Project description:We used culturing of fecal sample enrichments 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 from mucin. 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. Sequencing data was curated to determine gene expression profiles when comparing N-acetylgalactosamine, N-acetylglucosamine, gastric mucin oligosaccharides and cellobiose.
Project description:Beneficial modulation of the gut microbiome has high-impact implications not only in humans, but also in livestock that sustain our current societal needs. In this context, we have engineered an acetylated galactoglucomannan (AcGGM) fibre from spruce trees to match unique enzymatic capabilities of Roseburia and Faecalibacterium species, both renowned butyrate-producing gut commensals. The accuracy of AcGGM was tested in an applied pig feeding trial, which resolved 355 metagenome-assembled genomes together with quantitative metaproteomes. In AcGGM-fed pigs, both target populations differentially expressed AcGGM-specific polysaccharide utilization loci, including novel, mannan-specific esterases that are critical to its deconstruction. We additionally observed a “butterfly effect”, whereby numerous metabolic changes and interdependent cross-feeding pathways were detected in neighboring non-mannolytic populations that produce short-chain fatty acids. Our findings show that intricate structural features and acetylation patterns of dietary fibre can be customized to specific bacterial populations, with the possibility to create greater modulatory effects at large.
