Project description:Changes in microbiome composition have been associated with a wide array of human diseases, turning the human microbiota into an attractive target for therapeutic intervention. Yet clinical translation of these findings requires the establishment of causative connections between specific microbial taxa and their functional impact on host tissues. Here, we infused gut organ cultures with longitudinal microbiota samples collected from therapy-naïve irritable bowel syndrome (IBS) patients under low-FODMAP (fermentable Oligo-, Di-, Mono-saccharides and Polyols) diet. We show that post-diet microbiota regulates intestinal expression of inflammatory and neuro-muscular gene-sets. Specifically, we identify Bifidobacterium adolescentis as a diet-sensitive pathobiont that alters tight junction integrity and disrupts gut barrier functions. Collectively, we present a unique pathway discovery approach for mechanistic dissection and identification of functional diet-host-microbiota modules. Our data support the hypothesis that the gut microbiota mediates the beneficial effects of low-FODMAP diet and reinforce the potential feasibility of microbiome based-therapies in IBS.
Project description:Changes in microbiome composition have been associated with a wide array of human diseases, turning the human microbiota into an attractive target for therapeutic intervention. Yet clinical translation of these findings requires the establishment of causative connections between specific microbial taxa and their functional impact on host tissues. Here, we infused gut organ cultures with longitudinal microbiota samples collected from therapy-naïve irritable bowel syndrome (IBS) patients under low-FODMAP (fermentable Oligo-, Di-, Mono-saccharides and Polyols) diet. We show that post-diet microbiota regulates intestinal expression of inflammatory and neuro-muscular gene-sets. Specifically, we identify Bifidobacterium adolescentis as a diet-sensitive pathobiont that alters tight junction integrity and disrupts gut barrier functions. Collectively, we present a unique pathway discovery approach for mechanistic dissection and identification of functional diet-host-microbiota modules. Our data support the hypothesis that the gut microbiota mediates the beneficial effects of low-FODMAP diet and reinforce the potential feasibility of microbiome based-therapies in IBS.
Project description:Changes in microbiome composition have been associated with a wide array of human diseases, turning the human microbiota into an attractive target for therapeutic intervention. Yet clinical translation of these findings requires the establishment of causative connections between specific microbial taxa and their functional impact on host tissues. Here, we infused gut organ cultures with longitudinal microbiota samples collected from therapy-naïve irritable bowel syndrome (IBS) patients under low-FODMAP (fermentable Oligo-, Di-, Mono-saccharides and Polyols) diet. We show that post-diet microbiota regulates intestinal expression of inflammatory and neuro-muscular gene-sets. Specifically, we identify Bifidobacterium adolescentis as a diet-sensitive pathobiont that alters tight junction integrity and disrupts gut barrier functions. Collectively, we present a unique pathway discovery approach for mechanistic dissection and identification of functional diet-host-microbiota modules. Our data support the hypothesis that the gut microbiota mediates the beneficial effects of low-FODMAP diet and reinforce the potential feasibility of microbiome based-therapies in IBS.
Project description:The gut microbiota is essential for several aspects of host physiology such as metabolism, epithelial barrier function and immunity. Previous studies have revealed that host immune system as well as diet and other environmental factors have a strong impact on the composition and activity of gut microbiota, but the molecular requirements for such functional regulation remain unknown. We show that the bacteria belonging to phylum Bacteroidetes acquire their symbiotic activity in the colonic mucus, depending on a newly characterized molecular family encoded within the polysaccharide utilization loci (PUL), which we have named Mucus-Associated Functional Factor (MAFF). We used microarray analysis of colonic epithlial cells to determin the impact of MAFF genes on colonic homeostasis.
