Corni Fructus as a Natural Resource Can Treat Type 2 Diabetes by Regulating Gut Microbiota

Accumulating evidence suggests that gut microbiota plays a crucial role in the development of metabolic diseases, especially type 2 diabetes mellitus (T2DM). The nutrient-rich resource Cornus Fructus (CF) showed curative effects on diabetes mellitus. However, the mechanism underlying its hyperglycemic activity remains obscure. Herein, the antidiabetic potential of four extracts from CF, including saponin (CTS), iridoid glycoside (CIG), tannin (CT), and alcohol extract (CCA) was evaluated in vivo. The results showed that all four extracts could increase the body weight, decrease the blood glucose levels, and elevate the glucose tolerance. Moreover, insulin sensitivity and lipid profile were significantly improved in fed mice. In the [Formula: see text]-diversity index of samples, compared to the DM group, the diversity and richness of gut microbiota in mice to a certain extent were reduced in both CF extracts and Metformin (PC). Among them, there was statistical significance in PC (ACE, [Formula: see text]) and CCA (ACE, [Formula: see text]; chao1: [Formula: see text]). Beta diversity showed the same trend as the UPGMA clustering trees, which revealed that CF extracts could improve intestinal homeostasis in T2DM mice. Also, CF extracts could elevate the production of short-chain fatty acids, as well as regulate the composition of gut microbiota. The key bacteria related to T2DM including Firmicutes, Bacteroides, Lactobacillus, and Clostridium were modulated by metformin and CF. Altogether, CF is a potential nutrient-rich candidate that can be used in functional foods for the treatment of T2DM, and the change of gut microbiota might be a novel mechanism underlying its hyperglycemic activity.