mechanism which likely mediates plant - microbe interactions above and below ground. Salicylic acid is a ubiquitous phytohormone at low levels in most plants, yet are concentrated defense compounds in Populus, likely acting as a selective filter for rhizosphere microbiomes. We propagated twelve Populus trichocarpa genotypes which varied an order of magnitude in salicylic acid (SA)-related secondary metabolites, in contrasting soils from two different origins. After four months of growth, plant properties (leaf growth, chlorophyll content, and net photosynthetic rate) and plant root metabolomics specifically targeting SA metabolites were measured via GC-MS. In addition, rhizosphere microbiome composition was measured via Illumina MiSeq sequencing of 16S and ITS2 rRNA-genes.

RESULTS: Soil origin was the primary filter causing divergence in bacterial/archaeal and fungal communities with plant genotype secondarily influential. Both bacterial/archaeal and fungal evenness varied between soil origins and bacterial/archaeal diversity and evenness correlated with at least one SA metabolite (diversity: populin; evenness: total phenolics). The production of individual salicylic acid derivatives that varied by host genotype resulted in compositional differences for bacteria /archaea (tremuloidin) and fungi (salicylic acid) within one soil origin (Clatskanie) whereas soils from Corvallis did not illicit microbial compositional changes due to salicylic acid derivatives. Several dominant bacterial (e.g., Betaproteobacteria, Acidobacteria, Verrucomicrobia, Chloroflexi, Gemmatimonadete, Firmicutes) and one fungal phyla (Mortierellomycota) also correlated with specific SA secondary metabolites; bacterial phyla exhibited more negative interactions (declining abundance with increasing metabolite concentration) than positive interactions.

CONCLUSIONS: These results indicate microbial communities diverge most among soil origin. However, within a soil origin, bacterial/archaeal communities are responsive to plant SA production within greenhouse-based rhizosphere microbiomes. Fungal microbiomes are impacted by root SA-metabolites, but overall to a lesser degree within this experimental context. These results suggest plant defense strategies, such as SA and its secondary metabolites, may partially drive patterns of both bacterial/archaeal and fungal taxa-specific colonization and assembly.

RevDate: 2019-05-18

Birer C, ES Wright (2019)

Capturing the complex interplay between drugs and the intestinal microbiome.

Clinical pharmacology and therapeutics [Epub ahead of print].

Predicting drug interactions, disposition, and side effects is central to the practice of clinical pharmacology. Until recently, the human microbiome has been an underappreciated player in the dynamics of drug metabolism. It is now clear that humans are 'superorganisms' with about tenfold more microbial cells than human cells and harboring an immense diversity of microbial enzymes. Owing to the advent of new technologies, we are beginning to understand the human microbiome's impact on clinical pharmacology. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-18

Pathirana E, McPherson A, Whittington R, et al (2019)

The Role of Tissue Type, Sampling and Nucleic Acid Purification Methodology on the Inferred Composition of Pacific Oyster (Crassostrea gigas) Microbiome.

Journal of applied microbiology [Epub ahead of print].

AIMS: This study evaluated methods to sample and extract nucleic acids from Pacific oysters to accurately determine the microbiome associated with different tissues.

METHODS AND RESULTS: Samples were collected from haemolymph, gill, gut and adductor-muscle, using swabs and homogenates of solid tissues. Nucleic acids were extracted from fresh and frozen samples using three different commercial kits. The bacterial DNA yield varied between methods (P < 0.05) and each tissue harboured a unique microbiota, except for gill and muscle. Higher bacterial DNA yields were obtained by swabbing compared to tissue homogenates and from fresh tissues compared to frozen tissues, without impacting the bacterial community composition estimated by 16S rRNA gene (V1-V3 region) sequencing. Despite the higher bacterial DNA yields with QIAamp® DNA microbiome kit, the E.Z.N.A.® Mollusc DNA kit identified twice as many operational taxonomic units (OTUs) and eliminated PCR inhibition from gut tissues.

CONCLUSIONS: Sampling and nucleic acid purification substantially affected the quantity and diversity of bacteria identified in Pacific oyster microbiome studies and a fit-for-purpose strategy is recommended.

Accurate identification of Pacific oyster microbial diversity is instrumental for understanding the polymicrobial aetiology of Pacific oyster mortality diseases which greatly impact oyster production. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-18

Yu XL, Chan Y, Zhuang L, et al (2019)

Intra-oral single site comparisons of periodontal and peri-implant microbiota in health and disease.

Clinical oral implants research [Epub ahead of print].

OBJECTIVE: Periodontitis and peri-implantitis are oral infectious-inflammatory diseases that share similarities in their pathology and etiology. Our objective was to characterize the single-site subgingival and submucosal microbiomes of implant-rehabilitated, partially dentate Chinese subjects (n=18) presenting with both periodontitis and peri-implantitis.

MATERIALS AND METHODS: Subgingival/submucosal plaque samples were collected from four clinically-distinct sites in each subject: peri-implantitis submucosa (DI), periodontal pocket (DT), clinically-healthy (unaffected) peri-implant submucosa (HI), and clinically-healthy (unaffected) subgingival sulcus (HT). The bacterial microbiota present was analysed using Illumina MiSeq sequencing.

RESULTS: 26 phyla and 5,726 Operational Taxonomic Units (OTUs, 97% sequence similarity cut-off) were identified. Firmicutes, Proteobacteria, Fusobacteria, Bacteroidetes, Actinobacteria, Synergistetes, TM7 and Spirochaetes comprised 99.6% of the total reads detected. Bacterial communities within the DI, DT, HI and HT sites shared high levels of taxonomic similarity. 31 'core species' were present in >90% sites; with Streptococcus infantis/mitis/oralis (HMT-070/HMT-071/HMT-638/HMT-677) and Fusobacterium sp. HMT-203/HMT-698 being particularly prevalent and abundant. Beta-diversity analyses (Permanova-test, weighted-UniFrac) revealed the largest variance in the microbiota was at the subject level (46%), followed by periodontal health status (4%). Differing sets of OTUs were associated with periodontitis and peri-implantitis sites, respectively. This included putative 'periodontopathogens, such as Prevotella, Porphyromonas, Tannerella, Bacteroidetes [G-5] and Treponema spp. Interaction network analysis identified several putative patterns underlying dysbiosis in periodontitis/peri-implantitis sites.

CONCLUSIONS: Species (OTU) composition of the periodontal and peri-implant microbiota varied widely between subjects. The inter-subject variations in subgingival/submucosal microbiome composition outweighed differences observed between implant versus tooth sites, or between diseased versus healthy (unaffected) peri-implant/periodontal sites. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-18

Eble H, Joswig M, Lamberti L, et al (2019)

Cluster partitions and fitness landscapes of the Drosophila fly microbiome.

Journal of mathematical biology pii:10.1007/s00285-019-01381-0 [Epub ahead of print].

The concept of genetic epistasis defines an interaction between two genetic loci as the degree of non-additivity in their phenotypes. A fitness landscape describes the phenotypes over many genetic loci, and the shape of this landscape can be used to predict evolutionary trajectories. Epistasis in a fitness landscape makes prediction of evolutionary trajectories more complex because the interactions between loci can produce local fitness peaks or troughs, which changes the likelihood of different paths. While various mathematical frameworks have been proposed to investigate properties of fitness landscapes, Beerenwinkel et al. (Stat Sin 17(4):1317-1342, 2007a) suggested studying regular subdivisions of convex polytopes. In this sense, each locus provides one dimension, so that the genotypes form a cube with the number of dimensions equal to the number of genetic loci considered. The fitness landscape is a height function on the coordinates of the cube. Here, we propose cluster partitions and cluster filtrations of fitness landscapes as a new mathematical tool, which provides a concise combinatorial way of processing metric information from epistatic interactions. Furthermore, we extend the calculation of genetic interactions to consider interactions between microbial taxa in the gut microbiome of Drosophila fruit flies. We demonstrate similarities with and differences to the previous approach. As one outcome we locate interesting epistatic information on the fitness landscape where the previous approach is less conclusive.

RevDate: 2019-05-18

DiLegge MJ, Manter DK, JM Vivanco (2019)

A novel approach to determine generalist nematophagous microbes reveals Mortierella globalpina as a new biocontrol agent against Meloidogyne spp. nematodes.

Scientific reports, 9(1):7521 pii:10.1038/s41598-019-44010-y.

Root-knot nematodes (RKN) such as Meloidogyne spp. are among the most detrimental pests in agriculture affecting several crops. New methodologies to manage RKN are needed such as efficient discovery of nematophagous microbes. In this study, we developed an in vitro high-throughput method relying on the free-living nematode Caenorhabditis elegans and the infection of those nematodes with a soil slurry containing a microbiome likely to house nematophagous microbes. Nematodes were monitored for presence of infection and sub-cultured repeatedly for the purpose of isolating pure cultures of the microbe responsible for conferring the nematicidal activity. Once soil microbes were confirmed to be antagonistic to C. elegans, they were tested for pathogenicity against Meloidogyne chitwoodi. Using this methodology, the fungal isolate Mortierella globalpina was confirmed to be pathogenic in vitro against M. chitwoodi by nematode trapping via hyphal adhesion to the cuticle layer, penetration of the cuticle layer, and subsequently digestion of its cellular contents. M. globalpina was also observed to reduce disease symptomology of RKNs in vivo via significant reduction of root-galls on tomato (Solanum lycopersicum var. Rutgers).

RevDate: 2019-05-18

Cho EJ, Leem S, Kim SA, et al (2019)

Circulating Microbiota-Based Metagenomic Signature for Detection of Hepatocellular Carcinoma.

Scientific reports, 9(1):7536 pii:10.1038/s41598-019-44012-w.

Circulating microbial dysbiosis is associated with chronic liver disease including nonalcoholic steatohepatitis and alcoholic liver disease. In this study, we evaluated whether disease-specific alterations of circulating microbiome are present in patients with cirrhosis and hepatocellular carcinoma (HCC), and their potential as diagnostic biomarkers for HCC. We performed cross-sectional metagenomic analyses of serum samples from 79 patients with HCC, 83 with cirrhosis, and 201 matching healthy controls, and validated the results in the same number of subjects. Serum bacterial DNA was analyzed using high-throughput pyrosequencing after amplification of the V3-V4 hypervariable regions of 16S rDNA. Blood microbial diversity was significantly reduced in HCC, compared with cirrhosis and control. There were significant differences in the relative abundances of several bacterial taxa that correlate with the presence of HCC, thus defining a specific blood microbiome-derived metagenomic signature of HCC. We identified 5 microbial gene markers-based model which distinguished HCC from controls with an area under the receiver-operating curve (AUC) of 0.879 and a balanced accuracy of 81.6%. In the validation, this model accurately distinguished HCC with an AUC of 0.875 and an accuracy of 79.8%. In conclusion, circulating microbiome-based signatures may be potential biomarkers for the detection HCC.

RevDate: 2019-05-18

Marie Booth J, Fusi M, Marasco R, et al (2019)

The role of fungi in heterogeneous sediment microbial networks.

Scientific reports, 9(1):7537 pii:10.1038/s41598-019-43980-3.

While prokaryote community diversity and function have been extensively studied in soils and sediments, the functional role of fungi, despite their huge diversity, is widely unexplored. Several studies have, nonetheless, revealed the importance of fungi in provisioning services to prokaryote communities. Here, we hypothesise that the fungal community plays a key role in coordinating entire microbial communities by controlling the structure of functional networks in sediment. We selected a sediment environment with high niche diversity due to prevalent macrofaunal bioturbation, namely intertidal mangrove sediment, and explored the assembly of bacteria, archaea and fungi in different sediment niches, which we characterised by biogeochemical analysis, around the burrow of a herbivorous crab. We detected a high level of heterogeneity in sediment biogeochemical conditions, and diverse niches harboured distinct communities of bacteria, fungi and archaea. Saprotrophic fungi were a pivotal component of microbial networks throughout and we invariably found fungi to act as keystone species in all the examined niches and possibly acting synergistically with other environmental variables to determine the overall microbial community structure. In consideration of the importance of microbial-based nutrient cycling on overall sediment ecosystem functioning, we underline that the fungal microbiome and its role in the functional interactome cannot be overlooked.

RevDate: 2019-05-18

Van der Helm JJ, Schim van der Loeff MF, de Vries E, et al (2019)

Vaginal herb use and Chlamydia trachomatis infection: cross-sectional study among women of various ethnic groups in Suriname.

BMJ open, 9(5):e025417 pii:bmjopen-2018-025417.

OBJECTIVE: Vaginal steam baths with herb leaves (herb use) is practised by some Surinamese women. We assessed herb use among women from the five most prevalent ethnic groups, and if herb use is associated with Chlamydia trachomatis infection.

SETTING: Participants were recruited at a sexually transmitted infection (STI) clinic and a family planning clinic (FP) in Paramaribo, Suriname.

PARTICIPANTS: 1040 women were included subsequently, comprising the following ethnic groups: Creole (26.7%), Hindustani (24.6%), Javanese (15.7%), Maroon (13.3%) and mixed descent (19.7%).

METHODS: Nurses collected a questionnaire and vaginal swabs for nucleic acid amplification C. trachomatis testing.

PRIMARY OUTCOMES: Determinants of vaginal herb use and C. trachomatis infection via univariable and multivariable logistic regression.

RESULTS: Herb use was most common among Maroon (68.8%) and Creole women (25.2%). In multivariable analysis including only Maroon and Creole women, determinants significantly associated with vaginal herb use were (OR; 95% CI): Maroon ethnic descent (5.33; 3.26 to 8.71 vs Creole), recruitment at the STI clinic (2.04; 1.24 to 3.36 vs FP), lower education levels (3.80; 1.68 to 8.57 lower vs higher, and 2.02; 0.90 to 4.51 middle vs higher). Lower age and recruitment at the STI clinic were associated with C. trachomatis infection, but not vaginal herb use.

CONCLUSION: In Suriname, vaginal herb use is common among Maroon and Creole women. Education, ethnic group and recruitment site were determinants for herb use. Vaginal herb use was not a determinant of C. trachomatis infection. Future research should focus on the effect of herb use on the vaginal microbiome and mucosal barrier.

RevDate: 2019-05-18

Frimodt-Møller N (2019)

The urine microbiome - Contamination or a novel paradigm?.