Project description:The human gut microbiota is crucial for degrading dietary fibres from the diet. However, some of these bacteria can also degrade host glycans, such as mucins, the main component of the protective gut mucus layer. Specific microbiota species and mucin degradation patterns are associated with inflammatory processes in the colon. Yet, it remains unclear how the utilization of mucin glycans affects the degradation of dietary fibres by the human microbiota. Here, we used three dietary fibres (apple pectin, β-glucan and xylan) to study in vitro the dynamics of colon mucin and dietary fibre degradation by the human faecal microbiota. The dietary fibres showed clearly distinguishing modulatory effects on faecal microbiota composition. The utilization of colon mucin in cultures led to alterations in microbiota composition and metabolites. Metaproteome analysis showed the central role of the Bacteroides in degradation of complex fibres while Akkermansia muciniphila was the main degrader of colonic mucin. This work demonstrates the intricacy of complex glycan metabolism by the gut microbiota and how the utilization of host glycans leads to alterations in the metabolism of dietary fibres. Metaproteomics analysis of this data reveals the functional activities of the bacteria in consortia, by this contributing to a better understanding of the complex metabolic pathways within the human microbiota that can be manipulated to maximise beneficial microbiota-host interactions.
Project description:The human gut microbiota is crucial for degrading dietary fibres from the diet. However, some of these bacteria can also degrade host glycans, such as mucins, the main component of the protective gut mucus layer. Specific microbiota species and mucin degradation patterns are associated with inflammatory processes in the colon. Yet, it remains unclear how the utilization of mucin glycans affects the degradation of dietary fibres by the human microbiota. Here, we used three dietary fibres (apple pectin, β-glucan and xylan) to study in vitro the dynamics of colon mucin and dietary fibre degradation by the human faecal microbiota. The dietary fibres showed clearly distinguishing modulatory effects on faecal microbiota composition. The utilization of colon mucin in cultures led to alterations in microbiota composition and metabolites. Metaproteome analysis showed the central role of the Bacteroides in degradation of complex fibres while Akkermansia muciniphila was the main degrader of colonic mucin. This work demonstrates the intricacy of complex glycan metabolism by the gut microbiota and how the utilization of host glycans leads to alterations in the metabolism of dietary fibres. Metaproteomics analysis of this data reveals the functional activities of the bacteria in consortia, by this contributing to a better understanding of the complex metabolic pathways within the human microbiota that can be manipulated to maximise beneficial microbiota-host interactions. In this study two different mucin samples were used: commercial porcine gastric mucin and in house prepared porcine colonic mucin. This dataset analyses the proteome of: A) autoclaved porcine colonic mucin; B) not autoclaved porcine colonic mucin; C) porcine gastric mucin.
Project description:The indigenous human gut microbiota is a major contributor to the human superorganism with established roles in modulating nutritional status, immunity, and systemic health including diabetes and obesity. The complexity of the gut microbiota consisting of over 1012 residents and approximately 1000 species has thus far eluded systematic analyses of the precise effects of individual microbial residents on human health. In contrast, health benefits have been shown upon ingestion of certain so-called probiotic Lactobacillus strains in food products and nutritional supplements, thereby providing a unique opportunity to study the global responses of a gut-adapted microorganism in the human gut and to identify the molecular mechanisms underlying microbial modulation of intestinal physiology, which might involve alterations in the intestinal physico-chemical environment, modifications in the gut microbiota, and/or direct interaction with mucosal epithelia and immune cells. Here we show by transcriptome analysis using DNA microarrays that the established probiotic bacterium, L. plantarum 299v, adapts its metabolic capacity in the human digestive tract for carbohydrate acquisition and expression of exo-polysaccharide and proteinaceous cell surface compounds. This report constitutes the first application of global gene expression profiling of a gut-adapted commensal microorganism in the human gut. Comparisons of the transcript profiles to those obtained for L. plantarum WCFS1 in germ-free mice revealed conserved L. plantarum responses indicative of a core transcriptome expressed in the mammalian gut and provide new molecular targets for determining microbial-host interactions affecting human health. Hybridization of the samples against a common reference of gDNA isolated from L. plantarum 299v
Project description:Irritable Bowel Syndrome (IBS) is a disorder of the gut-brain axis, characterized by altered gut function and frequent psychiatric co-morbidity. Although altered intestinal microbiome profiles have been documented, their relevance to the clinical expression of IBS is unknown. To evaluate a functional role of the microbiota, we colonized germ-free mice with fecal microbiota from healthy controls or IBS patients with accompanying anxiety, and monitored gut function and behavior. Mouse microbiota profiles clustered according to their human donors. Despite having taxonomically similar composition as controls, mice with IBS microbiota had distinct serum metabolomic profiles related to neuro- and immunomodulation. Mice with IBS, but not control microbiota, exhibited faster gastrointestinal transit, intestinal barrier dysfunction, innate immune activation and anxiety-like behavior. These results support the notion that the microbiota contributes to both intestinal and behavioral manifestations of IBS and rationalize the use of microbiota-directed therapies in ameliorating IBS.
