TNF and irritable bowel syndrome: More interestingly, an increase in an unknown genus from the Peptostreptococcaceae was reported to be a sign of anti-TNF response in children with IBD.17 The role of Alistipes, belonging to the order Bacteroidales, remains unclear.48 However, its connection with worse gut health seems probable based on recent studies,49,50 and thus its decrease after therapy may be meaningful.