Association of Mycobacterium avium paratuberculosis With Crohn's Disease: A Large Multicenter Study From a Tuberculosis-Endemic RegionSudheer KumarVuyyuruauthorUrvashiSinghauthorPrasenjitDasauthorShivBasantauthorVishwajeetSinghauthorSaroj KantSinhaauthorKusumSharmaauthorB SRamakrishnanauthorKannanPalaniyandiauthorRupeshPokharnaauthorBhartiMalhotraauthorShobnaBhatiaauthorGopal KrishnaDhaliauthorRajibSarkarauthorCharuSharmaauthorSiddharthaDattaguptaauthorManjulaSinghauthorRakeshKochharauthorSreenivasVishnubhatlaauthorVineetAhujaauthorBackgroundThe causal relationship between Crohn's disease (CD) and Mycobacterium avium subspecies paratuberculosis (MAP) remains controversial.MethodsThis multicenter observational study was conducted across seven tertiary care centers in India enrolled newly diagnosed, treatment-na\"\ive Crohn's disease (CD) patients as cases, and treatment-na\"\ive intestinal tuberculosis (ITB), ulcerative colitis (UC), and healthy individuals undergoing sigmoidoscopy for hemorrhoids as controls. Mycobacterium avium subspecies paratuberculosis (MAP) detection was performed using serology for MAP antibodies, PCR, RT-qPCR, and solid/liquid cultures on blood and colonic biopsies. In situ PCR and immunohistochemistry (IHC) were additionally applied to paraffin-embedded tissue sections to evaluate MAP presence across groups.FindingsA total of 889 participants were recruited (CD=148, ITB=288, UC=251 and non-IBD controls=202) were included. The seropositivity of MAP was significantly higher in patients with CD compared to controls (20.6% 13/63 vs healthy controls: 16.2\% 12/74; ITB: 7.8\% 9/116; UC: 4.8\% 4/84; pInterpretationFindings of our study suggest an increased association of MAP and CD. Future studies should explore possible causal role of MAP in CD and potential therapeutic options to target MAP.QR Microbiology2026-05-20Oxford University Press (OUP)Article