Consumer Reports is an independent, non-profit organization dedicated to helping consumers. We make it easy to buy the right product from a variety of retailers. Clicking a retailer link will take you to that retailer’s website to shop. When you shop through retailer links on our site, we may earn an affiliate commission – 100% of the fees we collect are used to support our mission. Learn more. Our service is unbiased: retailers can’t influence placement. All prices are subject to change.
The concept of probiotics is credited to Élie Metchnikoff, a Russian scientist born in the mid-1800s, whose work provided profound insights into immunology and microbes. He developed a theory about aging that over the years had been forgotten in mainstream medicine but is now embraced by many scientists: namely, that health is influenced by toxic bacteria in the gastrointestinal (GI) tract. He is said to have noticed that people who lived to be over 100 years old in the Balkan States and Russia drank sour milk, which we now call yogurt or kefir, every day. In fact, Bulgarian yogurt cultures even today are regarded as highly therapeutic.
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.)

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.
Evidence from clinical trials is mixed and often of low quality, but findings from meta-analyses suggest that probiotics can provide benefits in the treatment of some conditions, such as infectious and antibiotic-associated diarrhoea. As such, taking probiotics after antibiotic treatment is an increasingly common practice. However, two studies recently reported in Cell question whether taking highly concentrated supplements of so-called good bacteria aids the recovery of normal gut flora.
When it comes to feminine health, the focus is all about balance. Whether you are trying to starve off annoying yeast infections and BV or recurrent urinary tract infections, the secret to optimal health lies in balancing out the bacteria that are already in your system. That’s why these vH Probiotics with Prebiotics and Cranberry contain prebiotic compounds to promote the growth of good bacteria in the digestive and reproductive systems.
While taking a daily probiotic supplement may seem like an easy answer to cure common gut ailments, it’s always best to try for a food first approach, since you can get probiotics from the foods you eat. Probiotics can be found in foods such as yogurt, cheese, miso, sauerkraut, and kimchi. But, adding a supplement into the mix if you haven’t achieved the desired effect through diet alone can be effective.
​​​​​​Lactobacilli dominate a healthy vaginal microbiota. Menstrual cycles, sexual activity, diet, certain medications, hygiene, and other factors can occasionally disrupt the vaginal microbiome. AZO Feminine Balance Daily Probiotic has been clinically demonstrated to contribute to the colonization of these important lactobacilli in the vagina.* The result: restoring the natural balance of good bacteria and yeast to maintain vaginal health.*
If that's not enough, your doctor may also suggest a probiotic supplement. But don't go and grab just anything off the pharmacy shelf. Probiotic supplements are not all the same, and they often contain different strains to serve different needs, says naturopathic physician Amy Fasig. Example: What one person gets to battle strep throat is different from what would be prescribed for someone suffering from Irritable Bowel Syndrome, she says.
★100% NATURAL, NON-GMO, GLUTEN FREE★NewRhythm 50 Billion Probiotics is Formulated with 100% Natural Ingredients and Independently Tested in 3rd Party Labs in USA. Our Turmeric Supplement is Verified NON-GMO, Gluten Free and Verified Free of Sugar, Soy, Yeast, Egg, Wheat, Corn, Peanuts, Fish, Shellfish, Magnesium Stearate, Artificial Ingredients, Fillers, Binders, Preservatives.
This high-potency (25 billion CFU) supplement blends 12 different strains in a base of inulin. The Ther-Biotic Complete capsules are vegetarian (made from hydroxypropyl methylcellulose, water) and the formula is free of common allergens, such as milk, eggs, fish, tree nuts, peanuts, wheat, gluten, and soy so it’s perfect for those with allergies. There are 60 capsules per bottle.
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.

