Gut microbiome in gestational diabetes: a cross-sectional study of mothers and offspring 5 years postpartum

Introduction An altered gut microbiome composition is shown to be associated with various diseases and health outcomes. We compare the gut microbiota of women who developed gestational diabetes mellitus (GDM) with that of those who did not, and the gut microbiota of their offspring, to determine any differences in the composition and diversity of their gut microbiota, which may be correlated with their GDM state. Material and methods All women were at high risk for GDM and participated in the Finnish Gestational Diabetes Prevention Study (RADIEL). Stool samples were obtained, 5years postpartum, from 60 GDM-positive women, 68 non-GDM control women, and their children (n=109), 237 individuals in total. 16S ribosomal RNA gene sequencing was employed to determine the composition of bacterial communities present. Statistical correlations were inferred between clinical variables and microbiota, while taking into account potential confounders. Results In mothers, no significant differences were observed in microbiota composition between the two groups. Genus Anaerotruncus was increased in children of women with GDM (p<0.001). Beta-diversity measures showed that a mother and her child have a more similar microbiome composition when compared with unrelated children, other mothers, or the children compared with each other (p<0.001). Conclusions These results suggest that there may be no discernible microbiome basis to GDM susceptibility in high-risk women, whereas microbiome differences between the offspring could be of greater biological significance. The heterogeneous nature of the disease could be obscuring potential differences between women. A longer time-series study, with carefully defined subject subgroups, may be an appropriate course of future investigation into GDM and the microbiome.