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

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