Abstract
OBJECTIVE: Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse maternal and neonatal outcomes. The gut microbiota has been implicated in the pathogenesis of metabolic disorders, including GDM. To characterize the gut microbiota in GDM patients with different fetal birth weight outcomes and to compare these profiles with those of their newborns and non-GDM controls. METHODS: This study included 54 patients with normal blood and 70 patients with GDM, which were categorized based on fetal birth weight outcomes including GDM with fetal growth restriction (FGR), normal birth weight, and macrosomia. Maternal fecal samples were collected before delivery. Neonatal meconium samples were obtained post-delivery. 16S rRNA gene sequencing was performed to analyze the gut microbiota composition. RESULTS: GDM patients exhibited a decrease in Firmicutes and an increase in Bacteroidetes compared to non-GDM controls. Mothers with GDM with FGR had higher levels of Firmicutes and lower levels of Bacteroidetes and Actinobacteria compared to those with normal birth weight or macrosomia. Neonates of mothers with GDM with macrosomia showed a decrease in Firmicutes and an increase in Proteobacteria compared to the other groups. Neonates of mothers with GDM with FGR had increased Firmicutes and decreased Proteobacteria and Actinobacteria. By α-diversity analysis, the Shannon index and OTUs of mothers in GDM with FGR were higher than others. The neonatal Shannon index and OTUs in the GDM with normal macrosomia group were lower than those in the other two groups, but the differences were not statistically significant. Correlation analysis revealed significant associations between specific microbial taxa and maternal biochemical indicators, as well as neonatal Apgar scores. No environmental factors were found to be related to maternal α-diversity among them. Neonatal α-diversity were correlated with c-glutamyltranspeptidase (GGT), high-density lipoprotein (HDL), aspartate transaminase (AST) and maternal age. CONCLUSIONS: GDM is associated with distinct gut microbiota profiles that vary with different fetal birth weight outcomes. These findings suggest that the gut microbiota may play a role in the pathogenesis of GDM and its associated adverse pregnancy outcomes. Further research is warranted to explore the potential of gut microbiota-based interventions for improving maternal and neonatal health in GDM.