This cabbage condiment can frequently be found atop a mighty hot dog, but its roots trace all the way back to the 4th century B.C. Cabbage was fermented to preserve the veggie, resulting in what we all know as sauerkraut. Palmer points out that modern techniques for canning sauerkraut results in a product packed in a vinegar solution without live, active bacteria in the mix. For most probiotic power, eat fresh sauerkraut (look for live cultures on the label or buy it in the refrigerated section) or make it yourself at home.
In addition to its powerful probiotic strands, the Vitamin Bounty Women’s Pro-Daily Probiotic also features a proprietary women’s health formula. This blend includes many of the minerals and plant extracts that have been found to be the most beneficial to women’s health, making it ideal for any women that have experienced feminine health problems. Specifically, this Vitamin Bounty formula includes Ashwagandha Root Powder, Cranberry Fruit Powder and Black Cohosh Root Powder.
Many studies have been conducted about the benefits of probiotics on a large number of health issues and conditions. Here, I’ll focus on the more thoroughly researched probiotics benefits, largely by sharing the results and data of meta-analyses on the subjects. Then, I have listed several areas of emerging research on the benefits of probiotics, reflected in small or pilot studies with promising results on probiotic benefits, as well as ways probiotics can be accessed.
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.
Unfortunately, the U.S. has no federal standards for probiotic supplements. Therefore, you run the risk of purchasing a product without any guarantee that it contains its advertised probiotic strains, that the strains are alive, or that the product is free from unhealthy ingredients. Therefore, it may be best to choose a brand-name probiotic that has research backing their effectiveness. Here are some examples:
Cleaning up your diet to remove things that bother you and to add nutrients you and your microbiota need, physical activity to reduce stress and increase feel-good neurotransmitters, mindfulness to discover how your thoughts affect your feelings, and daily consumption of probiotic pills and foods are easy ways to improve your mental health outlook.
The price is great on these, but definitely BEWARE! I do not recommend taking 2 pills in the beginning if you have not taken probiotics in the past! I had been eating very clean for a couple months, but got a sinus infection and was recommended by a nutritionist to take a probiotic to boost gut health since I was on antibiotics. Anyway-taking 2 pulls a day gave me horrible diarrhea, until I figured out they were causing the issue and cut back the pills to one a day! Everything fine since then, will try to build back up to 2 a day...I also take at bedtime just in case there would be any stomach issues!
"There is an increasing interest in probiotic interventions," wrote the authors of one of the most recent studies, a meta-analysis of previous research in a recent issue of the Journal of the American Medical Association. Those researchers found that probiotics were particularly useful against a common gastrointestinal problem: antibiotic-associated diarrhea (AAD).

While Lebwohl isn't comfortable endorsing a specific brand publicly, he did say "a widely used brand in which the compound is bifidobacteria or lactobaccilus seems like a reasonable way to go in a patient who is eager to give this a try, but would be best done under the supervision of a healthcare professional.” He does advise looking for a supplement with between 1 billion and 10 billion colony-forming units, or CFUs.

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." 

Cynthia is the assistant editor and frequent contributor. She’s originally from California, but has lived in many countries including South Korea, China and Germany. She currently lives with her husband in Minnesota. Cynthia is passionate about helping families find the best advice for family life and safety. Cynthia also has experience in early childhood education and holds a TEFL-C certificate from Teachers College, Columbia University. She has been writing about family-focused topics, advice and trends since 2014.
Unless you know that your body is lacking in a particular type of probiotic, you should just look for broad-spectrum probiotics that contain a mix of different strains of bacteria, Warren says: "We have billions of bacteria in our gut, so by taking a supplement with a range of different strains, you will ensure you are not overdoing or missing one type." Keatley also stresses the importance of finding a supplement with a diversity of bacteria strains to keep overgrowth of any one strain in check. "Providing too much of an advantage to one strain of probiotic may push out another strain we didn't know was important until it's too late," she points out.
The current probiotic push lends itself to the question, "If humans got along fine without taking a probiotic supplement for thousands of years, why are they so important now?" Although there is no definitive answer to this question, there have been some significant cultural changes that have had an impact on the gut flora (the population of organisms that populate our intestines). These include the use of antibiotics, diets lacking in gut-healthy plant food, refrigeration and improved sterilization of foods. What we don't yet know is true is if probiotics actually turn around these changes and support the health of your gut flora.

