RT Journal Article SR Electronic T1 Does Helicobacter pylori protect against asthma and allergy? JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 561 OP 567 DO 10.1136/gut.2007.133462 VO 57 IS 5 A1 Blaser, Martin J A1 Chen, Yu A1 Reibman, Joan YR 2008 UL http://gut.bmj.com/content/57/5/561.abstract AB