CFU: This is the number of "colony forming units" present in each dose, which are measured in the billions. And while more isn't always better, "you want at least 20 to 50 billion CFU," says Dr. Nazareth. Just for reference, a very high dose is 400 CFU, which most experts agree is not necessary unless your health care practitioner specifically recommends this for you. It's also important to check for the guaranteed CFU upon expiration, which should be listed clearly. "Some products only guarantee the CFU number at the time of manufacturing, therefore will be less potent by the time the product reaches your home," she says.

Selecting a multi-strain probiotic is also consistent with the theory that filling your gut with enough good bacteria outcompetes any bad bacteria for the same space and resources. In your gut, the more diversified the good bacteria, the harder it is for the baddies to gain a foothold. With all this in mind, we only looked at supplements containing multiple strains of bacteria.
CFU: This is the number of "colony forming units" present in each dose, which are measured in the billions. And while more isn't always better, "you want at least 20 to 50 billion CFU," says Dr. Nazareth. Just for reference, a very high dose is 400 CFU, which most experts agree is not necessary unless your health care practitioner specifically recommends this for you. It's also important to check for the guaranteed CFU upon expiration, which should be listed clearly. "Some products only guarantee the CFU number at the time of manufacturing, therefore will be less potent by the time the product reaches your home," she says.
If you decide to use a probiotic supplement and get clearance from your doctor for doing so, be sure to read the label carefully. You want to be sure that the supplement contains live strains of the bacteria or yeast, and that the life of these strains is guaranteed at the time of use, and not at the time of manufacture. Other points of comparison are the number of bacteria strains and the number of colony-forming units, although this does not necessarily guarantee results.
Yes, they may help. Lebwohl says there are reputable studies that show a link between the use of probiotics and the reduction in IBS symptoms, citing this meta-analysis. It's estimated that 11 percent of the world population complains of symptoms like abdominal cramps, diarrhea, constipation, excessive gas and/or mucus in their stools. While for some the condition can be attributed to certain dietary triggers, others appear to be stress-related, which brings us to the heart of where many claims about the effectiveness of probiotics lie—in the gut-brain axis.
However, a 2003 pilot study and 2011 randomized, controlled trial both reported that RA activities remained unchanged, but the subjects treated with probiotics reported statistically significantly higher levels of “subjective well-being.” One suggested reason for this was that the trials were too short to establish changes in the observable changes in the internal earmarks of RA.
Even for healthy people, there are uncertainties about the safety of probiotics. Because many research studies on probiotics haven’t looked closely at safety, there isn’t enough information right now to answer some safety questions. Most of our knowledge about safety comes from studies of Lactobacillus and Bifidobacterium; less is known about other probiotics. Information on the long-term safety of probiotics is limited, and safety may differ from one type of probiotic to another. For example, even though a National Center for Complementary and Integrative Health (NCCIH)-funded study showed that a particular kind of Lactobacillus appears safe in healthy adults age 65 and older, this does not mean that all probiotics would necessarily be safe for people in this age group.
Niv Zmora, Gili Zilberman-Schapira, Jotham Suez, Uria Mor, Mally Dori-Bachash, Stavros Bashiardes, Eran Kotler, Maya Zur, Dana Regev-Lehavi, Rotem Ben-Zeev Brik, Sara Federici, Yotam Cohen, Raquel Linevsky, Daphna Rothschild, Andreas E. Moor, Shani Ben-Moshe, Alon Harmelin, Shalev Itzkovitz, Nitsan Maharshak, Oren Shibolet, Hagit Shapiro, Meirav Pevsner-Fischer, Itai Sharon, Zamir Halpern, Eran Segal, Eran Elinav. "Personalized Gut Mucosal Colonization Resistance to Empiric Probiotics Is Associated with Unique Host and Microbiome Features." Cell (First published: September 6, 2018) DOI: 10.1016/j.cell.2018.08.041
The bad news about constipation is that there can be many causes, from simple causes like dehydration and lack of fiber to complicated structural causes or disease. While constipation may seem to be only a nuisance that causes uncomfortable symptoms such as abdominal bloating or pain, the truth is that constipation increases the risks of several diseases.
We are clearly getting to the strain level by going beyond “Saccharomyces boulardii” and to “Saccharomyces boulardii CNCM I-745”. They did a great job by actually putting it on the label so you don’t even have to contact the company to see exactly what strain you’re getting. (P.S. this is a well-researched strain that I highly recommend, especially for preventing antibiotic-associated diarrhea.) 

