Regular exposure to dogs during early infancy can reduce the risk of developing asthma and allergies, according to various studies in the past. This latest study suggests that changes in gut microbes may be the cause for this effect.

The study was done by researchers from the University of California- San Francisco (UCSF) and University of Michigan. In this study, mice were exposed to dust from homes where dogs lived. According to the researchers, this triggered a ‘reshaping’ of their gastrointestinal microbiomes and decreased immune system reactivity to common allergens.

Protein and cockroach allergens were exposed to the mice, and the researchers found that the incidence of inflamed lungs, which is associated with asthma, was reduced significant in the mice exposed to dust linked to dogs, as compared to the mice exposed to dust from homes with no dogs.

The researchers singled out a particular species of bacteria for this study- Lactobacillus johnsonii. When this was fed to the mice, airway inflammations linked to respiratory viral infections or allergens were prevented.

Professor Susan Lynch from the UCSF led the study, and she said that “the composition and function of the gut microbiome strongly influence immune reactions and present a novel avenue for development of therapeutics for both allergic asthma and a range of other diseases.” She adds, “Gut microbiome manipulation represents a promising new therapeutic strategy to protect individuals against both pulmonary infection and allergic airway disease.”