Comparing IgA1 and IgA2 effect on bacterial growth within each group also showed that, while non‐IBD IgA2 were more neutralizing than IgA1 in the non‐IBD group (Fig 5C), this discrepancy was abrogated in both CD (Fig 5D) and UC (Fig 5E) groups. Here, IGHA1 is linked to inflammatory bowel disease.