Lead exposure in early stages ups obesity risk

New York:  Exposure to lead during the development stages and early childhood is likely to increase the risk of obesity in adulthood, finds a new research.

The results of the study conducted on mice found that exposure to lead during early development stages of life can change the gut microbiota -- a complex community of micro-organisms that live in the digestive tracts of animals -- in a way that it significantly raises the chances of obesity in adulthood.

"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 at the University of Michigan in US.

Adult male mice exposed to lead during the gestation period and infancy stages were 11 percent larger than those not exposed. 

Mice exposed to lead during early development stages showed differences in their gut microbiota and had fewer aerobes and more anaerobes in their gut.

In both males and females, developmental lead impacted the adult microbiome, the researchers maintained, adding that the study only observed adult onset obesity in the males.

Lead was added to the drinking water of mice mother prior to breeding through nursing their young. The lead levels were carefully designed to be within human population exposure levels.

Once weaned, the offspring were raised to adulthood without additional exposure, and then tested for lead effects acquired from their mothers, the researchers explained in the study published in the journal Toxicological Sciences.

Lead is found throughout the environment in natural and man-made settings. For decades, researchers have found many health problems associated with exposure, even at levels lower than the threshold for safety set by the US Centers for Disease Control and Prevention (CDC).

In the study, the researchers used deep DNA sequencing of bacterial specific genes to examine the guts of both males and females. 

Those exposed to lead had all of the similar complexity in microbiota as those not exposed. The differences were in the balance of the different groups of micro-organisms.