alleviates hyperglycemia and regulates gut microbiota and metabolic profiles in mice.

Unlabelled: is the dominant species of the genus in the gut, which is genomically heterogeneous and difficult to isolate; hence, scarce research was carried out for this species. This study aimed to investigate the effect of on hyperglycemia. Thirty-nine strains were isolated from healthy individuals, and three strains (HF2123, HF1478, and HF2130) that had the highest glucose consumption were selected to evaluate the effects of supplementation on hyperglycemia. Microbiomics and non-target metabolomics were used to uncover the underlying mechanisms. Oral administration of in diabetic db/db mice increased the expression and secretion of glucagon-like peptide-1 (GLP-1), significantly improved hyperglycemia, insulin resistance, and lipid accumulation, and alleviated the pathological morphology in the pancreas, liver, and colon. changed the composition of the gut microbiota of diabetic db/db mice, which was characterized by increasing the ratio of Bacteroidetes to Firmicutes and increasing the relative abundance of genera , , and . After intervention with , fecal metabolic profiling showed that fumaric acid and homocysteine contents decreased, and glutamine contents increased. Furthermore, amino acid metabolism and cAMP/PKA signaling pathways were enriched. Our findings indicate that improved glucose metabolism abnormalities in diabetic db/db mice. Especially, one of the strains, HF2130, has shown superior performance in improving hyperglycemia, which may have the potential as a probiotic against hyperglycemia.

Importance: As a core member of the human intestinal ecosystem, has been associated with glucose metabolic homeostasis in previous studies. However, these results have often been derived from metagenomic studies, and the experimental studies have been based solely on the type of strain DSM 18205. Therefore, more experimental evidence from additional isolates is needed to validate the results according to their high genomic heterogeneity. In this study, we isolated different branches of strains and demonstrated that could improve the metabolic profile of hyperglycemic mice by modulating microbial activity. This finding supports the causal contribution of in host glucose metabolism.