Metabolomics Based Biomarkers of Green Beans Intake

While there is considerable interest in legumes as a food source, there are no validated biomarkers for green beans (Phaseolus vulgaris, L.) intake. The objective of the current work is to identify and assess the dose-response of food intake biomarkers of green beans. In an acute intervention study, 27 participants consumed green beans in the study center and urine samples were collected pre- and post-consumption. Metabolites were measured by nuclear magnetic resonance (¹H-NMR) and liquid chromatography-mass spectrometry (LC-MS). Statistical analysis determined features that changed post-consumption of green beans. Selected metabolites were assessed for dose-response in a follow-up study (n = 16). Analysis revealed 745 ¹H-NMR spectral regions and 318 LC-MS features that increased in intensity over time following consumption of green beans. Three ¹H-NMR and 12 LC-MS metabolites displayed a dose-response relationship to increasing portion size of green beans (p <0.05), including amino acid conjugates (glycine conjugate, N-phenylacetylglutamine), hydroxyabscisic acid glucuronide and amino-hydroxybenzoic acid. Partial least squares discriminant analysis predicted low or high green bean intake with 91.6% accuracy. We identified 15 urinary food intake biomarkers of green beans. A biomarker panel classified individuals as low or high green bean consumers with good accuracy, progressing ongoing efforts to improve dietary assessment methods.