Low-fiber diets may trigger gut bacteria to erode intestinal mucus, studies show
Research from the Ludwig Institute indicates that when dietary fiber is scarce, gut microbes can turn to the gut's mucus lining for nourishment, potentially harming the host.
Scientists at the Ludwig Institute for Cancer Research reported that insufficient dietary fiber prompts gut bacteria to feed on the protective mucus layer, increasing production of toxic phenol metabolites. In a Proceedings of the National Academy of Sciences paper, AbuSalim and Rabinowitz showed that both fiber and indigestible plant proteins—dubbed "proteins imitating fiber" (Prif)—reprogram microbial metabolism toward health-promoting phenols derived from phenylalanine and away from harmful tyrosine-derived compounds.
A companion Nature Metabolism study demonstrated that mammalian cells can generate many phenol and indole metabolites on their own, remaining elevated even after antibiotics disrupt the microbiome. Isotope-labeling experiments in mice traced the harmful metabolites to host-derived mucus proteins, while the beneficial ones originated from dietary Prif. The findings suggest that labeling Prif on food packages could help guide dietary choices to support metabolic health. Funding came from the Ludwig Institute, NIH, NIDDK, the Princeton Alliance, Princeton University, and the Rutgers Cancer Institute.
Why it matters
Understanding how low fiber diets alter gut microbes helps shape dietary guidelines to prevent inflammation and disease.
In this story