EBioMedicine pii:S2352-3964(19)30317-2 [Epub ahead of print].

RevDate: 2019-05-18

Hagihara M, Yamashita R, Matsumoto A, et al (2019)

The impact of probiotic Clostridium butyricum MIYAIRI 588 on murine gut metabolic alterations.

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy pii:S1341-321X(19)30039-X [Epub ahead of print].

INTRODUCTION: Clostridium butyricum MIYAIRI 588 (CBM 588) is a probiotic bacterium used in antidiarrheal medicine in Japan. A few studies analyzed the changes in gut microbiome in patients treated with antimicrobials based on metagenomics sequencing. However, the impact of CBM 588 on gut metabolic alterations has not been fully elucidated. This study was to reveal the impact of CBM 588 on gut metabolic alterations.

MATERIAL AND METHODS: In this in vivo study, mice were divided into four groups and CBM 588, clindamycin (CLDM), and normal saline (control) was orally administered (1. CLDM, 2. CBM 588, 3. CBM 588 + CLDM, 4. water) for 4 days. Fecal samples were collected to extract DNA for metagenomics analysis. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to obtain relative Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway abundance information derived from metagenomics data.

RESULTS: CLDM treatment resulted in a dramatic increase in Firmicutes phylum compared to non-CLDM-treated groups (control and CBM 588-treated group). Then, the CBM 588 + CLDM-treated group showed a trend similar in many metabolic pathways to the CLDM-treated group. On the other hand, the CBM 588 + CLDM-treated group showed higher relative abundance compared to the CLDM-treated group especially in starch and sucrose metabolism.

DISCUSSION: We concluded that CBM 588 caused a gut microbiome functional shift toward increased carbohydrate metabolism. These results support the hypothesis that CBM 588 treatment modulates gut microbiome under dysbiosis conditions due to antimicrobials.

RevDate: 2019-05-18

Harris TA, Gattu S, Propheter DC, et al (2019)

Resistin-like Molecule α Provides Vitamin-A-Dependent Antimicrobial Protection in the Skin.

Cell host & microbe pii:S1931-3128(19)30207-0 [Epub ahead of print].

Vitamin A deficiency increases susceptibility to skin infection. However, the mechanisms by which vitamin A regulates skin immunity remain unclear. Here, we show that resistin-like molecule α (RELMα), a small secreted cysteine-rich protein, is expressed by epidermal keratinocytes and sebocytes and serves as an antimicrobial protein that is required for vitamin-A-dependent resistance to skin infection. RELMα was induced by microbiota colonization of the murine skin, was bactericidal in vitro, and was protected against bacterial infection of the skin in vivo. RELMα expression required dietary vitamin A and was induced by the therapeutic vitamin A analog isotretinoin, which protected against skin infection in a RELMα-dependent manner. The RELM family member Resistin was expressed in human skin, was induced by vitamin A analogs, and killed skin bacteria, indicating a conserved function for RELM proteins in skin innate immunity. Our findings provide insight into how vitamin A promotes resistance to skin infection.

RevDate: 2019-05-18

Goel N, Nadler A, Reddy S, et al (2019)

Biliary microbiome in pancreatic cancer: alterations with neoadjuvant therapy.

HPB : the official journal of the International Hepato Pancreato Biliary Association pii:S1365-182X(19)30522-2 [Epub ahead of print].

BACKGROUND: Neoadjuvant therapy for pancreatic cancer is being employed more commonly. Most of these patients undergo biliary stenting which results in bacterial colonization and more surgical site infections (SSIs). However, the influence of neoadjuvant therapy on the biliary microbiome has not been studied.

METHODS: From 2007 to 2017, patients at our institution who underwent pancreatoduodenectomy (PD) and had operative bile cultures were studied. Patient demographics, stent placement, bile cultures, bacterial sensitivities, SSIs and clinically-relevant postoperative pancreatic fistulas (CR-POPF) were analyzed. Patients who underwent neoadjuvant therapy were compared to those who went directly to surgery. Standard statistical analyses were performed.

RESULTS: Eighty-three patients received neoadjuvant therapy while 89 underwent surgery alone. Patients who received neoadjuvant therapy were more likely to have enterococci (45 vs 22%, p < 0.01), and Klebsiella (37 vs 19%, p < 0.01) in their bile. Resistance to cephalosporins was more common in those who received neoadjuvant therapy (76 vs 60%, p < 0.05). Neoadjuvant therapy did not affect the incidence of SSIs or CR-POPFs.

CONCLUSION: The biliary microbiome is altered in patients undergoing pancreatoduodenectomy (PD) after neoadjuvant therapy. Most patients undergoing PD with a biliary stent have microorganisms resistant to cephalosporins. Antibiotic prophylaxis in these patients should cover enterococci and gram-negative bacteria.

RevDate: 2019-05-18

Jeong Y, Kim JW, You HJ, et al (2019)

Gut Microbial Composition and Function Are Altered in Patients with Early Rheumatoid Arthritis.

Journal of clinical medicine, 8(5): pii:jcm8050693.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation of the joints and extra-articular manifestations. Recent studies have shown that microorganisms affect RA pathogenesis. However, few studies have examined the microbial distribution of early RA patients, particularly female patients. In the present study, we investigated the gut microbiome profile and microbial functions in early RA female patients, including preclinical and clinically apparent RA cases. Changes in microbiological diversity, composition, and function in each group were analyzed using quantitative insights into microbial ecology (QIIME) and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt). The results revealed the dysbiosis due to decreased diversity in the early RA patients compared with healthy subjects. There were significant differences in the microbial distribution of various taxa from phylum to genus levels between healthy subjects and early RA patients. Phylum Bacteroidetes was enriched in early RA patients, while Actinobacteria, including the genus Collinsella, was enriched in healthy subjects. Functional analysis based on clusters of orthologous groups revealed that the genes related to the biosynthesis of menaquinone, known to be derived from gram-positive bacteria, were enriched in healthy subjects, while iron transport-related genes were enriched in early RA patients. Genes related to the biosynthesis of lipopolysaccharide, the gram-negative bacterial endotoxin, were enriched in clinically apparent RA patients. The obvious differences in microbial diversity, taxa, and associated functions of the gut microbiota between healthy subjects and early RA patients highlight the involvement of the gut microbiome in the early stages of RA.

RevDate: 2019-05-17

Zheng F, Zhu D, Giles M, et al (2019)

Mineral and organic fertilization alters the microbiome of a soil nematode Dorylaimus stagnalis and its resistome.

The Science of the total environment, 680:70-78 pii:S0048-9697(19)31929-1 [Epub ahead of print].

Although the effects of fertilization on the abundance and diversity of soil nematodes have been widely studied, the impact of fertilization on soil nematode microbiomes remains largely unknown. Here, we investigated how different fertilizers: no fertilizer, mineral fertilizer, clean slurry (pig manure with a reduced antibiotic burden) and dirty slurry (pig manure with antibiotics) affect the microbiome of a dominant soil nematode and its associated antibiotic resistance genes (ARGs). The results of 16S rRNA gene high throughput sequencing showed that the microbiome of the soil nematode Dorylaimus stagnalis is diverse (Shannon index: 9.95) and dominated by Proteobacteria (40.3%). Application of mineral fertilizers significantly reduced the diversity of the nematode microbiome (by 28.2%; P < 0.05) but increased the abundance of Proteobacteria (by 70.1%; P = 0.001). Microbial community analysis, using a null hypothesis model, indicated that microbiomes associated with the nematode are not neutrally assembled. Organic fertilizers also altered the diversity of the nematode microbiome, but had no impact on its composition as illustrated by principal coordinates analysis (PCoA). Interestingly, although no change of total ARGs was observed in the nematode microbiome and no significant relationship existed between nematode microbiome and resistome, the abundance of 48 out of a total of 75 ARGs was enriched in the organic fertilizer treatments. Thus, the data suggests that ARGs in the nematode microbiome still had a risk of horizontal gene transfer under fertilization and nematodes might be a potential refuge for ARGs.

RevDate: 2019-05-17

Awoyemi A, Trøseid M, Arnesen H, et al (2019)

Effects of dietary intervention and n-3 PUFA supplementation on markers of gut-related inflammation and their association with cardiovascular events in a high-risk population.

Atherosclerosis, 286:53-59 pii:S0021-9150(19)30409-5 [Epub ahead of print].

BACKGROUND & AIMS: Dysbiosis of the gut microbiota is associated with increased levels of circulating lipopolysaccharide (LPS) and subsequent activation of systemic inflammation. Diet is an important modulator of the gut microbiome. We aimed to investigate whether circulating markers of gut-related inflammation, LPS binding protein (LBP) and soluble CD14 (sCD14) can be modulated by n-3 PUFA supplementation and/or diet counselling, and whether these markers are related to cardiovascular (CV) outcome.

METHODS: 484 men aged 65-75 years, at high CV-risk, were included and randomized in a 2 × 2 factorial design to 36-month intervention with dietary counselling, n-3 PUFA supplementation, or both. N-3 PUFA supplementation was placebo-controlled. ELISAs were used for determination of the biomarkers measured at baseline and study-end. A composite endpoint was defined as new CV-events and CV-mortality after 36 months.

RESULTS: There were no significant differences in changes of either LBP or sCD14 in the intervention groups compared to their respective controls (n-3 PUFA vs. placebo: p = 0.58, p = 0.15, diet vs. no-diet: p = 0.53, p = 0.59, respectively). The group with LBP levels above median had about 2-fold unadjusted risk of suffering an endpoint compared to the group below (HR 2.22, 95% CI 1.25-3.96; p = 0.01). A similar tendency was seen for sCD14 (HR 1.72, 95% CI 0.97-3.03; p = 0.06). After adjusting for covariates, LBP remained significantly associated with a two-fold CV-risk, whereas sCD14 gained statistical significance, however, lost when hsCRP was added to the model.

CONCLUSIONS: In our population, markers of gut-related inflammation associated with 36-month CV outcome. However, neither n-3 PUFA nor diet intervention had an effect on these markers.

RevDate: 2019-05-17

Bautista-de Los Santos QM, Chavarria KA, KL Nelson (2019)

Understanding the impacts of intermittent supply on the drinking water microbiome.

Current opinion in biotechnology, 57:167-174 pii:S0958-1669(18)30165-4 [Epub ahead of print].

Increasing access to piped water in low-income and middle-income countries combined with the many factors that threaten our drinking water supply infrastructure mean that intermittent water supply (IWS) will remain a common practice around the world. Common features of IWS include water stagnation, pipe drainage, intrusion, backflow, first flush events, and household storage. IWS has been shown to cause degradation as measured by traditional microbial water quality indicators. In this review, we build on new insights into the microbial ecology of continuous water supply systems revealed by sequencing methods to speculate about how intermittent supply conditions may further influence the drinking water microbiome, and identify priorities for future research.

RevDate: 2019-05-17

Yu L, He J, Wang L, et al (2019)

Incidence, aetiology, and serotype spectrum analysis of adult HFMD patients: a retrospective observational cohort study in Northern Zhejiang, China.

International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases pii:S1201-9712(19)30222-X [Epub ahead of print].

BACKGROUND: Hand, foot, and mouth disease (HFMD) was rare among adults, whereas its clinical significance was underestimated. This study tried to systematically elucidate the epidemiological characteristics of adult HFMD.

METHODS: 266 adult patients of HFMD were recruited, with 40 healthy subjects served as the control. Swap or serum samples were collected. Enterovirus strain was tested by RT-PCR, and the cytokine expression was examined by commercial kits. Social-demographic data was collected through follow-up phone calls. Daily meteorological data were obtained from the China Meteorological Data Sharing Service System. Social-economic data was collected from the statistical bureau.

RESULTS: This study found several unique spatiotemporal patterns of the adult HFMD. Having children diagnosed as HFMD recently was a risk factor of HFMD, whereas keeping pets was an HFMD protective factor. Results of the study implied the existence of subclinical carriers or misdiagnosed patients who might be the latent infectious source of HFMD. Further, our study also indicated adults may act as the main infectious source of trans-regional spread of HFMD.

CONCLUSION: This study revealed the potential hazards of adult HFMD and reminded us of the vital clinical significance of further research to adult HFMD.

RevDate: 2019-05-17

Forster CS, Hsieh MH, Pérez-Losada M, et al (2019)

A single intravesical instillation of Lactobacillus rhamnosus GG is safe in children and adults with neuropathic bladder: A phase Ia clinical trial.

The journal of spinal cord medicine [Epub ahead of print].

CONTEXT/OBJECTIVE: Manipulation of the microbiome is an emerging approach to promote health. We conducted a Phase Ia safety study of a single bladder instillation of probiotics in asymptomatic patients with neuropathic bladder to determine the tolerability and safety of a single Lactobacillus instillation.

DESIGN: Phase Ia safety study.

SETTING: Outpatient rehabilitation clinic at a rehabilitation hospital (adults) and urology clinic at a free-standing children's hospital (children).

PARTICIPANTS: Ten patients with neuropathic bladder were included: five children with spina bifida and five adults with spinal cord injury.

INTERVENTIONS: A single Lactobacillus rhamnosus GG (Culturelle, 20 billion live organisms) instillation.

OUTCOME MEASURES: After the instillation, participants self-monitored symptoms using the Urinary Symptoms Questionnaire for People with Neuropathic Bladder using Intermittent Catheterization daily for one week. Repeat urinalysis, urine culture, and 16S bacterial rRNA-based microbiome analyses were performed 7-10 days after instillation.

RESULTS: Probiotic instillation was well-tolerated. One child had upper respiratory tract symptoms during the trial, and two had transient cloudy urine. No adults reported any symptoms following instillation. Lactobacillus did not grow on culture post-instillation. There were differences in beta diversity of the urine microbiome in children vs. adults with neuropathic bladder (P < 0.0156). Lactobacillus was present in the pre-instillation urinary microbiomes all of the adults and 4 out of 5 of the pediatric subjects, and identified in 4 out of 5 of both the adult and pediatric subjects' post-instillation urinary microbiomes.

CONCLUSION: Intravesical instillation of Culturelle probiotic may be safe and well-tolerated in patients with neuropathic bladder.

