Identification of microbial metabolites derived from in vitro fecal fermentation of different polyphenolic food sources.
OBJECTIVE
The biological effects of dietary polyphenols are linked to their bioavailability and catabolism in humans. The colon, with its symbiotic microbiota, is an active site where complex polyphenolic compounds are possibly modified to smaller and more absorbable molecules. The aim of this study was to identify the major metabolites derived from microbial colonic fermentation of some common polyphenol-rich foods.


METHODS
An in vitro fecal fermentation model was applied to 16 polyphenol-rich foods and polyphenolic precursors. Phenolic metabolites were identified by high-performance liquid chromatography coupled with tandem mass spectrometric detection.


RESULTS
Twenty-four phenolic fermentation metabolites were characterized. Some metabolites were common to several polyphenol-rich foods, whereas others were characteristic of specific sources.


CONCLUSIONS
The metabolites identified in vitro likely are generated in the human colon after consumption of polyphenol-rich foods. Their occurrence in plasma and/or urine should be considered when evaluating the bioavailability of polyphenols from specific food groups in humans and in the definition of markers of exposure to specific foods or food groups in epidemiologic studies. However, the search for these and other microbial metabolites after a feeding study in vivo should consider their possible further conjugation at the level of the liver.
The φ(2) Laboratory of Phytochemicals in Physiology, Human Nutrition Unit, Department of Public Health, University of Parma, Via Volturno, Parma, Italy.
Margherita
M
Dall'Asta
Luca
L
Calani
Marianna
M
Tedeschi
Lucia
L
Jechiu
Furio
F
Brighenti
Daniele
D
Del Rio
D001419:Bacteria / Q000378:metabolism*; D001682:Biological Availability; D003106:Colon / Q000382:microbiology*; D004032:Diet; D005243:Feces / Q000382:microbiology*; D005285:Fermentation; D006801:Humans; D059808:Polyphenols / Q000378:metabolism*
D059808:Polyphenols