A new study published in the Proceedings of the National Academy of Sciences says that the presence of household dogs may help reduce the risk of asthma developing in children. Scientists found that exposing mice to dust from homes with dogs changed the composition of gut microbes significantly in the mice. The mice were then exposed to common allergens, and the findings show that mice that had been exposed to the dust from homes with dogs had fewer allergic reactions than mice exposed to dust from homes without.

According to Susan Lynch, an associate professor in the division of gastroenterology at the University of California and the senior author of the study, the presence of dogs in a home may allow the GI tract to be inoculated, and lead to a more mature immune response. The findings, she said, are consistent with previous research based on human observations, and are likely to apply to people. Dr. Lynch hopes the study could lead to the development of microbial based therapies to prevent asthma and other allergies.