RevDate: 2019-05-17

Ramadan M, Solyman S, Yones M, et al (2019)

Skin Microbiome Differences in Atopic Dermatitis and Healthy Controls in Egyptian Children and Adults, and Association with Serum Immunoglobulin E.

Omics : a journal of integrative biology, 23(5):247-260.

Atopic dermatitis (AD) is a complex, multifactorial, chronic pruritic inflammatory skin disease. We report the first microbiome study and new insights on the relationship between skin microbiota variation and AD susceptibility in a population sample from Egypt. We characterized the skin microbiome in 75 patients with AD and 20 healthy controls using Illumina MiSeq sequencing of 16S rRNA gene. Overall, bacterial diversity of skin microbiome in patients with AD was less than those of the healthy subjects. Genus level analysis revealed significant abundance variations by age, disease severity, locality, or immune response. Among these genera, Streptococcus, Cutibacterium, and Corynebacterium appeared to be specific signatures for AD in children, adolescents, and adults, respectively, while Staphylococcus was noted as a potential biomarker candidate for AD. Additionally, functional potential of metagenomes shifted the overall metabolic pathways to participate in the exacerbation of disease. Total immunoglobulin E (IgE) levels were positively correlated with relative enrichment of certain Staphylococcus aureus subspecies. Finally, AD-related differences in skin bacterial diversity appeared to be in part linked to the serum IgE level. These new observations attest to the promise of microbiome science and metagenomic analysis in AD specifically, and clinical dermatology broadly.

RevDate: 2019-05-17

Aruoma OI, Hausman-Cohen S, Pizano J, et al (2019)

Personalized Nutrition: Translating the Science of NutriGenomics Into Practice: Proceedings From the 2018 American College of Nutrition Meeting.

Journal of the American College of Nutrition, 38(4):287-301.

Adverse reactions to foods and adverse drug reactions are inherent in product defects, medication errors, and differences in individual drug exposure. Pharmacogenetics is the study of genetic causes of individual variations in drug response and pharmacogenomics more broadly involves genome-wide analysis of the genetic determinants of drug efficacy and toxicity. The similarity of nutritional genomics and pharmacogenomics stems from the innate goal to identify genetic variants associated with metabolism and disease. Thus, nutrigenomics can be thought of as encompassing gene-diet interactions involving diverse compounds that are present in even the simplest foods. The advances in the knowledge base of the complex interactions among genotype, diet, lifestyle, and environment is the cornerstone that continues to elicit changes in current medical practice to ultimately yield personalized nutrition recommendations for health and risk assessment. This information could be used to understand how foods and dietary supplements uniquely affect the health of individuals and, hence, wellness. The individual's gut microbiota is not only paramount but pivotal in embracing the multiple-functional relationships with complex metabolic mechanisms involved in maintaining cellular homeostasis. The genetic revolution has ushered in an exciting era, one in which many new opportunities are expected for nutrition professionals with expertise in nutritional genomics. The American College of Nutrition's conference focused on "Personalized Nutrition: Translating the Science of NutriGenomics Into Practice" was designed to help to provide the education needed for the professional engagement of providers in the personalized medicine era.

RevDate: 2019-05-17

Amato KR, Maurice CF, Guillemin K, et al (2019)

Multidisciplinarity in Microbiome Research: A Challenge and Opportunity to Rethink Causation, Variability, and Scale.

BioEssays : news and reviews in molecular, cellular and developmental biology [Epub ahead of print].

This essay, written by a biologist, a microbial ecologist, a biological anthropologist, and an anthropologist-historian, examines tensions and translations in microbiome research on animals in the laboratory and field. The authors trace how research questions and findings in the laboratory are extrapolated into the field and vice versa, and the shifting evidentiary standards that these research settings require. Showing how complexities of microbiomes challenge traditional standards of causation, the authors contend that these challenges require new approaches to inferences used in ecology, anthropology, and history. As social scientists incorporate investigations of microbial life into their human studies, microbiome researchers venture into field settings to develop mechanistic understandings about the functions of complex microbial communities. These efforts generate new possibilities for cross-fertilizations and inference frameworks to interpret microbiome findings. Microbiome research should integrate multiple scales, levels of variability, and other disciplinary approaches to tackle questions spanning conditions from the laboratory to the field.

RevDate: 2019-05-17

Bosch TCG, Guillemin K, M McFall-Ngai (2019)

Evolutionary "Experiments" in Symbiosis: The Study of Model Animals Provides Insights into the Mechanisms Underlying the Diversity of Host-Microbe Interactions.

BioEssays : news and reviews in molecular, cellular and developmental biology [Epub ahead of print].

Current work in experimental biology revolves around a handful of animal species. Studying only a few organisms limits science to the answers that those organisms can provide. Nature has given us an overwhelming diversity of animals to study, and recent technological advances have greatly accelerated the ability to generate genetic and genomic tools to develop model organisms for research on host-microbe interactions. With the help of such models the authors therefore hope to construct a more complete picture of the mechanisms that underlie crucial interactions in a given metaorganism (entity consisting of a eukaryotic host with all its associated microbial partners). As reviewed here, new knowledge of the diversity of host-microbe interactions found across the animal kingdom will provide new insights into how animals develop, evolve, and succumb to the disease.

RevDate: 2019-05-17

Bauer KC, Rees T, BB Finlay (2019)

The Gut Microbiota-Brain Axis Expands Neurologic Function: A Nervous Rapport.

BioEssays : news and reviews in molecular, cellular and developmental biology [Epub ahead of print].

Does exploration of the gut microbiota-brain axis expand our understanding of what it means to be human? Recognition and conceptualization of a gut microbiota-brain axis challenges our study of the nervous system. Here, integrating gut microbiota-brain research into the metaorganism model is proposed. The metaorganism-an expanded, dynamic unit comprising the host and commensal organisms-asserts a radical blurring between man and microbe. The metaorganism nervous system interacts with the exterior world through microbial-colored lenses. Ongoing studies have reported that gut microbes contribute to brain function and pathologies, even shaping higher neurological functions. How will continued collaborative efforts (e.g., between neurobiology and microbiology), including partnerships with the arts (e.g., philosophy), contribute to the knowledge of microbe-to-mind interactions? While this is not a systemic review, this nascent field is briefly described, highlighting ongoing challenges and recommendations for emerging gut microbiota-brain research.

RevDate: 2019-05-17

Zuo K, Li J, Xu Q, et al (2019)

Dysbiotic gut microbes may contribute to hypertension by limiting vitamin D production.

Clinical cardiology [Epub ahead of print].

BACKGROUND: Accumulating studies have suggested that gut microbiota (GM) dysbiosis and vitamin D3 deficiency each play an important role during the progression of hypertension (HTN). However, few studies have characterized the underlying interaction between gut microbiota shift and vitamin D3 deficiency in HTN patients.

HYPOTHESIS: This study aimed to evaluate the possible crosstalk between GM dysbiosis and vitamin D deficiency in the pathogenesis of HTN METHODS: In a cohort of 34 HTN patients and 15 healthy controls, we analyzed the fecal microbiota products, GM composition, and the interaction between GM and vitamin D3.

RESULTS: Vitamin D3 was significantly decreased in feces of HTN patients (p=0.006, vs. controls) and was correlated with altered GM, including decreased Shannon index (R2 =0.1296, p=0.0111) and Pielou evenness (R2 =0.1509, p=0.0058). Moreover, vitamin D3 positively correlated with HTN-reduced bacterial genera, including Subdoligranulum (R2 =0.181, p=0.0023), Ruminiclostridium (R2 =0.1217, p=0.014), Intestinimonas (R2 =0.2036, p=0.0011), Pseudoflavonifractor (R2 =0.1014, p=0.0257), Paenibacillus (R2 =0.089, p=0.0373) and Marvinbryantia (R2 =0.08173, p=0.0464). Partial least squares structural equation modeling showed that 27.7% of the total effect of gut microbiome on HTN was mediated by limiting vitamin D production. Finally, receiver operating characteristic curve analysis revealed the predictive capacity of differential gut microbiome signatures and decreased vitamin D3 to distinguish HTN patients (AUC=0.749, p=0.006).

CONCLUSIONS: Our findings suggest that the GM dysbiosis contributing to the development of HTN might be partially mediated by vitamin D3 deficiency. Future studies involving the underlying mechanism and intervention strategies targeting microbiome composition and vitamin D3 to counteract the progression of HTN are warranted.

RevDate: 2019-05-17

Sato Y, Hori T, Koike H, et al (2019)

Transcriptome analysis of activated sludge microbiomes reveals an unexpected role of minority nitrifiers in carbon metabolism.

Communications biology, 2:179 pii:418.

Although metagenomics researches have illuminated microbial diversity in numerous biospheres, understanding individual microbial functions is yet difficult due to the complexity of ecosystems. To address this issue, we applied a metagenome-independent, de novo assembly-based metatranscriptomics to a complex microbiome, activated sludge, which has been used for wastewater treatment for over a century. Even though two bioreactors were operated under the same conditions, their performances differed from each other with unknown causes. Metatranscriptome profiles in high- and low-performance reactors demonstrated that denitrifiers contributed to the anaerobic degradation of heavy oil; however, no marked difference in the gene expression was found. Instead, gene expression-based nitrification activities that fueled the denitrifiers by providing the respiratory substrate were notably high in the high-performance reactor only. Nitrifiers-small minorities with relative abundances of <0.25%-governed the heavy-oil degradation performances of the reactors, unveiling an unexpected linkage of carbon- and nitrogen-metabolisms of the complex microbiome.

RevDate: 2019-05-17

Armour CR, Nayfach S, Pollard KS, et al (2019)

A Metagenomic Meta-analysis Reveals Functional Signatures of Health and Disease in the Human Gut Microbiome.

mSystems, 4(4): pii:mSystems00332-18.

While recent research indicates that human health is affected by the gut microbiome, the functional mechanisms that underlie host-microbiome interactions remain poorly resolved. Metagenomic clinical studies can address this problem by revealing specific microbial functions that stratify healthy and diseased individuals. To improve our understanding of the relationship between the gut microbiome and health, we conducted the first integrative functional analysis of nearly 2,000 publicly available fecal metagenomic samples obtained from eight clinical studies. We identified characteristics of the gut microbiome that associate generally with disease, including functional alpha-diversity, beta-diversity, and beta-dispersion. Using regression modeling, we identified specific microbial functions that robustly stratify diseased individuals from healthy controls. Many of these functions overlapped multiple diseases, suggesting a general role in host health, while others were specific to a single disease and may indicate disease-specific etiologies. Our results clarify potential microbiome-mediated mechanisms of disease and reveal features of the microbiome that may be useful for the development of microbiome-based diagnostics. IMPORTANCE The composition of the gut microbiome associates with a wide range of human diseases, but the mechanisms underpinning these associations are not well understood. To shift toward a mechanistic understanding, we integrated distinct metagenomic data sets to identify functions encoded in the gut microbiome that associate with multiple diseases, which may be important to human health. Additionally, we identified functions that associate with specific diseases, which may elucidate disease-specific etiologies. We demonstrated that the functions encoded in the microbiome can be used to classify disease status, but the inclusion of additional patient covariates may be necessary to obtain sufficient accuracy. Ultimately, this analysis advances our understanding of the gut microbiome functions that constitute a healthy microbiome and identifies potential targets for microbiome-based diagnostics and therapeutics.

RevDate: 2019-05-17

Werbner M, Barsheshet Y, Werbner N, et al (2019)

Social-Stress-Responsive Microbiota Induces Stimulation of Self-Reactive Effector T Helper Cells.

mSystems, 4(4): pii:mSystems00292-18.

Stressful life events are considered a risk factor for autoimmune disorders, though the mechanisms are unclear. Here we demonstrate that chronic social stress induces virulence-associated transcriptional patterns in the murine gut microbiota. The stress-influenced microbiota increased the presence of effector T helper cells in the mesenteric lymph nodes, including myelin-autoreactive cells. Inhibition of the bacterial quorum sensor QseC, which is also responsive to norepinephrine, diminished the presence of effector T helper cells and bacteria such as Acinetobacter in the mesenteric lymph nodes, without remarkably affecting the gut microbial composition. Together, our results delineate a model in which the immune reaction to stress-responsive microbiota may compromise tolerance to self and therefore may increase the risk for autoimmune diseases in susceptible individuals. IMPORTANCE How do stressful life events increase the risk for autoimmune disorders? Here we show that chronic social stress in mice promotes the expression of virulent genes in the gut microbiota and alters the microbial translocation into the mesenteric lymph nodes. Our results also suggest that the consequent immune response to the stress-affected microbiota may endanger the tolerance for self. The presence of specific translocated bacteria and the immune response in the mesenteric lymph nodes can be diminished using an inhibitor of the bacterial communication system without drastically affecting the gut microbial composition as antibiotics do.

RevDate: 2019-05-17

de la Cuesta-Zuluaga J, Kelley ST, Chen Y, et al (2019)

Age- and Sex-Dependent Patterns of Gut Microbial Diversity in Human Adults.

mSystems, 4(4): pii:mSystems00261-19.

Gut microbial diversity changes throughout the human life span and is known to be associated with host sex. We investigated the association of age, sex, and gut bacterial alpha diversity in three large cohorts of adults from four geographical regions: subjects from the United States and United Kingdom in the American Gut Project (AGP) citizen-science initiative and two independent cohorts of Colombians and Chinese. In three of the four cohorts, we observed a strong positive association between age and alpha diversity in young adults that plateaued after age 40 years. We also found sex-dependent differences that were more pronounced in younger adults than in middle-aged adults, with women having higher alpha diversity than men. In contrast to the other three cohorts, no association of alpha diversity with age or sex was observed in the Chinese cohort. The association of alpha diversity with age and sex remained after adjusting for cardiometabolic parameters in the Colombian cohort and antibiotic usage in the AGP cohort. We further attempted to predict the microbiota age in individuals using a machine-learning approach for the men and women in each cohort. Consistent with our alpha-diversity-based findings, U.S. and U.K. women had a significantly higher predicted microbiota age than men, with a reduced difference being seen above age 40 years. This difference was not observed in the Colombian cohort and was observed only in middle-aged Chinese adults. Together, our results provide new insights into the influence of age and sex on the biodiversity of the human gut microbiota during adulthood while highlighting similarities and differences across diverse cohorts. IMPORTANCE Microorganisms in the human gut play a role in health and disease, and in adults higher gut biodiversity has been linked to better health. Since gut microorganisms may be pivotal in the development of microbial therapies, understanding the factors that shape gut biodiversity is of utmost interest. We performed large-scale analyses of the relationship of age and sex to gut bacterial diversity in adult cohorts from four geographic regions: the United States, the United Kingdom, Colombia, and China. In the U.S., U.K., and Colombian cohorts, bacterial biodiversity correlated positively with age in young adults but plateaued at about age 40 years, with no positive association being found in middle-aged adults. Young, but not middle-aged, adult women had higher gut bacterial diversity than men, a pattern confirmed via supervised machine learning. Interestingly, in the Chinese cohort, minimal associations were observed between gut biodiversity and age or sex. Our results highlight the patterns of adult gut biodiversity and provide a framework for future research.