The other thing to remember is that these microorganisms are not all created equally. In fact, the genus, strain, and species all need to be the same for the results that found in the study to be the results that one hopes to achieve when taking it. For example, with the strain Lactobacillus rhamnosus GG, the genus is Lactobacillus, the species is rhamnosus, and the strain is GG. If any one of those is different in your supplement, you may not attain the same results.
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) 

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.
Two dangerous diseases in newborns, necrotizing enterocolitis (NEC) and neonatal sepsis, may meet their match with well-designed probiotic supplements. Both of these conditions are common in premature babies and are most dangerous in low birth weight and very low birth weight infants. Research has confirmed that when a pregnant mother takes high-quality probiotics during pregnancy, her baby is significantly less likely to develop either NEC or sepsis, particularly when the baby is breastfed after birth (and mom is still taking the supplements) and/or when probiotics are added to formula. A probiotic supplement with multiple strains seems to be the most effective in these cases.

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.


Once GI experts realized there is more to the lower gut than first assumed, the push to understand the diverse roles these bacteria play became urgent. Many mysteries still need solving, but clinical evidence increasingly indicates that people in good health should optimize lower gut bacteria. You can accomplish this by eating prebiotics to encourage the growth of your existing gut microbes, and probiotics to add to the ones that are already there.
If you have an immune system problem or another serious health condition, you may have a greater chance of issues. Some reports have linked probiotics to serious infections and other side effects. The people most likely to have trouble are those with immune system problems, people who've had surgery, and others who are critically ill. Don't take probiotics if you have any of those issues.
While more research is necessary to truly understand the widespread benefits of different probiotic strains, we do know that not all probiotics are created equal. The Lactobacilli, for instance, live in our digestive, urinary and genital systems and can be found in some fermented foods like yogurt. Bifidobacteria normally live in the intestines as lactic acid bacteria, and are also found in fermented foods. According to nutrition expert Alex Caspero, RD, “For certain conditions, you want to ensure you are taking the strand that is most likely to benefit you.” Here is a simple breakdown to help you determine the best probiotic for you.
Candida yeast species, on the other hand, can cause numerous infections in and on you. Although they are usually present in controlled amounts, Candida overcomes your usual defenses and establishes itself when conditions are favorable, such as when you take antibiotics and many beneficial bacteria, which normally would control Candida, are killed. Unlike the Saccharomyces yeasts, which are not invasive, Candida species form hyphae, finger-like projections that penetrate tissues, causing deep infections that are difficult to eliminate. Candida is also able to weaken your immune defenses.
With Prebiotin, you can easily add prebiotic fiber to your diet without worrying about eating huge amounts of troublesome foods or hunting down hard-to-find ingredients. You also won’t have to worry about loading up on high-calorie foods that can negatively affect any effort to lose weight. Combining Prebiotin prebiotic fiber with a diet enriched with probiotic foods can only help your effort to positively influence the bacterial balance in your lower gut.
I’m 65 years of age. I have been taking acid reflux medication daily for at least 15 years and recently my doctor said my kidneys were declining. I’ve read that acid reflux medications taken over a long period of time, can cause kidney damage. By taking a probiotic, will it help reduce stomach acid, where I may be able to stop taking my acid reflux medication altogether?
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.
Notably, after someone was tagged a “persister” or “resister” clear patterns emerged on how probiotics would impact his or her indigenous microbiome and gut bacteria profile. "Although all of our probiotic-consuming volunteers showed probiotics in their stool, only some of them showed them in their gut, which is where they need to be," Eran Segal said in a statement. "If some people resist and only some people permit them, the benefits of the standard probiotics we all take can't be as universal as we once thought. These results highlight the role of the gut microbiome in driving very specific clinical differences between people."
×