Margaret Karagas, Ph.D.
NIEHS grantees reported that arsenic in drinking water from private wells in New Hampshire was associated with significant effects on the gut microbiome of male, but not female, infants. The effect was strongest in babies who were not exclusively breast fed.
In 204 6-week-old infants from the New Hampshire Birth Cohort Study, researchers analyzed urinary arsenic, the overall microbiome community composition, and bacterial taxa critical for immune training in infancy. Well water used by the mothers in the cohort exhibited total arsenic concentrations ranging from below the limit of detection to 57 micrograms per liter. Only 2 percent of wells exceeded the U.S. Environmental Protection Agency maximum contaminant level of 10 micrograms per liter.
The researchers found associations with overall microbiome community composition among formula-fed males but not among breastfed infants or formula-fed females. Exclusively breastfed babies also had lower urinary arsenic concentrations than formula- or mixed-fed infants in the cohort.
According to the authors, this was the first study to look at the association between infant arsenic exposure and gut microbiome composition in the U.S. Previous studies examined associations in mice and researched the effects on the gut microbiome composition in children in areas of the world with higher levels of arsenic contamination in drinking water.
Citation: Hoen AG, Madan JC, Li Z, Coker M, Lundgren SN, Morrison HG, Palys T, Jackson BP, Sogin ML, Cottingham KL, Karagas MR. 2018. Sex-specific associations of infants' gut microbiome with arsenic exposure in a US population. Sci Rep 8(1):12627.