Childhood exposure to lead significantly increases a person's risk of becoming obese later in life, according to a new study.
Researchers in the latest study on mice found that lead exposure during early development changes gut microbiota in a way that significantly increases the risk of obesity in adulthood.
Study results revealed that adult male mice exposed to lead while in the womb and in early childhood were 11 percent larger than mice that were never exposed to lead.
Further analysis revealed that the gut microbiome in mice exposed to lead was very different to those from mice that weren't exposed to lead. Mice exposed to lead during early development had fewer aerobes and more anaerobes in their gut.
"In both males and females, developmental lead impacted the adult microbiome," said Dana Dolinoy, an associate professor of environmental health sciences and of nutrition sciences at the University of Michigan. "We only observed adult onset obesity in the males, but females may have shown effects on obesity if we had followed them longer."
"Early life exposure to lead causes a long lasting impact on gut microbiome, and the change of gut microbiome may partially contribute to the increased body weight in adult life," said lead author Chuanwu Xi, associate professor of environmental health science at the University of Michigan School of Public Health.
In the experiment, researchers added lead to the drinking water of female mice before breeding to when they were done nursing their young. However, researchers stopped exposing mice to lead after they were fully weened.
"The lead levels in the mouse mothers were carefully designed to be within human population exposure levels. Our lowest dose is near the current U.S. Centers for Disease Control and Prevention's blood lead action level of 5 micrograms per deciliter, while the higher dose mirrors exposure levels during the 1960s and '70s," Dolinoy added. "Since we are investigating the effects of the developmental origins of disease, it is important to evaluate current and historically relevant lead levels."
The findings were published in the journal Toxicological Sciences.
