When you hear the word probiotics, your mind may immediately jump to supplements. While supplements are certainly an easy and effective way to get a daily dose of good bacteria, there are also a number of different foods with probiotic properties that can be beneficial for your gut and overall health.
These probiotic foods, usually classified as “fermented foods,” provide some of the same benefits as probiotic supplements1, like supporting digestive health. But fermented foods also deliver additional, unique benefits through their antioxidant, antimicrobial, metabolic health-promoting, and FODMAP-reducing properties.
Since these fermented products are derived from healthy foods like milk, cucumbers, cabbage, beans, and tea, they also provide intrinsic nutritional benefits from vitamins, minerals, fiber, and phytochemicals too. Of note, fermented foods are one of the few natural sources of vitamin K22 (a unique form of vitamin K important for bone and heart health), found in especially high amounts in natto, kefir, and miso.
If you’re looking for a way to improve your nutrition, gut, and overall health through your diet, start by including some or all ten of these probiotic powerhouse foods.
Yogurt is probably the most well-known, and easily accessible, probiotic food out there. It’s made by combining milk or cream with live, active cultures—another term for probiotics.
Different yogurts contain varying types of probiotics. Some of the most common starter cultures used to create fermented milk products (like yogurt) feature several specific probiotic strains3. These may include Lactobacillus acidophilus LA-5, Lactobacillus rhamnosus HN001, Lactobacillus paracasei Lpc-37, Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus, and Bifidobacterium lactis Bb-12. In many cases, yogurt manufacturers will list exactly which probiotics are in each type of yogurt.
Research has indicated4 that yogurt may improve intestinal transit time (read: move contents through your bowels to ultimately help you go number two more quickly and efficiently), stimulate the part of your immune system that resides in your gut, and facilitate lactose digestion to help those with lactose intolerance.
In addition to yogurt serving as a great source of protein, calcium, and B vitamins, it also has the potential to function as a synbiotic. A synbiotic leverages the synergistic benefits of prebiotics and probiotics5 simultaneously. How can you elevate your yogurt to synbiotic status? Simply add fresh fruit, which is a great source of prebiotic fiber, not to mention natural sweetness, vitamins, minerals, and antioxidants too.
Keep in mind that not all yogurts are created equally. When choosing a yogurt, opt for a plain, unsweetened variety. Bonus points if the dairy source is grass-fed.
Kefir is a fermented milk drink that’s probably best described as a thin drinkable yogurt. It’s made by combining different yeasts and beneficial bacteria, collectively called “kefir grains,” with milk proteins.
The resulting kefir drink contains a variety of different strains of Lactobacilli bacteria (including Lactobacillus kefiri), fungus, and different species of beneficial yeasts6. Saccharomyces cerevisiae, Saccharomyces unisporus, and Candida kefyr yeast species predominate.
In addition to supporting gut health through beneficial probiotic microbes, a 2019 review in the journal Nutrients7 points out that the Lactobacilli bacteria strains found in kefir protect from bad bacteria, stimulate the immune system, lower cholesterol, and have antioxidant, anti-allergy, anti-diabetic, and anticancer properties.
These potential benefits are from preclinical research (i.e., in rodent and cell culture models), so what do we know from well-designed studies of humans consuming kefir?
The clinical science demonstrates that kefir can:
As with yogurt, less is more when it comes to ingredient lists. Martin Singh, M.D., an integrative gastroenterologist, says, “just make sure to avoid kefir with added sugar and flavorings; plain, full-fat varieties have the most benefit.”
In its basic form, sauerkraut is a fermented food made by combining salt with cabbage in a closed container, where spontaneous fermentation occurs over time.
Although there are many different types of probiotic bacteria found in sauerkraut14, lactic acid bacteria from Leuconostoc and Lactobacillus genera dominate the natural fermentation process. Three of the most common bacterial species present include Leuconostoc mesenteroides, Lactobacillus plantarum, and Lactobacillus brevis.
Researchers from an experimental study in Functional Foods in Health and Disease tested the amount of probiotics in different quantities of sauerkraut and found that even a two-tablespoon serving delivers a meaningful amount of good bugs, about 1.5 million colony-forming units (CFU).
But if you want to reap the probiotic benefits of sauerkraut, you can’t just grab any jar off the shelf. Pasteurized, processed sauerkraut has little to no viable bacteria left in it. It’s raw, refrigerated sauerkraut you want. The ingredients should be cabbage and salt and not much more.
Miso is a fermented paste made by combining soybeans with salt and a fungus called koji (Aspergillus oryzae)—the same fungus used to make sake.
Like sauerkraut, miso is loaded with lactic acid probiotic bacteria, including many unique strains of Tetragenococcus halophilus, which was shown to stimulate the immune system15 in animal and cell models.
Keep in mind that not all pickles are made the same way. Raw, fermented pickles are made with water and salt, while some commercial brands are made with vinegar.
