You may think that pets are bad for asthma. And you’d be right. Sort of.

It’s true that pets are a common asthma trigger-- proteins in their skin, saliva, and urine cause allergic reactions in 30% of asthmatics. Not only that, their fur collects several other asthma triggers such as dust, pollen, and mold. So if your child already struggles with asthma, getting a dog or other furry friend is probably not the wisest choice.

That being said, getting a dog while your child’s still very young may actually help protect them from getting asthma. How?

Scientists at the University of California San Francisco and the University of Michigan exposed mice to dog dust (dead skin cells from dogs) and found that the bacteria in the mice’s guts changed in a way that diminished their immune systems’ response to common allergens. As you probably know, asthma is an overreaction of one’s immune system to allergens. So, at least in theory, if human children are exposed to dog dust the bacteria in their guts will change in the same way, diminishing their immune systems’ response to allergens and preventing the development of asthma.

The results of the study support the hygiene hypothesis, a popular theory that blames the development of autoimmune diseases (such as asthma) in Western nations on a lack of exposure to microbes (which happens as a result of good hygiene).

The scientists didn’t go as far as to recommend exposing infants to dog dust, but they did say that “gut microbiome manipulation represents a promising new therapeutic strategy.” Currently, they’re conducting further studies to try to find ways to put this new medical knowledge to good use.