A recent study conducted by the Johns Hopkins Children's Center and other institutions found that children exposed to dirt and bacteria during their first 12 months were less likely to develop allergic reactions, asthma and wheezing.
Results of the study showed that exposure to allergens and bacteria created a protective effect on the child's immune system.
The research team collected data from 467 inner-city newborns from Boston, New York, St. Louis and Baltimore. The researchers also visited the homes of the babies to measure their allergen levels and the type of allergens present in the surroundings. In addition, they also gathered and analyzed the bacterial content of the dust from 104 homes out of 467 homes included in the study.
"Our study shows that the timing of initial exposure may be critical," chief of the Division of Allergy and Immunology at the Johns Hopkins Children's Center and study author Robert Wood, M.D. said in a press release. He also explained that bacteria and allergens may play a role in training the immune system and protecting the child from the precursors of asthma, such as wheezing.
Previous studies showed that children who grew up in farms, where there were higher amounts of pet dander and dust, were less likely to develop asthma and suffer from allergies. Scientists believed that microorganisms present in the farm's soil boosted the children's immunity. However, another study proved that children living in the city were less prone to allergies and asthma if they were exposed to pollutants and mouse allergens at an early age.
This new study provided a link between the two studies, and further claimed that babies exposed to allergens on their first 12 months could benefit from the protective effect of the allergens against developing asthma and allergic reactions but not after 13 months of age.
This study was published in the June 6 issue of Journal of Allergy and Clinical Immunology.
