Enterococcus faecium HDRsEf1 induces changes in gut microbiota and metabolites to maintain host health

Gut microbiota plays a pivotal role in host immunity and overall health. Enterococcus faecium HDRsEf1 (Ef1), a novel potential probiotic, has been reported to enhance immune defense against pathogenic invasion; however, its effects on inflammation and gut microbiota remain poorly understood. This study aimed to evaluate the impact of Ef1 on host health, gut microbiota, and fecal metabolite profiles using DSS-induced colitis in mice and nursery pig models. In mice, Ef1 effectively mitigated growth retardation and organ damage caused by DSS-induced inflammation. In nursery pigs, Ef1 administration reduced markers of inflammation and oxidative stress, including IL-1β, IL-6, TNF-α, and MDA, while increasing the anti-inflammatory cytokine IL-10 and the antioxidant enzyme SOD. Furthermore, Ef1 modulated gut microbiota composition, promoting beneficial genera such as Ruminococcus and Acetobacter, while suppressing potentially harmful genera like Acinetobacter. Metabolomic analysis revealed that Ef1 enriched anti-inflammatory metabolites in the gut. Collectively, these findings indicate that Ef1 can beneficially modulate gut microbiota and metabolite profiles, thereby enhancing host health.