Dirty Dogs Could Be a Child’s Best Friend
Parents of children with allergies are familiar with the routine cleanings and keeping potential allergens away, including the family pet. It turns out that the family dog that carries dust from outdoors into the home may actually benefit babies. New research suggests that the dust that comes in with the dog can impart immune protection to infants. A study performed on mice showed that microbes in the dust enter the intestines of the babies and improve the microbial mix, leading to the action of the immune system to fight disease, instead of initiating an allergic reaction.
The findings of a study reported in Science News and in the science journal “Proceedings of the National Academy of Sciences” showed that homes with a dog contain more diverse microbes than those with no pets. Human infants ingest some degree of dust, so researchers fed different types of dust to mice to determine the differences in results. Those that had the dust with a diversity of microbes had significantly milder reactions when exposed to a common trigger: cockroach allergen.
The mice that got the no-dog dust had inflammation in the airways, along with an excess of mucus and immune proteins associated with allergic reactions. These reactions were, however, virtually nonexistent in the mice exposed to the dog-dust. Additionally, the dog-dust caused a change in the microbiome in the intestines. It caused the mice to develop colonies of Lactobacillus johnsonii, a protective bacterium that lives in the mammalian gut. This bacterium helps fend off respiratory syncytial virus (RSV) that is common in children under 1 year of age. These results suggest that not only does exposure to dog-dust help prevent symptoms of allergies and asthma, but it may help to fend off the occurrence of RSV.