A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility.
Level 5 - mechanism / opinion, no new human data
Preclinical animal model (gnotobiotic mice colonized with synthetic human gut microbiota)
PubMed 27863247 · doi:10.1016/j.cell.2016.10.043
What was done
Gnotobiotic mice were colonized with a synthetic human gut microbiota consisting of fully sequenced commensal bacteria. Researchers examined the effects of chronic and intermittent dietary fiber deprivation on the colonic mucus layer and subsequent susceptibility to infection with the enteric pathogen Citrobacter rodentium.
What was found
The abstract reports qualitative mechanistic findings without numerical data. In the absence of dietary fiber, commensal microbes utilized host-secreted mucus glycoproteins as an energy source, degrading the colonic mucus barrier. This degradation permitted increased epithelial access by Citrobacter rodentium, resulting in lethal colitis.
Why it matters
It demonstrates a direct mechanism whereby low-fiber intake causes gut microbes to erode the protective mucus barrier, heightening vulnerability to enteric pathogens.
Limits
The study was conducted entirely in gnotobiotic mice using a simplified synthetic microbiota rather than a natural human community. The abstract provides no specific sample sizes, statistical measures, or quantitative effect estimates. Findings cannot be directly assumed to replicate identically in human intestinal physiology.
Cited by
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