Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder characterized by hyperglycemia and insulin resistance. Plantain shell powder (PHP) serves as a high-quality source of dietary fiber, widely utilized in food additives and pharmaceutical applications. In this study, we investigated the hypoglycemic activity and underlying mechanisms of PHP by examining its effects on intestinal microbiota and metabolism in T2DM mice induced by a high-fat diet and streptozotocin (STZ). Our findings indicate that PHP significantly enhances blood glucose homeostasis and insulin sensitivity, reduces organ damage, and regulates blood lipid levels as well as short-chain fatty acid concentrations; notably, higher doses of PHP yielded optimal results. In addition, PHP can regulate the ratio of Bacteroidota to Firmicutes and increase the relative abundance of beneficial bacteria such as Bacteroidales, Muribaculaceae, and Parabacteroides. Furthermore, PHP enhances the enrichment of key metabolic pathways, including α-linolenic acid metabolism, monobactam biosynthesis, and PPAR signaling pathways, thereby promoting the production of beneficial metabolites. Complex interactions exist among these beneficial bacteria and metabolic pathways that are associated with improved metabolic function, regulation of glucose homeostasis, enhancement of insulin sensitivity, and reduction of inflammation. Our study demonstrates that PHP can ameliorate T2DM by reversing alterations in gut microbiota and metabolic profiles caused by T2DM while promoting the regulation of beneficial microbial populations.
