Colonic metabolites of berry polyphenols: the missing link to biological activity?

Abstract

The absorption of dietary phenols, polyphenols and tannins (PPT) is an essential step for biological activity and effects on health. Although a proportion of these dietary bioactive compounds are absorbed intact, depending on their chemical structure and the nature of any attached moiety (e.g. sugar, organic acid), substantial amounts of lower molecular weight catabolites are absorbed after biotransformation by the colon microflora. The main products in the colon are (a) benzoic acids (C6–C1), especially benzoic acid and protocatechuic acid; (b) phenylacetic acids (C6–C2), especially phenylacetic acid per se; (c) phenylpropionic acids (C6–C3), where the latter are almost entirely in the dihydro form, notably dihydrocaffeic acid, dihydroferulic acid, phenylpropionic acid and 3-(3′-hydroxyphenyl)-propionic acid. As a result of this biotransformation, some of these compounds can each reach mm concentrations in faecal water. Many of these catabolites are efficiently absorbed in the colon, appear in the blood and are ultimately excreted in the urine. In the case of certain polyphenols, such as anthocyanins, these catabolites are major products in vivo; protocatechuic acid is reported to represent a substantial amount of the ingested dose of cyanidin-3-O-glucoside. The major catabolites of berries, and especially blackcurrants, are predicted based on compositional data for polyphenols from berries and other sources. Since microbial catabolites may be present at many sites of the body in higher concentration than the parent compound, it is proposed that at least a part of the biological activities ascribed to berry polyphenols and other PPT are due to their colonic catabolites.

Assessment of white grape pomace from winemaking as source of bioactive compounds, and its antiproliferative activity

“…The assayed concentrations of polyphenols (10-100 lg/ml) in the culture medium could be associated with those present in some food sources, such as white wine, cocoa, black currant, or tea (Lamuela-Raventós, Romero-Pé rez, André s-Lacueva, & Tornero, 2005; Recamales, Sayago, González-Miret, & Hernanz, 2006;Wang, Lu, Miao, Xie, & Yang, 2008;Williamson & Clifford, 2010). These amounts of polyphenols have shown antiproliferative effects in the cells; however, human health effects of these compounds depend on their bioavailability.…”

Impact of dose on the bioavailability of coffee chlorogenic acids in humans

“…26 This is in contrast with the dihydrocaffeic acid and dihydroferulic acid metabolites, which are detected in a wide range of values between individual volunteers, and are also produced from a range of dietary (poly)phenolic compounds. 27,28 The combined presence of these quinic acid ester metabolites in plasma and urine are convenient biomarkers of coffee consumption even after relatively low doses of intake. caffeic, dihydrocaffeic, dihydroferulic and dihydro(iso)ferulic acids, 3-and 4-Osulphated ferulic, caffeic, dihydrocaffeic and dihydroferulic acids were !…”

Gut Microbiota Metabolism of Anthocyanin Promotes Reverse Cholesterol Transport in Mice Via Repressing miRNA-10b

“…In vivo intervention in human subjects and most animal test systems have shown that only approximately 0.1% of the intact anthocyanins are typically absorbed, and the maximum plasma concentration (Cmax) of anthocyanins is usually less than 0.1 μmol/L. [8][9][10] Recent studies have suggested that after the ingestion, anthocyanins are rapidly biotransformed into various metabolites, 11,12 raising the possibility that those metabolites, either working on their own or in combination with the parent anthocyanins, in protecting the subjects from developing atherosclerosis. metabolism of Cy-3-G or produced by the spontaneous degradation of Cy-3-G under physiological conditions at neutral pH.…”