Abstract: Objective:To study the hypoglycemic effect and mechanism of probiotics on type 2 diabetic mice. Method:The α-glucosidase inhibitory activity was used to evaluate the hypoglycemic effect of 34 strains. The hydrophobicity and self-aggregation ability were used to evaluate probiotic properties. The type 2 diabetes mouse model was established by high-fat diet combined with streptozotocin. All mice were treated with probiotics for 8 weeks,measured the blood glucose level,glucose tolerance,glycosylated hemoglobin,insulin and insulin resistance levels,serum proinflammatory cytokines levels,glucagon-like peptide-1,and the concentration of short-chain fatty acids in fecal. Result:In vitro,L. paracasei J5 and L. casei K11 showed effective inhibition of α-glucosidase,and intestinal adhesion ability. In vivo,L. casei K11 significantly reduced blood glucose level in mice(P<0.05),improved impaired glucose tolerance and insulin resistance(P<0.05). The strains significantly reduced serum tumor necrosis factor-α and interleukin-6 levels in mice. The level of glucagon-like peptide-1 in serum and the concentration of short-chain fatty acids in fecal were significantly increased(P<0.05). Conclusion:L. paracasei K11 could significantly regulate blood glucose in type 2 diabetic mice. The mechanism might be related to regulating the production of short-chain fatty acids by the gut microbiota,promoting glucagon-like peptide-1 secretion and regulating proinflammatory cytokines level.