Gastric bacteria protect against asthma

The gastric bacteria Helicobacter pylori significantly reduce the risk of developing the allergy-related asthma variant

02/07/2011

The gastric bacterium Helicobacter pylori appears to reduce the risk of allergic bronchial asthma. This has been proven by studies of a science team from the University of Mainz and the University of Zurich. Animals that showed the germ were more resistant to allergenic substances.

The stomach bacterium Helicobacter pylori is blamed for a number of serious stomach diseases. Patients who are infected with the bacteria almost never notice the infection. The infestation leads in many cases to an increased secretion of gastric acid. Many notice first symptoms in the form of heartburn, stomach pressure and upper abdominal pain. As a result, patients may, for example, contract gastritis, gastric ulcers or duodenal ulcers. In an animal experiment, scientists from the University of Zurich, in collaboration with doctors from the University Medical Center Johannes Gutenberg University Mainz, found that infection with H. pylori may also have a protective effect on the development of allergy-induced asthma.

"The gastric bacterium Helicobacter pylori protects against allergy-related asthma, and immunologists from the University of Zurich, together with allergy experts from the University Medical Center of the Johannes Gutenberg University Mainz, have shown this to the animal model."

In the experiment, mice were infected with the bacteria early after birth. In the experimental set-up, the researchers observed that the infected animals did not respond to mass-triggering asthma substances or were much weaker than non-infected rodents. The recent study by the two universities thus confirmed previous observational study, according to which mostly adolescents and young adults arithmetically have a lower risk of asthma if they themselves are Helicobacter pylori carriers. The study also provided important clues to the underlying mechanism. According to researchers, the stomach bacteria affect elementary cells of the immune system. „The early infection prevents the maturation of the dendritic cells in the lung and leads to an accumulation of regulatory T cells, which are crucial for the suppression of asthma“, Prof. Anne Müller, scientist for molecular cancer research at the University of Zurich, explained the triggered protective mechanism. Dendritic cells play a crucial role in the activation of immune cells, whereas regulatory T cells prevent excessive immune reactions, as they are the case with allergies.

For the study, the experimental animals were infected by ingesting the bacteria. The animals were very young at the moment of infection and just a few days old, the animals responded to very strong allergenic triggers hardly or only very diminished. The animals were already fully grown, the bacterial infection could trigger only a relatively low allergy protection. However, the activated protection could only be maintained as long as the animals carried the germs. After antibiotic therapy, the protective mechanism was lost again. Here, according to the researchers, there is a special context. More and more people around the world are suffering from the allergenic asthma form, especially in the western industrial nations. The rapidly increasing use of antibiotics could have promoted the allergic asthma variant, so the opinion of the scientists.

Foundation for asthma research
The research could be the basis for further studies to make asthma mechanisms more explainable later „develop preventive and therapeutic strategies“ said the lung and allergy researcher Prof. Christian Taube of the University of Mainz in the science magazine„Journal of Clinical Investigation“.

About half of all people worldwide are likely to carry the stomach germ Helicobacter pylori. Most people do not notice the infection because it is usually asymptomatic. In some cases, gastritis, gastric ulcer or gastritis may then occur. In rare cases, gastric cancer (gastric cancer) may develop. For this reason, conventional medicine has begun to treat the bacteria with antibiotic drugs. The World Health Organization (WHO) classified H. pylori in 1994 as Group I of defined carcinogens. Accordingly, Helicobacter pylori were also fought if the infection was asymptomatic and there was no serious disease. Probably, the massive increase in asthma new cases with the targeted eradication of the stomach bacterium Helicobacter pylori in direct connection. It became clear that the increased and excessive use of antibiotics could have negative health consequences. (Sb)

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