Diabetes Mellitus (DM) is a complex metabolic disorder characterized by chronic hyperglycemia and poses significant global health challenges. Conventional treatments, such as insulin therapy and lifestyle modifications, have shown limited efficacy in addressing the multifactorial nature of DM. Emerging evidence suggests that gut microbiota, a diverse community of microorganisms critical for metabolism and immune function, plays a pivotal role in metabolic health. Dysbiosis, an imbalance in gut microbiota composition, has been linked to insulin resistance, obesity, and DM. Gut microbiota influences glucose metabolism through mechanisms, including short-chain fatty acid production, gut permeability regulation, and immune system interactions, indicating a bidirectional relationship between microbial health and metabolism. Clinical and experimental studies demonstrate that modulating gut microbiota through dietary interventions (prebiotics, probiotics, synbiotics) improves glycemic control and insulin sensitivity in DM patients. Fecal Microbiota Transplantation (FMT) has also shown promise in restoring healthy gut microbiota and alleviating DM-related metabolic disturbances. However, challenges remain, including the need for personalized treatments due to individual microbiota variability and the unknown long-term effects of these interventions. Future research should focus on elucidating the mechanisms by which gut microbiota influences metabolism and refining personalized approaches to enhance DM management.