Microbial Metabolites of Flavan-3-Ols and Their Biological Activity

Abstract

Flavan-3-ols are the main contributors to polyphenol intake. Many varying beneficial health effects in humans have been attributed to them, including the prevention of cardiovascular disease and cancer. Nevertheless, the mechanisms by which these flavonoids could exert beneficial functions are not entirely known. Several in vitro studies and in vivo animal models have tried to elucidate the role of the specific colonic metabolites on the health properties that are attributed to the parent compounds since a larger number of ingested flavan-3-ols reach the colon and undergo there microbial metabolism. Many new studies about this topic have been performed over the last few years and, to the best of our knowledge, no scientific literature review regarding the bioactivity of all identified microbial metabolites of flavan-3-ols has been recently published. Therefore, the aim of this review is to present the current status of knowledge on the potential health benefits of flavan-3-ol microbial metabolites in humans while using the latest evidence on their biological activity.

Interplay between Dietary Polyphenols and Oral and Gut Microbiota in the Development of Colorectal Cancer

“…Many polyphenols have little bioavailability and reach the colon almost unaltered. There, they encounter the gut microbes, resulting in a two-way interaction in which polyphenols modulate the gut microbiota composition, and the intestinal microbes catabolize the ingested polyphenols to release metabolites that are often more active and better absorbed than the native phenolic compounds Polyphenols present in fruits, vegetables, and cereals have emerged as one of the main families of natural compounds; most of them have been considered functional foods with potential biological activities in many pathologies, such as cardiovascular diseases, diabetes, obesity and inflammation-related diseases, neurodegenerative disorders, and cancer [26,56]. Several health activities have been associated to dietary polyphenols, including antioxidant properties [57], anti-proliferative action [58], anti-inflammatory effects [59], anti-hypertensive and antithrombotic activities [60].…”

Cocoa, Chocolate, and Human Health

“…The impact of all these metabolites for health has not yet been completely elucidated. Nevertheless, current data suggest possible evidence that these microbial metabolites might also be relevant for human health [7].…”

From Preclinical Stroke Models to Humans: Polyphenols in the Prevention and Treatment of Stroke

“…For example, flavan-3-ols, phenolic compounds characterized by a generally low bioavailability, are extensively metabolized by host and gut microbiota enzymes. Phenyl-γ-valerolactones and phenylvaleric acids, the main microbial metabolites of flavan-3-ols, might be responsible for the beneficial effects attributed to their parent compounds, including neuroprotection [ 43 ]. Daidzein, an isoflavone endowed with beneficial properties enriched in soy food, is metabolized by gut microbiota to equol, which possesses higher antioxidant activity and affinity for estrogen receptors than the parent compound.…”