What Is in Them, What Research Shows & What to Check.
Fermented foods are food first. Explore each one: how it is made, whether it still has live cultures, what research in people has and has not found, a normal serving, and what to check before you eat it: histamine, sodium, pregnancy and unpasteurized products, medicines, and allergies. Foods are kept apart from probiotic supplements.
Search by fermented food, benefit, body system, goal, symptom or lab test. Each result explains why it matches and how strong the evidence is.
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Lactic-fermented milk
Vitamin B12Riboflavin (B2)CalciumPhosphorusProtein
Normal serving (USDA): 1 cup (8 fl oz), 245 g
What research says about yogurt as a food: lactose digestion, observational links with health, a small cholesterol trial base, what live cultures mean, and label and pregnancy cautions.
Fermented milk drink (kefir grains)
Vitamin AVitamin B12Riboflavin (B2)CalciumProtein
Normal serving (USDA): 1 cup, 243 g
What a 2023 review of 16 human trials found for fermented-milk kefir, why the evidence is limited and often low quality, and cautions for pregnancy and weakened immunity.
Cheddar, Parmesan, Swiss, Gouda
CalciumSeleniumVitamin B12ProteinVitamin A
Normal serving (USDA): 1 ounce (28.35 g), about one slice
Aged cheese (cheddar, Parmesan, Swiss, Gouda) as a fermented food: USDA nutrients, cholesterol trials, and sodium, pregnancy, histamine, tyramine and milk allergy cautions.
Cultured milk
Riboflavin (B2)CalciumVitamin B12PhosphorusProtein
Normal serving (USDA): 1 cup, 245 g
Cultured buttermilk as a food: USDA nutrients per cup, what small studies found on cholesterol and blood pressure, and sodium, lactose, pregnancy and milk allergy cautions.
Strained fermented milk
Normal serving (USDA): Use the Nutrition Facts serving on the package (no USDA household portion in our data)
Skyr and quark, thick fermented milks: what small trials found on protein, fullness and muscle, composition we could verify, and lactose, pregnancy and allergy cautions.
Yogurt drinks
Normal serving (USDA): Use the Nutrition Facts serving on the package (no USDA household portion in our data)
Lassi and ayran, two yogurt drinks: what we could verify about their salt and sugar, one small gum-health trial, and lactose, pregnancy, sodium and milk allergy cautions.
Fermented soybean paste, Aspergillus oryzae koji, Glycine max
Normal serving (USDA): 1 tablespoon (17 g)
Miso is a salty fermented soybean paste. What reviews and cohort studies found, why sodium and soy allergy matter, and why miso is not automatically a probiotic food.
Fermented soybeans (Bacillus subtilis), Glycine max
CopperManganeseIronProteinZinc
Normal serving (USDA): 1 cup (175 g)
Natto is a Japanese fermented soybean food rich in vitamin K2. Read the warfarin caution first, then what studies found on bone markers and mortality, and the soy allergy point.
Fermented soybean cake (Rhizopus), Glycine max
CopperManganeseProteinRiboflavin (B2)Phosphorus
Normal serving (USDA): 1 cup (166 g)
Tempeh is a firm fermented soybean cake from Indonesia. What reviews say, why human evidence is limited, and the allergy and fermentation-safety points to know.
Fermented soy and wheat sauce (shoyu), Fermented soy sauce (tamari)
Normal serving (USDA): 1 tablespoon (16 g) soy sauce with wheat; tamari 1 tablespoon is 18 g
Soy sauce and tamari as foods: USDA sodium values, wheat and gluten, soy allergy, MAOI medicines and histamine, plus what research does and does not show.
Fermented tofu (sufu, furu, fuyu)
Normal serving (USDA): 1 block (11 g)
Fermented tofu (sufu, furu, fuyu) as a food: USDA sodium values, histamine and tyramine, homemade botulism cases, soy allergy and what research does not show.
