GP Clinics


Gut Microbiota Is Altered by Household Disinfectants

Weekly use of specific household cleaning products around infants is associated with increased body mass index (BMI) at an older age, according to new research from Canada.
“Antibacterial cleaning products have the capacity to change the environmental microbiome and alter risk for child overweight,” the researchers wrote. “Our study provides novel information regarding the impact of these products on infant gut microbial composition and outcomes of overweight in the same population.”
Researchers analyzed microbes in fecal matter of 757 infants enrolled in the Canadian Healthy Infant Longitudinal Development birth cohort. Gut flora was evaluated at age 3 to 4 months, and weight was measured at age 1 and 3 years to determine any exposure to disinfectants, detergents, or eco-friendly products.
Infants exposed to disinfectants were 2 times more likely to have higher levels of Lachnospiraceae at age 3 to 4 months. Infants with higher Lachnospiraceae had higher BMI at 3 years old compared with children not exposed to disinfectants during infancy.
Lachnospiraceae increasingly became more abundant for the highest versus lowest quintile of use (adjusted odds ratio [OR] of 1.93), whereas abundance of Haemophilus declined (adjusted OR of 0.36). 
Enterobacteriaceae levels were lower when eco-friendly products were increasingly used (adjusted OR of 0.45). Increased Lachnospiraceae significantly conciliated associations of the top 30th centile of household disinfectant use with higher BMI z score and increased likelihood for being overweight or obesity at age 3. 
This association was not observed with detergents or eco-friendly cleaners, which suggests infants living in households where eco-friendly cleaners were used had different microbiota and therefore were less likely to be overweight as toddlers.
“Although child overweight was less common in households that cleaned with eco-friendly products, the lack of mediation by infant gut microbiota suggests another pathway for this association,” the researchers concluded.

Tun MH, Tun HM, Mahoney JJ, et al; the CHILD Study Investigators. Postnatal exposure to household disinfectants, infant gut microbiota and subsequent risk of overweight in children [Published online September 17, 2018]. CMAJ.