Functional medicine doctor Mark Hyman, M.D. points out that “[vinegar] kills the live bacteria, defeating the purpose of fermentation." He adds, "When you buy fermented foods, make sure they were prepared naturally, without the use of vinegar."
As pickles sit in your refrigerator, they can also lose their probiotic potency. To reap the most benefits from your pickles, make sure to eat them within two to four months.
Lastly, shop for cleaner labels. Many pickle brands add one or more artificial dyes simply to make them a more vibrant color (that bright yellow-green hue you’re accustomed to seeing). These added colorants are unnecessary.
Green olives are an often overlooked probiotic food that are actually covered with species of 17Lactobacillus 17bacteria17, particularly Lactobacillus pentosus and Lactobacillus plantarum, both of which are categorized as lactic acid bacteria.
Lactobacillus pentosus helps support the immunoprotective functions of mucosa (the cells that line our entire GI tract). Lactobacillus plantarum has been shown through research to have multiple health benefits, including promoting immune function, improving symptoms of irritable bowel syndrome (IBS), and even reducing LDL (bad) cholesterol.
Animal studies also reveal L. plantarum's wide-reaching immunomodulatory potential through its antifungal, antiviral, anti-allergy, and anti-tumor properties.
There is a caveat though. You have to make sure the olives are cured in brine and not plain water. The good news is that most store-bought olives fit the bill. An easy way to check is by looking at the ingredient list. If water and salt are both listed, the olives are most likely cured in brine.
Tempeh, which originates in Indonesia, is traditionally made from fermented soybeans utilizing a specific fungus (Rhizopus oligosporus), but tempeh may also include other types of beans or whole grains.
In addition to the general benefits of probiotics, tempeh also acts as a prebiotic18, or a food source that stimulates the growth or activity of good bacteria that already live in your gut. Specifically, soy and bean tempeh have been shown to increase the amounts of Bifidobacterium, Lactobacillus, Escherichia coli, and Enterococcus bacteria in a simulated model of the digestive tract.
The bitter taste and sticky texture of natto may take some getting used to, but the potential benefits are worth it. Natto is a Japanese fermented food (often served for breakfast) that’s made from combining soybeans with Bacillus subtilis var. natto, a spore-forming bacterium that acts as both a probiotic and a prebiotic20.
Spore-forming bacteria like the Bacillus genus are gaining more attention because they seem to survive the digestive tract21 better than other types of probiotic bacteria and act via unique immunomodulatory mechanisms, like producing antimicrobial peptides.
Natto is packed with macro- and micronutrients. Along with over 30 grams of protein, 1 cup of natto22 delivers 9 grams of fiber and is rich in calcium, iron, magnesium, potassium, zinc, copper, manganese, selenium, vitamin C, and vitamin K2.
Kombucha isn’t really a food—it’s a fermented tea made by combining black tea or green tea (or others like oolong or rooibos) and sugar with a specific combination of bacteria and yeast called a SCOBY (symbiotic culture of bacteria and yeast). But since it’s so rich in probiotics and has a long history (over 2,000 years of consumption), it’s earned a rightful place on this list.
Kombucha contains yeasts from the Candida and Zygosaccharomyces genera, as well as an abundance of good microbes from the Komagataeibacter, Lactobacilli, Bifidobacteria, Lyngbya, and Gluconobacter genera.
Although no clinical trials exist to evaluate kombucha's health impact in humans, animal and cell studies demonstrate this unique beverage has antimicrobial23, antifungal, and anticancer24 properties. Kombucha has also been shown to improve leaky gut syndrome25 in a study of mice.
Plus, it comes in all kinds of delicious and creative flavors, like ginger, cranberry, and blueberry, so you can find one that you really love.
A staple in Korean cuisine, kimchi is a combination of napa cabbage, Korean radishes, and other veggies with salt and probiotic bacteria from Lactobacillus and Bifidobacteria varieties. This probiotic vegetable side dish has the incremental benefit of various herbal seasonings like garlic, ginger, and chili powder.
Clinical studies featuring kimchi point to its positive effects on metabolic health parameters like blood glucose, lipids27, insulin resistance, and blood pressure28. When fermented and fresh kimchi went head-to-head in a Nutrition Research29 study29, both sets of veggies improved metabolic health, but the fermented dish produced greater improvements in body fat, blood sugar, blood pressure, and cholesterol levels.
Lindsay Boyers is a holistic nutritionist specializing in gut health, mood disorders, and functional nutrition. Lindsay earned a degree in food & nutrition from Framingham State University, and she holds a Certificate in Holistic Nutrition Consulting from the American College of Healthcare Sciences.
She has written twelve books and has had more than 2,000 articles published across various websites. Lindsay currently works full time as a freelance health writer. She truly believes that you can transform your life through food, proper mindset and shared experiences. That's why it's her goal to educate others, while also being open and vulnerable to create real connections with her clients and readers.