Plant polyphenols bioavailability and modulation of the gut microbiota consortium: a paradigm shift in understanding their effects on diseases

A growing body of evidences suggests that the regular consumption of fruit and vegetables (FAV) reduces the risk of chronic human illnesses. They are rich sources of polyphenols, which have been shown, through epidemiological cohort studies or through mechanistic in vitro or animal studies, to prevent coronary heart diseases, chronic inflammatory diseases, obesity, diabetes, neurodegenerative diseases, cancer, and many others. Once believed to act as antioxidants in the body, polyphenols are now suspected to trigger detoxification mechanisms and induce genes associated with energy metabolism, chronic anti-inflammatory state and endogenous-antioxidant network at the cellular level. Yet, how they exert this action is still open to much debate. Indeed, polyphenols display poor bioavailability and short residence time in the body. They are recognized as xenobiotics and are rapidly metabolized and excreted in the urine and feces. Interestingly, during their passage in the gut, they may interact with the enterocyte/microbiota consortium and reduce the chronic inflammation known to be associated with disease state. This presentation will thus present new concepts to explain the mode of action of FAV polyphenols. It will specifically dwell on bioavailability of these molecules and their pre-biotic action in the gut.