Statistical analysis of IgA1 anti‐glycan reactivity showed lower recognition of one disaccharide (4‐P‐GlcNac‐1,4‐Man‐Sp), one α‐Gal (Gal‐1,4‐Gal‐1,4‐Glc), and a higher affinity toward one sialylated oligosaccharide (Gal‐1,3‐(Neu5Ac‐2,6)‐GalNac, P < 0.1) by CD IgA1 relative to non‐IBD IgA1 (Fig 3C and Appendix Table S8). Here, IGHA1 is linked to inflammatory bowel disease.