What Are Fermented Foods? Foods That Can Contain Probiotics

Fermented foods are foods and beverages made through controlled microbial growth and enzymatic conversions. This process can create beneficial bacteria known as probiotics and may enhance the food’s nutritional profile and shelf life.

At a glance

Term: Fermented Foods
What it is: Category of food
Section: Food and nutrition
In one line: They’re foods like yogurt, kimchi, or kombucha where good bacteria have been allowed to grow, which can be good for your gut.

What Fermented Foods means

Fermented foods are made using an ancient process of food preservation. It involves microorganisms like bacteria and yeast breaking down components in food, such as sugars, into other products like acids or alcohol. This controlled process not only preserves the food but also transforms its flavor, texture, and nutritional properties. Common examples include yogurt, kefir, sauerkraut, kimchi, miso, and kombucha. While originally developed for practical reasons before refrigeration, fermentation is now also valued for the unique tastes and potential health benefits it creates.

The interest in fermented foods today is often linked to the gut microbiome, which is the vast community of microbes living in your digestive tract. The fermentation process can produce probiotics, which are live, beneficial microorganisms. When you eat fermented foods that contain these live cultures, you are introducing these helpful microbes to your system. A diverse and balanced gut microbiome is generally associated with good overall health, and consuming foods with probiotics is one way some people support it.

Beyond probiotics, fermentation changes food in other ways. It creates the distinct tangy, sour, or savory flavors found in things like sourdough bread or cheese. The process can also make certain nutrients more accessible for your body to absorb. For example, fermenting dairy to make yogurt can help break down lactose, making it easier for some people to digest. In some cases, the microorganisms can even synthesize new nutrients, such as certain B vitamins, increasing the food’s nutritional value.

It’s helpful to know that not all fermented foods contain live probiotics. Processes like baking, pasteurizing, or filtering can kill the live cultures. Sourdough bread, for instance, is fermented, but the bacteria are killed during baking. Similarly, many beers and wines are filtered. If you’re specifically looking for a probiotic benefit, check product labels for phrases like ‘live and active cultures.’ Including a variety of fermented foods can be a great way to add new flavors and nutrients to your diet, but they are one part of a broader healthy eating pattern.

How to add them to your diet

Start with small servings to see how your digestive system responds, especially if you’re new to these foods.
Incorporate them into meals you already enjoy. Try adding kimchi to fried rice, sauerkraut to a sandwich, or using kefir in a smoothie.
Read labels if you are looking for probiotics. Look for terms like ‘live and active cultures’ on yogurt and kefir.
Explore different types to find what you like. The range of flavors is wide, from the tangy taste of kombucha to the savory flavor of miso paste.
Consider making your own. Simple ferments like sauerkraut or pickled vegetables can be made at home with basic equipment.

Fermented Foods vs. similar terms

Compared with	How Fermented Foods differs	What the other term means
Probiotics	Fermented foods are a potential source of probiotics, but not all contain live cultures by the time you eat them.	Probiotics are the specific strains of live, beneficial microorganisms themselves, which can be found in some foods or taken as supplements.
Prebiotics	Fermented foods can contain live bacteria (probiotics), which are different from the compounds that feed bacteria.	Prebiotics are types of dietary fiber that act as food for the beneficial bacteria already living in your gut.

Common misconceptions

Myth: All fermented foods are full of probiotics. Some fermented products are processed in ways that kill the live microorganisms. For example, the heat from baking kills the cultures in sourdough bread, and pasteurization kills them in some yogurts and sauerkrauts.
Myth: Eating fermented foods will solve my digestive problems. While they can support a healthy gut for many people, they are not a treatment for medical conditions. Digestive health is complex and depends on your entire diet, lifestyle, and individual health status.
Myth: More is always better when it comes to fermented foods. Introducing a large amount of fermented foods too quickly might cause temporary gas or bloating for some people. It’s usually best to start with small portions and gradually increase your intake.

Related terms

When to bring in a professional

While fermented foods can be a healthy part of many diets, it’s a good idea to talk to a professional in certain situations.

Talk to a registered dietitian for personalized advice on how to include fermented foods in your diet, especially if you have an existing health condition.
Consult a doctor for any persistent digestive issues like pain, bloating, or significant changes in bowel habits.
Speak with your doctor before making major dietary changes if you have a compromised immune system.
Check with a healthcare provider if you have a histamine intolerance, as some fermented foods can be high in histamines.

How this entry was made: drafted with AI assistance from general, widely published definitions, checked in a separate verification pass for invented numbers and claims, and edited by the Millennials Wellness editors. General information only, not medical, financial or legal advice. Last checked October 2026. Our ground rules · Back to the glossary