Die Rolle von Fettsäuren aus der Kuhmilch in der Entwicklung von allergischen Erkrankungen und Asthma bronchiale

Recent studies have demonstrated that farm milk from traditional farm settings possesses allergo-protective properties. Highly prevalent fatty acids in farm milk have been proposed to be one of responsible factors for allergy protection. Moreover, it has previously observed an association between the consumption of these fatty acids and benefit to human health. The aim of this work was the investigation of the allergo-protective properties of specific milk fatty acids and to identify and characterize potential single protective fatty acid groups in farm milk. To this end the differences in the fatty acid distribution between farm and shop milk, and serum samples from farmers and non-farmers of the PASTURE/Efraim study group were examined. A single protocol was therefore first established and then verified, which enabled the analysis of the fatty acid patterns in milk and also in different human blood compartments (serum and erythrocytes). The analyses of the fatty acid profile in farm milk and shop milk samples revealed that farm milk samples contained higher levels of conjugated linoleic acids (CLA) than shop-bought milk. The presence of CLA was significantly influenced by season of collection and the animal husbandry. A comparison of the fatty acid profiles in serum samples from farmers and non-farmers showed significantly increased CLA levels in farmers´ serum. In addition a strong correlation between the CLA content in milk and serum was found, indicating the bioavailability of the milk fatty acids in humans after milk consumption. Milk rich in CLAs was found to be inversely associated with symptoms of early asthma. No association with allergen specific IgE was found. The findings of the epidemiological data were then translated into a murine in vivo model of acute allergic airway inflammation to specifically investigate the effects of pasteurization on the allergo-protective properties of farm milk and its CLA content. An established mouse model of experimental asthma was modified to mimic the conditions of farm milk consumption in mice. Analysis of the asthmatic phenotype revealed no amelioration due to the consumption of pasteurized farm milk. The results indicate that pasteurization of the milk alters the protective components in milk and thereby removes the allegro-protective properties of the farm milk. These data provide first evidence that the CLA content of the farm milk is very important for the protection against the development of allergy and asthma. However, it seems that there is no explanation for a causal association between the milk CLAs itself and asthma symptoms in early childhood. However, CLA may be considered a good indicator (biomarker) for farm milk with allergo-protective properties.