Fermentation

What is fermentation?

Fermentation is a natural process where beneficial bacteria and yeast break down food sugars. This creates lactic acid, which preserves food and develops unique flavors. Humans have used fermentation for thousands of years to preserve vegetables, dairy, and grains while making them more nutritious ^[1].

How fermentation supports gut health

Fermented foods contain live beneficial bacteria called probiotics. These microbes survive digestion and reach your intestines, where they support your gut microbiome. A diverse microbiome is linked to better digestion, stronger immunity, and even improved mood ^[2].

A landmark Stanford study showed that regular consumption of fermented foods increases microbial diversity more effectively than fiber alone. Participants eating a high-fermented-food diet showed steady increases in microbiome diversity and decreases in inflammatory markers over 17 weeks ^[3].

Popular fermented foods

Sauerkraut

Fermented cabbage that originated in Eastern Europe. It is rich in lactobacillus bacteria and vitamin C. Choose unpasteurized sauerkraut from the refrigerated section—pasteurization kills beneficial bacteria.

Kimchi

A Korean staple made from fermented vegetables, usually napa cabbage and radishes, with chili, garlic, and ginger. It contains diverse bacterial strains and compounds that may support immune function.

Yogurt and kefir

Fermented dairy products containing billions of live cultures per serving. Kefir has more bacterial diversity than yogurt. Choose plain varieties without added sugar for maximum benefits.

Kombucha

Fermented tea containing acetic acid bacteria and yeast. It provides probiotics and antioxidants, though sugar content varies by brand. Start with small amounts if you are new to fermented foods.

Beyond probiotics: additional benefits

Fermentation breaks down compounds that interfere with nutrient absorption. Phytic acid in grains and legumes binds minerals like iron and zinc. Fermentation reduces phytic acid, making these minerals more available ^[1]. Fermented foods also produce B vitamins and enzymes that support digestion.