Anti‐diabetic and gut microbiota modulation effects of sacha inchi (Plukenetia volubilis L.) leaf extract in streptozotocin‐induced type 1 diabetic mice

Abstract

BACKGROUND Sacha inchi (Plukenetia volubilis L.) tea has been used as adjuvant treatment in the therapy of diabetes in Pu’er, Yunnan province of China. The effect of sacha inchi tea on diabetes and the underlying mechanisms remain unknown. This study was conducted to investigate the influence of the water extract of sacha inchi (P. volubilis L.) leaves (PWE) on hypoglycemic activity and gut microbiota composition in mice with streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM). During the 6 weeks of the study, T1DM mice were intragastrically administered with 400 mg/kg body weight (BW) PWE per day. RESULTS Treatment with PWE reduced the excessive loss of BW and over intake of food. PWE treatment not only significantly decreased the blood glucose levels but also improved the oral glucose tolerance. PWE treatment caused protective histopathological transformations in the pancreas sections, leading to decreased insulin resistance and improved insulin sensitivity. PWE treatment also significantly ameliorated the disorder of the gut microbiota structure and increased the richness and diversity of intestinal microbial species in T1DM mice. At the genus level, the populations of several crucial bacteria, such as Akkermansia, Parabacteroides, and Muribaculum, increased in the PWE treatment group, but the abundance of Ruminiclostridium and Oscillibacter decreased. CONCLUSIONS PWE can ameliorate the hyperglycemic symptoms of STZ-induced T1DM mice, and the anti-diabetic effect of PWE was related to the amelioration of the gut microbial structural disorder and the enrichment of functional bacteria.