Isolation and Characterization of a Resveratrol-Metabolizing Human Gut Bacterium

Presenter: Margaret Lin

Faculty Sponsor: Hang Xiao

School: UMass Amherst

Research Area: Agriculture and Agronomy / Food Science

Session: Poster Session 6, 4:15 PM - 5:00 PM, 165, D16

ABSTRACT

Resveratrol (RSV), a natural dietary polyphenol found in plants, undergoes biotransformation by gut bacteria, producing metabolites that can contribute to its overall bioactive potential. However, to date, very few intestinal strains have been isolated from human feces that play a role in resveratrol metabolism, and these strains are mainly restricted to Coriobacteriia. The purpose of this study is to isolate a new bacterial strain capable of transforming resveratrol to deepen our understanding on the interaction between resveratrol and human gut bacteria. Human stool samples were screened and a bacterium displaying resveratrol-metabolizing capabilities was isolated, with all analytes quantified under liquid chromatography-mass spectrometry (LC-MS). Notably, only one sample could produce 3,4′-dihydroxy-trans-stilbene, while all samples and the isolated bacterium could only produce dihydroresveratrol via reduction. Through 16S rRNA and whole genome sequencing, the isolate was identified as Enterococcus lactis, henceforth known as E. lactis UMA_R1. The time-course formation of dihydroresveratrol revealed that E. lactis UMA_R1 began resveratrol conversion upon entering the stationary growth phase at 4 hours and was completed by 12 hours. Further analysis on the metabolic capabilities of E. lactis UMA_R1 on other polyphenolic compounds suggests that transformation of these compounds may undergo alternative metabolic pathways besides reduction. These findings highlight interindividual differences and advance our knowledge on the key players of resveratrol metabolism in the gut microbiome while more is to be explored about the exact mechanisms these gut bacteria undergo.

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