CD79A and irritable bowel syndrome: Yang and colleagues showed that different strains of Bacteroides ovatus can drive either high or low mucosal IgA production in mice mono-colonized with different human fecal strains.81 Similarly, Palm and collaborators isolated two strains of B. fragilis from IBD patients that showed either high or low IgA coating, and used them to colonize germ-free mice with induced colitis.