Researchers have discovered a new approach to preventing or treating a stomach bacterium associated with an increased risk of stomach cancer as well as gastritis and duodenal ulcers.
Writing in the journal 'Nature Microbiology', a team of researchers from the Technical University of Munich (TUM), the University of Duisburg-Essen at Essen University Medical Centre and the University of Bristol, detail how they discovered a completely new approach to infections related to the Helicobacter pylori bacterium.
Helicobacter pylori, otherwise known as H. pylori, is a spiral bacterium that lives in the lining of the stomach. Infections commonly occur during childhood, colonising the human stomach. Once someone has H. pylori, it stays in the stomach throughout life and can be fatal, unless it is treated with particular antibiotics.
However antibiotics not only destroy the bacterium itself but also the 'good germs' of the gut flora. At a time when H. pylori infection is developing increasing resistance, this new discovery could prove vital in treating diseases caused by this species.
"This is an interesting finding, any interaction identified between a bacterial pathogen and our bodies presents us with a new target by which we could one day prevent the disease it causes," said co-author Dr Darryl Hill from the University of Bristol's School of Cellular and Molecular Medicine.
The research team found that H. pylori attach to the epithelial cells in the gastric mucosa. They were able to detect a highly specific and exceptionally strong variant of this adhesion, in which the bacterial surface molecule, HopQ, binds to the Carcinoembryonic Antigen-related Cell Adhesion Molecules, or CEACAMs for short, inside the stomach.
In contrast to previously known binding partners of the bacterium, this bond is independent of sugar structures. The authors found that this ensures that it is stable in the acidic environment of the stomach. CEACAMs are not produced in healthy stomach tissue, but primarily when there is an inflammation of the gastric mucosa (gastritis) caused by the H. pylori infection.
Scientists are currently researching various approaches in order to replace current types of treatment for H. pylori infection, which have many side effects. The adhesion of the bacterium to stomach cells could be prevented with a soluble version of HopQ or parts of the protein, and the damaging effects of the germ could potentially be suppressed, according to this latest study.
As a further therapeutic option, the researchers are pursuing the approach of using specifically developed antibodies against CEACAMs in order to fight diseases associated with the bacterium. An additional treatment option being considered is immunisation against the HopQ protein and thus vaccination against infection with the bacterium.