The Hair of the Dog
The Hair of the Dog
There’s an old saying that “the hair of the dog that bit you” is a cure for hangover. Well, I don’t recommend it—drinking too much, that is. Or drinking to cure a hangover, for that matter. But actual dog hair, and dander, may be just what the doctor ordered to allergy-proof your children.
New research published in the Proceedings of the National Academy of Sciences suggests that when children are exposed to dogs at an early age, they become significantly less likely to develop allergies, or asthma, at a later age. The research was conducted on mice, so it’s too soon to say for sure that having a dog in the household can protect a child from birth. But the researchers believe the effect should be the same in humans as it is in rodents.
For some reason, when exposed to “dog dust” the immune systems of test mice tended to have fewer of the types of immune cells that are believed to play a key role in allergic asthma. What’s more, exposure to dogs, and their dander (dried skin cells), was also linked to the presence of a particular type of gut bacteria. This bacterium, Lactobacillus johnsonii, is believed to play a role in keeping the immune system from overreacting.
Allergies occur when the immune system stages an outsized response to the presence of simple, non-harmful airborne allergens; proteins such as dust mites or pollen, for example. In essence, having a dog in the home appears to influence the makeup of the “gut microbiome” of people living in the home. “Gut microbiome” is a term that describes the makeup of the complex community of microscopic bacteria living in our guts.
Science is increasingly focusing on the gut microbiome, and its impact on everything from inflammation to nutrition. Eating a diet filled with prebiotics—the kinds of foods good bacteria thrive on—is linked to better health. Dietary fiber is one such food source, and it’s found in abundance in vegetables, fruits and whole grains. So even if you don’t want to raise a dog, you can still influence your health by eating a whole foods diet and keeping your gut happy.
Kei E. Fujimura, Tine Demoor, Marcus Rauch, Ali A. Faruqi, Sihyug Jang, Christine C. Johnson, Homer A. Boushey, Edward Zoratti, Dennis Ownby, Nicholas W. Lukacs,. House dust exposure mediates gut microbiome Lactobacillus enrichment and airway immune defense against allergens and virus infection. PNAS, December 16, 2013 DOI: 10.1073/pnas.1310750111