Skin and gut microbiota composition and immune regulatory response differentiate IgE and non-IgE cow's milk allergy patients with atopic dermatitis.

Precise identification of food allergy and atopic dermatitis (AD) endotypes in infants is needed to target treatments effectively. Therefore, we investigated markers associated with changes in the microbiota and immune responses within the gut-skin axis of immunoglobulin E (IgE) and non-IgE-mediated cow's milk allergy (CMA) patients with AD. We report that the skin microbiota of patients with IgE CMA differs significantly from healthy controls (HCs) and from patients with non-IgE CMA, despite similar AD severity. Regarding the immune response to bacteria, we found a significant increase in soluble CD14 in patients with non-IgE CMA compared to patients with IgE CMA. Patients with a non-IgE CMA have more regulatory T cells in their blood that migrate into the intestine than patients with IgE CMA. These findings provide insights into the complex interplay between the damaged epithelial barrier, microbiome, and immune responses in CMA patients with AD.