Microbiome-Driven Therapeutic Strategies for Type 2 Diabetes: A Systematic Review of Microbiota Modulation, Glycaemic Outcomes, and Transplantation.

Type 2 diabetes mellitus (T2DM) arises from the body's ineffective use or production of insulin. Recent research highlights the significant role of the gut microbiome in metabolism and immunity, indicating that microbial dysbiosis may be associated with T2DM development. This systematic review will explore the link between gut dysbiosis and Type 2 Diabetes Mellitus (T2DM), assess the impact of microbially-targeted therapies such as probiotics, prebiotics, dietary changes, and fecal microbiota transplantation (FMT) on glycaemic and metabolic outcomes in adults with T2DM, and determine if clinical trials validate the application of these therapies for T2DM treatment. An extensive literature search was conducted using PubMed up to January 2024, adhering to PRISMA 2020 guidelines, to identify eligible studies. The studies included were randomized controlled trials or observational studies reporting measurable outcomes related to metabolic health in adults aged 18 and older. A total of 25 studies show that individuals with Type 2 Diabetes Mellitus (T2DM) have lower gut microbial diversity, featuring fewer butyrate-producing bacteria and more inflammation-related bacteria. Probiotic supplementation and dietary fiber intake significantly improve hemoglobin A1c (HbA1c) levels and insulin sensitivity in T2DM patients. Gut microbiota dysbiosis is linked to Type 2 Diabetes Mellitus (T2DM), suggesting that the gut microbiome could be a therapeutic focus. However, while interventions like dietary changes, probiotics, and fecal microbiota transplantation show potential, current evidence does not support their routine clinical application. Recommendations for microbiome interventions should rely on strong evidence from effective longitudinal clinical trials verifying both efficacy and safety.