Early-life gut microbiome composition and milk allergy resolution.

BACKGROUND: Gut microbiota may play a role in the natural history of cow's milk allergy.

OBJECTIVE: We sought to examine the association between early-life gut microbiota and the resolution of cow's milk allergy.

METHODS: We studied 226 children with milk allergy who were enrolled at infancy in the Consortium of Food Allergy observational study of food allergy. Fecal samples were collected at age 3 to 16 months, and the children were followed longitudinally with clinical evaluation, milk-specific IgE levels, and milk skin prick test performed at enrollment, 6 months, 12 months, and yearly thereafter up until age 8 years. Gut microbiome was profiled by 16s rRNA sequencing and microbiome analyses performed using Quantitative Insights into Microbial Ecology (QIIME), Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt), and Statistical Analysis of Metagenomic Profiles (STAMP).

RESULTS: Milk allergy resolved by age 8 years in 128 (56.6%) of the 226 children. Gut microbiome composition at age 3 to 6 months was associated with milk allergy resolution by age 8 years (PERMANOVA P = .047), with enrichment of Clostridia and Firmicutes in the infant gut microbiome of subjects whose milk allergy resolved. Metagenome functional prediction supported decreased fatty acid metabolism in the gut microbiome of subjects whose milk allergy resolved (η2  = 0.43; ANOVA P = .034).

CONCLUSIONS: Early infancy is a window during which gut microbiota may shape food allergy outcomes in childhood. Bacterial taxa within Clostridia and Firmicutes could be studied as probiotic candidates for milk allergy therapy.