CD79A and allergic disease: It also plays a profound role in shaping the infant gut microbiota (GM) and immune system.4,5 Exclusive formula feeding is associated with changes in the GM,6 intestinal environment, and incidences of various diseases, such as necrotizing enterocolitis (NEC),7 obesity, and allergies.8 The primary differences between formula and breast milk include the lack of human milk oligosaccharides (HMOs), microbes, such as Lactobacillus and Bifidobacterium, and antimicrobial components, such as IgG and IgA in formula.5,9