Gut microbiome and serum metabolome changes in gestational diabetes mellitus after diet-exercise intervention

Gestational diabetes mellitus (GDM) poses risks to both the mother and fetus. Diet and exercise interventions (DEI) improve blood glucose control and pregnancy outcomes, but the underlying mechanisms, especially those involving the gut microbiota and serum metabolites, are unclear. In this study, we conducted a comparative analysis of pre- and post-DEI outcomes by assessing HbA1c, fasting glucose, the diversity and functional pathways of the gut microbiota, and serum metabolomics. Post-DEI, the women maintained normal glycemic levels without delivery complications or adverse neonatal outcomes. The gut microbiota alpha/beta diversity remained stable, although the abundances of specific species (e.g., Faecalibacterium sp. and Prevotellamassilia sp.) and functional pathways (e.g., flavonoid biosynthesis and bacterial chemotaxis) were altered. Metabolomics identified 132 differentially regulated metabolites (83 upregulated and 49 downregulated) enriched glycerophospholipids, steroids and steroid derivatives, fatty acyls, and carboxylic acids and derivatives. In conclusion, while DEI did not significantly alter the gut microbial community structure, it potentially exerted targeted modulatory effects on specific microbial functions in women with GDM. Furthermore, DEI also induced alterations in serum metabolites and associated metabolic functions.