he Mechanisms of Wild Pigs-derived Bifidobacterium animalis Microbiota and Genomic Interactions Anti-ETEC Induced Disease in Mice

Enterotoxigenic Escherichia coli (ETEC) is a major pathogen causing diarrhea in young animals, significantly impacting animal husbandry development. Bifidobacterium animalis (B.animalis) is a probiotic, but its protective mechanisms against disease in animals remain incompletely understood. This study aims to elucidate the defensive mechanisms of B.animalis through an ETEC animal disease model. The findings demonstrate that B.animalis mitigated ETEC-induced damage to intestinal villi and crypts, enhanced nutrient absorption, and improved growth performance recovery. Additionally, B.animalis increased the expression of tight junction protein genes, maintained intestinal barrier integrity, and enhanced immune function through regulation of the Toll-like receptor 4 (TLR4)/NF-κB signaling pathway. Notably, B.animalis elevated intestinal butyrate levels, decreased the abundance of Erysipelatoclostridium and Alistipes, and stimulated the growth of Lactobacillus and Bacillus, thereby restoring microbial balance disrupted by ETEC. Furthermore, transcriptome analysis revealed that B. animalis influences signaling pathway gene expression and interacts with gut microbiota to combat diarrhea diseases. Mechanistically, B.animalis protects intestinal health by maintaining barrier integrity, modulating intestinal microbiota composition to produce beneficial metabolites, and influencing signaling pathway gene expression. These findings provide theoretical support for utilizing B. animalis as a green alternative to combat diseases.