Oral treatment with improves insulin sensitivity in mice.

An altered intestinal microbiota composition is associated with insulin resistance and type 2 diabetes mellitus. We previously identified increased intestinal levels of , an anaerobic bacterium belonging to the butyrate-producing family, in metabolic syndrome subjects who received a faecal transplant from a lean donor. To further assess the effects of on insulin sensitivity, we orally treated obese and diabetic mice with alive and glycerol or heat-inactive as control. Insulin tolerance tests and hyperinsulinemic-euglycemic clamp experiments revealed that alive treatment improved insulin sensitivity compared control treatment. In addition, treatment increased energy expenditure in mice. Active treatment was found to increase faecal butyrate concentrations and to modify bile acid metabolism compared with heat-inactivated controls. Our data suggest that administration potentially alters the function of the intestinal microbiome and that microbial metabolites may contribute to the improved metabolic phenotype.