RevDate: 2019-05-17

Lutz HL, Ramírez-Puebla ST, Abbo L, et al (2019)

A Simple Microbiome in the European Common Cuttlefish, Sepia officinalis.

mSystems, 4(4): pii:mSystems00177-19.

The European common cuttlefish, Sepia officinalis, is used extensively in biological and biomedical research, yet its microbiome remains poorly characterized. We analyzed the microbiota of the digestive tract, gills, and skin in mariculture-raised S. officinalis using a combination of 16S rRNA amplicon sequencing, quantitative PCR (qPCR), and fluorescence spectral imaging. Sequencing revealed a highly simplified microbiota consisting largely of two single bacterial amplicon sequence variants (ASVs) of Vibrionaceae and Piscirickettsiaceae. The esophagus was dominated by a single ASV of the genus Vibrio. Imaging revealed bacteria in the family Vibrionaceae distributed in a discrete layer that lines the esophagus. This Vibrio was also the primary ASV found in the microbiota of the stomach, cecum, and intestine, but occurred at lower abundance, as determined by qPCR, and was found only scattered in the lumen rather than in a discrete layer via imaging analysis. Treatment of animals with the commonly used antibiotic enrofloxacin led to a nearly 80% reduction of the dominant Vibrio ASV in the esophagus but did not significantly alter the relative abundance of bacteria overall between treated versus control animals. Data from the gills were dominated by a single ASV in the family Piscirickettsiaceae, which imaging visualized as small clusters of cells. We conclude that bacteria belonging to the Gammaproteobacteria are the major symbionts of the cuttlefish Sepia officinalis cultured from eggs in captivity and that the esophagus and gills are major colonization sites. IMPORTANCE Microbes can play critical roles in the physiology of their animal hosts, as evidenced in cephalopods by the role of Vibrio (Aliivibrio) fischeri in the light organ of the bobtail squid and the role of Alpha- and Gammaproteobacteria in the reproductive system and egg defense in a variety of cephalopods. We sampled the cuttlefish microbiome throughout the digestive tract, gills, and skin and found dense colonization of an unexpected site, the esophagus, by a microbe of the genus Vibrio, as well as colonization of gills by Piscirickettsiaceae. This finding expands the range of organisms and body sites known to be associated with Vibrio and is of potential significance for understanding host-symbiont associations, as well as for understanding and maintaining the health of cephalopods in mariculture.

RevDate: 2019-05-17

Zegeye EK, Brislawn CJ, Farris Y, et al (2019)

Selection, Succession, and Stabilization of Soil Microbial Consortia.

mSystems, 4(4): pii:mSystems00055-19.

Soil microorganisms play fundamental roles in cycling of soil carbon, nitrogen, and other nutrients, yet we have a poor understanding of how soil microbiomes are shaped by their nutritional and physical environment. In this study, we investigated the successional dynamics of a soil microbiome during 21 weeks of enrichment on chitin and its monomer, N-acetylglucosamine. We examined succession of the soil communities in a physically heterogeneous soil matrix as well as a homogeneous liquid medium. The guiding hypothesis was that the initial species richness would influence the tendency for the selected consortia to stabilize and maintain a relatively constant community structure over time. We also hypothesized that long-term, substrate-driven growth would result in consortia with reduced species richness compared to the parent microbiome and that this process would be deterministic with relatively little variation between replicates. We found that the initial species richness does influence the long-term community stability in both liquid media and soil and that lower initial richness results in a more rapid convergence to stability. Despite use of the same soil inoculum and access to the same major substrate, the resulting community composition differed greatly in soil from that in liquid medium. Hence, distinct selective pressures in soils relative to homogenous liquid media exist and can control community succession dynamics. This difference is likely related to the fact that soil microbiomes are more likely to thrive, with fewer compositional changes, in a soil matrix than in liquid environments. IMPORTANCE The soil microbiome carries out important ecosystem functions, but interactions between soil microbial communities have been difficult to study due to the high microbial diversity and complexity of the soil habitat. In this study, we successfully obtained stable consortia with reduced complexity that contained species found in the original source soil. These consortia and the methods used to obtain them can be a valuable resource for exploration of specific mechanisms underlying soil microbial community ecology. The results of this study also provide new experimental context to better inform how soil microbial communities are shaped by new environments and how a combination of initial taxonomic structure and physical environment influences stability.

RevDate: 2019-05-17

Cai TT, Li H, Ma J, et al (2019)

Differential Markov random field analysis with an application to detecting differential microbial community networks.

Biometrika, 106(2):401-416.

Micro-organisms such as bacteria form complex ecological community networks that can be greatly influenced by diet and other environmental factors. Differential analysis of microbial community structures aims to elucidate systematic changes during an adaptive response to changes in environment. In this paper, we propose a flexible Markov random field model for microbial network structure and introduce a hypothesis testing framework for detecting differences between networks, also known as differential network analysis. Our global test for differential networks is particularly powerful against sparse alternatives. In addition, we develop a multiple testing procedure with false discovery rate control to identify the structure of the differential network. The proposed method is applied to data from a gut microbiome study on U.K. twins to evaluate how age affects the microbial community network.

RevDate: 2019-05-17

Youngblut ND, Reischer GH, Walters W, et al (2019)

Host diet and evolutionary history explain different aspects of gut microbiome diversity among vertebrate clades.

Nature communications, 10(1):2200 pii:10.1038/s41467-019-10191-3.

Multiple factors modulate microbial community assembly in the vertebrate gut, though studies disagree as to their relative contribution. One cause may be a reliance on captive animals, which can have very different gut microbiomes compared to their wild counterparts. To resolve this disagreement, we analyze a new, large, and highly diverse animal distal gut 16 S rRNA microbiome dataset, which comprises 80% wild animals and includes members of Mammalia, Aves, Reptilia, Amphibia, and Actinopterygii. We decouple the effects of host evolutionary history and diet on gut microbiome diversity and show that each factor modulates different aspects of diversity. Moreover, we resolve particular microbial taxa associated with host phylogeny or diet and show that Mammalia have a stronger signal of cophylogeny. Finally, we find that environmental filtering and microbe-microbe interactions differ among host clades. These findings provide a robust assessment of the processes driving microbial community assembly in the vertebrate intestine.

RevDate: 2019-05-17

Sherchand SP, A Aiyar (2019)

Ammonia generation by tryptophan synthase drives a key genetic difference between genital and ocular Chlamydia trachomatis isolates.

Proceedings of the National Academy of Sciences of the United States of America pii:1821652116 [Epub ahead of print].

A striking difference between genital and ocular clinical isolates of Chlamydia trachomatis is that only the former express a functional tryptophan synthase and therefore can synthesize tryptophan by indole salvage. Ocular isolates uniformly cannot use indole due to inactivating mutations within tryptophan synthase, indicating a selection against maintaining this enzyme in the ocular environment. Here, we demonstrate that this selection occurs in two steps. First, specific indole derivatives, produced by the human gut microbiome and present in serum, rapidly induce expression of C. trachomatis tryptophan synthase, even under conditions of tryptophan sufficiency. We demonstrate that these indole derivatives function by acting as de-repressors of C. trachomatis TrpR. Second, trp operon de-repression is profoundly deleterious when infected cells are in an indole-deficient environment, because in the absence of indole, tryptophan synthase deaminates serine to pyruvate and ammonia. We have used biochemical and genetic approaches to demonstrate that expression of wild-type tryptophan synthase is required for the bactericidal production of ammonia. Pertinently, although these indole derivatives de-repress the trpRBA operon of C. trachomatis strains with trpA or trpB mutations, no ammonia is produced, and no deleterious effects are observed. Our studies demonstrate that tryptophan synthase can catalyze the ammonia-generating β-elimination reaction within any live bacterium. Our results also likely explain previous observations demonstrating that the same indole derivatives inhibit the growth of other pathogenic bacterial species, and why high serum levels of these indole derivatives are favorable for the prognosis of diseased conditions associated with bacterial dysbiosis.

RevDate: 2019-05-17

Dodiya HB, Kuntz T, Shaik SM, et al (2019)

Sex-specific effects of microbiome perturbations on cerebral Aβ amyloidosis and microglia phenotypes.

The Journal of experimental medicine pii:jem.20182386 [Epub ahead of print].

We demonstrated that an antibiotic cocktail (ABX)-perturbed gut microbiome is associated with reduced amyloid-β (Aβ) plaque pathology and astrogliosis in the male amyloid precursor protein (APP)SWE /presenilin 1 (PS1)ΔE9 transgenic model of Aβ amyloidosis. We now show that in an independent, aggressive APPSWE/PS1L166P (APPPS1-21) mouse model of Aβ amyloidosis, an ABX-perturbed gut microbiome is associated with a reduction in Aβ pathology and alterations in microglial morphology, thus establishing the generality of the phenomenon. Most importantly, these latter alterations occur only in brains of male mice, not in the brains of female mice. Furthermore, ABX treatment lead to alterations in levels of selected microglial expressed transcripts indicative of the "M0" homeostatic state in male but not in female mice. Finally, we found that transplants of fecal microbiota from age-matched APPPS1-21 male mice into ABX-treated APPPS1-21 male restores the gut microbiome and partially restores Aβ pathology and microglial morphology, thus demonstrating a causal role of the microbiome in the modulation of Aβ amyloidosis and microglial physiology in mouse models of Aβ amyloidosis.

RevDate: 2019-05-17

Zhang J, Lacroix C, Wortmann E, et al (2019)

Gut microbial beta-glucuronidase and glycerol/diol dehydratase activity contribute to dietary heterocyclic amine biotransformation.

BMC microbiology, 19(1):99 pii:10.1186/s12866-019-1483-x.

BACKGROUND: Consuming red and processed meat has been associated with an increased risk of colorectal cancer (CRC), which is partly attributed to exposure to carcinogens such as heterocyclic amines (HCA) formed during cooking and preservation processes. The interaction of gut microbes and HCA can result in altered bioactivities and it has been shown previously that human gut microbiota can transform mutagenic HCA to a glycerol conjugate with reduced mutagenic potential. However, the major form of HCA in the colon are glucuronides (HCA-G) and it is not known whether these metabolites, via stepwise microbial hydrolysis and acrolein conjugation, are viable precursors for glycerol conjugated metabolites. We hypothesized that such a process could be concurrently catalyzed by bacterial beta-glucuronidase (B-GUS) and glycerol/diol dehydratase (GDH) activity. We therefore investigated how the HCA-G PhIP-N2-β-D-glucuronide (PhIP-G), a representative liver metabolite of PhIP (2-Amino-1-methyl-6-phenylimidazo [4,5-b] pyridine), which is the most abundant carcinogenic HCA in well-cooked meat, is transformed by enzymatic activity of human gut microbial representatives of the phyla Firmicutes, Bacteroidetes, and Proteobacteria.

RESULTS: We employed a combination of growth and enzymatic assays, and a bioanalysis approach combined with metagenomics. B-GUS of Faecalibacterium prausnitzii converted PhIP-G to PhIP and GDH of Flavonifractor plautii, Blautia obeum, Eubacterium hallii, and Lactobacillus reuteri converted PhIP to PhIP-M1 in the presence of glycerol. In addition, B-GUS- and GDH-positive bacteria cooperatively converted PhIP-G to PhIP-M1. A screen of genes encoding B-GUS and GDH was performed for fecal microbiome data from healthy individuals (n = 103) and from CRC patients (n = 53), which revealed a decrease in abundance of taxa with confirmed GDH and HCA transformation activity in CRC patients.

CONCLUSIONS: This study for the first time demonstrates that gut microbes mediate the stepwise transformation of PhIP-G to PhIP-M1 via the intermediate production of PhIP. Findings from this study suggest that targeted manipulation with gut microbes bearing specific functions, or dietary glycerol supplementation might modify gut microbial activity to reduce HCA-induced CRC risk.

RevDate: 2019-05-17

Basic M, A Bleich (2019)

Gnotobiotics: Past, present and future.

Laboratory animals, 53(3):232-243.

Gnotobiotics or gnotobiology is a research field exploring organisms with a known microbiological state. In animal research, the development of gnotobiotics started in the late 19th century with the rederivation of germ-free guinea pigs. Cutting-edge achievements were accomplished by scientists in the Laboratories of Bacteriology at the University of Notre Dame (LOBUND). The primary goals of gnotobiotics were not only the development of the equipment required for long-term husbandry but also phenotypic characterization of germ-free animals. The first isolators were designed by Reynolds and Gustafsson as rigid-wall stainless steel autoclave-like chambers, which were subsequently replaced by Trexler's flexible-film polyvinyl plastic isolators. Flexible-film or semi-rigid isolators are commonly used today. The long-term maintenance of gnotobiotic rodents is performed in positive-pressure isolators. However, to facilitate gnotobiotic experimental procedures, short-term husbandry systems have been developed. Gnotobiotic animal husbandry is laborious and requires experienced staff. Germ-free animals can be rederived from existing rodent colonies by hysterectomy or embryo transfer. The physiology and anatomy of germ-free rodents are different from those of specified pathogen-free (SPF) rodents. Furthermore, to guarantee gnotobiotic status, the colonies need to be regularly microbiologically monitored. Today, gnotobiotics provides a powerful tool to analyse functional effects of host-microbe interactions, especially in complex disease models. Gnotobiotic models combined with 'omics' approaches will be indispensable for future advances in microbiome research. Furthermore, these approaches will contribute to the development of novel therapeutic targets. In addition, regional or national gnotobiotic core facilities should be established in the future to support further applications of gnotobiotic models.

