Effect of Lactobacillus mali APS1 and L. kefiranofaciens M1 on obesity and glucose homeostasis in diet-induced obese mice

• Probiotic APS1 and M1 can affect energy and glucose homeostasis in vivo.
• Two strains exhibited completely opposite results in the feature of obesity.
• APS1 and M1 influenced fat accumulation and insulin resistance in vivo.
• APS1 and M1 modulated gut microbiota and inflammatory cytokines expression in vivo.

The effects of two kefir strains, Lactobacillus mali APS1 (APS1) and L. kefiranofaciens M1 (M1), on energy and glucose homeostasis in diet-induced obese mice were investigated. Unexpectedly, these two strains exhibited completely opposite results. The high-fat diet (HFD) mice orally administered with APS1 had significantly reduced body weight gain, body fat, liver weight, and fat accumulation in the mesenteric adipose depot compared with HFD counterparts not receiving APS1. Dietary supplementation with APS1 also effectively maintained the blood glucose level. Conversely, M1-treated mice showed 23% higher body weight gain and 2.1-fold higher body fat than their HFD counterparts. Pyrosequencing analysis indicated that the selective modulation of gut microbiota by dietary treatment with two kefir strains may interact to affect insulin sensitivity, GLP-1 production, barrier integrity, and lipid metabolism. Regulation of inflammatory cytokines by the strains M1 and APS1 also played a key role in metabolic parameters of obesity.