The alleviative effect of protein-polysaccharide complex coacervation microcapsules on loperamide-induced constipation in mice.

The rising incidence of constipation and side effects of clinical drugs have spurred research on natural functional ingredients for its prevention and treatment. Probiotics and dietary fibers have diverse bioactivities but are limited by poor stability and low bioavailability. Herein, a novel microcapsule system co-loading Ganoderma lucidum dietary fiber (GLDF) and Lactobacillus fermentum CECT5716 was constructed using whey protein (WP) and xanthan gum (XG) via hybrid spray drying-complex coacervation. Optimal WP-XG interaction (driven by electrostatic forces and hydrogen bonds) was achieved at pH 3.75 and 5:1 mass ratio; microcapsules with 1:1 wall-to-core ratio showed the best performance, with 72.3% post-encapsulation probiotic viability and enhanced stability under simulated gastrointestinal conditions and storage. Animal experiments confirmed that the microcapsules effectively alleviated loperamide (LOP)-induced constipation in mice, associated with regulating gut microbiota, promoting short-chain fatty acids (SCFAs) production, inhibiting colonic inflammation, repairing intestinal tight junctions, and downregulating aquaporins. In conclusion, the microcapsules prepared in this study provide a feasible strategy for the efficient co-delivery of probiotics and dietary fibers, and the developed composite functional ingredient holds great application potential in the field of constipation prevention and treatment.