IL4 and asthma: Emerging studies have shown that the intestinal microbiota composition of children with asthma is significantly different from that of healthy children (7), with the diversity of intestinal microbiota decreased, the number of bifidobacterium decreased, Th1 cytokines (IFN-g and TNF-a) down-regulated, and Th2-type cytokines (IL-4, IL-5) and Th17-type cytokine (IL-17A)s up-regulated (8).