The study, which will continue until 2006, has received the Ortiz de Landazuri Scholarship for 2004. This is an annual award by the Department of Health of the Navarre Government in recognition of the best project in basic research. For a number of years now the team has been following a line of investigation on the nutritional modulation of neoplasic and allergic illnesses by means of probiotic and prebiotic foods. Prior to this, they carried out a study on kefir where it was shown that this enhances the digestion of nutrients and their absorption through the digestive tract. The study is aimed at assessing the physiological, morphological and immunological effects observed in healthy and transgenic experimental animals, produced by various probiotic and prebiotic substances contained in experimental diets. Amongst the prebiotics being used are quercetine and sphyngolipids. The first is a flavonoid found in most vegetables while sphyngomyelin is found in the cellular membranes of vegetables. With probiotics we find two types of bacteria, Lactobacillus casei and Bifidobacterium bifidum which are present in yoghourts and milk products that are partially fermented. One of the primary aims of the study is to find out if the probiotic and prebiotic foods have a beneficial effect on healthy persons using the latest techniques in molecular biology and cellular growths. The second phase consists of growing human cells from biopsies from patients who have undergone gastroscopy after prior informed permission being requested and granted and prior authorisation of the Committee of Bioethics. The final stage will use highly advanced techniques such as immunohistochemistry. Moreover, the researchers try to pinpoint the effects these foods have on the prevention of important illnesses such as neoplasic illness, allergies and nutritional intolerance and ailments that have an autoimmune component at a gastrointestinal level. One of these is cancer of the colon. It has been observed that the diarrhoeas suffered by cancer of the colon patients diminish on taking probiotics. What they want to study is if these products can also be used to actually prevent the disease. Finally, another aim of the study is to investigate the immunomodulation through the action of these factors as well as the new lines of biotherapies in order to stimulate the anaerobic flora and lymphatic tissue associated with the intestine and, in this way, stimulate the intestinal immune activity against pathogens.