Swedish researchers at Umeå University have identified early markers of stomach cancer by studying how ulcer bacteria can survive in the acidic environment of the stomach

Gastritis is inflammation of the lining of the stomach. Common causes include infection with Helicobacter pylori and this bacteria is also linked to the development of duodenal ulcers and stomach cancer.

The scientists at Umeå University have managed to reveal how the stomach ulcer bacteria ‘Helicobacter pylor’ avoids the corrosive stomach acid in the stomach.

The stomach wall is pH neutral and safe for the bacteria. Therefore, the bacteria have evolved a protein that looks like a gripper that enables it to stick to safe cells on the stomach wall, lining.

But even so, the bacteria can only survive for a few ours in the harsh environment of the stomach. Since small cell pieces continually fall off the cell wall and are exposed to the acidic environment.

The ulcer bacterium – still attached to these cell pieces – then release their grip when the environment becomes too hostile and then swim to and attaches to new fresh cells exposed on the stomach wall.

In the acidic stomach environment, Helicobacter pylori benefits from the protection of the pH-neutral gastric mucus layer. The bacterium’s adhesion protein has a pH-sensitive mechanism allowing the bacterium to timely escape when shedding cells and mucus enter the acidic gastric juice, and allowing the bacterium to return to stomach lining and recycle the infection. Credit: Örjan Furberg, Nopolo.se | Umeå University

They are thus able to infect the stomach wall again, which becomes chronic gastritis, the lining becomes inflamed with possible symptoms that include nausea, vomiting and bloating. Complications may include bleeding, stomach ulcers, and stomach tumors.

The researchers have been able to show how this continued cycle work in favor of the bacteria survival and this knowledge could result in new ways to affect their survival and possibly help prevent stomach cancer.


Jeanna A. Bugaytsova et al “Cell Host & Microbe, article: Helicobacter pylori Adapts to chronic infection and gastric disease through pH-responsive BabA mediated adherence” March 9, 2017, Cell Host & Microbe. DOI: 10.1016 / j.chom.2017.02.013