Commonly used household cleaners could be making children overweight by altering their gut microbiota.

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 (WHO) 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 using disinfectants. They did not find the same association with detergents or eco-friendly cleaners. Professor and principal investigator Anita Kozyrskyj said, "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; 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."

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," Kozyrskyj said.

She suggested that the use of eco-friendly products may be linked to healthier overall maternal lifestyles and eating habits, in turn contributing to healthier gut microbiomes and infant weight. The study provides novel information regarding the impact of these products on infant gut microbial composition and outcomes of increased weight in the same population. The full findings are present in - Canadian Medical Association Journal.