Characteristics of Placental Bacterial DNA Communities in Pregnant Women with Gestational Diabetes Mellitus and Association with Early Neonatal Gut Microbiota and Short-Term Perinatal Outcomes

Abstract

Gestational diabetes mellitus (GDM) affects maternal metabolism and may be associated with altered placental bacterial DNA community profiles and early neonatal gut microbiota. This prospective cohort study assesses GDM’s impact on the placental-neonatal gut microbial axis and links key bacterial taxa to short-term perinatal outcomes and clinical significance. Pregnant women with GDM and healthy controls were enrolled. Placental tissue and first-pass neonatal meconium samples were collected. Bacterial community composition, diversity, and differential genera were analyzed using 5-region 16S rRNA sequencing. FEAST was used to model potential maternal-neonatal microbial sources. Associations among gestational weight gain (GWG), microbial features, and the risk of neonatal hospitalization were also assessed. The GDM and control groups showed significant differences in placental and early neonatal meconium microbial community structures, with increased α-diversity and distinct community separation in both sample types. In placental samples, Brevundimonas was decreased, whereas Lactobacillus and Sphingomonas were enriched. In neonatal meconium, potentially inflammation-related genera, including Staphylococcus, Streptococcus , and Clostridium , were enriched. GWG had limited effects on overall community structure but exerted refined regulation on specific genera. Source tracking showed a reduced placenta-attributed similarity contribution to neonatal meconium microbiota in the GDM group. The abundances of specific placental genera, including Escherichia, Curvibacter , and Pelomonas , were significantly associated with neonatal hospitalization. GDM is associated with altered placental bacterial DNA community profiles and early neonatal meconium microbiota, potentially affecting maternal-neonatal microbial continuity. Specific bacterial genera are associated with early neonatal hospitalization. The study provides a microbial perspective for understanding GDM-related perinatal risk.