Gut microbiota dysbiosis, circulating microbial genetic traces, and their role in gestational diabetes

Abstract

Diabetes mellitus is a leading metabolic and non-communicable disease, affecting nearly 537 million adults worldwide. Recent research highlights the gut microbiota as a crucial factor in the onset and progression of diabetes. Gut microbial dysbiosis, an imbalance in microbial composition, has been increasingly recognized as a contributor to diabetes pathogenesis during pregnancy. The gut microbiome is influenced by multiple internal and external factors, which can worsen diabetes-related complications. A higher abundance of pathogenic microbes may lead to the release of microbial metabolites or DNA into circulation, contributing to metabolic disorders such as obesity, cardiovascular disease, and liver dysfunction. Microbial nucleic acids have been identified in the bloodstream of individuals with diabetes and in pregnant women, suggesting the existence of a circulating or blood microbiome. Various physiological and pathological conditions may permit gut microbes or their components to enter the bloodstream. This review introduces the concept that the blood microbiome may play a critical role during pregnancy, potentially increasing susceptibility to diabetes. It emphasizes the mechanistic link between gut dysbiosis, microbial translocation, and pregnancy-associated metabolic disturbances. Exploring gut and blood microbiome interactions in pregnancy could reveal early biomarkers and therapeutic targets for gestational diabetes mellitus. Future studies should focus on longitudinal microbiome analyses and interventions to restore microbial balance, offering new preventive strategies against diabetes during pregnancy.

Keywords: Gut dysbiosis; Gestational diabetes mellitus; Microbial DNA; Systemic inflammation; Maternal-foetal health; Biomarkers

Core Tip: Pregnancy represents a unique metabolic state, where immune tolerance and insulin sensitivity are tightly regulated. Recent evidence suggests that gut microbiota dysbiosis may compromise the intestinal barrier, leading to the release of microbial genetic traces into the bloodstream. These microbial signals can activate host immune pathways and may aggravate systemic inflammation, thereby exacerbating gestational diabetes mellitus. This review highlights emerging insights into the link between gut dysbiosis, microbial translocation into circulation, and the worsening of diabetic outcomes in pregnancy. Understanding this gut-blood axis could open new opportunities for predictive biomarkers and targeted interventions to improve maternal and foetal health.