Helicobacter pylori and functional dyspepsia: a real causal link?

This chapter reviews the evidence for a link between functional dyspepsia and Helicobacter pylori infection from three angles. In the section on pathophysiology, we evaluate how H. pylori could theoretically produce dyspeptic symptoms: many mechanisms can be proposed. In the discussion on epidemiology, we evaluate possible associations between the occurrence of symptoms and infection. Here, many studies claiming a coincidence or chronological sequence of infection and symptoms are criticized because of their poor design. In the section on the improvement of functional dyspepsia by the treatment of H. pylori infection, the conclusion is reached that if such an effect occurs at all--which is unlikely--it is very weak. The controversy on the link between H. pylori infection and functional dyspepsia is presently ongoing. Some authors are still trying to save an elegant concept that once looked so plausible but now has the facts against it.