According to a study, household disinfectants could make children overweight

According to a new study published Monday in the Canadian Medical Association Journal, multi-surface cleaners and other household disinfectants commonly used could make children overweight by modifying the bacteria in their intestines.

Canadian researchers found that infants living at least once a week with antimicrobial disinfectants were at least twice as likely to have higher concentrations of Lachnospiraceae bacteria between 3 and 4 months of age. The study also shows that the body mass index (BMI) of children with higher levels of Lachnospiraceae was 3 years old and that their body mass index (BMI) was higher than that of children not living in homes. frequently used.

The bacterium Lachnospiraceae is "a normal component of our gut microbiota," said Anita Kozyrskyj, lead author of the study and pediatric professor at the University of Alberta, in a CMAJ podcast.

However, she explained that animal studies have shown that higher levels of Lachnospiraceae are associated with higher resistance to body fat and insulin.

"Guilty" linking the use of disinfectant and the weight

The new report uses data from the Canadian Longitudinal Development of Healthy Infants Study, launched in 2009 by researchers who actively monitor participants as they grow and develop in the mid-to-late years. pregnancy in childhood and adolescence.

When infants were 3 to 4 months old, their parents provided a poop sample for each infant and answered questions about their home, Kozyrskyj explained. Samples of 757 infants were described and analyzed with data on BMI at older ages and parental use of disinfectant products.

One of the findings of the study is that about 80% of Canadian households use disinfectants, most often multi-surface cleaners, at least once a week, Kozyrskyj said.

Although researchers found an increase in frequent cleansing with disinfectants in Lachnospiraceae bacteria, they did not see the same association with washing detergents without the destroying ingredients of bacteria in disinfectants or green cleaners.

"These findings suggest that the gut microbiota was the culprit in the association between disinfectant use and overweight," Kozyrskyj said.

The gut microbiota refers to the community of bacteria that live together harmoniously in our digestive tract, explained Kozyrskyj. This community develops during infancy when we gain a larger number of bacterial species, each species decreasing or increasing in number over time.

"We each have a unique gut microbiota, but there are common patterns, we expect to find common microbes in childhood and in adulthood," Kozyrskyj said. "I would say that at the age of 3, we have a bacterial composition that we can call ours. And he stays with us for the rest of our life. "

This is important because previous research has established a link between intestinal microbiota composition and weight in adulthood.

Detect risk factors for obesity

Although the results of the study highlight the link between disinfectants and intestinal microbiota, Kozyrskyj noted that "it's still a big step in using the word causality."

That said, some of the evidence clearly indicates a direct cause-and-effect relationship between disinfectants and higher levels of the common intestinal bacteria. For example, animal studies have revealed similar changes in intestinal bacteria in piglets exposed to disinfectants.

And "a greater frequency of disinfectant use was associated with greater abundance of Lachnospiraceae," said Kozyrskyj. Nevertheless, she warned that more research is needed to confirm these findings and establish a cause and effect relationship.

In a published commentary, Moira K. Differding and Noel T. Mueller, both of the Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health in Baltimore, wrote that the results of the study were "biologically plausible".

Why? The bacteria we are exposed to during our childhood educates our immune system and programs our metabolic system, explained Differding and Mueller, none of whom participated in the new study. And in previously published studies, researchers have found that disruption in the natural development of intestinal bacteria in infants – due to cesarean section, prenatal and postnatal antibiotics,

"The prevalence of childhood obesity continues to increase on a global scale," said Differding and Mueller, adding that it is "more important than ever" to identify the factors of obesity risk and ways to prevent high weight gains in children.

Kozyrskyj said that a discovery in the new study had surprised the research team. Babies living in households that used environmentally friendly cleaners had a different microbiota – significantly lower enterobacteria rates – and were less likely to be overweight than toddlers. However, an analysis of the data did not show that this altered bacterial community was linked to the reduced risk of obesity in children.

"Mothers who use green products can be healthier," she said, adding that the mother's overall healthier lifestyle and eating habits can be beneficial to both intestinal bacteria and weight. of their children.

Because the results have yet to be confirmed, Kozyrskyj is not yet ready to recommend to consumers to buy environmentally friendly products. However, she said that the study had opened her eyes to the use of green products, including DIY vinegar cleaning solutions, in her own home.