Abstract
Polyphenols are widely studied phytochemicals with well-known antioxidant and anti-inflammatory properties. They are commonly present in fruits, vegetables, and plant-based foods. Beyond these classical roles, growing evidence shows that polyphenol-derived bioactive metabolites-produced or modified by the gut microbiota-can promote host health. These metabolites are increasingly recognized for shaping host-microbe interactions and influencing neurophysiological functions via the gut-brain axis. This review provides an overview of polyphenol transformation rates by the gut microbiome, highlighting their microbial transformation, anti-biofilm effects, and neuroprotective potential. In our opinion, a deeper understanding of the properties of these metabolites can significantly impact food science and biotechnology.