"Apparently the stomach pathogen H. pylori closely monitors the diets of those people whom it infects. Epidemiological evidence has long implied that there is a connection between H. pylori and the composition of the human diet. This is especially true for diets rich in salt," says Hanan Gancz, of the Uniformed Services University of the Health Sciences in Bethesda, Maryland, who presents the research on Tuesday at the 107th General Meeting of the American Society for Microbiology in Toronto.

"We noted that H. pylori growth rate shows a sharp decline at high salt concentrations. Moreover, bacterial cells exposed to increased salt exhibited striking morphological changes: cells became elongated and formed long chains," says Gancz. "We conclude that H. pylori exposed to high levels of salt in vitro exhibit a defect in cell division."

They also discovered transcription of two genes responsible for the virulence of the bacterium was increased during high-salt conditions.

"The altered expression patterns of some virulence genes may partially explain the increased disease risk that is associated with a high salt diet in H. pylori infected individuals," says Gancz.

H. pylori is a spiral-shaped bacterium that can live in the acidic environment of the stomach and duodenum which is the section of intestine below the stomach. It is the most common cause of ulcers of the stomach and duodenum, accounting for up to 90 percent of duodenal ulcers and up to 80 percent of gastric ulcers.