Pleiotropic roles of microbial bile acid metabolism in intestinal health and diseases.

Perturbation of microbial-derived bile acid (BA) metabolism is strongly linked to the pathogenesis of intestinal diseases, including inflammatory bowel disease, enteric infections, and colorectal cancer. Recent advances in artificial intelligence-assisted pipelines have enabled the identification of BA modification reactions, which have uncovered novel targets and the mechanisms contributing to intestinal diseases. In this review, we summarize recent studies on microbial enzymatic pathways and modifications of BAs, and their roles in promoting or preventing intestinal diseases. The mechanisms altering gut microbiota populations and microbial BA metabolic landscapes that influence intestinal diseases are further examined along with how microbial-derived BAs modulate intestinal immune responses. Based on these advances, we suggest different dietary patterns that reshape the gut microbiota community and BAs to prevent intestinal diseases. We further discuss current challenges in basic and translational research on microbial BA modifications in intestinal homeostasis and propose future directions to drive progress in this field.