Scientific study Stable Dust protects us from allergies and asthma

Children who grow up on the farm are less likely to suffer from allergies and asthma
Children who live in the city are more likely to suffer from allergies and asthma than farm children. This has been known for a long time. In the search for the cause, however, scientists were in the dark for a long time. An international research team, which includes scientists from Munich, has now discovered an enzyme in the body that could play an important role. Thus, certain ingredients of stable dust activate the enzyme A20, which can suppress allergic reactions in the respiratory tract, as the researchers report in the journal "Science".

Healthy air in the stable: Endotoxins activate enzymes in the airways that protect against allergies
"It was always known that protecting against allergies had something to do with stabling, but you did not know why," says Erika von Mutius, director of the Asthma and Allergy Outpatient Unit at the Dr. Ing. from Haunerschen Children's Hospital in Munich, in conversation with the news agency "dpa". "A20 is a newly discovered enzyme that apparently has a suppressive function."

In experiments with mice that took daily certain components of stable dust, it was found that the animals were less responsive to allergenic substances and less often suffered from asthma than their conspecifics who were not exposed to the influence of stable dust. The protective effect is due to the enzyme A20, which influences inflammatory reactions in the body, so by Mutius. "The enzyme itself has to be activated - and this does in some unknown way the stable dust." In people who suffered from asthma, A20 occurs to a lesser extent in the mucosa. "The enzyme is produced by a gene and if this gene is not quite right then there is a risk of asthma," explains the doctor.

Pulmonologist Bart Lambrecht and immunologist Hamida Hammad from the University of Ghent in Belgium had given small doses of endotoxins - a component of bacteria that activate the enzyme A20 - to their mice over a period of 14 days. The trial also included untreated animals that served as a control group. Subsequently, the mice of both groups were exposed to dust mites, which can also be allergic to humans. As it turned out, the animals that were previously treated with endotoxins showed no signs of allergy. In the control group, however, the mice suffered from allergic reactions.

Accordingly, endotoxins lead to activation of the enzyme A20 in the airways, which in turn suppresses allergic reactions. So far, researchers have mostly assumed that processes in the immune system play the crucial role. But: "It does not happen in the immune system. Rather, they are structural cells of the respiratory tract, "Lambrecht is quoted in the journal. "We need this environmental impact to calm the cell tissue so it can see what's dangerous and what's not." (Ag)