Get a Dog!

Several studies have shown that children exposed to dogs during early infancy have a much lower risk for developing allergies and asthma. Now, researchers and the University of California-San Francisco believe they know the reason and it’s in the gut. Mice were exposed to dust samples from homes with and without dogs. The immune systems of mice exposed to dust from homes with dogs had decreased reactivity to common allergens. The researchers examined the gut bacteria in these mice and observed that it had changed after exposure to the dust. In particular they noticed a greater presence of the bacteria Lactobacillus johnsonii. When this bacteria was introduced to a different group of mice, they exhibited nearly the same decrease in response to common allergens as the group exposed to dust samples from the homes with dogs. According to Dr. Susan Lynch, “Gut microbiome manipulation represents a promising new therapeutic strategy to protect individuals against both pulmonary infection and allergic airway disease.”
Proceedings of the National Academy of Sciences, December 2013