Characteristics of the gut microbiota in gestational diabetes mellitus associated with poor dietary habits: An observational study

Gestational diabetes mellitus (GDM) is increasingly associated with alterations in gut microbiota, particularly under the influence of poor dietary habits during pregnancy. However, specific microbial characteristics associated with GDM remain unclear. To address this, we used 16S rRNA gene sequencing to compare the gut microbiota of pregnant women with GDM and healthy pregnant individuals. We conducted amplicon sequence variant analysis, assessed α- and β-diversity, performed taxonomic profiling, and applied linear discriminant analysis effect size (LEfSe) as well as random forest modeling to identify differences in microbial composition and potential diagnostic biomarkers. Although overall microbial diversity did not differ significantly between the groups, distinct taxonomic shifts were observed. These differences suggest the presence of microbial dysbiosis associated with GDM and poor dietary patterns. Enrichment of beneficial genera in healthy pregnant individuals, along with an increased abundance of potentially dysbiotic taxa in the GDM group, highlights the potential role of gut microbiota in GDM pathogenesis. Notably, Butyricicoccus and Lachnospiraceae_UCG-004 emerged as candidate biomarkers for GDM diagnosis or risk stratification. These findings provide a foundation for future investigations into microbiota-targeted interventions and the development of noninvasive diagnostic strategies for GDM.