PT - JOURNAL ARTICLE AU - M J BLASER TI - Helicobacters are indigenous to the human stomach: duodenal ulceration is due to changes in gastric microecology in the modern era AID - 10.1136/gut.43.5.721 DP - 1998 Nov 01 TA - Gut PG - 721--727 VI - 43 IP - 5 4099 - http://gut.bmj.com/content/43/5/721.short 4100 - http://gut.bmj.com/content/43/5/721.full SO - Gut1998 Nov 01; 43