CD79A and digestive system infectious disorder: There is 55% more IgA in maternal breast milk (MBM) than donor breast milk, and a 49% higher concentration of IgA in infants supplemented with MBM when compared against infants given donor milk [17]. Rat pups given milk from IgA-deficient mothers are at increased risk of intestinal infections and a decrease in commensal bacteria [105,106].