Study suggests link between cleaners, obesity

Frequently using disinfectant to keep homes clean is being linked to weight gain in children, warns a University of Alberta study.

“We found that infants living in households where disinfectants were used at least weekly were twice as likely to have higher levels of the bacteria called Lachnospiraceae at three to four months of age,” said Anita Kozyrskyj, a pediatrics professor and lead on the investigation into how alteration of infant gut microbiome impacts health.

“At three years of age, those same children had a higher body mass index (BMI) than children who were not exposed to frequent home use of disinfectants as infants.”

And the discovery is more than just a link, she stresses.

“Our ‘mediation’ statistical analysis suggests that a gut microbiome enriched with Lachnospiraceae early in infancy was likely directly responsible for children becoming overweight or obese,” she added.

The study examined exposure to three categories of household cleaners — disinfectants, detergents and eco-friendly products — on the infant gut microbiome.

“We did not find a relationship between detergents and gut microbiome change or obesity risk that was independent of disinfectant usage,” said Kozyrskyj, adding that it is important to distinguish detergents from disinfectants since the usage of both is highly correlated.

More than 80 per cent of households use multi-surface cleaners with disinfectants weekly or more often, said Kozyrskyj, adding that infant exposure likely occurs through contact with aerosols or cleansed surfaces.

“Based on our study ’s finding, we recommend against frequent use of disinfectant cleaners in households with infants and suggest that parents consider alternative cleaning products.”

The study notes that infants in households with high use of environmentally friendly cleaners had decreased odds of becoming overweight or obese, but that was not related to their gut microbiome as an infant.

“Infants growing up in households with heavy use of eco cleaners had much lower levels of different types of gut microbes, such as Enterobacteriaceae. However, we found no evidence that these specific gut microbiome differences were associated with the reduced obesity risk,” said AllerGen trainee Mon Tun, a PhD candidate at the U of A and author of the study.

Rather, Tun believes that mothers in households using a lot of eco products may eat healthier food and, thus, have healthier microbiomes during pregnancy, which may in turn have a positive impact on the newborn microbiome and later weight gain.

What is clear, however, is that adults can help protect infant gut microbiome and cut risk of weight gain and obesity by eliminating disinfectant agents in household cleaning regimes, concludes Kozyrskyj.

The study — funded by Canadian Institutes of Health Research (CIHR) — published in the Canadian Medical Association Journal (CMAJ), used data from 757 children participating in AllerGen’s Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort.

The CHILD Study is collecting a range of health, lifestyle and environmental exposure information from nearly 3,500 mothers and children from pregnancy to age five.

It spans four provinces (B.C., Alberta, Manitoba and Ontario).