That said, supplements with higher numbers of CFUs are sometimes used to treat conditions such as irritable bowel syndrome (IBS), allergies, and respiratory illness. While probiotics have generally been found to be safe for most people with normal immune systems, too much can cause gas and upset stomach. We narrowed our search to supplements with dosages between 1 billion and 100 billion CFUs.

Florastor uses the unique strain Saccharomyces boulardii lyo, which works to strengthen digestive balance and boost immunity. To boost immunity, Florastor stimulates the production of immunoglobulin A — an antibody that helps defend your body against infection. If you’re on long-term antibiotics, this will be a good option for you as Florastor is genetically resistant to antibiotics. When taking a probiotic supplement at the same time as an antibiotic, Gans advises waiting at least two hours in between. Each box contains 50 capsules. Take one to two capsules per day.
Unlike MegaFood, the Renew Life label’s cold-storage recommendation is printed so small we nearly missed it (and it didn’t ship with a cold pack). If a probiotic requires refrigeration, be vigilant when buying it — the retailer that stores it or the company that ships it should keep it refrigerated until it gets to you. Otherwise, some of its potency might diminish in storage or transit.
Make sure dosages are listed in CFU, colony forming units. (Most brands list CFU in billions now: so 30 billion CFU, 100 billion CFU, and so on.) For one, this means that the bacteria strains are living, which is essential. When you’re looking at the cost of products, be sure to look at the cost per unit. I spoke to a woman the other day who had bought probiotics that had 2 billion CFU per capsule. In comparison, to get the 30 billion CFU I recommend, she’d have to take essentially half of her bottle to get the same dosage as one of our capsules.
According to a 2014 meta-analysis, probiotics benefit diabetics by improving insulin sensitivity and decreasing the autoimmune response found in diabetes. The authors suggest that the results were significant enough to conduct large, randomized, controlled trials (the “gold standard” of scientific studies) to find if probiotics may actually be used to prevent or manage diabetes symptoms. Combining probiotics with prebiotics may also help manage blood sugar, particularly when blood sugar levels are already elevated. (87)
Whether a brand of probiotics works really depends on its quality and your body's own gut. Everyone has a different set of gut flora so try several to see what works for you. Using a brand of at least 40 billion CFU is best. There seems to be some debate as to whether one should use refrigerated or unrefrigerated probiotics. I went with the side that claims unrefrigerated are sturdier and less prone to die off.
Inside your body bacterial and other microbial cells live in close contact with your own cells, and in healthy conditions the thing that separates them from you is a layer of mucus. Between that layer of mucus and the inside of you is a layer of skin-like cells one-cell thick. One thing you have to understand about your gastrointestinal (GI) tract is that although it resides within you, it is really connected to the outside world, from your lips to your anus, and the things that protect you from the outside world are the mucus; the skin-like layer of cells with immune, nervous, and endocrine cells below it; and the beneficial microbes. At least 70 percent of your immune system is in your GI tract! This is why taking probiotics benefits the immune system greatly.
Stability and organism types — Some probiotic strains need to be kept cold in order to preserve their potency. This applies to their production, transport, storage and sales. Others are shelf-stable and don’t require refrigeration. Unfortunately, most refrigerated probiotics never make it past the stomach because they aren’t stable. Instead, look for a shelf-stable product that contains soil-based organisms.
This content is strictly the opinion of Dr. Josh Axe and is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of medical advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Axe nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement or lifestyle program.
The research also showed that while probiotics colonised the gastrointestinal tract of some people, the gut microbiome of others just expelled them. There was no way of telling from their stool sample which category people fell into. “Some people accept probiotics in their gut, while others just pass them from one end to the other,” says Elinav. They found that the probiotic colonisation patterns were highly dependent on the individual. That tells us that the concept that everyone can benefit from a universal probiotic bought from the supermarket is empirically wrong, he says.

