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Myriad factors – antibiotics, diet, stress, and age, among them – affect the balance of diverse microbes present in your gut. While you can replenish your gut bacteria by eating well and incorporating natural probiotics (ex. yogurt and kefir) into a healthy diet, these processes can take weeks or months; taking a regular probiotic is an easy and effective way to ensure your gut (and immune system) stays healthy, always.
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.
Diversity of strains - research has demonstrated that bacteria prefer to colonize in different parts of your digestive tract, where there are various ecological niches. The more probiotic strains you ingest, the more coverage you’ll provide for each of these niches. Each strain of bacteria also has its own different purpose, so choosing a formula with many different strains gives you that many more benefits.
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.
We started our search with the most popular products from major supplement retailers like Amazon, Drugstore.com, GNC, and Whole Foods. That gave us over 200 supplements. With so many options, we then narrowed our search to 70 probiotics whose purity, potency, and projected efficacy have been vetted by an independent lab like ConsumerLab, Labdoor or the National Science Foundation (NSF). Those labs test — among other things — supplements’ actual composition against labels, verifying ingredient lists are truthful and that contaminants aren’t present. Because supplement claims aren’t regulated by the Food and Drug Administration (FDA), we wanted to make sure someone was testing whether they worked as described.
33 of 37 passed all purity tests, indicating an absence of harmful contaminant yeast, mold residues and bacteria, including the pathogenic strain of E. coli (E. coli O157:H7), Salmonella spp., and Staphylococcus aureus. The U.S. Pharmacopeia6 recommends a microbial limit of 100 CFU/g of combined yeast and mold in dietary supplements and non-detectable limits of E.coli, Salmonella, and Staphylococcus aureus. If a product met these standards, it received a full score.
After further analyzing the data, the researchers found that they could predict whether the probiotics would take hold in people's guts by examining their microbiome and gene expression in the gut taken at the start of the study. However, this prediction method needs to be confirmed in future studies. The researchers called for further research to better understand why some people resist colonization by probiotics, as that future research may enable researchers to counteract the resistance.

What's more, there's still a lot more to learn about the microbiome and probiotics, in general. "Truth be told, the research area of probiotics and health is still pretty much in its infancy," says registered dietitian Kate Scarlata. Research is growing in the area of gut microbiome daily—but it is much more complicated than first thought." With all these options and major gaps in the available information, where are you supposed to start? Here, gut experts narrow it down to three simple tips for picking the right probiotic for you.

Pinning down the exact causes of IBS is difficult because each person has his or her own combination of causes. One cause that is receiving much attention is that of a disrupted microbiome, as there is a strong association between having a gastrointestinal (GI) infection, like food poisoning, and the onset of IBS. Also, the FODMAP diet, and nonabsorbable antibiotics to kill gut microbiota, have provided relief in many patients, further supporting the suspicion of a disrupted microbiome as contributing to IBS.
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Clinically shown to work in 7 days§, AZO Complete Feminine BalanceTM works differently because it contains the power of INTELLIFLORA,TM the only clinically proven blend with the 4 vaginal lactobacilli species most commonly found in healthy women.* Specially designed to restore the vagina’s microflora, it’s a safe and beneficial probiotic for women’s health—including pregnant women.*§ Add it to your daily regimen for help with protection and ongoing vaginal health support.*
The large intestine is home to hundreds of trillions of bacteria. Fortunately, most are neutral or even beneficial, performing many vital body functions. For example, they help keep “bad” bacteria at bay, play a role in immunity, help us digest food and absorb nutrients and may even have anticancer effects. But will consuming them as probiotics in foods or capsules make a notable difference to your health—especially if you are already healthy? Here’s a look at the evidence.
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.

If you want to take advantage of the benefits of probiotics and you also want to make sure the beneficial bacteria you already have is optimized to its full potential, supplement your probiotic regimen with Prebiotin. A trained microbiologist cannot tell you which probiotics are the best ones to choose, so why try to do something you are not trained to do? Eat lots of foods with prebiotics in them and take a prebiotic supplement like Prebiotin. It’s the best thing you can do to maximize the benefits of both prebiotics and probiotics on the bacteria in your gut, and your overall good gut health.
Probiotics are found in everything from chocolate and pickles to hand lotion and baby formula, and millions of people buy probiotic supplements to boost digestive health. But new research suggests they might not be as effective as we think. Through a series of experiments looking inside the human gut, researchers show that many people's digestive tracts prevent standard probiotics from successfully colonizing them. Furthermore, taking probiotics to counterbalance antibiotics could delay the return of normal gut bacteria and gut gene expression to their naïve state. The research publishes as two back-to-back papers on September 6 in the journal Cell.
DNA-testing matches identity at a foundational, genetic level, so you know you’re getting the exact strains listed. New Chapter’s DNA-testing also verifies that you receive the specific strains researched for specific benefits: our strains boost immune defenses and enhance digestion, including bowel regularity and reducing occasional gas, bloating, diarrhea & constipation.*
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Known as the most clinically proven effective probiotic strain, Lactobacillus rhamnosus GG (otherwise known as “LGG”) has been clinically proven to maintain healthy numbers of bacteria and yeast for optimal digestive health. This powerful probiotic is also paired with some of the best probiotic strains for feminine health, making it an ideal choice for any woman that is looking for complete care from her probiotic.
Probiotics are a big and rapidly growing business and are now among the most popular dietary supplements. The term probiotic refers to dietary supplements (tablets, capsules, powders, lozenges and gums) and foods (such as yogurt and other fermented products) that contain “beneficial” or “friendly” bacteria. The organisms themselves are also called probiotics.
In a food sensitivity, the immune reaction is delayed, usually several hours to days after the exposure. Food sensitivities are the most difficult to determine since there is not an immediate reaction. These kinds of issues with foods can cause a wide range of physical and mental problems. An elimination diet followed by reintroduction is one of the best ways to determine a food sensitivity.
Taking relatively high doses of these probiotic strains before, during, and after antibiotic treatment can help your microbiome get back on its feet: B. Lactis, B. Infantis, L. Acidophilus, L. Casei, L. Bulgaricus, L. Paracasei, L. Rhamnosus GG, and S. Boulardii. Our antibiotic combatant MegaFood MegaFlora has six of these strains, as well as eight others. One serving contains 20 billion CFUs to replenish the good bacteria.

