Colonization of intestines with bacteria and the development of a gut microbiota in infancy are closely related to the development of the immune system. In fact, altered development of gut microbiotas is suspected to be associated with the onset of autoimmune or allergic diseases. Atopic eczema/dermatitis reflects inflammation of the skin and is the result of a process called atopic march, which constitutes a strong risk factor for the development of other allergic disease. Some cohort studies have shown that infants with atopic dermatitis have a low level of bacterial diversity in early infancy, as well as a low abundance of good bacteria and high abundance of bad bacteria.