Postbiotics from Bacillus amyloliquefaciens J and Lactiplantibacillus plantarum SN4 (PWE) alleviates E. coli-induced enteritis via gut barrier enhancement, microbiota modulation, and liver protection

Postbiotics are preparations made from inanimate microorganisms and/or their components that are beneficial to host health, but the underlying specific modes of action in relieving intestinal inflammation remain poorly understood. This study aims to investigate the anti-inflammatory activity, intestinal barrier recovery, antioxidant activity, and correction of microbial dysbiosis of PWE (postbiotics water extract), a novel postbiotics derived from Bacillus amyloliquefaciens J and Lactobacillus plantarum SN4 named PWE. In this study, C57BL/6 male mice were administered PWE by oral gavage for seven days, followed by a three-day K88 challenge to evaluate its protective effects against enteritis. Our results showed that PWE exerted an obvious protective effect on ETEC-challenged enteritis mice. Specifically, PWE improved overall health status and colon length, restored jejunal and colonic villi and crypt morphology, and reduced inflammatory cell infiltration. Moreover, PWE enhanced the expression of tight junction proteins, including Occludin, and upregulated the mRNA expression of ZO-1 and Claudin , modulated apoptosis-related genes ( BAX , Bcl2 , and Caspase-3 ), and strengthened liver antioxidant capacity. Gut microbiota analysis revealed that PWE rebalanced the microbial composition through decreasing Escherichia-Shigella abundance and increasing Lactobacillaceae and Lachnospiraceae abundance that promote SCFA production. Furthermore, correlation analysis demonstrated that these increases in abundance of Lactobacillaceae were associated with reduced intestinal inflammation and improved barrier function. Abundance of Ligilactobacillus was positively correlated to anti-apoptotic effects and antioxidant properties. In conclusion, our findings highlight the modulatory effects of the postbiotics PWE in alleviating intestinal inflammation, repairing barrier dysfunction, and restoring microbial imbalance through microbiota regulation and SCFA enhancement. These results provide new insights and strategies for combating bacterial infections diarrhea and improving intestinal health. • Postbiotics from Bacillus amyloliquefaciens J and Lactiplantibacillus plantarum SN4 (PWE) exerts anti-inflammatory effect against ETEC-induced enteritis mice. • PWE enhanced the expression of tight junction proteins, modulated apoptosis-related genes, and strengthen liver antioxidative capacity. • PWE rebalances microbial composition by decreasing Escherichia-Shigella abundance and increasing Lactobacillaceae and Lachnospiraceae abundance. • The reduction of intestinal inflammation and improvement of the intestinal barrier are associated with Lactobacillaceae abundance and SCFA enhancement.