That slice of sourdough bread? Fermented. How about that hunk of tangy Roquefort cheese or frothy brew? Fermented too. In ancient times, fermentation—the process that converts carbs into alcohols or acids—was one of the only ways to preserve food. But now there are more compelling reasons (think full flavor and loads of probiotics and nutrients) to try these less familiar options.

Kefir

A tangy, fermented-milk product similar to yogurt, kefir is delicious in smoothies and salad dressings. It’s filled with probiotics to help with digestion, along with calcium, protein, and potassium.

Kimchi

This traditional Korean dish is comprised of pickled vegetables such as cabbage and radishes. Thanks to lactobacilli and other beneficial bacteria, kimchi may help boost intestinal health.

Kombucha

A beverage made from blending a colony of bacteria and yeast with black tea and sugar and then allowing it to ferment, this tea is rich in enzymes, probiotics, and antioxidants.

Tempeh

A fermented whole-soybean product originally from Indonesia, tempeh is rich in vitamin B12, fiber, and protein. The fermentation process makes tempeh’s iron more bioavailable and easier to digest.