To come up with their latest findings, the scientists compared exposure to allergens from cat, cockroach, dog, dust mite and mouse on one hand, and wheezing episodes as reported by parents and allergy as assessed by skin-prick tests on the other.
Through the first three years of life, cumulative exposure to allergy-provoking substances from cats, mice, cockroaches and dust mites but not from dogs -- was associated with more wheezing and allergic reaction in the new study. This was an expected result, based on earlier research. But this association was reversed when the researchers analyzed exposures for just the first year of life, when greater exposure to certain allergens, those from cockroaches and mice, was associated with less risk of wheezing and allergy at three years.
These results indicate that immune responses might be shaped by exposures during the first year of life differently than they are by later exposures. "These findings suggest that concomitant exposure to high levels of certain allergens and bacteria in early life may be beneficial," the researchers wrote in the journal paper.
If the study results are borne out in follow-up research in other populations, it might warrant testing of new strategies, Lynch said, including, "microbial supplementation to inoculate children in early life with appropriate microbes to help protect them against wheezing and allergy."
Lynch's own work and research by several others in the field has led her to become convinced that "the composition and function of the gut microbiome strongly influence immune reactions and present a novel avenue for development of therapeutics for both allergic asthma and a range of other diseases."
According to Boushey, "Strict avoidance of allergens to lower asthma risk has been unsuccessful. Maybe permitting allergen exposures, with increased exposure to the
|Contact: Jeffrey Norris|
University of California - San Francisco