Murine gut microbial interactions exert anti-hyperglycemic effects

The correlations between gut microbiota and host metabolism have been studied extensively, whereas little relevant work has been done to investigate the impact of gut microbial interactions on host metabolism. With the use of a bacteriocin-targeting strategy, we aimed to identify the gut microbes associated with glucose and lipid metabolism by adjusting the gut microbial composition of mice fed a high-fat diet. To fulfill this goal, a Listeria monocytogenes (Lmo)-derived bacteriocin Lmo2776 secretion module was constructed and integrated into the genome of Escherichia coli Nissle 1917 (EcN), yielding the Lmo2776-secreting strain EcN-2776. In high-fat diet-fed mice, EcN-2776 administration decreased blood glucose and increased serum triglyceride, and gene amplicon sequencing of 16S rRNA in these mice indicated that intestinal secretion of Lmo2776 led to adjustment of the gut microbial composition. Specifically, Lmo2776 restricted the growth of Ligilactobacillus murinus, thus alleviating its inhibitory impact towards Faecalibaculum rodentium. Further analyses indicated that F. rodentium administration decreased the fasting blood glucose of high-fat diet-fed mice, an effect that may be attributable to the intestinal consumption of glucose by F. rodentium. In this study, we identified the gut microbes associated with glucose metabolism, uncovered their interactions, and deciphered the impact of these gut microbial interactions on the host glucose metabolism. Our findings may pave the way for the treatment of hyperglycemia from the perspective of gut microbial interactions.