TLR5 and irritable bowel syndrome: Finally, the overrepresentation of flagellated E. rectale strains in tCeD, combined with the reported enrichment of anti-flagellar antibodies in IBD patients,105 could imply a role for flagellins in disease etiology or manifestation, e.g. through activation of Toll-like receptor 5 and initiation of Th1 T cell responses.106