In vitro studies and animal studies show that yoghurts and fermented milks have a stimulating effect on the immune system. Studies on allergies in humans have shown a preventive and even curing effect of certain lactic acid bacteria. Nevertheless, the expected benefits such as increasing the efficacy of the immunisation processes, and improving local inflammatory responses, still need to be confirmed. No attempt at “curing” an allergy should be undertaken without a physician’s supervision.