Fecal microbiota transplantation improves functional constipation through the gut microbiome–bile acid–receptor axis

Functional Constipation (FC) is a prevalent gastrointestinal motility disorder worldwide that markedly impairs patients' quality of life, yet the currently available treatment options often show limited efficacy. In recent years, research has gradually revealed the critical role of the gut microbiota and bile acid metabolism in the pathogenesis of FC. Fecal Microbiota Transplantation (FMT), which restores the intestinal microecological balance by transferring gut microbiota from healthy donors, has demonstrated clinical efficacy in promoting bowel movements, improving stool consistency, and enhancing patients' quality of life. However, its underlying mechanisms remain incompletely understood. Current evidence indicates that FMT restores microbial diversity, increases beneficial taxa, and partially reconstructs the bile acids (BAs) profile, thereby modulating Farnesoid X Receptor (FXR) and Takeda G Protein-Coupled Receptor 5 (TGR5) mediated signaling pathways to enhance intestinal secretion and alleviate constipation-related symptoms. The resulting microbiota-bile acid-receptor pathway elucidates the mechanistic link between microbial remodeling and host gastrointestinal motility, thereby offering theoretical support for the therapeutic application of FMT in functional constipation.