Beneficial Effects of Dietary Polyphenols on Gut Microbiota and Strategies to Improve Delivery Efficiency

Abstract

The human intestine contains an intricate ecological community of dwelling bacteria, referred as gut microbiota (GM), which plays a pivotal role in host homeostasis. Multiple factors could interfere with this delicate balance, including genetics, age, antibiotics, as well as environmental factors, particularly diet, thus causing a disruption of microbiota equilibrium (dysbiosis). Growing evidences support the involvement of GM dysbiosis in gastrointestinal (GI) and extra-intestinal cardiometabolic diseases, namely obesity and diabetes. This review firstly overviews the role of GM in health and disease, then critically reviews the evidences regarding the influence of dietary polyphenols in GM based on preclinical and clinical data, ending with strategies under development to improve efficiency of delivery. Although the precise mechanisms deserve further clarification, preclinical and clinical data suggest that dietary polyphenols present prebiotic properties and exert antimicrobial activities against pathogenic GM, having benefits in distinct disorders. Specifically, dietary polyphenols have been shown ability to modulate GM composition and function, interfering with bacterial quorum sensing, membrane permeability, as well as sensitizing bacteria to xenobiotics. In addition, can impact on gut metabolism and immunity and exert anti-inflammatory properties. In order to overcome the low bioavailability, several different approaches have been developed, aiming to improve solubility and transport of dietary polyphenols throughout the GI tract and deliver in the targeted intestinal regions. Although more research is still needed, particularly translational and clinical studies, the biotechnological progresses achieved during the last years open up good perspectives to, in a near future, be able to improve the use of dietary polyphenols modulating GM in a broad range of disorders characterized by a dysbiotic phenotype.

Nutrigenomic Effects of Long-Term Grape Pomace Supplementation in Dairy Cows

“…Grape polyphenolics, possessing different chemical structures and activities, are essentially categorized into two major classes of compounds: flavonoids (the most abundant polyphenols) and non-flavonoids [37,39,41]. Even though the biological activity of GP extracts mostly relate to their antioxidant properties, the dietary intake of these bioactive compounds results in pleiotropic health-promoting responses, e.g., cardio-and neuroprotective, anti-diabetic, anti-cancer, anti-aging, anti-adipogenetic as well as prebiotic and anti-microbial beneficial effects [39,[41][42][43]. Overall, these evidences would suggest a link between polyphenol-rich food consumption and reduction in the incidence of numerous chronic disorders effect [42].…”

Where to Look into the Puzzle of Polyphenols and Health? The Postbiotics and Gut Microbiota Associated with Human Metabotypes

“…In the last years, among postbiotics derived from food products, phenolic‐derived metabolites produced by the gut microbiota are gaining attention as crucial mediators to understand the link between polyphenols consumption and health benefits as well as to unravel the host‐gut microbiota interactions. [ 8,115–118 ] Remarkably, these phenolic‐derived postbiotics might mediate the health benefits of dietary polyphenols due to, at least partly, their higher bioavailability and may also modulate the gut microbiota ecology with subsequent impact on both intestinal and systemic chronic disorders. [ 8,115,116 ] In this regard, outstanding progress has been made in the identification of biological activities of novel postbiotics among a vast number of phenolic‐derived metabolites generated by the gut microbiota, highlighting those derived from isoflavones, ellagitannins, and lignans that present both specificity and individual variability in their production.…”

Mechanisms of Action of Prebiotics and Their Effects on Gastro-Intestinal Disorders in Adults

“…Dietary polyphenols have also been studied in relation to colon cancer prevention, even if the data are conflicting [155]. In animal models, it was demonstrated that resveratrol supplementation reduced bacterial enzyme activity, such as the activity of b-glucuronidase, b-glucosidase, b-galactosidase, mucinase and nitroreductase, and this decrease was linked with a major decline in colonic tumor occurrence [156].…”