Effects of electroacupuncture on intestinal microflora and plasma metabolites in an insulin-resistant mouse model of type 2 diabetes mellitus

Objective: To investigate the effects of electroacupuncture (EA) at ST36 on intestinal microflora and plasma metabolites in a mouse model of type 2 diabetes mellitus (T2DM), to provide a theoretical basis and guidance for the clinical treatment of T2DM by traditional Chinese medicine (TCM). Methods: Sixteen T2DM db/db mice were randomly divided into treatment (T, n = 8) and model (M, n = 8) groups, and a further eight normal db/m+ mice reared under the same conditions served as a non-diabetic control group (C, n = 8). The general conditions of mice were observed weekly. After obtaining blood and stool samples, the mice were euthanized. Fasting blood glucose (FBG) was measured using a glucometer and fasting insulin (FINS) was measured in plasma by enzyme-linked immunosorbent assay (ELISA). Liver and colon tissues were embedded in paraffin and subjected to hematoxylin–eosin (HE) staining to observe pathological changes in these tissues. In addition, 16S ribosomal RNA (rRNA) sequencing was performed to analyze changes in the intestinal flora and metabolomics was employed to assess changes in metabolites in the blood. Results: EA significantly reduced FBG and FINS levels and alleviated pathological damage to the liver and colon. Furthermore, EA increased intestinal community richness and diversity by decreasing the relative abundance of Clostridium and incresasing the relative abundance of Lactobacillus. EA also reduced D-fructose levels in T2DM mice according to plasma metabolomics. Conclusion: EA has a positive regulatory effect on the intestinal flora and can regulate blood glucose and improve insulin resistance in T2DM model mice.