Interactions of gut microbiota with dietary polyphenols and consequences to human healthTomás-Barberán, Francisco A.; Selma, María V.; Espín, Juan C.Current Opinion in Clinical Nutrition & Metabolic Care: November 2016 - Volume 19 - Issue 6 - p 471–476 doi: 10.1097/MCO.0000000000000314 MICRONUTRIENTS: Edited by Edited by Henry C. Lukaski and Véronique Coxam Abstract Author Information Purpose of review Dietary (poly)phenolic compounds have received attention over the last 20 years as antioxidants with preventive properties against chronic diseases. However, the evidence of these effects in clinical trials is weak, mainly because of a considerable interindividual variability. Polyphenols bioavailability is low, and gut microbiota metabolize them into simpler metabolites. As gut microbiota vary among individuals, such interindividual variability should be considered as a moderating factor in clinical trials. In this review, we show evidence of interactions with gut microbiota that help understanding polyphenols’ health effects. Recent findings Recent studies indicate that dietary polyphenols are relevant in the modulation of gut microbiota and that these microorganisms convert polyphenols into active and bioavailable metabolites; hence, variations in gut microbiota can affect polyphenol activity. Summary The results show that study participants’ stratification by their polyphenol-metabolizing phenotypes would be necessary for clinical trials as specific metabotypes produce the bioactive metabolites responsible for the health effects. Metabotypes can also reflect the gut microbiota composition and metabolic status, and could be biomarkers of the potential polyphenol health effects mediated through gut microbiota. Research group on Quality, Safety, and Bioactivity of Plant Foods, CEBAS-CSIC, Murcia, Spain Correspondence to Francisco A. Tomás-Barberán, Research group on Quality, Safety, and Bioactivity of Plant Foods, CEBAS-CSIC, P.O. Box 164, Murcia, 30100, Spain. Tel: +34 968396200; e-mail: firstname.lastname@example.org Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.