Pre-Administration of Saccharomyces boulardii-Derived Postbiotics Effectively Prevents Dextran Sulfate Sodium-Induced Colitis in Mice.

Ulcerative colitis (UC) is effectively alleviated by Saccharomyces boulardii (S. boulardii), an important probiotic. Postbiotics, defined as beneficial non-viable microorganisms and/or their components, can potentially improve gut health. In this study, we utilized S. boulardii to prepare postbiotics via freeze-drying and spray-drying methods, characterized the resulting postbiotics, and investigated their efficacy and underlying mechanisms in preventing UC. In a mouse model of UC induced by dextran sulfate sodium (DSS), we found that prevention with two forms of S. boulardii postbiotics alleviated colitis symptoms triggered by DSS, mitigated colon tissue damage, maintained the distribution of intestinal occludin and ZO-1 proteins, and suppressed the secretion and expression of TNF-α, IL-1β, and IL-6 in serum and colon tissues. Additionally, S. boulardii postbiotics mitigated dysbiosis by modulating gut microbiota composition, including the balance between Bacteroidota and Firmicutes (F/B), as well as the levels of Akkermansia, Muribaculaceae, Dubosiella, and Turicibacter. In conclusion, as a novel biotherapeutic agent, S. boulardii postbiotics effectively prevent DSS-induced UC in mice. Compared to live S. boulardii, postbiotics may hold greater potential for UC prevention.