The Role of the Gut Microbiome in Type 2 Diabetes Mellitus

The gastrointestinal tract in humans hosts trillions of microorganisms, collectively termed the gut microbiota, which perform essential physiological processes and roles, including nutrient metabolism and immunomodulation. Influenced by genetics, age, diet, medication, and the environment, the disruption of this system leads to dysbiosis, which has been linked to a range of diseases, notably type 2 diabetes mellitus (T2DM). As the global prevalence of T2DM continues to trend upwards, research investigating and highlighting the influence the gut microbiome exerts on this disease is warranted. The literature was examined regarding microbial metabolites and metabolic signaling pathways, as well as interventions relating to diet, prebiotics, probiotics, pharmacological agents, and fecal microbiota transplantation (FMT). The gut microbiome, through its effects on insulin resistance, inflammation, bile acid signaling, and glucose-lipid metabolism, impacts the development and progression of T2DM. Furthermore, patients with T2DM have demonstrated reduced microbial diversity, depletion of butyrate-producing bacteria, and an increase in pathogenic species. Interventions including high-fiber diets, metformin, probiotics, and FMT were shown to enrich beneficial microbes and improve metabolic outcomes. Targeted modulation of the microbiome, such as through next-generation probiotics and CRISPR-based therapies, may enhance metabolic control in the context of the future of personalized medicine. This review investigates the intricate relationship between the gut microbiome and T2DM, emphasizing its role in disease pathogenesis, the factors that may impact the microbiome in these patients, as well as therapeutic approaches toward its management.