Country life protects children from asthma

Country life protects children from asthma: Bacteria and fungi protect farm children.

24/02/2011

Children who grow up in the countryside are better protected from asthma. An international research team led by Markus Ege from Dr. Ing. from Haunerschen Children's Hospital of Ludwig-Maximilians-University (LMU) in Munich has found that the country children are exposed to a larger number of microorganisms and therefore probably less likely to develop bronchial asthma than city children.

Children are more likely to come into contact with micro-organisms such as bacteria and fungi in rural areas than in the city. This is probably why rural children are less likely to suffer from autoimmune diseases and asthma, report the researchers around Markus Ege in the latest issue of the journal „The New England Journal of Medicine "Several studies have shown in the past that children who grow up in the countryside are at lower risk of allergy.

Two studies evaluated on pediatric asthma disorders
Together with scientists from the TU Munich, the University of Ulm and research institutions in France, Great Britain, Switzerland and the Netherlands, Ege and his team have evaluated two large-scale studies that also deal with the relationship between rural life and asthma. In the course of their study, the scientists analyzed the data of the PARSIFAL study with 6,963 participating children from southern Germany between the ages of 6 and 13 and took a blood sample and a dust sample of their mattress in a sub-sample of 489 children. In addition, the data of the GABRIELA study with 9,668 participating children from southern Germany, Austria and Switzerland at the age of 6 to 12 years were evaluated within the framework of the study. Again, a dust sample of her mattress was taken in 444 children and lung function was also measured.

Land children come into contact with more microorganisms
When investigating the genome of the bacteria and fungi found in house dust, the researchers around Markus Ege found that the concentration of microorganisms in house dust was much higher than in the city. At the same time, children living in rural areas had significantly fewer asthma-related illnesses, suggesting that the microorganisms have a protective effect against asthma, the researchers report. Several bacterial species have also been identified that may help reduce the risk of asthma, emphasized Markus Ege and colleagues. How this works, the experts could not yet clarify final. For example „It could be that a certain combination of microorganisms stimulates the innate immune system and thus counteracts the development of asthma.“ It would also be conceivable, „Although there are germs that cause asthma, but also benign germs that then overgrow these dangerous germs“, Explained the researchers. In addition, according to the experts, the diverse microorganisms in the lungs could contribute, similar to the intestinal tract, in keeping the germs in balance and not dominating the asthma-causing bacteria and fungi. Despite their assumptions, the scientists do not yet know exactly, „with which trick bacterial cells and fungal spores reduce the risk of asthma“, explained Markus Ege.

Vaccine against asthma possible?
To further investigate which microorganisms were responsible for reducing the risk of asthma, the researchers next want to analyze the effects of bacteria and fungi on asthma individually. „In the long term, this could help develop vaccines for asthma“, so the hope of Markus Ege. „Of particular interest are certain bacterial species of the genera Bacillus and Staphylococcus and fungi of the genus Eurotium“, explained the expert. Overall, their study confirms the assumption that children who come in contact with many microorganisms succumb to a lower risk of allergies and autoimmune diseases than adolescents who come into contact with only a few bacteria and fungi.

Hygienic hypothesis confirmed: pollution of air outside?
Their investigation has confirmed the so-called hygiene hypothesis that increases with decreasing microorganism contact, the risk of allergies and other autoimmune diseases, the researchers said. Thus, the experts indirectly also make the excessive hygiene, especially in children, responsible for the fact that asthma is one of the most common chronic diseases in children in Germany. According to the health authorities, up to ten percent of adolescents in this country are affected by asthma. However, the article by Markus Ege and colleagues does not make any statements as to whether the general pollution of air in the environment of the children has been taken into account. It seems reasonable to suppose that the generally better air conditions in relation to the lower risk of asthma can also play a role in rural areas. It remains to be seen how the follow-up examinations will be carried out at the LMU and whether a relationship between individual microorganisms and the risk of asthma is confirmed. (Fp)

Read about asthma:
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New hope for asthma therapy?
Alcohol can increase asthma and hay fever
Heartburn can cause asthma
Therapy options for bronchial asthma

Image: Hanspeter Bolliger