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 (pPeer reviewe
