Weizmannia coagulans BC99 improved intestinal motility and chronic constipation through regulating gut microbiota: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: This randomized, double-blind, placebo-controlled study aims to evaluate the effects and underlying mechanisms of an 8-week Weizmannia coagulans BC99 intervention in alleviating constipation in adults. METHODS: Constipated adults received BC99 (1 × 1010CFU/day) or a placebo for 8 weeks. Assessment included Completely Spontaneous Bowel Movements (CSBM), Depression Anxiety Stress Scale-21 (DASS-21), and Bristol Fecal Characteristics Scale (BSFS) scores, colonic transit time (CTT), gastrointestinal regulatory factors (ET-1, VIP, GAS, CGRP, SS), gut microbiota composition, and short-chain fatty acids (SCFAs) content in feces. This research was a randomized, double-blind, placebo-controlled study, which received approval from the Ethics Commission of the First Afffliated Hospital of Henan University of Science and Technology at 26 April 2024 (Ethical approval number 2024- 03-K0054), Clinical trial registration number is NCT06637397 ( https://clinicaltrials.gov/ , accessed on 26 April 2024). The present study was conducted from July 2024 to October 2024 at the College of Food and Bioengineering, Henan University of Science and Technology, in accordance with the tenets of the Declaration of Helsinki. RESULTS: BC99 significantly improved bowel movement frequency, stool characteristics, and psychological well-being. It reduced CTT and modulated levels of gastrointestinal peptides. Gut microbiota analysis revealed increased relative abundance of Lactobacillus, Bifidobacterium and decreased Escherichia-Shigella. BC99 also elevated fecal SCFAs levels (acetic, butyric, isovaleric acid) and inferred the key KEGG pathways associated with fatty acid metabolism and pathogen invasion. CONCLUSION: W. coagulans BC99 effectively alleviates constipation by enhancing intestinal motility, regulating gut microbiota, and increasing SCFA production, demonstrating its potential as a therapeutic probiotic.