Salt and cabbage make sauerkraut. During the fermentation process, microorganisms eat the sugar present in cabbage and produce carbon dioxide and acids. Fermentation produces probiotics that aid digestion and replenish gut microorganisms.
The spicy Korean cousin of sauerkraut is kimchi. For flavor, add scallions, radishes, and shrimp. Find it in the refrigerated department with sauerkraut, Asian sauces, and pickles, or prepare your own to optimize probiotics.
Kefir is drinkable yogurt. Kefir grains, colonies of yeast and lactic acid bacteria, ferment milk sugars to thicken and tarten it. Kefir, like yogurt, contains probiotics if the store-bought variety uses pasteurized milk.
SCOBY and sugar are added to green or black tea to make kombucha, a tart, effervescent tea. It ferments for a week or more. Kombucha carbonates from alcohol and gasses created during fermentation.
Miso is fermented soybean, barley, or rice paste. Fermentation produces healthy microorganisms, like other fermented foods. Soybean miso provides protein. Miso's salt content makes a little go a long way.
Tempeh is created from soybeans like tofu, except it's fermented and contains probiotics. Making tempeh requires fermenting and pressing soybeans into a cake. Grill, sauté, or bake it.
For good reason, yogurt is the most popular probiotic. By metabolizing lactose, healthy bacteria in milk create lactic acid and other helpful germs. The "Live & Active Cultures" seal guarantees 100 million probiotic cultures per gram at the time of manufacturing for yogurt.