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Cow Dung Makes the Difference
Bacteria from cowsheds train the
immune system of kids;
Feeding swines, clearing cowsheds, playing in hay – children love farms as they are like huge adventure playgrounds in their eyes. Life with a lot of animals is not only fun, it is also healthy. “Colleagues from Switzerland have observed that farm children suffer less frequently from hay fever and asthma than other children at the same age”, says Erika von Mutius, paediatrician at Ludwig-Maximilians-University of Munich, Germany.
The researchers assume bacteria in the dust of cowsheds, which possibly strengthen children’s immune system. In order to analyse the “cowshed-effect”, a study has been initiated three years ago and will be finished in 2010. “We addressed school children living in rural areas in Germany, Austria and Switzerland”, says the allergist. More than the half of about 40.000 questionnaires came back to the researchers. The data analysis showed that only six percent of the farm children suffered from asthma, whereas in the other children’s group it was twice as many. The difference in hay fever was even more. Only two percent of the farm kids were allergic to pollen, whereas other children were three times as much.
Bacteria found in the cowshed
The researchers also analysed the blood of the participating children to check the activity of the immune system. And they took dust samples from the children’s environment, for example from their mattresses. The researchers found two bacteria, which are not pathogene: Acinetobacter lwoffi from cowshed and Lactococcus lactis from lactic acid.
If children regularly come in contact with those germs, they will immunize since their immune system has to fight against the invaders. “As a result, the immune system becomes more tolerant and learns how to distinguish between harmless and disease-causing bacteria”, says von Mutius. In this case, pollen are not battled and a allergic reaction fails to appear. City children only seldom come in contact with those germs, their environment is too hygienic to hold the immune system at bay. Therefore, they often suffer from an overreaction of their immune system.
The “Shed-Effect“ has been shown in animal experiments
The protecting effect of cowshed bacteria has been shown in mice experiments. Why especially those bacteria of all protect against hay fever and asthma has not been found, yet, but the results confirm the widespread opinion that a little dirt would not be amiss. However, von Mutius warns against neglecting hygiene standards.
A tolerant immune system
proctects from hay fever;
© Andreas Zoellick/Pixelio.de
„Only special dirt is able to protect against allergies”, explains the paediatrician. Moreover, the contact to the bacteria has to be very early, between pregnancy and the age of three at best. Within this time, the child’s immune system develops and learns how to adapt to its environment. How long this naturally attained protection lasts is still not completely clear. “We believe that it endures till the early adult age”, says von Mutius.
However, the research is going on. The scientists want to find more farm germs with similar effects. Their research aims to the development of a vaccine which allows immunizing city children against hay fever and asthma in a natural way. “We are just at the beginning of our research, yet. We have to be sure that the germs do not have harmful adverse effects. I hope, we will be able to develop the vaccine before my retirement”, von Mutius says. Till then, about 15 years are left.