Metabolomics applied to nutritional epidemiology to identify biomarkers of food intake in the framework of the Metabo-Breast cancer project, SU.VI.MAX cohort
Résumé
The work presented is part of the Metabo-Breast cancer project (2015-2017, INCa, P.I. M. Touvier), which aims at: discovering predictive biomarkers of breast cancer and biomarkers of the quality of the usual diet and of specific foods using metabolomics, then relating these biomarkers to enhance our understanding of the role of nutrition on breast cancer. Here we focus on the objective of discovering biomarkers of food intake by the exploration of the food metabolome in serum samples from the SU.VI.MAX cohort.
SU.VI.MAX female subjects who filled at least ten 24h dietary records were stratified in deciles according to their level of adherence to the guidelines of the French Programme National Nutrition Santé. A total of 80 women was randomly selected in the 10th decile of the PNNS-GS distribution and 80 women matched for age, BMI and others factors were selected in the 1st decile.
Plasma samples collected at baseline in the SU.VI.MAX study were analyzed using UPLC-ESI-QToF. Metabolic profiles were acquired in positive and negative modes (scan range 50-1,000m/z). Data were pre-processed using Galaxy (Workflow4Metabolomics). 1575 and 601 ions were detected (positive and negative mode). Metabolomics profiles were compared using univariate and multivariate statistical methods to select the ions associated with the consumption of 58 foods/food groups.
84 and 30 ions (positive and negative mode) were found correlated with specific foods/food groups (r>0.3, p-value with BH<0.1). A few of them were known as biomarkers like proline-betaine for orange intake discovered in previous metabolomics studies. This demonstrates the relevance of our strategy. The identification of the other candidate biomarkers is ongoing (online database, literature and LC-MS/MS on LTQ-OrbiTrap).
This work will contribute to provide new biomarkers of food intake that are needed to improve the quality of dietary assessment in epidemiological studies.