Therapeutic potential of polysaccharides in type 2 diabetes mellitus via multi-target modulation of gut microbiota

Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by chronic hyperglycemia, which has recently emerged as a major global public health challenge owing to its increasing prevalence. An imbalance in intestinal microbiota can induce inflammation and insulin resistance by altering the secretion of its metabolites, such as lipopolysaccharides, branched-chain amino acids, short-chain fatty acids, and bile acids, ultimately leading to the development of T2DM. Owing to their notable pharmacological activity, minimal side effects, and low toxicity, polysaccharides have attracted significant attention. In particular, they can improve T2DM by modulating gut microbiota structure, promoting beneficial bacteria proliferation, and enhancing the integrity of the intestinal barrier. These comprehensive effects endow polysaccharides with great potential for treating T2DM. This review outlines the relationship between intestinal microbiota dysbiosis and T2DM. Subsequently, it delves into the mechanisms through which polysaccharides alleviate T2DM by modulating the gut microbiota, elucidating how polysaccharides achieve multi-target intervention in T2DM by modulating the structure and metabolism of gut microbiota. Finally, this review explores the impact of the structural characteristics of polysaccharides on the composition and function of gut microbiota and summarizes the structural characteristics of polysaccharides that can improve T2DM, providing new ideas for the development of polysaccharide functional foods and drugs to improve T2DM.