New players in the relationship between diet and microbiota: the role of macromolecular antioxidant polyphenols

Purpose Solid evidence has emerged supporting the role of polyphenols and fibers as gut microbiota modulators. These studies have been limited to the data available in food composition databases, which did not include the food content of non-extractable polyphenols (NEPP). The main objective of this work is to quantify the intake of the different types of dietary polyphenols including NEPP and to evaluate their impact on the composition and activity of the intestinal microbiota. Methods Cross-sectional descriptive study conducted on a sample of 147 adults with no declared pathologies. Dietary intake has been registered by a semi-quantitative Food Frequency Questionnaire (FFQ) and transformed into extractable (EPP) and NEPP, and dietary fibers based on available databases. Major phylogenetic types of the intestinal microbiota were determined by qPCR and fecal SCFA quantification was performed by gas chromatography. Results NEPP account for two-thirds of the total polyphenols intake. A combined analysis by stepwise regression model including all dietary fiber and (poly)phenols has identified hydrolysable (poly)phenol (HPP) intake, as the best predictor ofBacteroides-Prevotella-Porphyromonasgroup andBifidobacteriumlevels in feces. Also, HPPs were positively associated with butyric acid, while insoluble fiber was identified as a predictor of propionic acid in feces. Conclusion The intake of macromolecular (poly)phenols could contribute to modulate the gut microbiota by increasing the levels of certain intestinal microorganisms with proven health benefits.

Automated summary

Solid evidence supports the role of polyphenols and fibers as gut microbiota modulators, with NEPP accounting for two-thirds of total polyphenol intake. Hydrolysable polyphenol intake was identified as the best predictor for certain intestinal microorganism levels, while insoluble fiber was associated with propionic acid levels in feces. The intake of macromolecular polyphenols may help to modulate the gut microbiota and increase levels of beneficial microorganisms.