Effects of Ultrafine Ground Pea Dietary Fiber on Intestinal Flora and Metabolites in Diabetic Mice

The aim of this study is to clarify the effects of ultrafine ground pea dietary fiber (UGPDF) on the intestinal microflora and metabolites of diabetic mice so as to reveal the mechanism of its hypoglycemic effect. A diabetic mouse model was established by intritoneal injection of streptozotocin, and the diabetic mice were gavaged with either metformin or UGPDF with high-dose (0.9 g/ (mL·d)) and low-dose (0.45 g/ (mL·d)) for four weeks. The changes in blood glucose level and liver cell morphology were measured during the experimental period. The protein expression levels of phosphatidylinositol-3-kinase (PI3K), protein kinase B (AKT) and insulin-like growth factors (IGF) were detected by Western blot. The composition of the fecal microbial flora of mice in each group was analyzed by high-throughput sequencing. The results showed that UGPDF could regulate the abundance and diversity of the intestinal microflora in diabetic mice. The number of operational taxonomic units (OTUs) in the high-dose UGPDF group was 300 ± 36, and the Shannon and Simpson indexes of this group were significantly different from those of diabetic mice. UGPDF intervention increased the abundance of beneficial bacteria such as Lactobacillus and Lachnospiraceae (P < 0.05), and decreased the abundance of pathogenic bacteria such as Helicobater, Klebsiella compared to the model group (P < 0.05). Moreover, after UGPDF intervention, the contents of six short-chain fatty acids in the feces of mice were significantly increased, and the most significant effect was observed in the high-dose group, showing an increase in the contents of acetic acid, propionic acid and butyric acid by 63.7%, 75.9% and 96.0%, respectively, reaching a level similar to that of the normal group. At the same time, the results of liver Histological examination and Western blot showed that UGPDF could regulate the PI3K/AKT/IGF signaling pathway in the liver of diabetic mice, repair liver cell injury and improve insulin sensitivity.