Longitudinal associations between PM2.5 with gestational diabetes mellitus mediated by gut microbiome and potential mechanism: based on a prospective pregnant women cohort in China

The gut microbiota may moderate the associations between PM_2.5 exposure and blood glucose levels, and both PM_2.5 exposure and gut microbiota may be related to GDM, potentially involving pathways such as glycerophospholipid metabolism, sphingolipid metabolism and the insulin signaling pathway. However, lifestyle factors (diet and physical activity) and residential mobility were not measured, and the fecal microbiota was assessed at a single time point in mid-pregnancy. Thus, these limitations may contribute to residual confounding, exposure misclassification, and limited causal inference.