10 Best Natural Sources Of Probiotics, According To Nutrition Experts

Probiotics are well known for being beneficial for your gut and overall health.*

So, while you probably have a general idea of what probiotics are and do, you might be a little hazy on things like the best natural sources of probiotics.

For a little refresher: Probiotics are live microorganisms that can have health benefits* when you eat them or apply them to your body, according to the National Center for Complementary and Integrative Health (NCCIH).

Probiotics are mostly bacteria, but they can also be from yeast, says Keri Gans, M.S., R.D., author of The Small Change Diet.

They're naturally occurring in certain foods, particularly fermented options.

Taking a supplement can give you quick access to certain probiotics, but there are other options, too.

"One of the easiest ways to [get natural probiotics] is to increase the number of probiotic-rich foods in your diet," says Sophia Tolliver, M.D., MPH, a family medicine physician at the Ohio State University Wexner Medical Center.

Most cheeses are fermented, but not all cheese contains probiotics. Cheeses like cottage cheese, Gouda, and cheddar can contain probiotics (but it's important to check the label to be sure), Tolliver says.

Kefir is similar to yogurt, but it's slightly different. This is a fermented milk drink, and it's made by mixing kefir grains with milk, Cording says.

Kimchi is cabbage fermented with probiotic lactic acid bacteria, and it's a traditional staple in Korean cuisine.

Kombucha is made from SCOBY, which stands for symbiotic culture of bacteria and yeast, that is mixed with sweetened black or green tea.

Miso is a type of seasoning that's made by fermenting soybeans with salt and the fungus koji.

Pickles are created when cucumbers are left in a combination of salt and water.

Pickles go through a fermentation process, and that causes the food's naturally present lactic acid bacteria to thrive.

Sauerkraut is simply cabbage that's been fermented by lactic acid bacteria.

But, as with pickles, you'll want to be wary of the type of sauerkraut you buy if it's the probiotic perks you're after.

Traditional buttermilk is a little different from the stuff you find at the supermarket (that's called cultured buttermilk).

Yogurt is one of the best natural sources of probiotics, according to Cording. It's made from fermented milk and usually contains good bacteria like lactic acid bacteria and Bifidobacteria.

The actual type of probiotics in yogurt depends on the type you choose, although more common strains include different forms of Lactobacilli and Bifidobacterium. (Check the label of your yogurt for details.) 

The quantity of probiotic foods you should aim to include in your diet varies, Tolliver says.

However, the American Academy of Family Physicians generally recommends that adults try to consume 10 to 20 billion colony-forming units (CFU) per day.

"Keep in mind, probiotic concentrations vary across foods," Tolliver says. "For example, yogurt on average can contain one to five strains of different bacteria and 6 billion colony-forming units, whereas kefir can contain nearly 12 different strains of bacteria and 25 to 30 billion colony-forming units."

The biggest rule of thumb when picking out a probiotic supplement is to opt for one that contains at least 1 billion CFUs, Tolliver says.

But ultimately the science on each strain should dictate how many billion CFUs are in the product. To that end, you want to choose products that contain the most well-researched strains, like Lactobacillus, Bifidobacterium, or Saccharomyces boulardii, says Liping Zhao, Ph.D., chair of applied microbiology at Rutgers University.

"There need to be clinical trials to show that they have beneficial effects,"* he says. Otherwise, he points out, you're basically left guessing whether your probiotic is working for you.

Keep in mind that can be hard to consistently get enough probiotics in your day from diet alone.

"In order to reap the full benefits, I tend to recommend supplementation,"* Cording says. "There are so many different types of these bacteria, and certain foods will have some kinds but may not have much of others."

Cording stresses that she's "very much a food-first practitioner" but notes that, "sometimes we need to incorporate supplements to get the full benefits. Probiotics are one of those cases."*

A concentrated supplemental probiotic format is particularly relevant for targeted probiotics with clinical evidence for key health areas, like elevating your gut microbiome, for example.*