The U.S. Clinical Guide to Probiotic Products1, Canadian Guide to Probiotic Supplements2 and the WGO Global Guidelines for Probiotics and Prebiotics3 provide suggested effective amounts of specific strains for treating certain health conditions, such as constipation or IBS. All 37 products listed the species of bacteria they contained, but only 14 listed amounts of individual strains. We found that 9 of those 14 products provided beneficial bacteria at effective levels. The Center for Responsible Nutrition recommends4 the industry move toward specifying strains as a best-practice because whether a product works and for what purpose depends on its strains.
Back to the question of what are probiotics: There are five main types, each in its own classification called a genus. Within each genus there are multiple species, and within those species there are multiple strains. For example, Lactobacillus is a very common genus of probiotics. Within that genus are numerous species, such as rhamnosus. The genus and species of a microbe are always italicized, making it easy to know that a microbe is involved. In a species such as Lactobacillus rhamnosus (often abbreviated L. rhamnosus), there are many strains. An example of the name of a strain is L. rhamnosus GR-1.
"Probiotics applied topically sit on the skin's surface and prevent the skin cells from seeing the bad bacteria and parasites that can cause this immune system response," confirms Engelman. "This is known as 'bacterial interference,' as probiotics protect the skin and interfere with the ability of bad bugs like bacteria and parasites to provoke an immune reaction.
As far as effectiveness, keep in mind that unlike medications, dietary supplements do NOT need to be approved by the FDA. This means that manufacturers can sell supplements simply with "claims" of safety and effectiveness. Currently, researchers are undecided if probiotic supplements are effective. Some say probiotics are effective; others believe they offer no benefit whatsoever. It also remains unclear which probiotics (or combination of probiotics) work to treat certain diseases. Despite these issues, some studies have shown positive results. Still, more research is needed to confirm that probiotics are safe and effective.

What's more, people who have serious heart issues commonly have S. mutans in their heart valves—this is an undesirable type of bacteria that’s actually more often found in the mouth. If your oral microbiome is in balance, S. mutans are normally kept in control by more beneficial species, but if things get out of balance, they can reproduce and make their way into your bloodstream via openings in your gums, compromising your cardiovascular function.3
To avoid those and other problems, I strongly recommend buying a professional brand from a reputable health care professional or other vendor who stands by their products and undergoes third-party testing. Some of these professional brands have created advanced technology that preserves a probiotic supplement’s survival on the shelf and in your gut.
Because poor gut health is related to autoimmune responses like those found in rheumatoid arthritis (RA), probiotics have been a proposed treatment option for the condition. Only a few studies have been conducted in humans, and only one testing L. casei 01, a particular probiotic strain, was able to find a decrease in RA inflammation and progression of the disease.

Candida albicans is the most common species that causes yeast infections, but there are others. It is a normal inhabitant of the gastrointestinal tract and is often found in the female vaginal tract. Candida infections on the skin cause red, itchy rashes that often weep moisture, and in the vagina there is often a cottage-cheese-like discharge in addition to the skin symptoms.


An imbalance in the gut microbiota is believed to contribute to a number of health problems, particularly gastrointestinal issues, as well as immune dysfunction and infections. The bacterial balance can be disrupted by medical conditions, emotional and physical stress, and, most notably, use of antibiotics, which destroy the good bacteria along with the bad.
An imbalance in the gut microbiota is believed to contribute to a number of health problems, particularly gastrointestinal issues, as well as immune dysfunction and infections. The bacterial balance can be disrupted by medical conditions, emotional and physical stress, and, most notably, use of antibiotics, which destroy the good bacteria along with the bad.