Probiotics are live bacteria that are present in yogurt, other fermented foods, and in pills. They are promoted as a benefit to the human digestive system. Normally you have trillions upon trillions of bacteria within the colon. Normally we ingest bacteria every time we swallow. Many of these swallowed bacteria may be beneficial while most are simply innocuous and cause no problems. The question for everyone who takes a probiotic much beyond yogurt is whether they really are a health benefit. Here is what we know medically about probiotics.
We also found strains linked to five other health benefits like weight loss and lowering cholesterol. We feature options for those cases below, but they aren’t top picks because those use cases aren’t as heavily researched as immune health or IBS relief. Still, chances are any probiotic supplement is going to make some improvement to your digestive health, so don’t be afraid to experiment.
DNA Shift is a once-daily, powerful probiotic delivering 50 billion CFUs and 11 probiotic strains. It’s perfect for both men and women who want to improve their gut and brain health. With long-term use, you may even see improved mood and energy levels. This probiotic can help relieve the following: symptoms of gas and bloating, constipation indigestion, irregularity, leaky gut, and diarrhea induced by antibiotics.
EDITOR’S CHOICE: As the only probiotic formula we reviewed backed by a New York Times Bestselling author and expert in the human biome, the Garden of Life Dr. Formulated Once Daily Women’s Probiotic is our top choice for overall digestive and women’s health. With 50 billion cultures and 16 probiotic strains, this probiotic helps to promote women’s digestive, immune and vaginal health.
Made from aged, fermented soybeans, this paste is brimming with probiotics. You can buy miso paste in a bunch of varieties (white, yellow, red, brown) and the darker the color, the deeper the taste. Miso is a great way to add a burst of earthy, savory flavor for few calories (only 25 to 30 per tablespoon), plus protein, fiber, and bone-strengthening vitamin K, says Sharon Palmer, RDN, author of Plant-Powered for Life. "While we need more research about how these types of fermented foods contribute to health, it's a good idea to introduce more of them into your diet," she says. Use miso to glaze fish or chicken before cooking, mix into a stir-fry recipe, or add to liquid to make a miso broth. One caveat: Miso is very high in sodium. One teaspoon, enough to make a cup of miso soup, has 473 mg of sodium, 21% of the daily recommended limit and 32% of the daily limit for those with high blood pressure.
The bottom line: Stick to trusted whole food sources of probiotics if you don’t know a probiotic supplement brand you trust. “Kimchi, pickled beets, Greek yogurt and sauerkraut are great sources of probiotics. If you don’t like them, throw them into a food you do like, like a smoothie, and add your favorite fruit to help mask the flavor,” Taub-Dix says.
Fermenting a cucumber into a pickle amps up a cuke's powers, infusing the crunchy veggie with probiotics. Like sauerkraut, not all pickles offer the good bacteria, though. Look for those made with brine (salt and water) rather than vinegar. These brands will list "live cultures" on the label (like Bubbies). You can also use water, salt, and spices to naturally culture pickles and other veggies—like beets, green beans, and carrots—at home with delicious results. One warning: remember that pickles are salty—one dill can easily offer up more than 10% of your sodium needs in a day.
The benefits of probiotics don't stop at internal health. Research from the American Academy of Dermatology found that, whether applied topically or taken orally, probiotics can potentially help patients with skin issues such as acne, rosacea, and eczema. More studies need to be done though, so talk to your dermatologist before changing your regular routine.
Some studies suggest that certain probiotic strains may also help in mild to moderate ulcerative colitis and possibly for bloating and gas in irritable bowel syndrome (IBS). Probiotic supplements, on the whole, “improve global symptoms, bloating, and flatulence in IBS,” by modifying the gut microbiome, according to a 2014 monograph from the American College of Gastroenterology. As IBS researchers said in a paper in Gastroenterology & Hepatology in 2015, “The concept of manipulating the microbiome is one of the most promising new ways in which to treat patients with IBS, but there is still much to learn.”
