Micronutrients & recovery
Most dietary (poly)phenols are not absorbed intact in the small intestine but pass to the colon where gut microbiota catabolize them into absorbable metabolites, which then enter circulation and exert biological effects.
Eat a variety of plant-based foods rich in polyphenols (berries, tea, coffee, onions, citrus). You do not need to worry about the 'bioavailability' of the raw compound because your gut bacteria process them into active metabolites that enter your bloodstream. The specific benefits depend on your unique gut microbiome, so diversity in your diet helps ensure you have the right bacteria to process different polyphenols.
Although some parent (poly)phenols are absorbed intact in the small intestine, most pass to the colon where they are extensively catabolized and their microbial products absorbed into the circulation.
Why this rating
The paper is a comprehensive review citing numerous primary studies and systematic reviews, establishing a strong consensus on the mechanism.
Source
Bioavailability of Food Polyphenols: Current State of Knowledge
Gary Williamson · Annual Review of Food Science and Technology · 2025
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