Diversify your fiber sources across food types

What to Do

Eat fiber from multiple categories each day: legumes, whole grains, vegetables, fruits, nuts, and seeds. Each category contains different fiber types that feed different bacterial populations.

Why It Works

The fiber diversity hypothesis holds that different fibers (inulin, FOS, GOS, beta-glucan, pectin, resistant starch) selectively feed different beneficial species. A diet dominated by a single fiber source produces a less diverse microbiome than one with varied fiber types. This directly links to the "30 plants per week" finding from the American Gut Project.

Tips

• Legumes (lentils, chickpeas, black beans) are the single most fiber-dense food group at 12-15g per cup
• Oats provide beta-glucan; onions and garlic provide inulin; berries provide pectin
• Whole food fiber is superior to supplements because foods provide fiber diversity, polyphenols, and matrix effects simultaneously
• A simple rule: eat something from at least 3 different fiber categories at every meal