What are fermented foods?

Foods ferment as a result of the addition of microbes, such as bacteria and yeast. Many, but not all of these foods contain beneficial bacteria and when included regularly in your diet may bestow health benefits such as improving digestion and lowering the risk of certain conditions such as type 2 diabetes and heart disease.


Discover our full range of health benefit guides and check out the health benefits of fermenting, what are probiotics and our favourite fermented food recipes.

What are the healthiest fermented foods?

Apple cider vinegar on a spoon

1. Apple cider vinegar

Apple cider vinegar is made by crushing apples and allowing yeasts to ferment the natural sugars into acetic acid. It’s the unfiltered vinegar that retains the benefits because it contains the ‘mother,’ a collection of proteins, enzymes and friendly bacteria – you’ll recognise an unfiltered product because it will appear cloudy in the bottle.

Including apple cider vinegar in your diet may help improve fasting blood sugar and reduce HbA1c, a marker of long-term blood sugar control.

Discover the health benefits of apple cider vinegar.

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Use apple vinegar to make our spicy black bean tacos.

2. Cheese (including aged cheddar, parmesan, gouda and mozzarella)

Some cheese varieties are more effective than a probiotic supplement for delivering intact beneficial bacteria (probiotics) to the gut. Mozzarella, the Italian soft, fresh cheese is one such example, although levels of beneficial microbes may vary depending on the source of the milk used.

Discover the healthiest cheeses.

Be inspired by our recipes, including caprese salad, courgette, potato and cheddar soup, and parmesan spring chicken.

3. Kefir

Kefir benefits from a more diverse composition of beneficial bacteria and yeast than yogurt. These microbes are responsible for producing bioactive compounds that have numerous benefits for our health, from improving digestion to lowering cholesterol.

Discover the health benefits of kefir.

Enjoy kefir in our raspberry and kefir overnight oats and kefir breakfast smoothie.

4. Kimchi

A fermented combination of vegetables and spices, this traditional Korean food is now popular across the world. The process of fermentation, by mainly lactobacillus bacteria, may enhance the nutritional value of kimchi. This is because the bacteria themselves synthesise vitamins and minerals and the process of fermentation deactivates some less favourable compounds.

Including kimchi regularly in your diet may help you manage cholesterol and balance blood sugar levels.

Discover the health benefits of kimchi.

Add the bold flavour of kimchi to our kimchi fried rice, kimchi noodles and kimchi scrambled eggs.

5. Kombucha

Kombucha is a mildly fizzy, fermented drink made from sweetened tea and a specific culture known as a ‘scoby’ – a ‘symbiotic culture of bacteria and yeasts’. The bacteria and yeast in the scoby convert sugar into ethanol and acetic acid. The acetic acid is responsible for kombucha’s distinctive sour taste.

Kombucha contains small amounts of vitamins and minerals, including vitamin C and vitamins B1, B6 and B12, which are produced when the yeast breaks down the sugars. Levels are likely to vary by product.

Discover the health benefits of kombucha.

Make your own kombucha with our easy recipe.

Miso salmon with ginger noodles

6. Miso

A traditional ingredient in Japanese and Chinese cooking, miso paste is made from soybeans and grains that are fermented by koji enzymes and beneficial bacteria. Miso is rich in gut-friendly bacteria, protein, vitamins E and K as well as isoflavone plant compounds which may have anti-cancer benefits.

Discover the health benefits of miso.

Use miso to make our miso aubergines, miso salmon with ginger noodles and miso chicken and rice soup.

7. Natto

A traditional Japanese dish of fermented soybeans, natto is a rich source of beneficial bacteria. It’s traditionally consumed at breakfast and has a beneficial effect on the gut. Containing as much as 100 times more vitamin K2 than some cheeses, it’s particularly useful for those at risk of poor bone health.

However, if you’re on blood thinning medication, such as warfarin, you should refer to your GP or registered dietician before introducing vitamin K-rich foods into your diet.

Learn more about natto and what makes the Japanese diet so healthy.

8. Olives

Olives are one of the most popular fermented foods. Their natural saltwater fermentation makes them rich in lactobacillus, one of the most influential species of gut-friendly bacteria.

Discover the health benefits of olives.

Add salty olives to our chicken and olive casserole, cod with olives and crispy pancetta, and tuna, olive and spinach spaghetti.

9. Tempeh

A popular protein alternative, tempeh is a traditional soya product made from cooked, fermented soya beans. It’s rich in bone-friendly minerals including calcium, magnesium and phosphorus.

In addition to this, the fermentation process breaks down compounds known as anti-nutrients, which may inhibit our uptake of some of these valuable minerals.

This makes fermented foods, like tempeh, easier to digest and the nutrients they provide, easier to absorb.

Discover the health benefits of tempeh.

Be inspired by our chilli tempeh stir-fry and tempeh traybake.

10. Sauerkraut

Sauerkraut or ‘sour cabbage’ is essentially fermented cabbage and is thought to have originated in China more than 2,000 years ago. The process of fermentation initiates certain beneficial microbes and it’s these, along with the process itself, that makes sauerkraut such a healthy choice.

Fermented cabbage is especially heart-healthy, being fibre-rich and a source of beneficial bacteria that help to balance cholesterol levels. It’s also a good source of potassium, and its microbe content is thought to positively influence blood pressure.

Discover the health benefits of sauerkraut.

Discover how to make your own sauerkraut using our easy recipe.

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11. Sourdough

Typically made from just four ingredients – flour, water, salt and a starter culture – sourdough is easy to digest and highly nutritious. It’s the starter combined with the long fermentation which holds the key to sourdough’s taste, texture and health credentials.

A sourdough starter is a mix of flour and water, which is fermented by wild yeasts and lactic acid bacteria, which gives the sourdough its rise. Traditional sourdough undergoes a slow fermentation, which makes its vitamins and minerals more bioavailable. The process also kick-starts the breakdown of protein (gluten), making the bread easier to digest.

Although the beneficial microbes in the starter are lost during the baking process, compounds called polyphenols become more bio-available. These act as an important fuel source for our good gut microbes and, unlike many commercially produced loaves, sourdough is beneficial for blood sugar levels.

Discover the health benefits of sourdough.

Give sourdough a go with our step-by-step recipe to make your own starter, and use it to make our classic sourdough loaf.

12. Yogurt

Interestingly, studies suggest that a 100g serving of yogurt every day may be beneficial for mood and outlook. This is likely to be because of the relationship between the beneficial bacteria in our gut and the role they play in producing feel-good neurotransmitters such as serotonin and dopamine.

Discover the health benefits of yogurt.

Use up yogurt to make our roast aubergines with yogurt and harissa, instant frozen berry yogurt and roasted beetroot with za’atar, chickpeas and harissa yogurt.

Enjoyed this? Now try…

How to make kombucha
Gut-friendly recipes
Digestive health recipes and tips
Top 10 probiotics foods to support your gut health
How to make kefir

Got a question about gut health? Let us know in the comments below.

Kerry Torrens BSc. (Hons) PgCert MBANT is a registered nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including Good Food. Find her on Instagram at @kerry_torrens_nutrition_


All health content on goodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.

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