Shengmin Sang, Pei Wang and Aaron Yerke (2017). Avenanthramides and their microbial metabolites as the urinary exposure markers for whole grain oat intake: a kinetic study in humans. The FASEB Journal 31(1).
Laboratory for Functional Foods and Human Health, North Carolina A&T State University, Kannapolis, NC
Oats are commonly consumed as whole grains (WGs) and known to provide healthy nutrients to humans. In epidemiological and clinical studies, there are no biomarkers have been identified to reflect WG oat intake. Oats contain a unique type of compounds, avenanthramides (AVAs), which are a group of substituted N-cinnamoylanthranilic acids. In this study, we investigated whether AVAs and their metabolites as the exposure markers for WG oat intake. Our results on the metabolism of AVAs identified the reduction of the double bond in the cinnamic acid unit and the cleavage of the amide bond as the major metabolic pathways of AVAs, and the double bond reduced metabolites (DH-AVAs) as the microbial-derived metabolites of AVAs. We also investigated the urinary kinetic curves of AVAs and their microbial-derived metabolites in humans after taking oat bran as their breakfast. Our kinetic data indicated that the DH-AVAs had longer half-life and the combination of AVAs and DH-AVAs can cover longer time periods for correctly and objectively monitoring WG oats intake. Furthermore, not all participants can produce DH-AVAs. There are DH-AVAs producers and non-producers, which may lead to future personalized nutrition based on the profile of an individual’s gut microbiota.