Antidiabetic Effects of Lactobacillus casei Fermented Yogurt through Reshaping Gut Microbiota Structure in Type 2 Diabetic Rats

The viable bacterial strains in conventional yogurt are intolerant to bile acid, which consequently cannot survive the conditions and their beneficial bioactivities are thus lost. We have previously shown that Lactobacillus casei Q14 ( Lac-Q14), a probiotic, has the potential to alleviate diabetes in rats. Herein, we used Lac-Q14 as the starter culture to ferment yogurt and explore the mechanisms of the bioactivity in diabetic rats. The results showed that Lac-Q14 yogurt improved blood glucose and insulin level, lowered gene expression of critical enzymes involved in liver gluconeogenesis. Pyrosequencing showed an obvious change in the composition of intestinal microbiota in Lac-Q14 yogurt treated rats. The abundance of 21 genera differed significantly between the Lac-Q14 yogurt group and diabetes group. Quite a few short-chain fatty acid (SCFA)-producing bacteria were selectively enriched, along with increased concentrations of SCFA and downstream Glucagon-like peptide-1 (GLP-1) and Peptide YY (PYY) secretion.