Components analysis of Xuehua pear juice fermented by Lactobacillus caucasus LN6 and its potential mechanisms of ameliorating hyperglycemia by regulating gut microbiota.

Hyperglycemia is a major public health concern. Probiotic-fermented fruit juices provide a feasible strategy to mitigate high blood glucose. This study aimed to screen a probiotic strain with hypoglycemic activity, investigate its biotransformation during the fermentation of Xuehua pear juice, and investigate the mechanisms underlying its effects against hyperglycemia in mice. Results indicated that Lactobacillus caucasus LN6 showed an excellent adaptability to fermentation condition, and the α-glucosidase inhibition rate of the fermented Xuehua pear juice (FPJ) increased from 38.73 % to 71.09 %. FPJ significantly decreased fasting blood glucose, insulin levels in type 2 diabetes mellitus (T2DM) mice. Importantly, FPJ modulated the gut microbiota by increasing the abundance of beneficial bacteria (Lactobacillus, Dubosiella, and Bifidobacterium) and reducing that of harmful bacteria (Erysipelotrichaceae and Desulfovibrio), thereby potentially contributing to an improved intestinal environment, enhancing insulin sensitivity, and lowering blood glucose levels. This study offers new perspectives for developing functional pear products.