Gene mutation protects against stomach bacteria

Helicobacter pylori as the cause of gastritis and cancer

06/25/2013

Gastric pain, flatulence, nausea and vomiting - almost everyone suffers from it, does not always have to be related to bad eating or stress. Instead, an infection with the bacterium Helicobacter pylori may be behind it - one of the most common germs in the world that can colonize the human stomach. The Helicobacter pylori is not dangerous, because he is considered one „The main cause of gastritis, the gastroduodenal ulcer disease and can also cause cancer“, like a team of German and Dutch researchers in the „Journal of the American Medical Association“ (JAMA) writes.

One of the most common germs in the world
Helicobacter pylori infection is one of the most common chronic bacterial infections with a prevalence or disease rate of around 50% worldwide, whereby the infection rate in developing countries is much higher than in the industrial nations. But why does one get sick while other people's stomach is never colonized with Helicobacter pylori even though they live in high-transmission countries? Two working groups from Greifswald (Germany) and Rotterdam (Netherlands) have now addressed this question and are through „two independent genome-wide association studies and a subsequent meta-analysis“ came to interesting results with a total of 10,938 cases.

Genetic modification in the TLR1 gene reduces risk of infection
Thus, the researchers identified the gene, which is crucial for whether Helicobacter pylori can bind to the stomach in the stomach and so an individual is infected. In subjects who were not infected, therefore „more often a genetic change in the TLR1 gene (toll like receptor 1)“ passed, „that plays an essential role in innate immunity“, such a message from the University of Greifswald. The reason: „An amino acid exchange in the extracellular domain of TLR1 results in a lower binding capacity for triacetylated lipopeptides, a component of the bacterial membrane of Helicobacter pylori“, so the university continues. This amino acid exchange in the TLR1 gene would reduce the risk of Helicobacter pylori infection by 41 percent.

Work of the researchers „milestone“ in the study of Helicobacter pylori
As part of a subsequent expression analysis from the whole blood of the participating subjects, the research team also „a direct dependence of TRL1 expression for the quantitative detection of Helicobacter pylori in the stool of the subjects“ be able to show. However, further research would have to prove whether TLR1 is indeed the direct binding partner for Helicobacter pylori in the stomach or whether other factors could influence, writes the university. Nevertheless, the work of the two research groups according to their own statements „a milestone in the research of Helicobacter pylori dar“, because it could partly explain why the discoverer of Helicobacter pylori - Professor Berry Marshall - after a self-experiment to prove the clinical importance of the bacterium had never even developed antibodies against the bacterium, on the other hand, the findings „also be of great importance for the development of future vaccination strategies against Helicobacter pylori“, so continue the message.

Bacterium discovered in 1982 by two Australian researchers
Helicobacter pylori is a spiraling bacterium discovered by Australian researchers Barry Marshall and John Robin Warren in 1982 - and was later honored in 2005 when they were awarded the Nobel Prize for Medicine for their discovery. They found that Helicobacter pylori can cause gastritis and may be responsible for ulcers in the stomach and duodenum, and it is now known that Helicobacter pylori is also responsible for the development of gastric cancer and according to the University of Greifswald „the only bacterium recognized by the World Health Organization that can safely cause cancer.“ The stomach germ can lead to very different symptoms such as loss of appetite, stomach pain, pressure, nausea and vomiting or a bad taste in the mouth. Because the symptoms are often diffuse, many infected people do not notice the germ, so that it remains undiscovered as the cause of the symptoms, in part for years. In developing countries, the infection rate in the population is sometimes up to 90 percent. (No)

Picture: Angela Bausch