The Mechanism of Ultrasonic Lysis of Enterococcus faecium F11.1G in Repairing LPS-Induced Inflammatory Damage in IECs...

Lipopolysaccharide (LPS)-induced damage to the intestinal epithelial barrier leads to gut inflammation, and intracellular metabolites of lactic acid bacteria may participate in regulating this process to exert probiotic effects. This study aimed to investigate the repair effects and molecular mechanisms of ultrasonic disruption-treated Enterococcus faecium F11.1G (F11.1G) on the model (primary lamb IECs + 5 μg/mL LPS for 6 h). Then, results demonstrated that 10⁸ CFU/mL F11.1G significantly suppressed the excessive secretion of pro-inflammatory factors (IL-6, IL-8, IL-1β, TNF-α) induced by LPS. Gene Ontology (GO) analysis revealed that differentially expressed genes (DEGs) were primarily enriched in cellular response to lipopolysaccharide, inflammatory response, and canonical NF-κB signaling pathways. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed enrichment in NF-κB signaling pathway and MAPK signaling pathway. PPI network identified key genes including IL-1β, TNF, IL-8, RELB, FOS, TNFAIP3, NFKBIA, and MMP9. KEGG analysis indicated differentially abundant metabolites (DAMs) enrichment in purine metabolism and the endocannabinoid system. Spearman correlation analysis revealed positive correlations between pro-inflammatory genes and endogenous protective metabolites, such as adenosine and PEA, while showing negative correlations with multiple purine metabolites. Correlational analysis indicates that F11.1G alleviates intestinal inflammatory damage primarily by suppressing NF-κB/MAPK pathway activation and may synergistically regulate purine and endocannabinoid metabolism.