Protective Role of Helicobacter pylori Against Inflammatory Bowel Disease: A Hypothesis

INTRODUCTION During the past century, gastroenterologists have experienced major shifts in the occurrence of several common diseases affecting the digestive tract. The historic fall in the occurrence of gastric cancer and peptic ulcer disease during the twentieth century was accompanied by a simultaneous rise in the occurrence of inflammatory bowel disease and gastroesophageal reflux disease during the same time period (1,2). The fall of gastric cancer and peptic ulcer, as well as the rise of gastroesophageal reflux disease, are now mostly ascribed to the decline of H. pylori infection in the general population (3,4). Have the concomitant changes affecting inflammatory bowel disease been just a coincidence, or does yet another hidden association with H. pylori underlie these opposing times trends? The present article pursues the hypothesis that H. pylori infection may have protected its carriers against developing inflammatory bowel disease and that the increase of inflammatory bowel disease was in part caused by the loss of this protective influence.