If you’ve ever clicked on the 6:00 news or scrolled through the latest headlines on your smartphone, you probably know that supplements and vitamins are not typically backed by governmental entities like the FDA or the World Health Organization. This fact can leave supplement newbies a bit wary, which is exactly why we love the Garden of Life Dr. Formulated Once Daily Women’s Probiotic so much.
"In fact," she continues, "80% of immune system cells are found in the gut. In addition to the well-known GI benefits of minimizing bloat, gas, constipation, and diarrhea, probiotics aid in digestion by extracting nutrients, helping your body absorb minerals, produce vitamins, and make brain chemicals, including over 30 neurotransmitters along with mood-enhancing serotonin. A healthy person has over 100 trillion microbes, generally a five to one ratio of helpful to harmful."
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)
The statements on this website have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease. The contents of this website are not medical advice and are intended for general knowledge and informational purposes only. Probiotics support many facets of overall health when taken regularly as part of a balanced diet and healthy lifestyle.
Probiotics are live microorganisms (bacteria or yeast) that have been shown to have a health benefit for humans. They are available in supplement form or in probiotic foods and drinks. Probiotics are thought to be akin to (and to increase the level of) the "good" bacteria found in your intestines. These "good" bacteria are thought to enhance our health through their support of our immune systems.
That’s why adding probiotics and prebiotics to your diet provide the best possible outcome from a bacterial perspective. It isn’t always easy to eat naturally prebiotic-enriched foods, however, because they are often distasteful to eat in quantity. Would you enjoy eating several cups of raw onion or garlic every day? Probably not. Other foods that contain prebiotic fiber, such as bread and bananas, are high in calories. Consuming hundreds of calories of these foods every day is counterproductive if you’re trying to lose weight.
It’s great to get some healthy sour foods. I often add one tablespoon of apple cider vinegar to a drink, twice a day. Before breakfast and lunch or breakfast and dinner, add one tablespoon of apple cider vinegar in your meal, and then start consuming more fermented vegetables like sauerkraut and kimchi, or drinking kvass. Is apple cider vinegar a probiotic itself? No, but apple cider vinegar probiotic content makes it an excellent source of probiotics benefits.

Directions Take 2 Vegetarian Capsules with or without food. As a dietary supplement, take two (2) capsules once daily. For best results, take one (1) capsule during the day and one (1) capsules in the evening. Repeat the process daily. Do not exceed two capsules per day. As a dietary supplement, take one (1) veggie probiotic capsule once daily. Because our probiotic uses delayed release capsules, do not chew or crush. Our capsules help ensure the active probiotic strains reach your intestinal tract. Adults take 1 capsule daily. May be taken with or without food. Capsules can be opened. Contents can be taken directly with water or juice. Not intended for children.
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.
While past studies have investigated similar questions, they have all used patients' excrement as a proxy for microbe activity in the GI tract. Instead, Elinav, his colleague Eran Segal, (a computational biologist at the Weizmann Institute), and their teams spearheaded by Niv Zmora, Jotham Suez, Gili Zilberman Schapira, and Uria Mor of the Elinav lab collaborated with Zamir Halpern, Chief of Gastroenterology at the Tel Aviv Medical Center to measure gut colonization directly.