RevDate: 2019-05-17

Pannkuk EL, Laiakis EC, Girgis M, et al (2019)

Temporal Effects on Radiation Responses in Nonhuman Primates: Identification of Biofluid Small Molecule Signatures by Gas Chromatography⁻Mass Spectrometry Metabolomics.

Metabolites, 9(5): pii:metabo9050098.

Whole body exposure to ionizing radiation damages tissues leading to physical symptoms which contribute to acute radiation syndrome. Radiation biodosimetry aims to determine characteristic early biomarkers indicative of radiation exposure and is necessary for effective triage after an unanticipated radiological incident. Radiation metabolomics can address this aim by assessing metabolic perturbations following exposure. Gas chromatography-mass spectrometry (GC-MS) is a standardized platform ideal for compound identification. We performed GC time-of-flight MS for the global profiling of nonhuman primate urine and serum samples up to 60 d after a single 4 Gy γ-ray total body exposure. Multivariate statistical analysis showed higher group separation in urine vs. serum. We identified biofluid markers involved in amino acid, lipid, purine, and serotonin metabolism, some of which may indicate host microbiome dysbiosis. Sex differences were observed for amino acid fold changes in serum samples. Additionally, we explored mitochondrial dysfunction by tricarboxylic acid intermediate analysis in the first week with a GC tandem quadrupole MS platform. By adding this temporal component to our previous work exploring dose effects at 7 d, we observed the highest fold changes occurring at 3 d, returning closer to basal levels by 7 d. These results emphasize the utility of both MS-based metabolomics for biodosimetry and complementary analytical platforms for increased metabolome coverage.

RevDate: 2019-05-17

Estrada JA, I Contreras (2019)

Nutritional Modulation of Immune and Central Nervous System Homeostasis: The Role of Diet in Development of Neuroinflammation and Neurological Disease.

Nutrients, 11(5): pii:nu11051076.

The gut-microbiome-brain axis is now recognized as an essential part in the regulation of systemic metabolism and homeostasis. Accumulating evidence has demonstrated that dietary patterns can influence the development of metabolic alterations and inflammation through the effects of nutrients on a multitude of variables, including microbiome composition, release of microbial products, gastrointestinal signaling molecules, and neurotransmitters. These signaling molecules are, in turn, implicated in the regulation of the immune system, either promoting or inhibiting the production of pro-inflammatory cytokines and the expansion of specific leukocyte subpopulations, such as Th17 and Treg cells, which are relevant in the development of neuroinflammatory and neurodegenerative conditions. Metabolic diseases, like obesity and type 2 diabetes mellitus, are related to inadequate dietary patterns and promote variations in the aforementioned signaling pathways in patients with these conditions, which have been linked to alterations in neurological functions and mental health. Thus, maintenance of adequate dietary patterns should be an essential component of any strategy aiming to prevent neurological pathologies derived from systemic metabolic alterations. The present review summarizes current knowledge on the role of nutrition in the modulation of the immune system and its impact in the development of neuroinflammation and neurological disease.

RevDate: 2019-05-17

Ding J, Zhu D, Li H, et al (2019)

The gut microbiota of soil organisms show species-specific responses to liming.

The Science of the total environment, 659:715-723.

Liming is a common agronomic practice used for alleviating soil acidification to improve plant growth. However, it is still unclear how liming can affect the gut microbiota composition of soil fauna, and subsequently the nutrient cycling and litter decomposition mediated by soil fauna. In the present study the effect of liming on the gut microbiota of two types of soil fauna, Folsomia candida, and Enchytraeus crypticus was investigated by using 16S rRNA gene high-throughput sequencing. The results revealed that there are differences between the gut microbial communities of the two types of soil fauna as well as between the gut microbiome of the soil fauna and the surrounding soil. Enterobacteriaceae and Bacillaceae were the predominant families in the gut microbiota of E. crypticus, while Rickettsiaceae and Moraxellaceae were the predominant families in the gut microbiota of F. candida. Liming affected the gut microbiota of E. crypticus at both the taxonomical and core microbiota level. The gut microbiota of F. candida was not affected by liming. Structural equation models suggest that 97% of the variation in the E. crypticus gut microbiota could be explained by liming-induced changes in soil properties and the soil microbial community. The indirect effects of liming, caused by a shift in the soil microbial community, contributed more in reshaping the gut microbiota of E. crypticus than the direct effects of the changed soil properties did. These findings suggest that the effects of liming on the gut microbiota composition in soil fauna are species-specific and are likely dependent on the response of the host to changes in soil properties and the soil microbial community.

RevDate: 2019-05-16

Schwerdtfeger LA, Nealon NJ, Ryan EP, et al (2019)

Human colon function ex vivo: Dependence on oxygen and sensitivity to antibiotic.

PloS one, 14(5):e0217170 pii:PONE-D-19-03515.

BACKGROUND: Human intestines contain a heterogeneous collection of cells that include immune, neural and epithelial elements interacting in a highly complex physiology that is challenging to maintain ex vivo. There is an extreme oxygen gradient across the intestinal wall due in part to microbiota in the lumen and close to the gut wall, which complicates the design of tissue culture systems. The current study established the use of an organotypic slice model of human intestinal tissue derived from colonoscopy biopsies to study host-microbial interactions after antibiotic treatment, and the influence of oxygen concentration on gut wall function.

METHODS: Organotypic slices from human colon biopsies collected during routine colonoscopy provided three-dimensional environments that maintained cellular morphology ex vivo. Biopsy slices were used to study impacts of oxygen concentrations and antibiotic treatments on epithelial proliferation rates, and metabolites from tissue culture supernatants.

RESULTS: Immune function was validated via demonstration of a T lymphocyte response to Salmonella enterica serovar Typhimurium. Following 24 h of Salmonella exposure there was a significant increase in CD3+ T-lymphocytes in biopsy slices. Metabolite profiling of tissue culture supernatants validated the influence of antibiotic treatment under varied oxygen culture conditions on both host and microbiome-mediated metabolism. Epithelial health was influenced by oxygen and antibiotic. Increased epithelial proliferation was measured in lowered oxygen conditions (1% = 5.9 mmHg) compared to atmospheric conditions standard at 5000 feet above sea level in Colorado (~17% = 100 mmHg). Antibiotic treatment reduced epithelial proliferation only in 5.9 mmHg oxygen cultured slices.

CONCLUSIONS: A human colon organotypic slice model was established for applications ranging from gut epithelial proliferation to enteric pathogen influence on mucosal immune functions ex vivo. The results further support the need to account for oxygen concentration in primary tissue cultures, and that antibiotic use impacts gut-microbe-immune interactions.

RevDate: 2019-05-16

Khan MAW, Stephens WZ, Mohammed AD, et al (2019)

Does MHC heterozygosity influence microbiota form and function?.

PloS one, 14(5):e0215946 pii:PONE-D-18-12229.

MHC molecules are essential for the adaptive immune response, and they are the most polymorphic genetic loci in vertebrates. Extreme genetic variation at these loci is paradoxical given their central importance to host health. Classic models of MHC gene evolution center on antagonistic host-pathogen interactions to promote gene diversification and allelic diversity in host populations. However, all multicellular organisms are persistently colonized by their microbiota that perform essential metabolic functions for their host and protect from infection. Here, we provide data to support the hypothesis that MHC heterozygote advantage (a main force of selection thought to drive MHC gene evolution), may operate by enhancing fitness advantages conferred by the host's microbiome. We utilized fecal 16S rRNA gene sequences and their predicted metagenome datasets collected from multiple MHC congenic homozygote and heterozygote mouse strains to describe the influence of MHC heterozygosity on microbiome form and function. We find that in contrast to homozygosity at MHC loci, MHC heterozygosity promotes functional diversification of the microbiome, enhances microbial network connectivity, and results in enrichment for a variety of microbial functions that are positively associated with host fitness. We demonstrate that taxonomic and functional diversity of the microbiome is positively correlated in MHC heterozygote but not homozygote animals, suggesting that heterozygote microbiomes are more functionally adaptive under similar environmental conditions than homozygote microbiomes. Our data complement previous observations on the role of MHC polymorphism in sculpting microbiota composition, but also provide functional insights into how MHC heterozygosity may enhance host health by modulating microbiome form and function. We also provide evidence to support that MHC heterozygosity limits functional redundancy among commensal microbes and may enhance the metabolic versatility of their microbiome. Results from our analyses yield multiple testable predictions regarding the role of MHC heterozygosity on the microbiome that will help guide future research in the area of MHC-microbiome interactions.

RevDate: 2019-05-16

Zeichner SL, Mongodin EF, Hittle L, et al (2019)

The bacterial communities of the small intestine and stool in children with short bowel syndrome.

PloS one, 14(5):e0215351 pii:PONE-D-18-34368.

Short bowel syndrome (SBS) presents an increasing problem in pediatrics. SBS often results from surgical resection of necrotic bowel following necrotizing enterocolitis or treatment of anatomic gastrointestinal defects. SBS is associated with significant morbidity and mortality, and creates substantial burdens for patients, families, and the health system. Recent reports have demonstrated that the fecal microbiome of children with SBS is significantly different from healthy control and severe intestinal microbial imbalances is associated with poor growth. We hypothesized that children with SBS and adverse clinical features such as PN dependent, shorter bowel length and lack of ileocecal valve would demonstrate more gut dysbiosis compare with the SBS non-PN dependent. An improved understanding of SBS pathogenesis would enhance management and potentially suggest new interventions. We studied microbial communities of SBS and control non-SBS patients from the jejunum, obtained endoscopically or by ostomy aspiration, and stool. We enrolled SBS patients who did and did not require parenteral nutrition (PN), as a surrogate marker for the seriousness of their disease. We studied the microbiota using high-throughput DNA sequencing of 16S rRNA genes and statistical analyses. We found that microbial diversity was significantly greater in jejunal aspirate than in stool samples in SBS patients, unlike non-SBS patients; that SBS patients receiving enteral feeds had greater diversity, and that SBS patients on PN and enteral feeds had lower differences in diversity in jejunal vs. stool samples. We found a trend toward increased diversity in patients with an intact ileocecal valve, and found that certain taxa were more abundant in the certain sample types, and in SBS patients vs. non-SBS patients. SBS patients have lower microbial diversity, especially patients with more severe disease, patients requiring PN, and those lacking an ileocecal valve. SBS patients, particularly those with more complex characteristics, exhibit differences in their intestinal microbiota. Particular individual taxa were over- and under-represented in patients with more unfavorable disease. While diminished diversity and alterations in microbiota composition are likely consequences of SBS, future efforts aimed at increasing microbial diversity and interventions targeting specific microbiota characteristics might constitute a testable approach to ameliorate some clinical SBS clinical consequences.

RevDate: 2019-05-16

Sasmita AO (2019)

Modification of the gut microbiome to combat neurodegeneration.

Reviews in the neurosciences pii:/j/revneuro.ahead-of-print/revneuro-2019-0005/revneuro-2019-0005.xml [Epub ahead of print].

The gut microbiome was extensively researched for its biological variety and its potential role in propagating diseases outside of the gastrointestinal (GI) tract. Recently, a lot of effort was focused on comprehending the gut-brain axis and the bizarre communication between the GI system and the nervous system. Ample amount of studies being carried out also revealed the involvement of the gut microbiome in enhancing the degree of many neurological disorders, including neurodegenerative diseases. It was widely observed that there were distinct microbiome profiles and dysbiosis within patients suffering from Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. Various approaches to re-establish the balance of the gut microbiome, from antibiotic therapy, fecal microbiota transplant, or ingestion of psychobiotics, are discussed within this review within the specific context of combating neurodegenerative diseases. Present studies and clinical trials indicate that although there is an immense potential of gut microbiome modification to be preventive or therapeutic, there are still many intercalated components of the gut-brain axis at play and thus, more research needs to be carried out to delineate microbiome factors that may potentially alleviate symptoms of neurodegeneration.

RevDate: 2019-05-16

Mendes-Soares H, Raveh-Sadka T, Azulay S, et al (2019)

Model of personalized postprandial glycemic response to food developed for an Israeli cohort predicts responses in Midwestern American individuals.

The American journal of clinical nutrition pii:5490305 [Epub ahead of print].

BACKGROUND: Controlled glycemic concentrations are associated with a lower risk of conditions such as cardiovascular disease and diabetes. Models commonly used to guide interventions to control the glycemic response to food have low efficacy, with recent clinical guidelines arguing for the use of personalized approaches.

OBJECTIVE: We tested the efficacy of a predictive model of personalized postprandial glycemic response to foods that was developed with an Israeli cohort and that takes into consideration food components and specific features, including the microbiome, when applied to individuals from the Midwestern US.

DESIGN: We recruited 327 individuals for this study. Participants provided information regarding lifestyle, dietary habits, and health, as well as a stool sample for characterization of their gut microbiome. Participants were connected to continuous glucose monitors for 6 d, and the glycemic response to meals logged during this time was computed. The ability of a model trained using meals logged by the Israeli cohort to correctly predict glycemic responses in the Midwestern cohort was assessed and compared with that of a model trained using meals logged by both cohorts.

RESULTS: When trained on the Israeli cohort meals only, model performance for predicting responses of individuals in the Midwestern cohort was better (R = 0.596) than that observed for models taking into consideration the carbohydrate (R = 0.395) or calorie content of the meals alone (R = 0.336). Performance increased (R = 0.618) when the model was trained on meals from both cohorts, likely because of the observed differences in age distribution, diet, and microbiome.

CONCLUSIONS: We show that the modeling framework described in Zeevi et al. for an Israeli cohort is applicable to a Midwestern population, and outperforms commonly used approaches for the control of blood glucose responses. The adaptation of the model to the Midwestern cohort further enhances performance and is a promising means for designing effective nutritional interventions to control glycemic responses to foods. This trial was registered at clinicaltrials.gov as NCT02945514.

RevDate: 2019-05-16

Wang F, Sun NN, Li LL, et al (2019)

Hepatic progenitor cell activation is induced by the depletion of the gut microbiome in mice.

MicrobiologyOpen [Epub ahead of print].

