RT Journal Article SR Electronic T1 Mycobacterium avium subspecies paratuberculosis is a cause of Crohn's disease JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 755 OP 757 DO 10.1136/gut.49.6.755 VO 49 IS 6 A1 J Hermon-Taylor YR 2001 UL http://gut.bmj.com/content/49/6/755.abstract AB