CD79A and inflammatory bowel disease: High IgA-targeting of E. coli has been observed in inflammatory bowel disease patients and in children with severe acute undernutrition, and correlates with the presence of E. coli virulence factors; moreover, IgA-targeted E. coli strains have been shown to induce inflammation and intestinal damage when transplanted into gnotobiotic mice.2,9,10 Thus, the high IgA-targeting of E. coli observed here suggests expansion of pro-inflammatory pathobionts in the rCDI patients, which may not be fully cleared by FMT.