Even if some of the bacteria in a probiotic managed to survive and propagate in the intestine, there would likely be far too few of them to dramatically alter the overall composition of one's internal ecosystem. Whereas the human gut contains tens of trillions of bacteria, there are only between 100 million and a few hundred billion bacteria in a typical serving of yogurt or a microbe-filled pill. Last year a team of scientists at the University of Copenhagen published a review of seven randomized, placebo-controlled trials (the most scientifically rigorous types of studies researchers know how to conduct) investigating whether probiotic supplements—including biscuits, milk-based drinks and capsules—change the diversity of bacteria in fecal samples. Only one study—of 34 healthy volunteers—found a statistically significant change, and there was no indication that it provided a clinical benefit. “A probiotic is still just a drop in a bucket,” says Shira Doron, an infectious disease expert at Tufts Medical Center. “The gut always has orders of magnitude more microbes.”
There’s good and bad bacteria in there (fascinating fact: an estimated 100 trillion bacteria live inside your digestive tract): When the good outweighs the bad, your immune health soars; when the bad overpowers good, you get sick. You have diarrhea. Your immune system tanks. Your IBS, lactose intolerance, and other gut problems are exacerbated. It throws your entire system out of whack.

When seeking out the best probiotic for you, consider your overall health, dietary needs, antibiotic use, GI challenges, and similar concerns. Then, review our list of the ten best probiotic supplements, which offer everything from raw probiotics, which must be refrigerated, to shelf-stable, slow-release probiotics that concentrate fewer CFUs in tiny, once-daily capsules.
While raw probiotics tend to be the freshest (and most effective!) cultures on the market, it is important to ensure that you will store these properly in between each use. Cultures can die unrefrigerated in as little as a few hours, rendering them completely ineffective and, if you’re especially unlucky, even harmful to your body’s natural flora. Think about it, when has stale or moldy bread made your tummy feel better? The same thing goes for stale probiotic cultures!
Probiotics may also be of use in maintaining urogenital health. Like the intestinal tract, the vagina is a finely balanced ecosystem. The dominant Lactobacilli strains normally make it too acidic for harmful microorganisms to survive. But the system can be thrown out of balance by a number of factors, including antibiotics, spermicides, and birth control pills. Probiotic treatment that restores the balance of microflora may be helpful for such common female urogenital problems as bacterial vaginosis, yeast infection, and urinary tract infection.

If you’re looking for a great probiotic you can take every day to target everything from gut to skin health, the Culturelle Daily Probiotic is our top choice. Each capsule has 10 billion active cultures of 100 percent Lactobacillus GG, a probiotic that helps curb gas, bloating, and upset stomach, and works to boost your immune system. Each capsule has the probiotic equivalent of 10 cups of yogurt and is dairy-free, sugar-free, and gluten-free. This container comes with 30 pills to be taken just once a day (most recommend taking it at night, especially when you’re just starting on probiotics).
Fermenting a cucumber into a pickle amps up a cuke's powers, infusing the crunchy veggie with probiotics. Like sauerkraut, not all pickles offer the good bacteria, though. Look for those made with brine (salt and water) rather than vinegar. These brands will list "live cultures" on the label (like Bubbies). You can also use water, salt, and spices to naturally culture pickles and other veggies—like beets, green beans, and carrots—at home with delicious results. One warning: remember that pickles are salty—one dill can easily offer up more than 10% of your sodium needs in a day.
To factor strain-specific benefits into our efficacy score, we referenced the information in these guides. Products were rewarded for containing strains on these lists. Additionally, measured levels of each strain were compared to what is thought to be effective based on these guides, and scores were scaled accordingly. In cases where products did not list strain-specific amounts, or their listed strains were not included in these guides, total measured CFUs were compared to a general effectiveness threshold of 1 billion CFUs cited by research published in the American Journal of Clinical Nutrition11.
Probiotics for allergies are fast becoming a preferred treatment method because they are understood to be much safer than traditional allergic rhinitis medication. A nasal spray for allergies is often a ‘go to’ treatment, for example, but allergy nose spray medications often contain corticosteroids, like Beclometasone dipropionate, which could affect bone metabolism, blood cells, and the pituitary gland.
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