The homeostasis of the gut microbiome is crucial for human health and for liver function. However, it has not been established whether the gut microbiome influence hepatic progenitor cells (HPCs). HPCs are capable of self-renewal and differentiate into hepatocytes and cholangiocytes; however, HPCs are normally quiescent and are rare in adults. After sustained liver damage, a ductular reaction occurs, and the number of HPCs is substantially increased. Here, we administered five broad-spectrum antibiotics for 14 days to deplete the gut microbiomes of male C57BL/6 mice, and we measured the plasma aminotransferases and other biochemical indices. The expression levels of two HPC markers, SRY-related high mobility group-box gene 9 (Sox9) and cytokeratin (CK), were also measured. The plasma aminotransferase activities were not affected, but the triglyceride, lactate dehydrogenase, low-density lipoprotein, and high-density lipoprotein concentrations were significantly altered; this suggests that liver function is affected by the composition of the gut microbiome. The mRNA expression of Sox9 was significantly higher in the treated mice than it was in the control mice (p < 0.0001), and a substantial expression of Sox9 and CK was observed around the bile ducts. The mRNA expression levels of proinflammatory factors (interleukin [IL]-1β, IL-6, tumor necrosis factor [TNF]-α, and TNF-like weak inducer of apoptosis [Tweak]) were also significantly higher in the antibiotic-treated mice than the levels in the control mice. These data imply that the depletion of the gut microbiome leads to liver damage, negatively impacts the hepatic metabolism and function, and activates HPCs. However, the underlying mechanisms remain to be determined.

RevDate: 2019-05-16

Woodhams DC, Rollins-Smith LA, Reinert LK, et al (2019)

Probiotics Modulate a Novel Amphibian Skin Defense Peptide That Is Antifungal and Facilitates Growth of Antifungal Bacteria.

Microbial ecology pii:10.1007/s00248-019-01385-9 [Epub ahead of print].

Probiotics can ameliorate diseases of humans and wildlife, but the mechanisms remain unclear. Host responses to interventions that change their microbiota are largely uncharacterized. We applied a consortium of four natural antifungal bacteria to the skin of endangered Sierra Nevada yellow-legged frogs, Rana sierrae, before experimental exposure to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). The probiotic microbes did not persist, nor did they protect hosts, and skin peptide sampling indicated immune modulation. We characterized a novel skin defense peptide brevinin-1Ma (FLPILAGLAANLVPKLICSITKKC) that was downregulated by the probiotic treatment. Brevinin-1Ma was tested against a range of amphibian skin cultures and found to inhibit growth of fungal pathogens Bd and B. salamandrivorans, but enhanced the growth of probiotic bacteria including Janthinobacterium lividum, Chryseobacterium ureilyticum, Serratia grimesii, and Pseudomonas sp. While commonly thought of as antimicrobial peptides, here brevinin-1Ma showed promicrobial function, facilitating microbial growth. Thus, skin exposure to probiotic bacterial cultures induced a shift in skin defense peptide profiles that appeared to act as an immune response functioning to regulate the microbiome. In addition to direct microbial antagonism, probiotic-host interactions may be a critical mechanism affecting disease resistance.

RevDate: 2019-05-16

Boehme M, van de Wouw M, Bastiaanssen TFS, et al (2019)

Mid-life microbiota crises: middle age is associated with pervasive neuroimmune alterations that are reversed by targeting the gut microbiome.

Molecular psychiatry pii:10.1038/s41380-019-0425-1 [Epub ahead of print].

Male middle age is a transitional period where many physiological and psychological changes occur leading to cognitive and behavioural alterations, and a deterioration of brain function. However, the mechanisms underpinning such changes are unclear. The gut microbiome has been implicated as a key mediator in the communication between the gut and the brain, and in the regulation of brain homeostasis, including brain immune cell function. Thus, we tested whether targeting the gut microbiome by prebiotic supplementation may alter microglia activation and brain function in ageing. Male young adult (8 weeks) and middle-aged (10 months) C57BL/6 mice received diet enriched with a prebiotic (10% oligofructose-enriched inulin) or control chow for 14 weeks. Prebiotic supplementation differentially altered the gut microbiota profile in young and middle-aged mice with changes correlating with faecal metabolites. Functionally, this translated into a reversal of stress-induced immune priming in middle-aged mice. In addition, a reduction in ageing-induced infiltration of Ly-6Chi monocytes into the brain coupled with a reversal in ageing-related increases in a subset of activated microglia (Ly-6C+) was observed. Taken together, these data highlight a potential pathway by which targeting the gut microbiome with prebiotics can modulate the peripheral immune response and alter neuroinflammation in middle age. Our data highlight a novel strategy for the amelioration of age-related neuroinflammatory pathologies and brain function.

RevDate: 2019-05-16

Scott AJ, Alexander JL, Merrifield CA, et al (2019)

International Cancer Microbiome Consortium consensus statement on the role of the human microbiome in carcinogenesis.

Gut pii:gutjnl-2019-318556 [Epub ahead of print].

OBJECTIVE: In this consensus statement, an international panel of experts deliver their opinions on key questions regarding the contribution of the human microbiome to carcinogenesis.

DESIGN: International experts in oncology and/or microbiome research were approached by personal communication to form a panel. A structured, iterative, methodology based around a 1-day roundtable discussion was employed to derive expert consensus on key questions in microbiome-oncology research.

RESULTS: Some 18 experts convened for the roundtable discussion and five key questions were identified regarding: (1) the relevance of dysbiosis/an altered gut microbiome to carcinogenesis; (2) potential mechanisms of microbiota-induced carcinogenesis; (3) conceptual frameworks describing how the human microbiome may drive carcinogenesis; (4) causation versus association; and (5) future directions for research in the field.The panel considered that, despite mechanistic and supporting evidence from animal and human studies, there is currently no direct evidence that the human commensal microbiome is a key determinant in the aetiopathogenesis of cancer. The panel cited the lack of large longitudinal, cohort studies as a principal deciding factor and agreed that this should be a future research priority. However, while acknowledging gaps in the evidence, expert opinion was that the microbiome, alongside environmental factors and an epigenetically/genetically vulnerable host, represents one apex of a tripartite, multidirectional interactome that drives carcinogenesis.

CONCLUSION: Data from longitudinal cohort studies are needed to confirm the role of the human microbiome as a key driver in the aetiopathogenesis of cancer.

RevDate: 2019-05-16

Liu Y, Zhu A, Tan H, et al (2019)

Engineering banana endosphere microbiome to improve Fusarium wilt resistance in banana.

Microbiome, 7(1):74 pii:10.1186/s40168-019-0690-x.

BACKGROUND: Plant microbiome highlights the importance of endosphere microbiome for growth and health of the host plant. Microbial community analysis represents an elegant way to identify keystone microbial species that have a more central position in the community. The aim of this study was to access the interactions between the keystone bacterial species and plants during banana Fusarium wilt process, by comparing the endophytic bacterial and fungal community in banana roots and shoot tips during growth and wilting processes. The keystone bacterial species were isolated and further engineered to improve banana wilt resistance.

RESULTS: Banana endosphere microbiome structure varied during plant growth and wilting processes. Bacterial and fungal diversity in the shoot tips and roots increased with the development of the banana plantlets. The bacterial groups belonging to the Enterobacteriaceae family with different relative abundances were detected in all the samples. The Klebsiella spp. might be the keystone bacteria during the growth of banana plantlets. The relative abundance of Fusarium associated with the wilt disease did not increase during the wilting process. The endophytic Enterobacteriaceae strains Enterobacter sp. E5, Kosakonia sp. S1, and Klebsiella sp. Kb were isolated on Enterobacteriaceae selective medium and further engineered by expressing 1-aminocyclopropane-1-carboxylate (ACC) deaminase on the bacterial cell walls (designated as E5P, S1P, and KbP, respectively). Pot experiments suggested that plants inoculated with strains E5, E5P, S1, and S1P increased resistance to the Fusarium wilt disease compared with the controls without inoculation, whereas the Klebsiella inoculation (Kb and KbP) did not increase the wilt resistance. Compared with the inoculation with the wild strains E5 and S1, the inoculation with engineered strains E5P and S1P significantly increased wilt resistance and promoted plant growth, respectively. The results illustrated that the keystone species in the banana microbiome may not be dominant in numbers and the functional role of keystone species should be involved in the wilt resistance.

CONCLUSION: The ACC deaminase activity of engineered bacteria was essential to the Fusarium wilt resistance and growth promotion of banana plants. Engineering keystone bacteria in plant microbiome with ACC deaminase on the cell walls should be a promising method to improve plant growth and disease resistance.

RevDate: 2019-05-16

Heinken A, Ravcheev DA, Baldini F, et al (2019)

Systematic assessment of secondary bile acid metabolism in gut microbes reveals distinct metabolic capabilities in inflammatory bowel disease.

Microbiome, 7(1):75 pii:10.1186/s40168-019-0689-3.

BACKGROUND: The human gut microbiome performs important functions in human health and disease. A classic example for host-gut microbial co-metabolism is host biosynthesis of primary bile acids and their subsequent deconjugation and transformation by the gut microbiome. To understand these system-level host-microbe interactions, a mechanistic, multi-scale computational systems biology approach that integrates the different types of omic data is needed. Here, we use a systematic workflow to computationally model bile acid metabolism in gut microbes and microbial communities.

RESULTS: Therefore, we first performed a comparative genomic analysis of bile acid deconjugation and biotransformation pathways in 693 human gut microbial genomes and expanded 232 curated genome-scale microbial metabolic reconstructions with the corresponding reactions (available at https://vmh.life). We then predicted the bile acid biotransformation potential of each microbe and in combination with other microbes. We found that each microbe could produce maximally six of the 13 secondary bile acids in silico, while microbial pairs could produce up to 12 bile acids, suggesting bile acid biotransformation being a microbial community task. To investigate the metabolic potential of a given microbiome, publicly available metagenomics data from healthy Western individuals, as well as inflammatory bowel disease patients and healthy controls, were mapped onto the genomes of the reconstructed strains. We constructed for each individual a large-scale personalized microbial community model that takes into account strain-level abundances. Using flux balance analysis, we found considerable variation in the potential to deconjugate and transform primary bile acids between the gut microbiomes of healthy individuals. Moreover, the microbiomes of pediatric inflammatory bowel disease patients were significantly depleted in their bile acid production potential compared with that of controls. The contributions of each strain to overall bile acid production potential across individuals were found to be distinct between inflammatory bowel disease patients and controls. Finally, bottlenecks limiting secondary bile acid production potential were identified in each microbiome model.

CONCLUSIONS: This large-scale modeling approach provides a novel way of analyzing metagenomics data to accelerate our understanding of the metabolic interactions between the host and gut microbiomes in health and diseases states. Our models and tools are freely available to the scientific community.

RevDate: 2019-05-16

Rello J, Parisella FR, A Perez (2019)

Alternatives to antibiotics in an era of difficult-to-treat resistance: new insights.

Expert review of clinical pharmacology [Epub ahead of print].

INTRODUCTION: The rise of antibiotic resistance, the limited efficacy and the adverse events associated with antibiotics have urged the development of alternative measures to treat bacterial infections. Novel therapies which are pathogen specific and are safer to the healthy microbiome are being developed. Areas covered: This manuscript provides a compact overview of the feasibility and clinical impact of the latest novel therapies, with a focus on monoclonal antibodies (mAbs), vaccines, stem cells, bacteriophages and liposomes. This is a follow-up of a previous manuscript (doi: 10.1080/17512433.2016.1241141); a database search (PubMed, EMBASE, Cochrane) was used to identify recently published literature (from January 2016) which was not covered in the previous publication. Expert opinion: Among non-traditional agents, monoclonal antibodies have not been as successful as in other therapeutic areas. In particular many are developed to prevent hospital-acquired infections caused by S. aureus or P. aeruginosa and, so far, results have been overall disappointing. Stem cells and bacteriophages still have a long way to go. Vaccines are always desirable to prevent infections but again there is a lack of confirmatory results. Broad spectrum liposomes have shown promising results in treating severely infected patients and could be game changers in patient management.

RevDate: 2019-05-16

Fu S, Zhuang F, Guo L, et al (2019)

Effect of Baicalin-Aluminum Complexes on Fecal Microbiome in Piglets.

International journal of molecular sciences, 20(10): pii:ijms20102390.

The gut microbiome has important effects on gastrointestinal diseases. Diarrhea attenuation functions of baicalin (BA) is not clear. Baicalin-aluminum complexes (BBA) were synthesized from BA, but the BBA's efficacy on the diarrhea of piglets and the gut microbiomes have not been explored and the mechanism remains unclear. This study has explored whether BBA could modulate the composition of the gut microbiomes of piglets during diarrhea. The results showed that the diarrhea rate reduced significantly after treatment with BBA. BBA altered the overall structure of the gut microbiomes. In addition, the Gene Ontology (GO) enrichment analysis indicated that the functional differentially expressed genes, which were involved in the top 30 GO enrichments, were associated with hydrogenase (acceptor) activity, nicotinamide-nucleotide adenylyltransferase activity, and isocitrate lyase activity, belong to the molecular function. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that flagellar assembly, bacterial chemotaxis, lipopolysaccharide biosynthesis, ATP-binding cassette transporters (ABC) transporters, biosynthesis of amino acids, and phosphotransferase system (PTS) were the most enriched during BBA treatment process. Taken together, our results first demonstrated that BBA treatment could modulate the gut microbiomes composition of piglets with diarrhea, which may provide new potential insights on the mechanisms of gut microbiomes associated underlying the antimicrobial efficacy of BBA.

RevDate: 2019-05-16

Chang YL, Wang Z, Igawa S, et al (2019)

Lipocalin 2: A New Antimicrobial in Mast Cells.

International journal of molecular sciences, 20(10): pii:ijms20102380.

