Gut Microbiota Dysbiosis and Diabetes: Causal Relationship, Pathogenic Mechanisms, and Clinical Applications

Haide College, Ocean University of China, 266100 Qingdao, China

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Diabetes is a major global public health problem, and traditional studies have not yet fully clarified its pathogenesis. The gut microbiota, often called the host’s “second genome,” plays a key role in metabolism and immune regulation. Both type 1 and type 2 diabetes are associated with gut microbiota dysbiosis. This includes reduced microbial diversity, fewer short-chain fatty acid (SCFA)–producing bacteria, and an increase in opportunistic pathogens. Dysbiosis can promote insulin resistance, β-cell damage, and chronic inflammation. These effects are linked to impaired gut barrier function, metabolic endotoxemia, altered SCFA metabolism, accumulation of branched-chain amino acids, and immune dysfunction. Studies using germ-free animal models and fecal microbiota transplantation have confirmed a causal relationship between gut microbiota dysbiosis and diabetes. Intervention strategies targeting gut microbiota, such as probiotics, fecal microbiota transplantation and precision nutrition, provide new approaches for the prevention and treatment of diabetes. This review summarizes recent advances and provides a basis for more precise interventions in diabetes.