Korean fermented pastes, Gochujang (chili-soybean paste), Doenjang (soybean paste)
Normal serving (USDA): No USDA household portion; check the label serving size
Gochujang and doenjang, Korean fermented soy pastes: salt, histamine and Bacillus cereus findings, soy allergy, MAOI medicines and what the research really shows.
Oryza sativa, Vigna mungo
Normal serving (USDA): No official serving size found; the glycemic load study used 250 g
Idli and dosa are South Indian cakes made from fermented rice and black gram batter: what lab studies measured, blood sugar, gluten, rice arsenic and what is not proven.
Eragrostis tef
ManganeseCopperThiamin (B1)MagnesiumIron
Normal serving (USDA): 1 cup cooked teff grain (252 g); USDA lists no injera portion
Injera is a sour, spongy Ethiopian flatbread from fermented teff: USDA values for teff, what fermentation does to phytate and iron, gluten and celiac questions, and safety.
Aspergillus oryzae, Oryza sativa
Normal serving (USDA): No official serving size found
Koji is rice grown with the mold Aspergillus oryzae; amazake is the sweet drink made from it. What trials found on bowels and skin, sugar, mold safety and labels.
Secale cereale (rye bread), Saccharomyces cerevisiae, lactic acid bacteria
Normal serving (USDA): 1 glass, 240 mL (about 1 cup); no official serving, used for arithmetic only
Kvass is a lightly sour, fizzy drink fermented from rye bread. What one lab study measured for alcohol, sugar and fiber, and safety points on gluten, sugar and alcohol.
Water kefir grains (Lactobacillus spp., acetic acid bacteria and yeasts)
Normal serving (USDA): 200 mL a day was the amount in a 2026 trial; no official serving size
Water kefir (tibicos) is a dairy-free fizzy drink fermented from sugar water and kefir grains: what a 2026 trial found, trace alcohol, sugar and who should be careful.
Fermented fish (often anchovy) and salt
Normal serving (USDA): 1 tablespoon (about 15 mL); no official serving size, used for arithmetic only
Fish sauce is a salty, savory liquid from fermented fish. A 2025 study of 38 bottles measured sodium and histamine; see what that means for blood pressure, allergy and MAOIs.
Capsicum spp., lactic acid bacteria
Normal serving (USDA): No official serving size found; usually used by the drop or teaspoon
Fermented hot sauce is chili mash soured by lactic acid bacteria in salty brine: what lab studies measured, the sodium and heartburn questions, and what is not proven.
Olea europaea
Table olives (Olea europaea) as a food: USDA nutrients, why brining makes them high in sodium, what research does and does not show, and safety notes.
Brassica rapa subsp. pekinensis (fermented)
Kimchi, a traditional Korean fermented vegetable dish: what small human trials found, why a kimchi-derived probiotic is a different product, and sodium and biogenic amine cautions.
Brassica oleracea var. capitata (fermented)
What an 87-person crossover trial found for fresh and pasteurized sauerkraut, why live cultures were not required for the changes seen, and sodium, biogenic amine and pregnancy cautions.
Camellia sinensis, fermented with a SCOBY
Leaf
Kombucha is fermented sweet tea. What the few human trials show, and the cautions: home-brew contamination, lead from ceramic pots, alcohol, caffeine, pregnancy and weak immunity.
No fermented food matches all of these filters. Try removing one. Some topics (for example most herbs) are not fermented foods and live elsewhere on the site.
A link between a fermented food and a topic means the body needs the fermented food for that job, or that low intake is linked to it. It does not mean extra supplements help if your intake is already adequate. See each page’s evidence label.
Yogurt, kefir, aged cheese, buttermilk, skyr and lassi: milk changed by bacteria and yeasts. Lactose and milk allergy still matter.
Miso, natto, tempeh, soy sauce and other fermented soy foods. Some are very salty; natto has vitamin K.
Idli and dosa, injera and koji: grains and lentils fermented into batters and breads.
Fish sauce and fermented hot sauce: strong flavors, usually used in small amounts.
Fermented foods work alongside other nutrients. Here is what our sources link to them.