Mast cells (MCs) play a significant role in the innate immune defense against bacterial infection through the release of cytokines and antimicrobial peptides. However, their antimicrobial function is still only partially described. We therefore hypothesized that MCs express additional antimicrobial peptides. In this study, we used FANTOM 5 transcriptome data to identify for the first time that MCs express lipocalin 2 (LCN2), a known inhibitor of bacterial growth. Using MCs derived from mice which were deficient in LCN2, we showed that this antimicrobial peptide is an important component of the MCs' antimicrobial activity against Escherichia coli (E. coli). Since sphingosine-1-phosphate receptors (S1PRs) on MCs are known to regulate their function during infections, we hypothesized that S1P could activate LCN2 production in MCs. Using an in vitro assay, we demonstrated that S1P enhances MCs antimicrobial peptide production and increases the capacity of MCs to directly kill S. aureus and E. coli via an LCN2 release. In conclusion, we showed that LCN2 is expressed by MCs and plays a role in their capacity to inhibit bacterial growth.

RevDate: 2019-05-16

Evariste L, Barret M, Mottier A, et al (2019)

Gut microbiota of aquatic organisms: A key endpoint for ecotoxicological studies.

Environmental pollution (Barking, Essex : 1987), 248:989-999.

Gut microbial communities constitute a compartment of crucial importance in regulation of homeostasis of multiple host physiological functions as well as in resistance towards environmental pollutants. Many chemical contaminants were shown to constitute a major threat for gut bacteria. Changes in gut microbiome could lead to alteration of host health. The access to high-throughput sequencing platforms permitted a great expansion of this discipline in human health while data from ecotoxicological studies are scarce and particularly those related to aquatic pollution. The main purpose of this review is to summarize recent body of literature providing data obtained from microbial community surveys using high-throughput 16S rRNA sequencing technology applied to aquatic ecotoxicity. Effects of pesticides, PCBs, PBDEs, heavy metals, nanoparticles, PPCPs, microplastics and endocrine disruptors on gut microbial communities are presented and discussed. We pointed out difficulties and limits provided by actual methodologies. We also proposed ways to improve understanding of links between changes in gut bacterial communities and host fitness loss, along with further applications for this emerging discipline.

RevDate: 2019-05-15

Roh Y, Lee J, Kim WG, et al (2017)

Effect of Diet Change on Gut Microbiota: Observational Pilot Study of Four Urban Couples.

Journal of obesity & metabolic syndrome, 26(4):257-265.

Background: Recent studies have focused on changes in gut microbiota following a dietary change. We identified how the distribution of gut microbiota changed when the dietary habits of young city dwellers improved using an intervention in which married couples shared the same dietary habits.

Methods: Four married couples in their 30s with irregular eating habits and sedentary lifestyles were asked whether they had any uncomfortable symptoms. A nutritionist advised them to reduce their intake of processed meats, carbonated beverages, and late-night snacks. After a 6-week intervention, subjects were asked whether they observed any changes in their symptoms. Their stool samples were collected before and after the intervention and analyzed to determine whether the gut microbiota had changed.

Results: After the dietary intervention, some subjective symptoms of the participants improved. Specifically, a subject who complained of frequent abdominal pain/diarrhea and one who complained of fatigue showed improvement in those symptoms. In addition, some subjects showed improvements in symptoms such as skin disease or constipation. Intestinal microorganisms between spouses who share the same dietary habits were found to be similar.

Conclusion: Improvements in eating habits can change the distribution of gut microbiota and alleviate various uncomfortable medical symptoms. Within married couples, the distribution of gut microbiota became similar when the spouses shared the same dietary habits. These results suggest a possible correlation between family-level changes in eating habits and the health of all family members.

RevDate: 2019-05-15

Jansson JK, KS Hofmockel (2019)

Corrigendum to "The soil microbiome - from metagenomics to metaphenomics" [Curr Opin Micrbiol 43 (June 2018) 162-168].

RevDate: 2019-05-15

Cordovez V, Dini-Andreote F, Carrión VJ, et al (2019)

Ecology and Evolution of Plant Microbiomes.

Annual review of microbiology [Epub ahead of print].

Microorganisms colonizing plant surfaces and internal tissues provide a number of life-support functions for their host. Despite increasing recognition of the vast functional capabilities of the plant microbiome, our understanding of the ecology and evolution of the taxonomically hyperdiverse microbial communities is limited. Here, we review current knowledge of plant genotypic and phenotypic traits as well as allogenic and autogenic factors that shape microbiome composition and functions. We give specific emphasis to the impact of plant domestication on microbiome assembly and how insights into microbiomes of wild plant relatives and native habitats can contribute to reinstate or enrich for microorganisms with beneficial effects on plant growth, development, and health. Finally, we introduce new concepts and perspectives in plant microbiome research, in particular how community ecology theory can provide a mechanistic framework to unravel the interplay of distinct ecological processes-i.e., selection, dispersal, drift, diversification-that structure the plant microbiome. Expected final online publication date for the Annual Review of Microbiology Volume 73 is September 9, 2019. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

RevDate: 2019-05-15

Riiser ES, Haverkamp THA, Varadharajan S, et al (2019)

Switching on the light: using metagenomic shotgun sequencing to characterize the intestinal microbiome of Atlantic cod.

Environmental microbiology [Epub ahead of print].

Atlantic cod (Gadus morhua) is an ecologically important species with a wide-spread distribution in the North Atlantic Ocean, yet little is known about the diversity of its intestinal microbiome in its natural habitat. No geographical differentiation in this microbiome was observed based on 16S rRNA amplicon analyses, yet such finding may result from an inherent lack of power of this method to resolve fine-scaled biological complexity. Here, we use metagenomic shotgun sequencing to investigate the intestinal microbiome of 19 adult Atlantic cod individuals from two coastal populations in Norway - located 470 km apart. Resolving the species community to unprecedented resolution, we identify two abundant species, P. iliopiscarium and P. kishitanii, which comprise over 50% of the classified reads. Interestingly, the intestinal P. kishitanii strains have functionally intact lux genes, and its high abundance suggests that fish intestines form an important part of its ecological niche. These observations support a hypothesis that bioluminescence plays an ecological role in the marine food web. Despite our improved taxonomical resolution, we identify no geographical differences in bacterial community structure, indicating that the intestinal microbiome of these coastal cod is colonized by a limited number of closely related bacterial species with a broad geographical distribution. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-15

Ellison MJ, Conant GC, Lamberson WR, et al (2019)

Predicting residual feed intake status using rumen microbial profiles in ewe lambs.

Journal of animal science pii:5489819 [Epub ahead of print].

Including feed efficiency as a trait for selection has gained interest in the sheep industry because it can result in reduced feed inputs or improve stocking rates, both of which translate into increased profitability for the producer. It is of interest whether the feed efficiency status of a testing population of sheep could be predicted using rumen microbial profiles associated with divergent feed efficiency status in a training population of sheep. Two populations of ewes were fed the same diet and each group was evaluated for feed efficiency. A total of 20 animals in the testing population were selected for prediction assessment using feed efficiency, including the six top ranked, the six bottom ranked, and 8 middle ranked ewes stratified over the distribution. Rumen fluid samples were collected and DNA was extracted for sequencing. Using a rumen microbial profile associated with diverging feed efficiency created from the training population, multiple discriminant analyses were performed using the DISCRIM procedure of SAS to determine the probability of correctly identifying lambs in the testing population as low, medium, or high feed efficiency using their microbial profiles. A profile of six rumen microbial species were used to correctly (P < 0.001) predict all testing population ewes into their actual feed efficiency status. A regression analysis using the same microbial profile was used to predict feed efficiency values, which were strongly correlated (r = 0.71; P < 0.001) with actual feed efficiency values. These results indicate that specific rumen microbial species may play a role in feed efficiency, and that a microbial profile could be used to rank sheep for feed efficiency.

RevDate: 2019-05-15

Prussing C, Saavedra MP, Bickersmith SA, et al (2019)

Malaria vector species in Amazonian Peru co-occur in larval habitats but have distinct larval microbial communities.

PLoS neglected tropical diseases, 13(5):e0007412 pii:PNTD-D-18-01822 [Epub ahead of print].

In Amazonian Peru, the primary malaria vector, Nyssorhynchus darlingi (formerly Anopheles darlingi), is difficult to target using standard vector control methods because it mainly feeds and rests outdoors. Larval source management could be a useful supplementary intervention, but to determine its feasibility, more detailed studies on the larval ecology of Ny. darlingi are essential. We conducted a multi-level study of the larval ecology of Anophelinae mosquitoes in the peri-Iquitos region of Amazonian Peru, examining the environmental characteristics of the larval habitats of four species, comparing the larval microbiota among species and habitats, and placing Ny. darlingi larval habitats in the context of spatial heterogeneity in human malaria transmission. We collected Ny. darlingi, Nyssorhynchus rangeli (formerly Anopheles rangeli), Nyssorhynchus triannulatus s.l. (formerly Anopheles triannulatus s.l.), and Nyssorhynchus sp. nr. konderi (formerly Anopheles sp. nr. konderi) from natural and artificial water bodies throughout the rainy and dry seasons. We found that, consistent with previous studies in this region and in Brazil, the presence of Ny. darlingi was significantly associated with water bodies in landscapes with more recent deforestation and lower light intensity. Nyssorhynchus darlingi presence was also significantly associated with a lower vegetation index, other Anophelinae species, and emergent vegetation. Though they were collected in the same water bodies, the microbial communities of Ny. darlingi larvae were distinct from those of Ny. rangeli and Ny. triannulatus s.l., providing evidence either for a species-specific larval microbiome or for segregation of these species in distinct microhabitats within each water body. We demonstrated that houses with more reported malaria cases were located closer to Ny. darlingi larval habitats; thus, targeted control of these sites could help ameliorate malaria risk. The co-occurrence of Ny. darlingi larvae in water bodies with other putative malaria vectors increases the potential impact of larval source management in this region.

RevDate: 2019-05-15

Joyce A, McCarthy CGP, Murphy S, et al (2019)

Antibiotic resistomes of healthy pig faecal metagenomes.

Microbial genomics [Epub ahead of print].

Antibiotic resistance reservoirs within food-producing animals are thought to be a risk to animal and human health. This study describes the minimum natural resistome of pig faeces as the bacteria are under no direct antibiotic selective pressure. The faecal resistome of 257 different genes comprised 56 core and 201 accessory resistance genes. The genes present at the highest relative abundances across all samples were tetW, tetQ, tet44, tet37, tet40, mefA, aadE, ant(9)-1, ermB and cfxA2. This study characterized the baseline resistome, the microbiome composition and the metabolic components described by the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in healthy pig faeces, without antibiotic selective pressures. The microbiome hierarchical analysis resulted in a cluster tree with a highly similar pattern to that of the accessory resistome cluster tree. Functional capacity profiling identified genes associated with horizontal gene transfer. We identified a statistically significant positive correlation between the total antibiotic resistome and suggested indicator genes, which agree with using these genes as indicators of the total resistomes. The correlation between total resistome and total microbiome in this study was positive and statistically significant. Therefore, the microbiome composition influenced the resistome composition. This study identified a core and accessory resistome present in a cohort of healthy pigs, in the same conditions without antibiotics. It highlights the presence of antibiotic resistance in the absence of antibiotic selective pressure and the variability between animals even under the same housing, food and living conditions. Antibiotic resistance will remain in the healthy pig gut even when antibiotics are not used. Therefore, the risk of antibiotic resistance transfer from animal faeces to human pathogens or the environment will remain in the absence of antibiotics.

RevDate: 2019-05-15

Mitchell AB (2019)

The lung microbiome and transplantation.

Current opinion in organ transplantation, 24(3):305-310.

PURPOSE OF REVIEW: Lung transplantation survival is still limited compared with other solid organ transplant modalities, due to a range of factors that are continuing to be elucidated. However, new research is emerging which indicates that the microbiome of the lungs, and of other organs, may have important implications for immune response and mediating transplant outcomes. Pathogenic bacterial and viral species are known to have deleterious effects on the allograft, but taking a more global view, and considering the overall composition of the community of microbial species may undercover a greater understanding of the complex interplay involved in allograft dysfunction.

RECENT FINDINGS: The microbiome appears to have an important modulatory role on immune response in both normal development, and after transplantation. A range of microbial species contributes to the resident microscopic community, with the gut and blood microbiomes having a significant impact on the function of the lungs and resistance to infection. Movement of species from within and outside the respiratory tract occurs in the early transplant period, leading to a modified donor microbiome in the recipient. There is evidence to suggest that chronic lung allograft dysfunction may be facilitated by the respiratory microbiome and interactions with immune cells within the allograft.

SUMMARY: Further investigation of the respiratory microbiome, interactions with the microbiome of other organs and impact on immune and allograft function posttransplantation is needed. Promising insights are being gained regarding certain microbial profiles which may be associated with negative outcomes, and the mechanisms through which this occurs. As our understanding expands, the ability to modify the microbiome offers novel treatment strategies for combating allograft dysfunction.

RevDate: 2019-05-15

Chernikova D, Yuan I, M Shaker (2019)

Prevention of allergy with diverse and healthy microbiota: an update.

Current opinion in pediatrics, 31(3):418-425.

PURPOSE OF REVIEW: Microbiota consist of symbiotic microscopic neighbors that interact on and within our bodies in diverse and incompletely understood ways throughout our lifetime. Though various associations with allergic disease have been described, clear effective therapeutic interventions to prevent allergy have been elusive.

RECENT FINDINGS: The human microbiome is influenced by multiple factors, including: mode of infant delivery (vaginal vs. cesarean section), breastfeeding, diet, presence of siblings and pets, exposure to antibiotics and other medications (particularly antacids), lifestyle, and developmental context. Microbial species promoting atopic responses and tolerance have been described. Specific microbiota likely act through distinct metabolic pathways to promote the health of their human hosts, optimally directing the developing immune system away from pro-allergic, Th2-dominated responses to more T-regulatory-influenced behaviors.

SUMMARY: Evidence suggests that specific healthy infant microbiome signatures may influence development of some components of the allergic march of childhood by decreasing atopic dermatitis, asthma, and food allergy. Further understanding of factors that influence healthy microbiota may lead to specific strategies tailored for early intervention and disease prevention.

RevDate: 2019-05-15

Yao R, Wong CB, Nakamura K, et al (2019)

Bifidobacterium breve MCC1274 with glycosidic activity enhances in vivo isoflavone bioavailability.

Beneficial microbes [Epub ahead of print].

