Review of the Microbiome in Diabetes
Diabetes mellitus is a rapidly expanding global health challenge driven by complex interactions between genetic, environmental, metabolic, and immunological factors. Growing evidence highlights the gut microbiome as a critical regulator of glucose homeostasis, insulin sensitivity, immune modulation, and pancreatic β-cell function. This narrative review synthesizes current knowledge on the role of the human microbiome in the pathophysiology of both type 1 and type 2 diabetes. It examines how early-life microbial exposures influence immune tolerance and autoimmunity, how gut dysbiosis contributes to β-cell destruction, insulin resistance, and metabolic inflammation, and how microbial metabolites such as short-chain fatty acids, bile acids, and lipopolysaccharides mediate hostmicrobe interactions along the gut–liver–pancreas axis. The review further evaluates emerging therapeutic strategies, including dietary modulation, probiotics, prebiotics, synbiotics, and fecal microbiota transplantation, alongside methodological challenges inherent in microbiome research. While microbiome-targeted interventions hold considerable promise, significant gaps remain regarding causality, reproducibility, and long-term clinical efficacy. Addressing these challenges through well-designed longitudinal and multi-omic studies will be essential to translating microbiome science into effective preventive and therapeutic strategies for diabetes.