The idea that bacteria are beneficial can be tough to understand. We take antibiotics to kill harmful bacterial infections and use antibacterial soaps and lotions more than ever. The wrong bacteria in the wrong place can cause problems, but the right bacteria in the right place can have benefits. This is where probiotics come in. Probiotics are live microorganisms that may be able to help prevent and treat some illnesses. Promoting a healthy digestive tract and a healthy immune system are their most widely studied benefits at this time. These are also commonly known as friendly, good, or healthy bacteria. Probiotics can be supplied through foods, beverages, and dietary supplements.
Probiotics have also been researched for how they support the immune system. Studies suggest that probiotics can improve how the immune system functions such as by decreasing upper respiratory tract infections in adults and reducing the need for antibiotics. Studies in children show that a regular diet including probiotics reduces colds and flu-like symptoms and improves attendance in preschool and day care settings.
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.
But what if investigators could design probiotics to treat specific individuals? Many researchers think personalized probiotics are the most promising path forward for patients with compromised gut microbiomes. Last year Jens Walter of the University of Alberta and his colleagues published a study that gives a glimpse of this potential future. The researchers decided to see what it would take to get the bacteria in a probiotic to successfully colonize the intestines of 23 volunteers. They chose a particular strain of Bifidobacterium longum that earlier studies had indicated could survive in the human intestine. In the study, the volunteers consumed either a drink containing 10 billion live B. longum bacteria or a placebo in the form of a glucose-based food additive (maltodextrin) each day for two weeks. Periodic fecal samples revealed higher than typical levels of B. longum in participants who did not consume the placebo.
But before you start reaching for the calcium supplements, there may be a more effective way to support your bone health. Like many other parts of the body, the health of your bones is closely tied to the health of your gut, especially your intestines. Temporary intestinal inflammation can trigger an immune response in which your body releases interleukins, proteins that have an immune function but also absorb bone tissue. If the temporary inflammation remains unaddressed, these molecules can take a toll on your bones, eventually weakening them.14
In a separate study involving 21 healthy volunteers, also published today in Cell, the same group of researchers found that taking probiotics after treatment with broad spectrum antibiotics may actually delay the return of people's normal gut microbiome. This goes against the idea that probiotics can help "repopulate" people's gut bacteria after antibiotics wipe them out.

This dairy-free, gluten-free, vegetarian probiotic delivers live microorganisms, protected in stomach acid-resistant capsules to ensure effective delivery throughout your digestive system, from the stomach through your small intestines. The result is the repair and sustained maintenance of your intestinal micro-ecology, which in turn helps support healthy immune response and bowel regularity.


Every person's microbiome is different, which means what worked for others might not work for you. "What you eat, whether you were born by C-section or vaginally, what antibiotics you have been exposed to, and whether or not you have ever developed food-borne illness are just some of the many factors that impact your gut microbiome," explains Scarlata. And while research can help you determine which strains to take at which dosages, there may still be several different formulations to choose from.


Yes, they may help. Lebwohl says there are reputable studies that show a link between the use of probiotics and the reduction in IBS symptoms, citing this meta-analysis. It's estimated that 11 percent of the world population complains of symptoms like abdominal cramps, diarrhea, constipation, excessive gas and/or mucus in their stools. While for some the condition can be attributed to certain dietary triggers, others appear to be stress-related, which brings us to the heart of where many claims about the effectiveness of probiotics lie—in the gut-brain axis.