Polyphenols are plant derived compounds that exert many beneficial health effects to the human host. However, associated health benefits of dietary polyphenol are highly dependent on their intestinal metabolism, bioavailability, and absorption. Bifidobacteria, which represent the key members of gut microbiota, have been suggested to promote gut microbial homeostasis and may be involved in the metabolism of polyphenols. In this study, the capabilities of thirteen Bifidobacterium strains in hydrolysing polyphenol glycosides were evaluated. Among the tested strains, Bifidobacterium breve MCC1274 was found to possess the highest β-glucosidase activity and strong capability to convert daidzin and trans-polydatin to their aglycones; while kinetic analysis revealed that B. breve MCC1274 hydrolysed more than 50% of daidzin and trans-polydatin at less than 3 h of incubation. Further investigation using rats with an antibiotics-disturbed microbiome revealed that following the ingestion of daidzin glycoside, oral administration of B. breve MCC1274 significantly enhanced the plasma concentration of daidzein in rats pre-treated with antibiotics as compared to antibiotics-pre-treated control and non-treated control groups. The relative abundance of Actinobacteria and the total numbers of B. breve were also significantly higher in antibiotics-pre-treated rats administered with B. breve MCC1274 than that of the control groups. These findings suggest that B. breve MCC1274 is effective in enhancing the bioavailability of daidzein in the gut under dysbiosis conditions and may potentially improve intestinal absorption of isoflavones and promote human health.

RevDate: 2019-05-15

Garcez ML, Jacobs KR, GJ Guillemin (2019)

Microbiota Alterations in Alzheimer's Disease: Involvement of the Kynurenine Pathway and Inflammation.

Neurotoxicity research pii:10.1007/s12640-019-00057-3 [Epub ahead of print].

Alzheimer's disease (AD) is a neurodegenerative disease considered the major cause of dementia in the elderly. The main pathophysiological features of the disease are neuronal loss (mainly cholinergic neurons), glutamatergic excitotoxicity, extracellular accumulation of amyloid beta, and intracellular neurofibrillary tangles. However, other pathophysiological features of the disease have emerged including neuroinflammation and dysregulation of the kynurenine pathway (KP). The intestinal microbiota is a large and diverse collection of microorganisms that play a crucial role in regulating host health. Recently, studies have highlighted that changes in intestinal microbiota contribute to brain dysfunction in various neurological diseases including AD. Studies suggest that microbiota compositions are altered in AD patients and animal models and that these changes may increase intestinal permeability and induce inflammation. Considering that microbiota can modulate the kynurenine pathway and in turn neuroinflammation, the gut microbiome may be a valuable target for the development of new disease-modifying therapies. The present review aims to link the interactions between AD, microbiota, and the KP.

RevDate: 2019-05-15

York A (2019)

Skin microbiome relieves an itch.

Nature reviews. Microbiology pii:10.1038/s41579-019-0217-2 [Epub ahead of print].

RevDate: 2019-05-15

Martinson JNV, Pinkham NV, Peters GW, et al (2019)

Rethinking gut microbiome residency and the Enterobacteriaceae in healthy human adults.

The ISME journal pii:10.1038/s41396-019-0435-7 [Epub ahead of print].

Longitudinal human gut microbiome datasets generated using community-level, sequence-based approaches often report a sub-set of long-lived "resident" taxa that rarely, if ever, are lost. This result contrasts with population-level turnover of resident clones on the order of months to years. We hypothesized that the disconnect between these results is due to a relative lack of simultaneous discrimination of the human gut microbiome at both the community and population-levels. Here, we present results of a small, longitudinal cohort study (n = 8 participants) of healthy human adults that identifies static and dynamic members of the gut microbiome at the clone level based on cultivation/genetic discrimination and at the operational taxonomic unit/amplified sequence variant levels based on 16S rRNA sequencing. We provide evidence that there is little "stability" within resident clonal populations of the common gut microbiome bacterial family, Enterobacteriaceae. Given that clones can vary substantially in genome content and that evolutionary processes operate on the population level, these results question the biological relevance of apparent stability at higher taxonomic levels.

RevDate: 2019-05-15

Ma L, Shi Y, Siemianowski O, et al (2019)

Hydrogel-based transparent soils for root phenotyping in vivo.

Proceedings of the National Academy of Sciences of the United States of America pii:1820334116 [Epub ahead of print].

Root phenotypes are increasingly explored as predictors of crop performance but are still challenging to characterize. Media that mimic field conditions (e.g., soil, sand) are opaque to most forms of radiation, while transparent media do not provide field-relevant growing conditions and phenotypes. We describe here a "transparent soil" formed by the spherification of hydrogels of biopolymers. It is specifically designed to support root growth in the presence of air, water, and nutrients, and allows the time-resolved phenotyping of roots in vivo by both photography and microscopy. The roots developed by soybean plants in this medium are significantly more similar to those developed in real soil than those developed in hydroponic conditions and do not show signs of hypoxia. Lastly, we show that the granular nature and tunable properties of these hydrogel beads can be leveraged to investigate the response of roots to gradients in water availability and soil stiffness.

RevDate: 2019-05-15

Lachnit T, Bosch TCG, P Deines (2019)

Exposure of the Host-Associated Microbiome to Nutrient-Rich Conditions May Lead to Dysbiosis and Disease Development-an Evolutionary Perspective.

mBio, 10(3): pii:mBio.00355-19.

Inflammatory diseases, such as inflammatory bowel diseases, are dramatically increasing worldwide, but an understanding of the underlying factors is lacking. We here present an ecoevolutionary perspective on the emergence of inflammatory diseases. We propose that adaptation has led to fine-tuned host-microbe interactions, which are maintained by secreted host metabolites nourishing the associated microbes. A constant elevation of nutrients in the gut environment leads to an increased activity and changed functionality of the microbiota, thus severely disturbing host-microbe interactions and leading to dysbiosis and disease development. In the past, starvation and pathogen infections, causing diarrhea, were common incidences that reset the gut bacterial community to its "human-specific-baseline." However, these natural clearing mechanisms have been virtually eradicated in developed countries, allowing a constant uncontrolled growth of bacteria. This leads to an increase of bacterial products that stimulate the immune system and ultimately might initiate inflammatory reactions.

RevDate: 2019-05-15

Su Y, Xu YX, An WH, et al (2019)

[Assessment of Ecosystem Health of an Urban River Based on the Microbe Index of Biotic Integrity (M-IBI)].

Huan jing ke xue= Huanjing kexue, 40(3):1270-1279.

The index of biotic integrity (IBI) has been widely used in river ecosystem health assessment. However, few studies have reported the application of microbial communities in ecosystem health assessment so far, especially for urban rivers. In this study, the Illumina high-throughput sequencing technique was applied to analyze the microbial community diversity and composition of five urban rivers selected in Zhejiang Province. Canonical correlation analyses (CCA) and Spearman correlation analysis were used to evaluate the relationship between each taxonomic group and the water quality properties to select the most sensitive taxonomic groups as candidate indexes. The functional metrics, including the relative abundance of pathogenic bacteria, pollutant-degrading bacteria, and nutrient cycling bacteria were also selected as candidate indexes. Based on the distribution range, discriminatory power, and Pearson's correlation analysis for candidate indexes, five metrics, including the Shannon-index, the number of microbial phyla, the relative abundance of Verrucomicrobia, Chlorobi, and Mycobacterium were selected to establish a biotic integrity index of microbes (M-IBI) evaluation system. A ratio score system was used to get metrics into a uniform score for all sampling points, and the results showed that among the urban river samples studied, most of them (40.9%) were at "Great" level, 45.5% were at "Good" level, 9.1% were at "Moderate" level, and 4.5% were at "Bad" level. The index of M-IBI effectively discriminated the least, medium, and highly impaired sampling points and provided a good match with the water quality (R=0.753, P<0.01), indicating that the M-IBI has potential as an index to evaluate the health of urban river ecosystems.

RevDate: 2019-05-15

Medina D, Hughey MC, Walke JB, et al (2019)

Amphibian skin fungal communities vary across host species and do not correlate with infection by a pathogenic fungus.

Environmental microbiology [Epub ahead of print].

Amphibian population declines caused by the fungus Batrachochytrium dendrobatidis (Bd), have prompted studies on the bacterial community that resides on amphibian skin. However, studies addressing the fungal portion of these symbiont communities have lagged behind. Using ITS1 amplicon sequencing, we examined the fungal portion of the skin microbiome of temperate and tropical amphibian species currently coexisting with Bd in nature. We assessed co-occurrence patterns between bacterial and fungal OTUs using a subset of samples for which bacterial 16S rRNA gene amplicon data were also available. We determined that fungal communities were dominated by members of the phyla Ascomycota and Basidiomycota, and also by Chytridiomycota in the most aquatic amphibian species. Alpha diversity of the fungal communities differed across host species, and fungal community structure differed across species and regions. However, we did not find a correlation between fungal diversity/community structure and Bd infection, though we did identify significant correlations between Bd and specific OTUs. Moreover, positive bacterial-fungal co-occurrences suggests that positive interactions between these organisms occur in the skin microbiome. Understanding the ecology of amphibian skin fungi, and their interactions with bacteria, will complement our knowledge of the factors influencing community assembly and the overall function of these symbiont communities. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-15

Sun J, Zhan Y, Mariosa D, et al (2019)

Antibiotics Use and Risk of Amyotrophic Lateral Sclerosis in Sweden.

European journal of neurology [Epub ahead of print].

BACKGROUND AND PURPOSE: Previous animal studies have suggested disrupted intestinal microbiome in amyotrophic lateral sclerosis (ALS). Due to the known effect of antibiotics on gut microflora, the potential role of antibiotics use on the risk of ALS deserves an investigation.

METHODS: A nested case-control study was conducted using several Swedish national registers. We included 2,484 ALS patients diagnosed between July 1, 2006 and December 31, 2013 as cases and randomly selected five controls per case who were individually matched to the case by sex, birth year, and area of residence from the general Swedish population. Information on antibiotics prescriptions before ALS diagnosis was extracted from the Prescribed Drug Register for both cases and controls. Conditional logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS: After accounting for potential diagnostic delay in ALS by excluding all prescriptions within one year before diagnosis, any antibiotics use was associated with a higher risk of ALS. The ORs (95% CIs) were 1.06 (0.94-1.19), 1.13 (1.00-1.28), and 1.18 (1.03-1.35) when comparing one, 2-3, and ≥4 prescriptions to no prescription (P for trend = 0.0069). Similar results were noted for antibiotics used for respiratory infections and urinary tract as well as skin and soft tissue infections. Among different individual antibiotics, the risk of ALS was especially increased in relation to more than two prescriptions of beta-lactamase sensitive penicillin (OR=1.28; 95% CI 1.10-1.50).

CONCLUSIONS: Use of antibiotics, especially repeated, might be associated with a higher subsequent risk of ALS. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-15

Tuccinardi D, Farr OM, Upadhyay J, et al (2019)

Mechanisms Underlying the Cardiometabolic Protective Effect of Walnut Consumption in Obese Subjects: A Cross-Over, Randomized, Double-Blinded, Controlled Inpatient Physiology Study.

Diabetes, obesity & metabolism [Epub ahead of print].

AIMS: To assess the effects of walnuts on cardiometabolic outcomes in obese subjects and to explore underlying mechanisms using novel methods including metabolomic, lipidomic, glycomic, and microbiome analysis integrated with lipid particle fractionation, appetite-regulating hormones and hemodynamic measurements.

MATERIALS AND METHODS: 10 obese subjects were enrolled in this cross-over, randomized, double-blind, placebo-controlled clinical trial. Patients participated in two 5-day inpatient stays during which they consumed a smoothie containing 48g walnuts or a macronutrient-matched placebo smoothie without nuts, with a one-month washout period between the two visits.

RESULTS: Walnut consumption improved aspects of the lipid profile, i.e. reduced fasting small and dense LDL particles (p<.02) and increased postprandial large HDL particles (p<.01). Lipoprotein Insulin Resistance Score, glucose and insulin AUC decreased significantly after walnut consumption (p<.01, p<.02, p<.04, respectively). Consuming walnuts significantly increased 10 N-glycans, with 8 of them carrying a fucose core. Lipidomic analysis showed a robust reduction in harmful ceramides, hexosylceramides and sphingomyelins, which have been shown to mediate effects on cardiometabolic risk. Peptide YY AUC significantly increased after walnut consumption (p<.03). No major significant changes in hemodynamic, metabolomic analysis or in host health-promoting bacteria such as Faecalibacterium were found.

CONCLUSIONS: These data provide a more comprehensive mechanistic perspective of the effect of dietary walnut consumption on cardiometabolic parameters. Lipidomic and lipid nuclear magnetic resonance spectroscopy analysis showed an early but significant reduction in ceramides and other atherogenic lipids with walnut consumption that may explain the longer-term benefits of walnuts on insulin resistance, cardiovascular risk and mortality. This article is protected by copyright. All rights reserved.

RevDate: 2019-05-15

Goldmann K, Boeddinghaus RS, Klemmer S, et al (2019)

Unraveling spatio-temporal variability of arbuscular mycorrhiza fungi in a temperate grassland plot.

Environmental microbiology [Epub ahead of print].

Soils provide a heterogeneous environment varying in space and time; consequently, the biodiversity of soil microorganisms also differs spatially and temporally. For soil microbes tightly associated with plant roots, such as arbuscular mycorrhiza fungi (AMF), the diversity of plant partners and seasonal variability in trophic exchanges between the symbionts introduce additional heterogeneity. To clarify the impact of such heterogeneity, we investigated spatio-temporal variation in AMF diversity on a plot-scale (10 × 10 m) in a grassland managed at low intensity in southwest Germany. AMF diversity was determined using 18S rDNA pyrosequencing analysis of 360 soil samples taken at six time points within a year. We observed high AMF alpha- and beta-diversity across the plot and at all investigated time points. Relationships were detected between spatio-temporal variation in AMF OTU richness and plant species richness, root biomass, minimal changes in soil texture, and pH. The plot was characterized by high AMF turnover rates with a positive spatio-temporal relationship for AMF beta-diversity. However, environmental variables explained only ~20% of the variation in AMF communities. This indicates that the observed spatio-temporal richness and community variability of AMF was largely independent of the abiotic environment, but related to plant properties and the co-occurring microbiome. This article is protected by copyright. All rights reserved.

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

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In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

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Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

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In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

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Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

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When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

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With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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