London (ddp). After excessive sports, probiotic bacteria can help the exhausted immune system back on its feet. Australian researchers have shown that in a study with eight ausgepowerten athletes in their blood, the amount of a natural virus killer was significantly reduced. Already after one month of treatment with lactic acid bacteria, normalized to the value again, discovered the scientists. Whether the strengthened body system but actually better copes with the respiratory infections common in athletes, scientists from the University of Newcastle to Robert Clancy can not say. Imagine their study in the journal «British Journal of sports medicine» before (vol. 40, p. 351). Who wants to stay healthy is to move physically, doctors recommend. Sport can stimulate not only the metabolism, prevent obesity and the cardio vascular system to keep fit, but boosts to according to a variety of earlier studies also the immune system. But who exaggerates it, reached the opposite: too much training for high impacted the body so strongly that he loses his power and becomes susceptible to infections. In particular chronic or recurrent respiratory infections were already frequently associated with intensive sports training together. Responsible for this immunodeficiency seems diminished production of immune protein called interferon gamma, could prove Clancy and his colleagues, when they compared the blood values of exhausted athletes to those of fitter athlete. A consequence of this lack: In five of the eight studied exhausted athletes succeeded the immune system no longer, the so called Epstein-Barr viruses, which carry 98% of all adults in the body to keep under control. These viruses of herpes family and other respiratory diseases, pathogens are usually similar to herpes viruses in a suspended state after an infection and become active again only when the body system is weakened. Their presence in the saliva is therefore a typical references to a weakened immune system. Lack of interferon made by a one-month treatment with lactic acid bacteria of type acidophilus fix lactobacillus, a further study showed. Such probiotic microbes settle in to the gut and displace pathogenic germs or those who disturb the balance of the intestinal flora. The therapy also led that is only if one of the athletes of Epstein-Barr virus in the saliva prove could. Now, the scientists want to check whether the approach made a positive impact in other types of exhaustion.