While this feature contributes to the efficiency of the product, it is unclear whether this product is vegetarian like some of the other probiotics we reviewed. Therefore, if you have any dietary restrictions or needs, this may not be the best probiotic for you and may, in fact, cause additional stomach upset or irritation. It is however gluten-free.
​​​​​​AZO Complete Feminine BalanceTM is a daily probiotic supplement designed for the unique needs of women. Researchers that formulated the blend started by selecting species that are dominant in the healthy vaginal microbiota. Then they further refined the formula by selecting strains of probiotics that flourish in the vagina. The blend is clinically proven to help protect vaginal/feminine health.*
As the best-selling author of Happy Gut and a medical doctor who specializes in gut health and once suffered from IBS (irritable bowel syndrome), I have experienced for myself, as well as see on a daily basis, how a disrupted gut flora opens the door for unfriendly microbes to step in and take over, creating all sorts of pandemonium that causes patients to gain weight, feel sick and tired, and become more disease-prone.

B. Bifidum has also been shown to prevent intestinal pathogens or digestive disrupters from flourishing in the gut, essential in restoring the bacterial balance and optimizing digestion. Clinical research found it supports a significant reduction in IBS symptoms, an improvement in quality of life and even helps relieve occurrences of ulcerative colitis – a chronic inflammatory bowel disease. [1].
The vH Probiotics with Prebiotics and Cranberry are specifically designed to give you complete feminine tract care, and work to fight recurrent yeast infections and urinary symptoms. While this particular probiotic formula may provide some digestive relief, it is important to note that it is largely marketed towards women with these feminine health conditions. For that reason, women that are looking for more digestive care should consider a different probiotic that is more geared towards gut health.

This is one of the newer areas of probiotic research. Described as the “gut-brain axis,” researchers believe that the communication between the gut and the brain affects not just physical but also mental health and behavior. For example, a recent study found that probiotics can reduce anxiety, relieve stress and improve mental outlook. Another study found that the probiotics L. helveticus and Bifidobacterium longum reduced depression, anger, hostility and self-blame and improved problem-solving ability. Another study showed a difference in brain activity between women consuming yogurt and those consuming a placebo. More research needs to be done to confirm the effect of probiotics on mental and emotional health.

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.
Update: I think this product is being smeared by a competitor! Look at all the reviews in April. Suddenly, a butt ton of not just negative but 1 star reviews. It's uncanny. So, what would compel a competitor to do such a thing? Well, it was the only 50 CFU, enteric coated & 20 strain probiotic on Amazon & it cost about 15 bucks. That, while products far inferior to it were priced for - often times - 2 or 3x as much.
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.
Many Lactobacillus and Bifidobacterium species are naturals at protecting and improving gut health. Additionally, research in animals and humans has shown that probiotics decrease scores on depression assessments, thereby alleviating depression. As a matter of fact, there is a new term, psychobiotics, for these microbes that influence mental health conditions like depression.
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Although many manufacturers will make claims regarding the benefit of probiotics for all sorts of disorders, there is not always research to back up those claims. It can be difficult to conduct quality research on probiotics due to the wide variety of strains available. And many studies show mixed results. However, given that, there is some research support for the use of probiotics for the following health conditions:
Tempeh is made with fermented soybeans or grains that have been molded into a cake-like form. The nuttier, tangier cousin to tofu can be sliced for sandwiches, tossed into stir-fries, or marinated and grilled. In addition to probiotics, tempeh contains about 15 grams of protein per half-cup and is a good source of iron. Plus, soy foods contain compounds that may help keep cholesterol in check, according to a study in The American Journal of Clinical Nutrition. Palmer likes to use tempeh in place of tofu in dishes like stir-fries, salads, and side dishes.

If these issues and many others are connected to gut health, then what elements are essential for digestive health? Consider this: According to the National Institute of Diabetes and Digestive and Kidney Diseases, upward of 60 million to 70 million Americans are affected by digestive diseases. In addition, digestive disease and disorders cost the United States over $100 billion per year.

Helicobacter pylori (H. pylori) is a bacteria that causes chronic inflammation (gastritis) of the inner lining of the stomach, and also is the most common cause of ulcers worldwide. About 50% of people in the world carries or is infected with H. pylori. Common symptoms of H. pylori infection are occasional abdominal discomfort, bloating, belching or burping, and nausea and vomiting. H. pylori infection is difficult to erdicate, and treatment is with two or more antibiotics.

