BACKGROUND: Ghrelin is a body weight-regulating peptide produced and secreted 
primarily by the gastric mucosa. Helicobacter pylori infection impairs gastric 
ghrelin production, leading to a lower plasma ghrelin concentration. However, 
the effect of H. pylori eradication on plasma ghrelin levels and its relation to 
body weight change after H. pylori cure are still uncertain. We examined the 
association of plasma ghrelin levels with gastric ghrelin production and body 
weight change before and after H. pylori eradication.
METHODS: Plasma ghrelin concentrations, gastric ghrelin expression, and body 
weight were determined in a total of 134 consecutive individuals before and 12 
weeks after successful H. pylori eradication. Gastric ghrelin expression was 
evaluated by determining mRNA expression levels and the number of 
ghrelin-producing cells in gastric mucosa biopsy specimens by real-time reverse 
transcriptase-polymerase chain reaction and immunohistochemistry, respectively.
RESULTS: Plasma ghrelin concentration increased in 50 patients and decreased in 
84 patients after H. pylori eradication. After H. pylori cure, however, gastric 
preproghrelin mRNA expression was increased nearly fourfold (P < 0.0001), and 
the number of ghrelin-positive cells was increased or unchanged. In contrast, 
plasma ghrelin changes after H. pylori cure were inversely correlated with both 
body weight change (P < 0.0001) and initial plasma ghrelin levels (P < 0.0001).
CONCLUSIONS: Changes in plasma ghrelin concentrations before and after H. pylori 
cure were inversely correlated with body weight change and initial plasma 
ghrelin levels but not with gastric ghrelin production in Japanese patients.