Study’s Authors Identify the Second Trimester as a Critical Exposure Window
New research from the Icahn School of Medicine analyzed pilot microbiome data from the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort based in Mexico City to examine associations between prenatal lead (Pb) exposure and gut microbiome composition and function in children ages 9-11. The analysis found consistent negative associations between Pb exposure during the second and third trimesters of pregnancy and several assessments of gut microbiome composition and function at 9-11 years old. Specifically, the authors identified the second trimester of pregnancy as a critical exposure window. The underlying association mechanism between prenatal Pb exposure and the gut microbiome later in childhood could work in multiple ways, including altering the trajectory of immune system development, maternal gut microbiome transfer, and postnatal Pb exposure through breast milk. The authors propose that all of these mechanisms could work together, affecting long-term outcomes. The study also identified consistent associations between prenatal Pb exposure and decreased abundance of B. caccae in the gut microbiome. The authors report that their findings support a growing body of evidence that prenatal Pb exposure could alter gut microbial composition and function, which could lead to future health issues. They call for further studies with larger sample sizes to better understand the relationship.