Historically, people had plenty of probiotics in their diets from eating fresh foods from good soil and by fermenting foods to keep them from spoiling. Over a century ago, the Russian Nobel Prize winner Elie Metchnikoff theorized that “health could be enhanced and senility delayed by manipulating the intestinal microbiome with host-friendly bacteria found in yogurt.” Metchnikoff was ahead of his time with his view of probiotics benefits, but he also was aware that most citizens had regular access to probiotic foods.
Most bacteria are included through the fermentation process. Fermentation helps extend the shelf life of perishable foods. It is a slow decomposition process of organic substances induced by microorganisms or enzymes that essentially convert carbohydrates to alcohols or organic acids. The lactic acid supplies the bacteria that then add the health benefits to the food. You can purchase foods that are fermented or ferment them yourself.
Many women eat yogurt or insert it into the vagina to treat recurring yeast infections, a "folk" remedy for which medical science offers limited support. Oral and vaginal administration of Lactobacilli may help in the treatment of bacterial vaginosis, although there isn't enough evidence yet to recommend it over conventional approaches. (Vaginosis must be treated because it creates a risk for pregnancy-related complications and pelvic inflammatory disease.) Probiotic treatment of urinary tract infections is under study.
Given that you can get probiotics from the food you eat, you don't necessarily need to take a supplement, and Keatley says she prefers food sources of probiotics to supplements. However, she adds that "There are times when you really need a boost." One example might be during or after a course of antibiotics, as long as you have your doctor's OK, since antibiotics kill both good and bad bacteria: "Seeding your gut with good bacteria can lay the groundwork for a faster recovery and less constipation and diarrhea," Keatley points out. Angelone echoes Keatley's emphasis on food sources of probiotics, but also says that supplements can also play a useful role in "maintaining a healthy gut bacteria colony."
If you get sick often, probiotics might be the immune booster you've been looking for. The Cleveland Clinic says they've been shown to strengthen immunity by enriching and replenishing the good bacteria in the body. And when you eat foods with probiotics regularly, it's easier for your body to produce vitamins and enzymes that help keep your intestines happy. 

Because there's a huge variety of probiotic products available on the market, many people struggle to find the right one for them. "There are many different strains of bacteria in different combinations within different probiotic supplements," explains Brooke Scheller, a clinical and functional nutritionist. "For example, a probiotic may contain a single strain of bacteria or many. It may also contain other vitamins, minerals, or other ingredients that may tout health benefits," she says. There are many different dosages, delivery systems (powder, tablets, capsules), and formulations (refrigerated vs. shelf-stable), and some probiotics also contain prebiotics, which basically act as fertilizer for the probiotics. (Related: Why Your Probiotic Needs a Prebiotic Partner)

An imbalance between good bacteria and pathogenic bacteria, yeasts or fungi, or a change in the bacteria species that colonize the digestive tract is called dysbiosis. It can have short and long-term effects on our body functions. These disruptions can reduce the immune system’s effectiveness, create unpleasant digestive symptoms (diarrhea, constipation, gas, etc.), be a contributor to certain chronic illnesses like obesity, and participate in producing pro-inflammatory metabolites.
The side effects of antibiotic use are often not trivial. Many people experience discomfort and a change in bowel habits, but some experience more severe infections, such as opportunistic colonization of the gut with bacteria such as Clostridium difficile (C.diff), which affected half a million Americans in 2015 and was directly responsible for at least 15,000 deaths.
This Korean staple relies on lactic acid fermentation (also called lacto-fermentation) to turn cabbage or other vegetables into a spicy, pungent side dish that's packed with vitamin C. Order it at Korean restaurants or buy it in the refrigerated section of your grocery store (King's Kimchi is widely available at Walmart). For some guidance on making your own, turn to The Art of Fermentation ($23; amazon.com). Then, use it to spike veggie-laden rice bowls, top on soup, or serve alongside meat.
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