PubMed · 2026-05-12
A study of 198 adults found that eating more fiber, fruits, vegetables, nuts, and coffee reduces gut inflammation in people with inflammatory bowel disease — but the two main subtypes respond through completely different gut-bacteria pathways, suggesting that diet advice for these conditions should not be one-size-fits-all.
Gut microbiome diversity was lowest in Crohn's disease patients and correlated positively with intake of fiber, fruits, vegetables, and nuts across all 198 participants.
In Crohn's disease, coffee and whole wheat bread reduced the Harvey-Bradshaw inflammation index through specific bacterial species and their metabolites.
In ulcerative colitis, Mediterranean-style diets and fruits lowered C-reactive protein (an inflammation marker) by boosting microbial richness and short-chain fatty acid production — a class of compounds made when bacteria ferment plant fiber.
