Helicobacter pylori has been recognized as one of the most important factors that lead to chronic changes in the gastric mucosa. These changes have either direct or indirect impact on various intestinal hormones (gastrin, somatostatin, bombensin, cholecystokinin...) which regulate gastric secretion. Gastric secretion enhancement is mostly caused by higher concentration of serum gastrin. The mechanism in which the Helicobacter pylori infection influences the regulation of gastrin and other intestinal hormones is yet to be discovered. It is known that eradication of the Helicobacter pylori infection decreases serum gastrin concentration, thus decreasing gastric secretion and inflammatory changes of the gastric mucosa.