Vitamin A: The body can convert beta-carotene to vitamin A.
Vitamin A: Vitamin E and beta-carotene were tested together in the Finnish smoker trial.
Vitamin D: Vitamin D increases calcium absorption; both matter for bones, and treatment of rickets and osteomalacia includes both.
Vitamin D: NHS says vitamin D helps regulate calcium and phosphate.
Vitamin E: MedlinePlus says vitamin E helps the body use vitamin K; both affect blood clotting, which matters for people on blood thinners.
Vitamin E: Vitamin E and selenium were tested together and apart in the SELECT prostate cancer trial.
Vitamin E: Vitamin C and vitamin E were pooled with other antioxidants in the Cochrane mortality review.
Vitamin K: Vitamin D with K2 products exist; the site page does not claim an added benefit.
Vitamin B1 (thiamin): The NHS page covers B vitamins together; MedlinePlus says doctors may recommend other vitamins alongside thiamin for beriberi.
Vitamin B2: MedlinePlus says riboflavin works with the other B vitamins.
Vitamin B3 (niacin): Pellagra comes from too little niacin or tryptophan in the diet, so both matter for avoiding deficiency.
Vitamin B5: MedlinePlus covers pantothenic acid and biotin together; both are needed for growth and metabolism and for making fatty acids.
VegetablesOmega fatty acidsAntioxidantsSupplement formulasCompare supplementsNatural Remedy Safety
Aged cheese (cheddar, Parmesan, Swiss, Gouda) as a fermented food: USDA nutrients, cholesterol trials, and sodium, pregnancy, histamine, tyramine and milk allergy cautio…
Cultured buttermilk as a food: USDA nutrients per cup, what small studies found on cholesterol and blood pressure, and sodium, lactose, pregnancy and milk allergy cautio…
Skyr and quark, thick fermented milks: what small trials found on protein, fullness and muscle, composition we could verify, and lactose, pregnancy and allergy cautions.
Lassi and ayran, two yogurt drinks: what we could verify about their salt and sugar, one small gum-health trial, and lactose, pregnancy, sodium and milk allergy cautions.
Soy sauce and tamari as foods: USDA sodium values, wheat and gluten, soy allergy, MAOI medicines and histamine, plus what research does and does not show.
Fermented tofu (sufu, furu, fuyu) as a food: USDA sodium values, histamine and tyramine, homemade botulism cases, soy allergy and what research does not show.
Gochujang and doenjang, Korean fermented soy pastes: salt, histamine and Bacillus cereus findings, soy allergy, MAOI medicines and what the research really shows.
Idli and dosa are South Indian cakes made from fermented rice and black gram batter: what lab studies measured, blood sugar, gluten, rice arsenic and what is not proven.
Injera is a sour, spongy Ethiopian flatbread from fermented teff: USDA values for teff, what fermentation does to phytate and iron, gluten and celiac questions, and safe…
Koji is rice grown with the mold Aspergillus oryzae; amazake is the sweet drink made from it. What trials found on bowels and skin, sugar, mold safety and labels.
Kvass is a lightly sour, fizzy drink fermented from rye bread. What one lab study measured for alcohol, sugar and fiber, and safety points on gluten, sugar and alcohol.
Water kefir (tibicos) is a dairy-free fizzy drink fermented from sugar water and kefir grains: what a 2026 trial found, trace alcohol, sugar and who should be careful.
Fish sauce is a salty, savory liquid from fermented fish. A 2025 study of 38 bottles measured sodium and histamine; see what that means for blood pressure, allergy and M…
Fermented hot sauce is chili mash soured by lactic acid bacteria in salty brine: what lab studies measured, the sodium and heartburn questions, and what is not proven.
What randomized trials and reviews found for fermented foods and gut symptoms, inflammation and blood sugar, how strong that evidence is, and who should be careful.
Fermented Foods and Gut Health: What Trials FoundWhat the sources say about the safety of fermented foods, the documented risks of home fermentation including botulism, and who should be extra careful. No recipes or methods.
