Disinfectant use may be causing higher BMI (Body Mass Index) scores in our children. Infants in homes where disinfectants were used at least once weekly showed higher levels of certain gut bacteria. 3 years later, those same children had a higher BMI score.
Gut microbiota refers to the community of bacteria that live harmoniously together in our digestive tract. The gut flora develops during infancy and then changes over time. We each possess a unique gut microbiota, but there are common patterns that are expected to be found in children and adults. The bacteria that we are exposed to during our infancy both educates our immune system and programs our metabolic system. By 3 years of age, we have a bacterial composition we can call our own, and it stays with us for the remainder of our life. This is important because research has drawn a connection between gut microbiota composition and weight in adulthood (read our post this Wednesday for more info). A study published in the September 17, 2018 issue of Canadian Medical Association Journal links higher BMI (Body Mass Score) rates in children exposed to disinfectants, due to the effect of the disinfectant on gut flora.
The association of a higher BMI score at age 3 increased when the frequency of use of disinfectants increased from weekly to daily.
Infants living in households where antimicrobial disinfectants are used at least weekly were twice as likely to have higher levels of a bacteria called Lachnospiraceae at ages 3 to 4 months than children whose homes did not frequently use disinfectants. At 3 years of age, these same children had a higher body mass index (BMI) than children who did not live in homes that frequently use disinfectants.
The association of a higher BMI score at age 3 increased when the frequency of use of disinfectants increased from weekly to daily. These changes are compatible with the bacterial-killing actions of disinfectants containing bleach and hydrogen peroxide. Greater prominence of the Lachnospiraceae species in gut microbiota has also been associated with higher body fat and insulin resistance in human adults. Animal studies have found similar changes in the gut bacteria of piglets when exposed to disinfectants.
The new report uses data from the Canadian Healthy Infant Longitudinal Development Study, which began in 2009, with researchers actively following participants as they grew and developed, from mid-pregnancy, into childhood and adolescence. When infants were 3 or 4 months old, their parents provided a poop sample for each infant and answered questions about their home. Samples from 757 infants were profiled and analyzed along with BMI data at older ages, and noting parental use of disinfectant products. Roughly 80% of these Canadian households used disinfectant products, most often multi-surface cleaners, at least once weekly.
The study did not find increased weight gain or elevated levels of Lachnospiraceae when eco-friendly products were used. It’s believed that the composition of these products impacts the gut flora differently. Babies living in households that used eco-friendly cleaners had different microbiota -much lower levels of Enterobacteriaceae, which unlike Lachnospiraceae, correlated with normal BMIs in toddlers. It is unclear if this altered bacterial community is linked to the reduced obesity seen in these children. It might be that parents who use eco-friendly products have an overall healthier lifestyle and eating habits that benefits both the gut bacteria and weight of their children. It is increasingly clear that household cleaning products alter gut microbial composition. Further studies are needed to establish exactly how each one affects metabolic disease and weight.
Childhood obesity continues to rise globally. It is more important than ever to identify the risk factors involved and ways to prevent it. I know the manufacturers of these products don’t want us to stop using them, but I can’t help thinking- if using do-it-yourself vinegar cleaners or eco-friendly products can change this epidemic in children by even 1%, why not try it?