- Gut microbiota-derived metabolites are key molecular mediators between the microbiota and host.
- Several untargeted studies have demonstrated broad disturbances of the gut metabolome in IBD, which is in keeping with the known dysbiosis in gut bacterial communities.
- Metabolite groups of interest include short-chain fatty acids, bile acid metabolites and tryptophan metabolites, with essential roles for these in normal immune development, homeostasis and IBD.
- Multinational, longitudinal cohorts, sampling and analysis standardization and model systems will be required to expand our knowledge of these associations.
- Such approaches show promise for identifying new host targets and the microbial tools with which to target them. READ MORE HERE.
Gastrointestinal microbiota and immune cells interact closely and display regional specificity; however, little is known about how these communities differ with location. Here, we simultaneously assess microbiota and single immune cells across the healthy, adult human colon, with paired characterization of immune cells in the mesenteric lymph nodes, to delineate colonic immune niches at steady state. We describe distinct helper T cell activation and migration profiles along the colon and characterize the transcriptional adaptation trajectory of regulatory T cells between lymphoid tissue and colon. Finally, we show increasing B cell accumulation, clonal expansion and mutational frequency from the cecum to the sigmoid colon and link this to the increasing number of reactive bacterial species.