Close the fiber gap — aim for 25-38g per day

Increase your daily fiber intake to the recommended 25g (women) to 38g (men). Most Americans eat only about 15g/day. Add fiber gradually — 5g per week — to avoid bloating.

Why It Works

Dietary fiber is the primary fuel for beneficial gut bacteria. When bacteria ferment fiber, they produce short-chain fatty acids (butyrate, propionate, acetate) that nourish the gut lining, reduce inflammation, and regulate immune function. Low fiber starves these bacteria, reducing diversity and SCFA production.

Tips

• Legumes (lentils, chickpeas, black beans) are the single highest-impact addition at 12-15g per cup
• Increase slowly — jumping from 15g to 38g overnight causes significant gas and discomfort
• Whole food fiber is superior to supplements because it provides fiber diversity, polyphenols, and food matrix effects
• Drink adequate water as you increase fiber to prevent constipation