A slightly more surprising result, however, seems to be the way that probiotics may impact some of the symptoms of autism. Autism and gut health have been discussed for some time, as patients with the disorder typically suffer from a large number of digestive issues. However, based on animal studies, it seems possible that altering the quality of gut bacteria might benefit not only the digestive system, but the abnormal behaviors in autism, too. In 2016, a case study of a boy with severe autism was reported. While being treated with probiotics for digestive problems, the patient spontaneously improved on the ADOS scale, a diagnostic rating system for people with autism. The score dropped from 20 down three points to a stable 17, and according to the report, ADOS scores do not “fluctuate spontaneously along time” and are “absolutely stable.”
Taking probiotics can also help keep your urinary system working properly. While you might think that yeast imbalances or urinary tract issues are primarily women's problems, both are common in men as well, especially in those whose bacterial balance is off-kilter. Taking probiotics can help address these issues by encouraging the growth of good bacteria to crowd out unwanted yeast.10
Although people often think of bacteria and other microorganisms as harmful “germs,” many microorganisms help our bodies function properly. For example, bacteria that are normally present in our intestines help digest food, destroy disease-causing microorganisms, and produce vitamins. Large numbers of microorganisms live on and in our bodies. Many of the microorganisms in probiotic products are the same as or similar to microorganisms that naturally live in our bodies.
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. 

What about prebiotics vs probiotics? Prebiotics are the food fibers that go through the gut unchanged and are then used by good colon bacteria as a food source for their own growth. Everyone already has most of these good bacteria present, but often in small quantities. Prebiotics are used to stimulate their growth. Simply stated, you already grow your own probiotics within your colon. You do not rely on them to make the passage through the stomach acid — acid that can destroy many probiotic bacteria. That’s why taking a probiotic supplement or adding probiotic foods to your diet does not always help your digestive system. You can eat as many probiotic bacteria as you want, but if they don’t survive the trip to the colon, your effort will be fruitless.
When I polled friends and family about their personal experiences with probiotics, I got a real mixed bag of responses. Some called them a lifesaver and others felt no effects whatsoever. I put the anecdotes aside and talked to Ben Lebwohl, gastroenterologist and director of clinical research at Columbia University’s Celiac Disease Center, to get the straight poop on whether probiotics are miracle or myth.
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.
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)
Certain brands, like Attune (attunefoods.com; available at Whole Foods), have pumped up the dessert by adding probiotics. (Attune boasts 6.1 billion CFUs, or "colony forming units," a measure of live, active microorganisms per serving. As a comparison, some probiotic supplements may contain 1 to 50+ billion CFUs.) Sounds crazy, but it's backed by science. One study in the International Journal of Food Microbiology found that probiotics added to chocolate were able to reach the GI tract where they could get to work colonizing the gut with healthy bacteria.
Bacillus is an interesting genus because these microbes have the ability to form endospores, tough outer coatings, when conditions are not suitable for them to flourish. There are five species of probiotic Bacillus: clausii, coagulans, indicus, licheniformis, and subtilis. Not every species of Bacillus is probiotic. Some Bacillus species are usually pathogens. Bacillus may normally be found in the GI tract, but they generally do not take up residence for long and will pass through and be eliminated if not replenished. Bacillus are common food spoilage organisms and are also found in probiotic supplements and in soil, air, and water.
Probi is continuously thriving to develop and investigate new possible indications where probiotics may have positive and efficient effects to improve health. We are science-driven, and investigate new possibilities to find the Next Generation Probiotics. This concept involves new bacterial strains that has never before been cultivated and used for health-purposes. 
Made from fermented cabbage and other vegetables, sauerkraut is not diverse in probiotics but is high in organic acids (what gives food its sour taste) that support the growth of good bacteria. Sauerkraut is extremely popular in Germany today. It is high in vitamin C and digestive enzymes. It’s also a good source of natural lactic acid bacteria, such as lactobacillus.
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.
Some yogurts contain the aforementioned bacteria; however, because they are sensitive to oxygen, light, and dramatic temperature changes, make sure to look for yogurts with “live and active cultures.” Many commercial yogurts are heat-treated or pasteurized, resulting in the loss of these valuable cultures. Learn more about the smart way to shop for probiotics.

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.
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