Andrea Cassidy-Bushrow, Ph.D.
Henry Ford Health System
Lead exposure in the womb alters the infant gut microbiome, according to NIEHS-funded researchers. Both lead exposure and the early life microbiome have been linked to similar developmental health outcomes, but it has been unclear whether lead-related health effects are partially driven by the gut microbial community. This is the first human study to examine the influence of prenatal lead levels on the gut microbiome.
The researchers mapped growth rings in naturally shed teeth from 146 children to assess lead levels present in teeth before and after birth. Using genetic sequencing methods, they determined the types and abundance of bacteria and fungi present in child stool samples collected at approximately one and six months of age.
Prenatal tooth lead levels were significantly associated with the gut fungal community at one month of age. Specifically, higher lead resulted in a lower number of fungal species shown to be sensitive to lead and a higher number of lead-resistant fungal species. Lead did not have a significant effect on the newborn gut bacterial community. Differences in the microbial community were found for prenatal, but not postnatal, lead levels. This result highlights the advantage of using baby teeth to capture multiple exposure time points both before and after birth.
According to the researchers, the link between lead exposure and the infant gut microbiome could play a role in the impact of lead on childhood development.
Citation: Sitarik AR, Arora M, Austin C, Bielak LF, Eggers S, Johnson CC, Lynch SV, Kyun Park S, Hank Wu KH, Yong GJM, Cassidy-Bushrow AE. 2020. Fetal and early postnatal lead exposure measured in teeth associates with infant gut microbiota. Environ Int 144:106062.