Gut microbiota and type 2 diabetes: implications for personalized nutrition and emerging therapeutic strategies

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder characterized by insulin resistance, impaired glucose regulation, and chronic low-grade inflammation. Over the past decade, the gut microbiota (GM) has emerged as an important determinant of metabolic health, with increasing evidence showing that gut microbial dysbiosis and its associated metabolites influence intestinal barrier function, immune regulation, insulin sensitivity, and glucose homeostasis. Although previous studies have examined either GM, dietary interventions, or probiotic supplementation in T2DM, a comprehensive study linking microbial metabolites with personalized nutrition (PN) and emerging microbiota-based therapeutic strategies remains lacking. This review addresses this gap by discussing the mechanistic roles of important gut microbial metabolites, such as short-chain fatty acids (SCFAs), lipopolysaccharides (LPS), trimethylamine-N-oxide, indolepropionic acid (IPA), and bile acids (BAs), in the development and progression of T2DM. It further describes how dietary strategies, including high-fiber and prebiotic-rich diets, probiotics, synbiotics, polyphenol-rich foods, and PN, improve glycemic control and metabolic health. Recent advances in microbiota-targeted interventions, including postbiotics, next-generation probiotics, engineered probiotics, and fecal microbiota, are also discussed along with their therapeutic potential and existing clinical limitations. By combining mechanistic insights with nutritional and therapeutic perspectives, this review provides a single framework for understanding the diet-GM-host metabolic axis and offers future directions for developing microbiome-informed precision nutrition strategies for the prevention and management of T2DM.