Study on the preparation of postbiotic elements by fermentation of wheat by-products and their role in improving constipation.

Wheat bran and wheat starch process water are nutrient-rich but underutilized industrial by-products. This study presents a novel approach for the valorization of these waste streams by co-fermenting them with Lactobacillus paracasei EG9 to create a postbiotic-rich functional ingredient (FWB). The fermentation process significantly enhanced the substrate's nutritional profile, enriching it with short-chain fatty acids (SCFAs) and functional macromolecules, while improving its physicochemical properties. In vivo evaluation in a loperamide-induced constipation mouse model revealed that FWB intervention alleviated constipation symptoms in a distinct, non-linear, dose-dependent manner. The optimal dose significantly accelerated gastrointestinal motility, mitigated systemic inflammation, and facilitated colonic mucosal repair. Mechanistically, FWB exerted these therapeutic effects through a dual-action mechanism: directly supplying bioactive metabolites and indirectly reprogramming the gut microbiota-specifically normalizing the Firmicutes/Bacteroidetes ratio and enriching key SCFA-producing genera (e.g., Alistipes_A and Duncaniella). Overall, this research highlights FWB as a sustainable, multifunctional postbiotic ingredient, offering a promising and practically applicable strategy for the development of novel dietary interventions targeting intestinal health.