Include polyphenol-rich foods regularly

Eat polyphenol-rich foods daily: berries, dark chocolate (70%+), green tea, coffee, red/purple grapes, and colorful vegetables.

Why It Works

90-95% of dietary polyphenols reach the colon intact, where gut bacteria metabolize them. This interaction promotes growth of Lactobacillus and Bifidobacterium while reducing pathogenic species. Cocoa polyphenols specifically increase beneficial bacteria, and tea catechins reduce C. difficile growth in laboratory studies.

Tips

• Coffee counts — it is one of the largest polyphenol sources in the Western diet
• Color is a rough proxy for polyphenol content — deeper colors generally mean more polyphenols
• Polyphenols have prebiotic-like effects even though they are not technically classified as prebiotics
• Frozen berries retain their polyphenol content and are more affordable than fresh