Published Online: May 10, 2016
Cow’s milk allergy is the most common food allergy in young children, affecting 2-3%. A child may have to live with the limitations imposed by milk allergy for several years, as recent studies have shown that milk allergy often continues into later childhood and adulthood. Parents of milk allergic children often ask allergists to gauge whether their child’s milk allergy will resolve. The etiology and course of food allergy may involve deviation from immune tolerance that is driven by diet, commensal microbiota, and interactions between them. Previous work in this area has relied upon culture methods, which allow for examination of species specifically targeted and cultured, but exclude the large majority of bacterial organisms that cannot be cultured. These excluded organisms may play key roles in the natural history of milk allergy.
In a recent article published in The Journal of Allergy and Clinical Immunology (JACI) Bunyavanich and colleagues addressed the hypothesis that gut microbiota play a role in the natural history of milk allergy. Bunyavanich and colleagues used high-throughput sequencing to comprehensively characterize the infant gut microbiota of 226 children age 3-16 months with cow’s milk allergy. Their use of high-throughput sequencing allowed them to systematically profile bacterial taxa in the infant gut environment, including the vast majority that cannot be cultured. The research team followed these children up to age 8 years, finding that 56.6% of them outgrew their milk allergy. They used computational biology approaches to examine for links between early-life gut microbiota diversity, composition, and milk allergy resolution.
Dr. Bunyavanich and her colleagues found enrichment of specific bacterial taxa-- Clostridia and Firmicutes-- in the infant gut microbiome of 3-6 month old subjects whose milk allergy resolved by age 8 years. The microbiota of these young infants whose milk allergy resolved were associated with decreased fatty acid metabolism. The team’s results are the first to address the relationship between gut microbiota and food allergy resolution. Their findings suggest directions for prospective examination of the identified microbiota for potential therapeutic consideration. Early infancy may be an important window during which gut microbiota shape food allergy outcomes.
The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.