Microbiota in home indoor air may protect children from asthma

Published online: August 12, 2019

Several studies have indicated that early-life microbial exposures may influence the subsequent risk for asthma development, but what defines protective microbial exposures remains unclear. Earlier studies have suggested that one such factor may be diversity of the exposures. Recent results from the same study cohort as presented here showed that bacterial community features resembling those in farm homes also confer protection against asthma in urban homes. Whether specific taxa with particularly strong protective effects exist has remained unclear.   

Karvonen and her colleagues recently published a study in The Journal of Allergy & Clinical Immunology (JACI) where they tried to identify individual bacterial genera from the early-life indoor environment that were associated with the development of asthma. They used almost 400 living room dust samples, which were collected when the children were 2 months of age in the Finnish LUKAS birth cohort study. The children were followed up until the age of 10.5 years.

The authors found that house dust microbiota was phylogenetically different between homes of asthmatics and non-asthmatics. Large amounts of a certain type of bacteria, most likely from outdoors, reduced the child's risk of developing asthma. The abundance of these 12 groups of bacteria provided protection against asthma than the previously observed diversity of microbiota.

The authors’ findings confirm that phylogenetic differences in infant home microbiota are associated with subsequent asthma risk and suggest that communities of selected bacteria are more strongly linked to asthma protection than individual bacterial taxa or mere richness.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.