URINARY AND SERUM BIOMARKERS OF MILK AND CHEESE INTAKE ASSESSED BY METABOLOMICS APPROACH

Biomarkers of food intake are currently intensively investigated in the frame of the European Project `Food Biomarker Alliance` (FoodBAll) for a wide range of foods. In the future, validated biomarkers will serve as a tool for dietary assessment enabling the objective link between diet and disease outcomes in epidemiological studies. The randomized, controlled crossover study presented here aimed to identify urinary and serum biomarkers for the intake of two products of public health relevance, milk and cheese, in addition to a soy-based control. Eleven healthy volunteers (five women, six men) participated in the acute intervention study. Urine and serum samples were collected in the fasted state and up to 24 hours postprandially and were further analysed using a multiplatform approach combining untargeted gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). Using multivariate analysis, several urinary and serum biomarkers for milk, cheese as well as for soy drink after their acute intake have been identified. The majority of metabolites that specifically reflected the intake of milk were derived from lactose/galactose metabolism whereas an amino acid derivative was indicative of cheese intake. The kinetics of the biomarkers from the two dairy products was different when compared to biomarkers of the plant-based control (soy drink). Comparing urine and serum, the majority of identified biomarkers were discriminative in both biofluids but urine seemed to contain a higher number of biomarkers for the intake of these three food items. Overall, the outcomes of this study will serve as a basis for future validation studies under free-living conditions. Acknowledgements :  Swiss National Science Foundation