Comparison of the effects of three sourdough postbiotics on high-fat diet-induced intestinal damage.

There is significant interest in using postbiotics as an intervention strategy to address obesity. This study assesses the efficacy of postbiotics derived from different sourdough strains ( Lactiplantibacillus plantarum LP1, LP25, and Pediococcus pentosaceus PP18) in mitigating intestinal injury in zebrafish fed on a high-fat diet. We screened postbiotics for their anti-colon cancer cell effects and compared various preparation methods applied to live bacterial strains, including heat-killing at different temperatures, pH adjustments, and ultraviolet radiation exposure. Heat-killing at 120 °C proved to be the most effective preparation method. A marked variation in health effects was observed in the heat-killed microbial cells, as evidenced by their hydrophobicity and self-aggregation ability. A five-week high-fat dietary intervention study in zebrafish demonstrated that diets supplemented with 10 8 CFU g -1 K-LP25 significantly attenuated weight gain and body fat, along with reductions in FASN , Leptin , and SREBF1 mRNA expression. However, diets supplemented with 10 7 CFU g -1 K-PP18 only reduced Leptin and SREBF1 mRNA expression. K-PP18 was more effective at mitigating gut barrier damage, promoting colonic Occludin , ZO-1 , and Claudin-1 levels. Additionally, K-LP25 supplementation markedly downregulated the pro-inflammatory cytokines TNF-α , IL-6 , and IL-1β , reducing intestinal inflammation. Supplementation with K-LP1 and K-PP18 increased the abundance of Acinetobacter spp., whereas K-LP25 increased the abundance of Cetobacterium and Plesiomonas . Collectively, these findings suggest that inactivated strains confer protective effects against high-fat diet-induced intestinal damage in zebrafish, with variation observed across different species. Studying the effects of sourdough-derived postbiotics on gut health may open new avenues for dietary interventions to manage gut-related diseases.