150,151 It has been shown that the intestinal microbiota can degrade IgA, which plays a key role in mucosal immunology, and mice with documented degradation of secretory IgA are more susceptible to chemically-induced colitis.152 Host proteases such as trypsin are capable of degrading IgA, and microbial commensals such as Paraprevotella can prevent its degradation in the gut.9 Most studies have focused on understanding the interplay of bacterial exotoxins and the immune system to prevent disease. This evidence concerns the gene CD79A and colitis.