Enhancement of Intestinal Barrier Function by Butyryl-Fructooligosaccharides via Microbiota-Host Interactions in Colonic Organoid Models

Butyryl-fructooligosaccharides (B-FOSs) are prebiotic derivatives synthesized by ester-linked conjugation of fructooligosaccharides (FOSs) with butyrate, exhibiting enhanced prebiotic capabilities over conventional FOSs. However, their therapeutic mechanisms remain incompletely characterized. Our in vitro analyses revealed that B-FOSs resist gastrointestinal digestion and undergo fecal microbial fermentation, indicating their capacity to deliver butyrate to the colon. By integrating in vitro fecal fermentation with 3D colonoids derived from Lgr5+ intestinal stem cells, we systematically explored B-FOS-mediated microbiota–metabolite interactions. Organoid proliferation and viability were enhanced by B-FOS metabolites and a reshaped gut microbiota, which also counteracted liposaccharide (LPS)-induced epithelial disruption by upregulating ZO-1 and MUC2 expression. Notably, B-FOS-fermented supernatants demonstrated superior barrier-protective efficacy than was achieved using equivalent doses of butyrate, suggesting effects of other microbiota-derived metabolites. The B-FOS-modulated microbiota outperformed bacterial controls in terms of MUC2 and ZO-1 production, with Weissella identified as a critical degrader driving B-FOS metabolism and mucin biosynthesis.