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.
Every day, we’re exposed to toxins and inflammation-causing molecules from food and the environment that negatively impact digestion through pathways, such as leaky gut, known in the medical field as intestinal hyperpermeability. In leaky gut, the tight junctions that are supposed to keep disease-contributing compounds from leaving the digestive system are disrupted, allowing a lot of things through into the bloodstream that don’t belong there.
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.
Garden of Life RAW Probiotics are some of the most popular out there – and for good reason. Let’s start with the basics: You’ll get 85 billion CFUs and 31 to 33 probiotic strains out of your daily, whole-food, gluten-free, soy-free probiotic, which helps support the immune system, a healthy thyroid, nutrient absorption, digestive function, and a healthy microbial balance.
For Irritable Bowel Syndrome, patients who respond to a probiotic might take that in the long term, Lebwohl says, so as to maintain symptom control. With something like antibiotic-related diarrhea, you'd take it for a defined period of time until symptoms are gone. "This has been studied in children and adults and while study results have varied, meta-analyses suggest that probiotics can be protective in this context," he adds.
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.

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.
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).
“Microbiome” refers to the trillions of bacteria and microorganisms that live on and in our individual bodies. “There’s increased recognition of the various ways that the microbiome affects our health,” Lebwohl tells me. “And with that recognition comes the true observation that many bacteria are good for us. This goes against the old idea that bacteria equal germs, which equal harm. It turns out that many bacteria keep us healthy and probiotics could potentially support that notion.”
They can break down substances in foods that keep you from absorbing the micronutrients inside. They not only protect against the consequences of rogue molecules passing through a leaky gut, but they assist your intestinal cells in staying healthy to optimize nutrient absorption. In addition, some of the metabolic by-products of probiotics, such as short-chain fatty acids and vitamin production, are very nourishing to your GI tract.
Fizzy, tangy, and even slightly vinegar-esque, kombucha has a cult following for a reason. The tea gets its natural carbonation from the "scoby" (that float-y thing you see in some bottled varieties), which is actually the bacteria and yeast that ferment the drink and creates the probiotics. "There's not much scientific evidence specifically on the benefits of kombucha, but it is another strategy to introduce more live, active bacteria into your lifestyle," says Palmer. Many are made with fruit juice for added flavor, so read the label to see what you're getting, she advises. Stick to store-bought kombucha; it's tough to keep the tea sanitary when you make it yourself, and homebrewed kombucha been linked to nausea and even toxicity. Also note that due to the fermentation process, kombucha contains trace amounts of alcohol, so it's best to stick to one 12-ounce bottle a day.
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.
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.
In October 2013, the International Scientific Association for Probiotics and Prebiotics (ISAPP) organized a meeting of clinical and scientific experts on probiotics (with specialties in gastroenterology, pediatrics, family medicine, gut microbiota, microbiology of probiotic bacteria, microbial genetics, immunology, and food science) to reexamine the concept of probiotics. They define probiotics as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host." They also differentiated between products containing probiotics and those containing live or active cultures and established the following criteria:
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.
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.

Like some of the other probiotics we’ve reviewed, the HyperBiotics PRO-Women Probiotics with Cranberry Extract and D-Mannose do not need to be refrigerated in between uses. What sets this particular formula apart though is its longer shelf life made possible by the patented HyperBiotics ‘LiveBac’ manufacturing process. In fact, the HyperBiotics PRO-Women Probiotics formula can usually last for more than a year when stored in normal indoor conditions!


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.
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