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:Purpose: The gastric microbe Helicobacter pylori represents an ancestral constituent of the human microbiota that causes gastric disorders on the one hand, and is inversely associated with allergies and chronic inflammatory conditions on the other. This study aims to investigate the consequences of trans-maternal exposure to H. pylori extract in utero and during lactation on the regulatory T-cell transcriptome profile. Experiment type: Expression profiling by high throughput sequencing
Project description:An early settlement of a complex gut microbiota can protect against gastro-intestinal dysbiosis, but the effects of neonatal microbiota colonization on the maturation of the porcine gastric mucosa are largely unknown. The transcriptome of the oxyntic mucosa of 12 caesarian-derived pigs previously associated with microbiota of different complexity was studied. Pigs received sow blood serum at birth (d0), 2 mL of starter microbiota (10^7 CFU of each Lactob. Amylovorus (LAM), Clostr. glycolicum, and Parabacteroides spp.) on d1-d3 of age and either a placebo inoculant (simple association, SA) or an inoculant consisting of diluted feces of an adult sow (complex association, CA) on d3-d4 of age. Then pigs were fed a moist diet . Gastric samples were obtained at on euthanised pigs at 2 weeks of age.
Project description:The personalized communities of microorganisms (microbiota) that inhabit the distal guts of humans have evolved to process a variety of complex carbohydrates. Many gut bacteria depolymerize and ferment dietary fiber polysaccharides, mutualistically providing short-chain fatty-acids to their host. Some human gut bacteria have evolved to utilize components of host mucin glycoproteins—the major component of protective mucus—and recent studies have implicated specific mucin-degrading commensal bacteria in the development of intestinal inflammation. Thus, identifying new gut bacteria that possess the ability to degrade host mucins and determining how these organisms might cooperate or compete for mucin components during health and disease is an important goal. Here, we used culture on solid medium containing gastric mucin as the main carbon source to isolate a novel bacterium that is largely restricted to using the N-acetylglucosamine and N-acetylgalactosamine sugars found in mucin O-glycans. This butyrate-producing bacterium accesses these sugars from both polymeric gastric mucin and chemically released oligosaccharides and has a genome with correspondingly restricted carbohydrate-active enzyme content. Surprisingly, strains related to this isolate appear to be rare in the now numerous sequence-based microbiota surveys with only 32/3781 (0.85%) human subjects containing this bacterium with an overall relative abundance ranging from 0.004-0.057%. This combination of low prevalence and abundance, suggests that this species could occupy an unknown niche in which access to mucin is important but otherwise render it difficult to detect in mostly feces-based microbiota surveys.