Project description:Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people. The disorder of gut microbiota is involved in the pathophysiological process of various neurological diseases, and many studies have confirmed that gut microbiota is involved in the progression of PD. As one of the most effective methods to reconstruct gut microbiota, fecal microbiota transplantation (FMT) has been considered as an important treatment for PD. However, the mechanism of FMT treatment for PD is still lacking, which requires further exploration and can facilitate the application of FMT. As a model organism, Drosophila is highly conserved with mammalian system in maintaining intestinal homeostasis. In this study, there were significant differences in the gut microbiota of conventional Drosophila colonized from PD patients compared to those transplanted from normal controls. And we constructed rotenone-induced PD model in Drosophila followed by FMT in different groups, and investigated the impact of gut microbiome on transcriptome of the PD host. Microbial analysis by 16S rDNA sequencing showed that gut microbiota could affect bacterial structure of PD, which was confirmed by bacterial colonization results. In addition, transcriptome data suggested that gut microbiota can influence gene expression pattern of PD. Further experimental validations confirmed that lysosome and neuroactive ligand-receptor interaction are the most significantly influenced functional pathways by PD-derived gut microbiota. In summary, our data reveals the influence of PD-derived gut microbiota on host transcriptome and helps better understanding the interaction between gut microbiota and PD through gut-brain axis. The present study will facilitate the understanding of the mechanism underlying PD treatment with FMT in clinical practice.
Project description:Iron is an essential metal for both animals and microbiota, and neonates and infants of humans and animals, in general, are at the risk of iron insufficient. However, excess dietary iron usually causes negative impacts on the host and microbiota. This study aimed to investigate over-loaded dietary iron supplementation on growth performance, the distribution pattern of iron in the gut lumen and the host, intestinal microbiota, and intestine gene expression profile of piglets. Sixty healthy weaning piglets were randomly assigned to six groups: fed with diets supplemented with ferrous sulfate monohydrate at the dose of 50ppm (Fe50 group), 100ppm (Fe100 group), 200ppm (Fe200 group), 500ppm (Fe500 group), and 800ppm (Fe800) for three weeks. The results indicated that increasing iron had no effects on growth performance but increased diarrheal risk and iron deposition in intestinal digesta, tissues of intestine and liver, and serum. High iron also reduced serum iron-binding capacity, apolipoprotein, and immunoglobin A. The RNA-sequencing analysis revealed that iron changed colonic gene expression profile, such as interferon gamma-signal transducer and activator of transcription 2 based anti-virus and bacteria gene network. Increasing iron also shifted cecal and colonic microbiota, such as reducing alpha diversity, Clostridiales and Lactobacillus reuteri, and increasing Lactobacillus and Lactobacillus amylovorus. Collectively, this study demonstrated that high dietary iron increased diarrheal incidence, changed intestinal immune response-associated gene expression, and shifts gut microbiota. The results would enhance our knowledge of iron effects on the gut and microbiome in piglets, and further contribute to understanding these aspects in humans.