Genomic safety assessment and metabolic modulation by Enterococcus faecium 140,623, a probiotic strain from lactasin tablets: implications for obesity management.

The gut microbiota is crucial for host metabolism, making probiotics a promising approach for managing metabolic disorders like obesity. Enterococcus faecium serves as the core strain in the traditional probiotic Lactasin Tablets, yet its full probiotic potential and safety profile remain insufficiently characterized. This study provides a systematic evaluation of the genomic features, safety, and efficacy of E. faecium 140,623. Whole-genome sequencing revealed genes involved in carbohydrate metabolism, short-chain fatty acid (SCFA) production, bile acid (BA) biosynthesis, and bacteriocin synthesis. The strain demonstrated a favorable safety profile, showing susceptibility to critical antibiotics such as ampicillin and vancomycin, absence of transferable virulence or resistance genes, and robust tolerance to acidic and biliary conditions. In a mouse model, high-dose supplementation significantly reduced body weight and improved serum lipid profiles, lowering triglycerides, total cholesterol, and low-density lipoprotein cholesterol. E. faecium 140,623 also modulated gut microbiota structure, enriching beneficial genera such as Akkermansia and Bifidobacterium, and significantly increased cecal SCFAs, particularly acetate and propionate. BA profiling indicated profound metabolic alterations, including upregulation of primary BA biosynthesis. These results suggest that E. faecium 140,623 alleviates obesity and dyslipidemia via gut microbiota remodeling, enhanced SCFA production, and BA metabolism modulation, supporting its potential as a safe and effective probiotic for metabolic disease management.