Gut Microbiota and Metabolites: Biomarkers and Therapeutic Targets for Diabetes Mellitus and Its Complications.

Diabetes mellitus (DM) is a complex metabolic disease characterized by significantly elevated blood glucose levels as a result of dysfunctional or impaired pancreatic β-cells, leading to insulin deficiency. This condition can result in severe complications, including cardiovascular diseases, kidney failure, vision impairment, and nerve damage. Currently available anti-diabetic drugs do not fully prevent the progression of these complications. Moreover, they often have significant side effects. The gut microbiota plays a crucial role in influencing diet, energy metabolism, and blood glucose levels. Research shows a strong link between microbiota dysbiosis and DM, as well as the severity of its complications. Commensal bacteria can help manage blood glucose levels, reduce inflammation, regulate metabolism, and enhance the gut barrier. Conversely, opportunistic pathogens can worsen insulin resistance, promote metabolic disorders, disrupt gut integrity, and affect appetite and weight. This article describes the characteristics of gut microbiota in various types of DM and explores the role of the "gut microbiota-metabolite-signaling pathway" axis in DM and its complications. In addition, it highlights the therapeutic potential of traditional Chinese medicine and dietary interventions through modulation of the gut microbiota and metabolites. The aim is to provide comprehensive evidence supporting the integration of TCM dietary therapy, targeted dietary strategies, and specific probiotics as alternative and complementary therapies for DM and its complications.