How do you prevent asthma and allergies in children is a common question asked among pediatric allergy and asthma specialists. In a recent study published by The New England Journal of Medicine, scientists may have found a sort of magic ingredient to prevent asthma in children: microbes from farm animals, carried into the home in dust. The researchers were so convinced by their study, that they raised the possibility of developing a spray to do the same thing for children who do not have regular contact with cows and horses.
In previous blog posts, we have discussed extensively the Hygiene Hypothesis and Increasing Allergies and Can Early Exposure to Allergens and Microbes Protects Against Wheezing? This most recent study, seems to confirm the idea that has been circulating for years: that a growing number of children were developing asthma because their daily environments were simply too clean. It is a major problem because as many as 10% of grade school children have asthma and there is no cure for this chronic disease.
If children are exposed to microbes that stimulate their immune systems in the first few years of life, it may be able to prevent asthma, the hygiene hypothesis says. The most consistent findings were from studies that compared children who grew up on farms had less asthma than children who grew up in other environments.
The researchers looked at two very similar farming communities, the Amish and Hutterite children. Children from an Amish community had a very low prevalence of asthma and allergies, the Hutterite children are as allergic as your average American. In the Amish farm, the cowsheds are located right next to their homes, bringing in more microbes (6 times higher than that found in Hutterite houses). The children and Amish women, including pregnant ones, presumably have more frequent contact with more microbes.
None of the Amish children had asthma and they had a larger proportion of neutrophils, white blood cells that are the immune system’s paramedic and part of the innate immune system. By contrast, 20% of the Hutterite children had asthma and their blood was swarming with eosinophils, which provoke allergic reactions. There are drugs now that target the eosinophils in people with asthma. New Asthma Drug Nucala (Mepolizumab) for Severe Eosinophilic Asthma
The researchers analyzed dust from both homes and they found the Amish dust was loaded with debris from bacteria, the Hutterite dust was not. The authors are not suggesting that people start packaging Amish dust and selling it in pharmacies to protect children from asthma, but this is an important step in recognizing the rise in asthma in children and how to prevent asthma going forward in children.
The old adage “let them eat dirt” may ring true to help prevent asthma and allergies in children. This is a very small study and more will have to be done in the future. But the study also shows that genes aren’t destiny and disease emerges from the dance between genes and environment. Microbes may help stimulate the immune system and help to prevent asthma. So think twice before you use hand sanitizers and disinfectant wipes when your children are at the park.