Stachyose Improves Inflammation through Modulating Gut Microbiota of High-Fat Diet/Streptozotocin-Induced Type 2 Diabetes in Rats

Abstract

Scope: The present study is undertaken to assess the effects of stachyose (STS) on type 2 diabetes in rats and changes in the gut microbiota compared to metformin (MET).

Methods and results: The type 2 diabetic model is successfully established via a high-fat diet /streptozotocin in Wistar rats, and STS or MET is administered for 4 weeks. Blood is collected to analyze biochemical parameters, pancreas for mRNA expression of related gene, and contents of colon for gut microbiota. STS or MET decreases serum LPS, mRNA expression of IL-6, and tumor necrosis factor-α (TNF-α). In addition, STS and MET show a similar shifting of the structure of the gut microbiota and a selective enrichment of key species. At the genus level, STS shows selective enrichment of Phascolarctobacterium, Bilophila, Oscillospira, Turicibacter, and SMB5, but MET demonstrates a selective effect on Sutterella, Prevotella, 02d06, and rc4. The correlation analysis indicates that STS and MET decrease IL-6 and TNF-α and increase Akt/PI3K expression, which are relative to key species of gut microbiota.

Conclusion: STS decreases pancreatic mRNA expression of IL-6 and TNF-α via key species of gut microbiota. The mechanism of this effect is similar to that of MET.

Keywords: gut microbiota; inflammatory cytokines; metformin; stachyose; type 2 diabetes.