Early life exposure to certain disinfectants used at home could be making children overweight by altering the composition of their gut bacteria, suggests new research.
Babies living in households that used eco-friendly cleaners had different microbiota and were less likely to be overweight as toddlers, showed the findings published in CMAJ (Canadian Medical Association Journal).
For the study, the researchers analysed the gut flora of 757 infants from the general population at age 3-4 months and weight at ages 1 and 3 years, looking at exposure to disinfectants, detergents and eco-friendly products used in the home.
The researchers looked at data from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort on microbes in infant fecal matter. They used World Health Organization growth charts for body mass index (BMI) scores.
Associations with altered gut flora in babies 3-4 months old were strongest for frequent use of household disinfectants such as multi-surface cleaners, which showed lower levels of Haemophilus and Clostridium bacteria but higher levels of Lachnospiraceae.
The researchers also observed an increase in Lachnospiraceae bacteria with more frequent cleaning with disinfectants.
They, however, did not find the same association with detergents or eco-friendly cleaners.
"We found that infants living in households with disinfectants being used at least weekly were twice as likely to have higher levels of the gut microbes Lachnospiraceae at age 3-4 months," said Anita Kozyrskyj, Professor at the University of Alberta in Canada.
"When they were 3 years old, their body mass index was higher than children not exposed to heavy home use of disinfectants as an infant," Kozyrskyj said.
"Those infants growing up in households with heavy use of eco cleaners had much lower levels of the gut microbes Enterobacteriaceae," she said.
Kozyrskyj suggests that the use of eco-friendly products may be linked to healthier overall maternal lifestyles and eating habits, contributing in turn to the healthier gut microbiomes and weight of their infants.