More than a third of people say gut health is the biggest benefit they’re seeking from food, according to a 2024 survey. If you’re concerned with your digestive health, it’s time to get familiar with probiotic foods, certain fermented foods rich in beneficial bacteria.
No doubt you’ve heard the term probiotic. This technically refers to live organisms in amounts known to provide health benefits. You can score probiotics through supplements and certain fermented foods, though not all fermented foods can be characterized as containing probiotics.
Read on to learn why you should be getting beneficial bacteria from your foods and how to tell which foods have them.
What are probiotics?
Probiotics are good bacteria that help maintain a healthy balance in the gut. Everyone’s gut is unique — like a fingerprint — but one of the most important features of a healthy gut is the diversity of microbes that reside there. Think of these beneficial bugs as each playing a different role on a team, so just like a baseball team needs a pitcher, a catcher, and so on, you need many different critters to form a healthy microbial community.
Are probiotics good for you?
Consuming microbes through probiotic foods and other fermented items is irrefutably good for you. The varied roles of gut microbes include producing certain vitamins or helping you absorb nutrients better, aiding in digestion and keeping bad microbes from causing harm. Your gut environment paves the way to a healthy body and mind. For instance, the majority of your immune system cells originate in the gut, as do most of your mood-regulating chemical messengers.
Probiotics in supplement form can be good for you, but there’s no one-size-fits-all approach. If you’re interested in addressing a health concern, work with a registered dietitian to help you identify the specific strain that has scientific evidence of an improved outcome. For instance, certain bacterial strains may help relieve constipation or traveler’s diarrhea, or help with stress and anxiety.
What are fermented foods?
Fermented foods are made using microorganisms, such as bacteria, yeast, or mold. Sometimes food can be fermented by natural compounds that are already present. Fermented foods have been a staple in human diets across cultures for hundreds of years. From Korean kimchi to German sauerkraut to Japanese miso, fermented foods hold cultural significance. These days, fermented foods are also prized for their numerous health benefits.
Additional fermented foods include yogurt, kefir, kombucha, cheese, pickles and sourdough bread. However, depending on how the product was produced, the microbes may or may not be present in the end product. For example, heat destroys microbes, so the live cultures aren’t typically present in baked goods (such as sourdough bread) or canned sauerkraut and pickles. (Look for jarred varieties in the refrigerator section of your grocery store to increase the likelihood you’ll be getting the beneficial bacteria.) Technically, wine and beer are fermented, but unless you’re buying a specialty product, there’s a slim chance it contains live active cultures.
Meanwhile, there’s promising evidence that consuming fermented foods with live active cultures can help improve your gut and overall health. Research has tied these foods with better metabolic health, such as improved fasting blood glucose and healthier triglyceride levels. A 2021 study by Stanford University researchers found that consuming six servings of fermented foods daily for 10 weeks led to a boost in microbiome diversity and lower levels of inflammatory markers associated with conditions such as stress, Type 2 diabetes, and rheumatoid arthritis.
Additionally, yogurt, a fermented dairy food, has been linked with a lower risk of heart disease and Type 2 diabetes while kimchi has been shown to have anti-obesity effects.
What’s the difference between probiotic-rich foods and fermented foods?
Here’s where things get a little bit tricky. While many people refer to live cultures as probiotics, that’s not quite accurate. Remember the agreed-upon scientific definition is that a probiotic is a live organism in an amount that provides a health benefit. The live organism is further characterized by the genus, species and strain. Some of these probiotic strains may be used in snack foods, dried fruits and more.
Fermented foods are a little different. They have probiotic-activity, but since the strain and amount aren’t known, they aren’t characterized as probiotic-rich foods. Even so, recall that regularly eating various fermented foods has been found to improve gut health, so it’s not necessary to get caught up in the lingo. What’s more important is to include a range of these foods as often as you can — ideally, multiple times a day.
The 10 best probiotic foods
- Low-sugar yogurt
- Kefir
- Cottage cheese made with live and active cultures (most brands don’t contain them, so look for it on the label)
- Refrigerated sauerkraut
- Kombucha
- Kimchi
- Miso paste
- Tempeh
- Refrigerated pickles
- Certain cheeses, including Swiss, provolone and cheddar
Tips to eat more probiotic foods
- Include a yogurt that's low in added sugar with breakfast. Have it with fruit and nuts, blended into a smoothie, spread over whole grain toast, or mixed into oatmeal.
- Snack on drinkable yogurt, kefir and cottage cheese that contains live active cultures.
- Add sauerkraut to sandwiches, burgers, scrambled eggs and avocado toast. You can also blend a quarter-cup of sauerkraut into your favorite fruit and veggie smoothie.
- Sip on kombucha that's low in added sugar.
- Use the liquid brine from pickles and other fermented veggies to make a salad dressing or sandwich spread.
- Use kimchi to kick up the flavor in scrambled eggs, sandwiches, and whole grain bowls.
Who should eat probiotic-rich and fermented foods?
Most people benefit from gut-healthy foods. Eating these foods regularly promotes a more diverse gut microbial environment, which in turn may help relieve digestive issues, such as constipation, and lead to improvements in stress, anxiety, depression, nutrient absorption and metabolic health.
Unless you have a food sensitivity or intolerance to one (or more) of these foods, there’s no real downside to eating them, other than perhaps being unfamiliar with ways to enjoy them. The best evidence suggests aiming for six servings of fermented foods daily. If this sounds unmanageable, consider that serving sizes may be smaller than what you’re used to. A serving of kombucha and yogurt can be as small as six ounces, while a typical bottle of kombucha might have two to three times that amount.
More tips for improving your gut health
- Fill your plate with at least 75% plant foods. This amount helps ensure you meet the fiber target of 21 to 38 grams per day. Plus, plant foods are rich in prebiotic fibers and polyphenols in plant foods that help feed your gut microbes, enabling more diversity.
- Diversify the plants on your plate. One study found gut health benefits, such as a greater range of microbial species and reduction in certain antibiotic resistance genes, among people who ate 30 unique plant foods per week compared to those eating 10 or fewer different types of plants. If you’re worried about that amount, consider that spices, coffee, tea, oats, brown rice, beans, nuts, seeds, fruits and veggies all count.
- Get sufficient activity. There’s evidence that moderate exercise can increase microbial diversity, lower inflammation and reduce intestinal permeability, which are signs of a healthy gut.
- Sleep for seven to nine hours each night. Researchers have found an interplay between sleep and gut health, noting a positive correlation between microbiome diversity and increased sleep efficiency and duration.
- Find helpful ways to cope with stress. Stress can affect your gut permeability and negatively alter your microbial community. Tools to lower stress include exercise (from gentle to intense), deep breathing and meditation, spending time in nature and social connection. Working with a therapist is another great tool.
