RT Journal Article SR Electronic T1 Protective effects of Helicobacter pylori for IBD are related to the cagA-positive strain JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 393 OP 394 DO 10.1136/gutjnl-2017-313805 VO 67 IS 2 A1 A R Lord A1 L A Simms A1 K Hanigan A1 R Sullivan A1 P Hobson A1 G L Radford-Smith YR 2018 UL http://gut.bmj.com/content/67/2/393.abstract AB