Fermented Foods Safety and Home Fermentation RisksFermented foods and probiotic supplements are not the same thing. Definitions from an expert panel, what trials of supplements found, safety points, and where evidence is missing.
Fermented Foods vs Probiotic SupplementsWhy some fermented foods contain histamine and tyramine, what MAOI medicine labels say about them, and how limited the evidence is for histamine intolerance.
Histamine, Tyramine and Fermented FoodsWhat "live and active cultures" means on US yogurt labels, which fermented foods still have live microbes when sold, and why live cultures do not make a food a probiotic.
Live Cultures on Labels: Yogurt and KefirYogurt and kefir are both fermented milks. What each research base shows, what live cultures do and do not mean, and why no direct comparison could be found.
Yogurt vs KefirGreek (strained) yogurt vs regular yogurt: what straining is, what sources document about protein and processing, the limited trials on Greek yogurt, and where evidence is missing.
Greek Yogurt vs Regular YogurtKimchi and sauerkraut are both fermented vegetable foods. What small trials found for each, what is and is not known about live cultures, and why they cannot be ranked.
Kimchi vs SauerkrautFermented pickles and vinegar pickles are not the same. What small trials found, why salty pickled foods raise questions in cohort studies, and what counts as probiotic.
Pickles: Fermented vs VinegarSourdough bread claims checked against trials and reviews: blood sugar, minerals, gut bacteria, digestibility and gluten, with a clear warning for people with celiac disease.
Sourdough Bread: Claims CheckedKombucha is a fermented tea drink. What human trials and reviews found, why proper evidence is thin, and the alcohol, caffeine, contamination and pregnancy points to know.
Kombucha (Food Guide)What "probiotic", "live and active cultures" and "fermented" can mean on food and drink labels, what expert panels say a label should show, and why the same word can describe very different products.
Probiotic Claims on Food LabelsKimchi and sauerkraut have their profiles with the other vegetables.
VegetablesKombucha is profiled under teas.
Herbal Teas & ExtractsProbiotic supplements are a different product from fermented foods.
Vitamins & Supplements: ProbioticsNo. An expert panel (ISAPP) says fermented foods are defined by how they are made, and some have no living microbes when eaten: baked sourdough, pasteurized fermented vegetables, vinegar, soy sauce, wine and most beers. [1] Yogurt, kefir, most cheeses, miso, natto and tempeh do contain live microbes. [1] The panel also says a food should be called "probiotic" only when a well-defined live strain has a shown health benefit. [1] See live cultures on labels.
It depends on the food. The NHS says to avoid unpasteurized milk, cream, yogurt and butter in pregnancy because of listeria, and says soft white-rind and soft blue cheeses should be thoroughly cooked. [4] That NHS page does not mention kefir or probiotic drinks, so check the label for pasteurization and ask your midwife or doctor. [4] See foods in pregnancy.
The NHS lists histamine as something a person can be intolerant to, found in foods and drinks such as wine and cheese. [5] Food intolerance is not an allergic reaction, and the NHS advises seeing a GP rather than cutting foods out on your own. [5] NCCIH adds that tyramine-rich soy foods such as tofu and soy sauce can interact dangerously with MAOI antidepressants. [6]
They are different products. NCCIH says probiotics are live microbes found in yogurt and other fermented foods as well as in supplements, and the risk of harm is higher for people with weakened immune systems. [2] The NHS says the evidence for probiotics is limited and uncertain, with some evidence for irritable bowel syndrome, and that shop products may differ from the strains tested in trials. [3] See fermented foods versus probiotic supplements.
Some can be, so check the Nutrition Facts label. The FDA says adults should have less than 2,300 mg of sodium a day, that more than 70 percent of it comes from packaged and prepared foods, and that 5 percent of the Daily Value or less per serving is low and 20 percent or more is high. [7] For example, see soy sauce and tamari. Soy and wheat are major allergens, so check labels if you are allergic. [8]
Content last updated . This section has not been medically reviewed.
