Lactobacillus agilis SNF7 Presents Excellent Antibacteria and Anti-Inflammation Properties in Mouse Diarrhea Induced by Escherichia coli

<i>Escherichia coli</i> (<i>E. coli</i>) is a common pathogen that causes diarrhea in newborns and animals. Antibiotics are typically used to treat bacterial diarrhea, a global intestinal health issue. Probiotics have gained interest as a potential substitute for antibiotics in the management of <i>E. coli</i>-induced diarrhea and present novel therapeutic options. In this study, the probiotic properties of <i>Lactobacillus agilis</i> SNF7 (<i>L. agilis</i> SNF7) isolated from feces were investigated, and whole genome sequencing was performed to evaluate the properties of the strain. Furthermore, we investigated the protective effects of <i>L. agilis</i> SNF7 in a mouse model of <i>E. coli</i> K99 infection. <i>L. agilis</i> SNF7 exhibits a high survival rate in artificial gastroenteric fluid and bile salt environments, along with an antagonistic effect against <i>E. coli</i> O₁₁₁:K₅₈ (B₄), <i>Staphylococcus aureus</i> (<i>S. aureus</i>), and <i>E. coli</i> K99. Multiple genes with probiotic properties, including bacteriostasis, anti-inflammation, antioxidant, CAZyme, and the utilization of carbohydrate compounds, were identified in genome. <i>L. agilis</i> SNF7 prevented the gut barrier from being damaged by <i>E. coli</i> K99, reducing the clinical manifestations of the infection. Furthermore, <i>L. agilis</i> SNF7 reduced the expression of inflammatory cytokines (IL-6, IL-1β, and TNF-α) by inhibiting the phosphorylation of proteins linked to the NF-κB and MAPK signaling pathways. <i>L. agilis</i> SNF7 improved the intestinal microbial barrier, controlled the balance of the intestinal microecology, and reduced the entry of harmful microbes into the intestine. By controlling gut flora and reducing the inflammatory response, <i>L. agilis</i> SNF7 may be able to prevent and treat <i>E. coli</i> K99 infections. The application of <i>L. agilis</i> SNF7 in the creation of probiotic formulations to stop intestinal illnesses brought on by <i>E. coli</i> infections is clarified by this work.