Are you consuming the 3 K’s (kefir, kimchi, & kombucha!) + other fermented foods for gut health and immunity? If not, read on to learn about a recently published study that found high-fiber and fermented foods, rich in active cultures, may help shape the human microbiome, reduce markers of inflammation, and benefit your immune system.

Before I share the study findings with you, let me provide a quick overview of fermented foods and the fermentation process.

Graphic with 3 images of fermented foods including yogurt, kefir, and kombucha.

What is fermentation?

Fermentation involves enzymatic conversions of food components by live microorganisms (i.e., yeast, lactic acid bacteria) into alcohol or organic acids. 

The fermentation process not only acts as a natural method of food preservation but also supports the gut microbiota by providing a direct source of good bacteria to your gastrointestinal tract. (1)

Some fermented foods, such as milk products, have live bacteria added to them. Typically these include the probiotic strains Lactobacillus bulgaricus and Streptococcus thermophilus.

While others, such as sauerkraut, are produced from beneficial bacteria like Lactobacillus plantarum that naturally reside on cabbage. (2)

Fermented Foods to Include in Your Diet

With the increasing interest in recent years in gut health, you will find a wide variety of fermented foods at your grocery store.

In addition, you can try making fermented foods at home. Commonly eaten fermented foods to support your digestive system and overall health include:

Jars of colorful fermented foods.

Dairy Products & Non-Dairy Alternatives

Yogurt, Greek Yogurt, Non-Dairy Yogurt

Yogurt is a fermented dairy (or non-dairy) product that has been around since ancient times. Increasingly, you can choose from a wide variety of plant-based yogurts made from coconut, soy, or cashew milk.

Tip! Always read the label and choose yogurts without added sugars or flavorings and look for ones with “live active cultures.”


Kefir is a fermented drinkable yogurt often made from dairy milk. Research has shown that kefir may help improve lactose digestion in those who are intolerant. (3)


Good news for cheese lovers! Some varieties of cheese, including Gouda, cheddar, and mozzarella that have been fermented but not heated afterward, retain live cultures. (4, 5)

Fermented Vegetables


Kimchi is a Korean side dish made from fermented cabbage, cucumbers, or radishes. Its flavorings include chili pepper flakes and garlic, along with other probiotic strains such as Lactobacillus kimchii.


Sauerkraut is a fermented cabbage that has been finely chopped and added to water with sea salt. To ensure live strains of bacteria, purchase raw sauerkraut (and kimchi) in the refrigerator section of your supermarket, as pasteurization kills off good bacteria.

Fermented Beverages


The bubbly, fermented tea known as kombucha has gained a lot of popularity as of late. Made from yeast, sugar, black tea, and unique flavors, some versions contain alcohol formed during fermentation.

Water Kefir

Water kefir is a fermented, carbonated beverage that uses water kefir grains to ferment sugar water instead of milk. The result is a fizzy drink that may contain small amounts of beneficial bacteria.

Fermented Soy


Commonly enjoyed in miso soup, miso is a fermented paste made by inoculating soybeans with a mold called Koji. Due to its umami flavor, Miso is a delicious way to season various foods.


Tempeh is a high-protein fermented soybean product. Originating from India, some people describe the taste as nutty, earthy, and tangy. Crumbled tempeh makes a tasty plant-based alternative to ground meat.


Not for the faint of heart (in my honest opinion), natto is a fermented soybean product with a distinctively slimy texture and pungent smell. However, if you enjoy natto, you’ll be happy to know that it’s rich in vitamin K2, an essential nutrient for bone and cardiovascular health.

Tip! It’s important to note that not all fermented foods contain live organisms. This includes some foods that have been pasteurized or baked, such as sourdough bread, soy sauce, and pickled/brined vegetables.

Interestingly, although sourdough bread doesn’t contain live organisms, it may be more easily digested by people with non-celiac gluten sensitivity (NOT celiac disease), as the sourdough bacteria plus enzymes produced during fermentation may degrade part of the gluten. (6)

What did the study find? Health benefits of eating fermented foods & a high-fiber diet


The study, published in Cell, was a 17-week randomized prospective design comparing the gut microbiome and immune response in 2 groups.

The first group (18 people) increased their average daily fiber intake from 21.5 to 45.1 grams daily. The second group (18 people) increased their daily fermented food intake from 0.4 to 6.3 servings per day.

After 17 weeks, participants’ stool samples were analyzed for microbiota composition, function, and metabolic output. In addition, an assessment of blood samples looked at the impact of fermented foods and a high-fiber diet on immunity.


Unlike previous findings, microbiota diversity wasn’t increased with a high fiber diet (although this may have occurred with a longer time period). However, microbiome function, microbial proteins, and microbe density were all increased as a beneficial result of the high-fiber diet.

And not only did the diet high in fermented foods increase microbiota diversity, but it also reduced markers of inflammation which may have beneficial effects on overall health.

You can read the complete study here and also be sure to check out this article I was quoted in at Verywell Fit.

Are you as excited as I am to eat more fermented foods?

I sure hope so! And, to make the transition not only easy but also delicious, I’ve put together a fabulous new cookbook for you featuring 40 fermented foods recipes!

Cookbook Cover with photo of yogurt popsicles and text: 40 Fermented Foods Recipes for Gut and Immune Health.

You’ll LOVE this cookbook featuring 12 breakfast ideas, 16 entrees, 7 snacks and side dishes, and 5 desserts (including the luscious chia yogurt popsicles pictured above). All starring my favorite fermented foods!

Are you ready to boost your health? Click on the link below!

Let’s Chat! Do you have any questions about fermented foods or the study? What are your favorite fermented foods to eat?

Looking for more digestive health resources? Check out these posts!

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