Helicobacter pylori bad or good stomach bacterium?

Positive effects of infection with Helicobacter pylori noted
So far, the gastric bacterium Helicobacter pylori has been mainly associated with the development of diseases such as gastric mucosal inflammation, gastric ulcers or gastric cancer, which is why a colonization with the bacterium is generally considered by doctors to be negative. However, scientists from the University of Graz, the Medical University of Graz and the New York University School of Medicine have found in a recent study that Helicobacter pylori apparently also develops positive effects in the human organism.

"The bacterium Helicobacter pylori, which can colonize the stomach, has a bad reputation," according to the Communication of the Institute of Molecular Biosciences at the University of Graz. It is responsible for the development of gastritis, gastric ulcers and even cancer. However, the current studies of scientists from Graz and New York show that the bacterium by no means only has negative effects. The researchers published their surprising results in the renowned specialist journal "Cell Reports".

Helicobacter pylori infections also have beneficial effects in the human body. (Image: fotoliaxrender / fotolia.com)

Complex interaction of bacteria barely studied
The research team around Dr. Sabine Kienesberger from the Institute of Molecular Biosciences at the University of Graz investigated the effects of Helicobacter infection in the stomach, intestine and lungs over a period of six months. In the mouse model, the scientists observed the consequences of colonization with the bacterium. So far, little research has been done on which bacteria are "good" and which are "bad", the scientists explain their investigation. Basically, this is difficult to distinguish because there is little information about the complex interaction of the bacteria, whose total mass is about two kilograms of our body weight. This also applies to the stomach bacterium Helicobacter pylori.

Little is known about positive effects of Helicobacter pylori
Many negative effects of Helicobacter pylori infection are described in detail in the literature, but also possible positive effects were found. "We know, for example, that in societies where Helicobacter is more prevalent, children are less likely to develop asthma," says the lead author of the current study. Sabine Kienesberger. Therefore, the scientists have also considered possible positive effects of Helicobacter infection in their investigation.

Stimulation of the immune system
The research team discovered several interesting relationships that were previously unknown. So did Dr. Kienesberger and colleagues note that in an infection with Helicobacter an accumulation of certain T cells in the lungs occurs. "These cells play an important role in the immune system," says the lead author of the study. The scientists were also able to observe changes in the composition of the intestinal flora. "These in turn can lead to a stimulation of the immune system," according to the Communication of the Institute of Molecular Biosciences.

Shifts in hormone balance
Furthermore, according to the researchers, shifts in the hormone balance due to Helicobacter infection have been shown. For example, the concentration of the "hunger hormone" ghrelin has increased. This stimulates appetite for overproduction. "Ghrelin is known to also affect the immune system," Dr. Kienesberger continues. According to the scientists, the Helicobacter infection and the corresponding effects in the mouse model could be observed as a dynamic process over a longer period of time, which is a special feature of the current study. Surprising here were "the early and sometimes conflicting effects on the lungs, although it was only at later times an increasing immune reaction in the stomach was observed," emphasizes Dr. med. Kienesberger. The study will provide a sound basis for the targeted investigation of the complex interaction of helicobacter, microbiome and immune system. (Fp)