Novel Enterococcus faecium P2 as a probiotic for mitigating Clostridioides difficile infection.

Clostridioides difficile (C. difficile) is a well-recognized pathogen responsible for severe intestinal disorders, including pseudomembranous colitis and toxic megacolon. Probiotics have shown considerable promise in the prevention and management of gastrointestinal diseases. In this study, we isolated Enterococcus faecium (E. faecium) P2 from the feces of a healthy child and evaluated its probiotic efficacy against C. difficile infection (CDI) using a mouse model. In vitro assessments demonstrated that E. faecium P2 exhibits high safety, tolerates gastrointestinal stressors, forms robust biofilms, and inhibits both the growth and biofilm formation of C. difficile. In vivo, prophylactic administration of E. faecium P2 prior to CDI onset significantly alleviated intestinal damage, as evidenced by reduced average total clinical scores and lower mortality rates. Furthermore, E. faecium P2 upregulated the expression of intestinal mucosa-associated proteins, including MUC-2 and the tight junction proteins ZO-1 and Claudin-1, indicating a protective effect on the intestinal barrier. E. faecium P2 also modulated the inflammatory response by decreasing pro-inflammatory factors and increasing the anti-inflammatory cytokine IL-10. Fecal microbiota analysis revealed that E. faecium P2 helps restore the microbial balance disrupted by CDI. Collectively, these findings highlight the potential of E. faecium P2 as a probiotic candidate for the prevention of CDI.