Want to protect your kids from a future of allergies?  Get a dog.  New research suggests that early exposure to pets may lead to changes in the gut that prevent the development of asthma and allergies.

Over the last few years, researchers have found that children who grew up with pets were less likely to develop allergies, but they were never quite sure why.  A new collaborative study from researchers at the University of California, San Francisco, the University of Michigan, the Henry Ford Health System, and Georgia Regents University, Augusta, may have found the answer - and that answer lies in the gut.

Researchers found that mice that were exposed to dust from households where dogs lived had major changes in the composition of their gut microbes - or the bacteria that live within the digestive tract.  When these mice were later exposed to common allergy triggers, they had significantly reduced allergic responses compared with mice that had been exposed to dust from homes without dogs or that weren't exposed to any dust.

The study leads researchers to believe that having dogs in the house changes the microbes within the gut and "might inoculate the GI tract" of babies and improve their immune response in such a way that they are less sensitive to allergens, said Susan Lynch, an associate professor in the division of gastroenterology at University of California, San Francisco and a senior author of the study.

The findings, published in the Proceedings of the National Academy of Sciences, give a reasonable explanation for why kids with pets are less likely to have allergies.  

"It seems to be that early life exposure to dogs, and cats to a lesser extent, can protect against asthma allergens," Lynch told LiveScience.

It's probably not a good idea to run out and get a pet for the sole purpose of protecting kids against asthma.  But if you do have a dog, it might be worth giving him an extra pet for his contribution to protecting your kids' health.

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