Remember that dietary supplements are not tested by the U.S. Food and Drug Administration like medications. And the probiotic strains in the supplements may not be specific for the condition you're looking to treat. You may want to consult with a practitioner, like a registered dietitian, who is familiar with probiotics. Always tell your physician what you are doing that may affect your health.
Importantly, patients with gastrointestinal conditions are not the only ones taking probiotics. 3·9 million people in the USA alone regularly take probiotic supplements, with promised benefits ranging from improved digestion and immune function to improved mental health and prevention of heart disease. However, evidence for these benefits is lacking, and because probiotics are often sold as supplements, manufacturers in many countries are not required to provide evidence of their safety and efficacy to regulatory bodies. The ubiquity of probiotic products would suggest that, at worst, they are harmless. Nevertheless, some safety concerns have been raised, including the risk of contamination, possibility of fungaemia or bacteraemia (particularly in immune-compromised, elderly, or critically ill individuals), small intestinal bacterial overgrowth, and antibiotic resistance. Adding to concerns, clinical trials of probiotics have not consistently reported safety outcomes.
Additionally, it's a good idea to take note of the number of colony-forming units (CFUs) that are in the supplement you're considering, Angelone says. CFU count tells you the number of viable, active bacteria present in a tablet, she explains, and one billion (yes, seriously) is a typical dose. However, if you're struggling with a specific health condition, you may need more than that, Warren says. Your doctor can help you decide whether that's the case and may be able to steer you toward a good supplement to get you started. Here are a few to consider if you decide that probiotics are right for you.
A diet high in vegetables, fruit, and fiber, along with probiotics for weight loss, supports a more diverse gut microbiome, which in turn helps weight loss. Instead of waiting for the next magical diet or weight-loss supplement to arrive, focus on improving your gut health with probiotic foods and drinks with live cultures, in addition to maintaining healthy lifestyle factors.
A closer look at the science underlying microbe-based treatments, however, shows that most of the health claims for probiotics are pure hype. The majority of studies to date have failed to reveal any benefits in individuals who are already healthy. The bacteria seem to help only those people suffering from a few specific intestinal disorders. “There is no evidence to suggest that people with normal gastrointestinal tracts can benefit from taking probiotics,” says Matthew Ciorba, a gastroenterologist at Washington University in St. Louis. “If you're not in any distress, I would not recommend them.” Emma Allen-Vercoe, a microbiologist at the University of Guelph in Ontario, agrees. For the most part, she says, “the claims that are made are enormously inflated.”
In the first study, 25 human volunteers underwent upper endoscopies and colonoscopies to sample their baseline microbiome in regions of the gut. 15 of those volunteers were then divided into two groups. The first group consumed generic probiotic strains, while the second was administered a placebo. Both groups then underwent a second round of upper endoscopies and colonoscopies to assess their internal response before being followed for another 2 months.
Probiotic therapy may also help people with Crohn's disease and irritable bowel syndrome. Clinical trial results are mixed, but several small studies suggest that certain probiotics may help maintain remission of ulcerative colitis and prevent relapse of Crohn's disease and the recurrence of pouchitis (a complication of surgery to treat ulcerative colitis). Because these disorders are so frustrating to treat, many people are giving probiotics a try before all the evidence is in for the particular strains they're using. More research is needed to find out which strains work best for what conditions.
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.
Unless you have a perfect gut and are already eating lots of fermented foods—which is rare, although you can work up to this point—it’s difficult to get all the probiotics you need from diet alone. Most of us don’t have perfect guts—everything from antibiotics to high-carbohydrate diets to being born via a C-section can compromise the balance of bacteria in our microbiome. Supplementing with a probiotic can help to restore imbalances, and it’s also just a great preventative health measure, helping to keep your microbiome in balance and your immune system healthy to ward off illnesses.
Yogurt: It can contain Streptococcus thermophilus, Lactobacillus bulgaricus, L. acidophilus, and Bifidobacterium bifidum. Research has shown links with yogurt to have positive effects on the gut microbiota and is associated with a reduced risk for gastrointestinal disease and improvement of lactose intolerance (especially among children), type 2 diabetes, cardiovascular disease, allergies and respiratory diseases, as well as improved dental and bone health.
"I recommend supplementing with the species lactobacillus and bifidobacterium, and there are different strains within those species that are each beneficial. Garden of Life and Align probiotics contain bacteria that help the gut microbiome and maintain digestive balance, and 1MD's Complete Probiotics Platinum is one of the best probiotics with over 50 billion live cultures that help with gut and digestive health."
Taking a probiotic every day is a good way to help prevent getting sick and having to go on antibiotics in the first place. Preventative measures, of course, are preferred. Another that is believed to help is upping your vitamin D intake when your immune system needs a boost. Diet is also huge in terms of preventing sickness. Studies show that you can change your microbiome within hours of adjusting your diet. If you’re not into sauerkraut, even just cutting back on sugar and eating more whole foods can make a difference.
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.
Consuming probiotics regularly will reduce the risk of this. "The concept is that if we have an unhealthy, unbalanced gut environment, toxins can be released into the bloodstream and cause inflammation throughout the body," Engelman adds. "This shift in gut flora and the subsequent inflammation can cause a flare-up in the skin of those who are predisposed to acne, eczema, or rosacea."
As with other types of supplements, scientists are still discovering the full potential of probiotics. However, when taken regularly, it is believed that they help support digestive health by helping maintain the balance of beneficial and non-beneficial bacteria in your digestive tract. Having a natural balance of good bacteria in the digestive tract can help defend against occasional digestive issues. In addition, probiotics play an important role in supporting immune health, since 70% of the body's immune system is found in the digestive tract.∗
×