For instance, Lee et al. (2021) discovered that children with IgE-mediated FA exhibited higher species richness (Chao1 index) in their gut microbiota in comparison to the healthy children, and Fazlollahi et al. (2018) observed increased bacterial diversity (Chao 1 and Shannon indices) in the fecal samples of children affected with egg allergies. The gene discussed is IGHE; the disease is egg allergy.