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. 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. 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: 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. 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. 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. Getting even more specific for you olive aficionados, a 2019 study in Frontiers in Microbiology demonstrated that Spanish-style green olives have particularly rich bacterial diversity17. 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. In addition to being packed with protein19 (over 30 grams in one cup of tempeh), this fermented food delivers a meaningful amount of calcium, magnesium, potassium, zinc, and manganese too. 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 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. Kimchi ends up with a rich variety of lactic acid bacteria26, most notably Leuconostoc, Lactobacillus, Weissella. 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. 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.
