How much fiber do you need for gut health?

Fiber is the most underrated nutrient for gut health — and most people don't get nearly enough.

How much you need

The Dietary Guidelines for Americans recommend about 14 grams of fiber per 1,000 calories. That translates roughly to:

• Women: about 22–28 g a day, depending on age.
• Men: about 28–34 g a day, depending on age.

Yet surveys suggest most American adults eat only around 15 grams a day.

What the research shows

A 2019 review in The Lancet, commissioned by the World Health Organization, pooled data from 185 prospective studies and 58 clinical trials. People eating 25–29 grams of fiber daily had a 15–30% lower risk of all-cause mortality, coronary heart disease, stroke, type 2 diabetes and colorectal cancer compared with those eating the least. The data suggested that higher intakes could bring even greater benefits.

Why fiber matters for your gut

Many fibers aren't digested in the small intestine. Instead, bacteria in your colon ferment them, producing short-chain fatty acids such as butyrate, which help fuel colon cells and support a healthy gut lining. A varied, fiber-rich diet supports a diverse microbiome.

Easy ways to add fiber

• Add beans or lentils to soups, salads and bowls.
• Choose oats or whole-grain bread at breakfast.
• Snack on fruit, nuts and seeds.
• Fill half your plate with vegetables.
• Sprinkle chia or ground flaxseed on yogurt.

Go slowly

Increasing fiber too fast can cause gas and bloating. Add a few grams every few days and drink plenty of water.

Wondering about supplements too? Read are probiotics worth taking.