Another role for dietary fiber shown here, abstract:
Despite the accepted health benefits of consuming dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic mouse model, in which animals were colonized with a synthetic human gut microbiota composed of fully sequenced commensal bacteria, we elucidated the functional interactions between dietary fiber, the gut microbiota, and the colonic mucus barrier, which serves as a primary defense against enteric pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation, together with a fiber-deprived, mucus-eroding microbiota, promotes greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium. Our work reveals intricate pathways linking diet, the gut microbiome, and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics.
Dietary fiber can have many beneficial effects, including the production of short chain fatty acids that are good for colonic health and of course fiber helps with bowel movements to avoid constipation. This mouse study shows that when there is a deficiency of dietary fiber, the gut microbiota that would normally digest fiber will instead start using the gut mucus as an energy source, eroding the protective lining on the colon and allowing pathogenic organisms to have access.
