It is a widespread disease with an average prevalence of 20% among children in Europe.28,29 The skin inflammation is dominated by Th2 cells in the acute response with a higher expression of IL-4 and IL-13 and enhancement of serum IgE production.30 An imbalance in the GM diversity and composition is evident in patients with AD already before any manifestations of the disease occur,31–33 strongly indicating that the early GM is crucial for disease development. Here, IL4 is linked to dermatitis.