Profiling of Microbial-Derived Phenolic Metabolites in Human Feces after Moderate Red Wine Intake

A controlled and randomized trial study involving 41 healthy volunteers (33 intervention and 8 control subjects) was performed in order to establish changes in the microbial-derived phenolic metabolite profile of feces after moderate consumption of red wine (250 mL/day, 4 weeks). Out of the 35 phenolic metabolites identified, 10 compounds (mainly benzoic and 4-hydroxyvaleric acids) showed statistically significant increases (P < 0.05) after the wine intake. Also, the total phenolic metabolites content was significantly (P < 0.05) higher in the samples after the wine intake (625 +/- 380 mu g/g feces) in comparison to the samples before (358 +/- 270 mu g/g feces), and a tentative distribution of the volunteers into three groups could be established: <500, 500-1000, and >1000 mu g/g feces. These results suggest that a different gut microbial capacity to metabolize wine polyphenols exists among the human population, as observed for polyphenols from other sources.