Weizmannia Coagulans BC99 Prevents Loperamide-Induced Functional Constipation in Mice Through Increased Intestinal Peristalsis and Modulation of Gut Microbiota Dysbiosis

<b>Objectives:</b> Constipation is one of the most prevalent gastrointestinal disorders worldwide. Recent studies have demonstrated that probiotics may alleviate constipation by restoring gut microbiota balance. <b>Methods:</b> This study investigated the effects of <i>Weizmannia coagulans</i> BC99 (formerly <i>Bacillus coagulans</i> BC99) on gut microbiota and intestinal function in a loperamide-induced mouse model of functional constipation. BALB/c mice were randomly divided into six groups: control, model, phenolphthalein, BC99-L (2 × 10⁷ CFU/day), BC99-M (2 × 10⁸ CFU/day), and BC99-H (2 × 10⁹ CFU/day). After 14 days of supplementation, constipation was induced in mice via loperamide administration. <b>Results:</b> BC99 significantly increased fecal water content, gastrointestinal transit rate, microbial metabolic activity, and butyric acid production, while decreasing the abundance of inflammation-related metabolic pathways. Moreover, BC99 improved levels of gastrointestinal regulatory peptides, including motilin and somatostatin. The Firmicutes-to-Bacteroidetes ratio was elevated in the BC99-M and the BC99-H group compared to the model group, indicating that BC99 effectively modulated gut microbiota composition and host biosynthetic pathways. <b>Conclusions:</b><i>Weizmannia coagulans</i> BC99 alleviated and prevented loperamide-induced functional constipation in mice by enhancing intestinal peristalsis and restoring gut microbial homeostasis.