Household cleaners can alter infant microbiota and increase obesity risk, study suggests

17 Sep 2018 --- Commonly used household cleaners could be making children overweight by altering their gut microbiota, a Canadian study published in the Canadian Medical Association Journal (CMAJ) has found.

The study analyzed the gut flora of 757 infants from the general population at age three to four months and weight at ages one and three years, looking at exposure to disinfectants, detergents and eco-friendly products used in the home.

“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 three to four months; when they were three years old, their body mass index was higher than children not exposed to heavy home use of disinfectants as an infant,” says Anita Kozyrskyj, a University of Alberta Pediatrics Professor and principal investigator on the SyMBIOTA project, an investigation into how alteration of the infant gut microbiome impacts health.

Researchers from across Canada 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 multisurface 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 did not find the same association with detergents or eco-friendly cleaners. Studies of piglets have found similar changes in the gut microbiome when exposed to aerosol disinfectants.

Importantly, babies living in households that used eco-friendly cleaners had different microbiota and were less likely to be overweight as toddlers.

“Those infants growing up in households with heavy use of eco cleaners had much lower levels of the gut microbes Enterobacteriaceae. However, we found no evidence that these gut microbiome changes caused the reduced obesity risk,” she says.

She 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.

“Antibacterial cleaning products have the capacity to change the environmental microbiome and alter risk for overweight children,” write the authors. “Our study provides novel information regarding the impact of these products on infant gut microbial composition and outcomes of overweight in the same population.”