Probiotic supplements provide a boost to the naturally-occurring beneficial bacteria that live inside your body’s digestive tract.
Taking a probiotic supplement every day is a fantastic way to improve your digestion, boost your gut health, improve your immune system, and reduce inflammation.
Want to find the best probiotics on the market? Our research team put together these rankings to find the cleanest and most effective probiotic supplements:
1. 1MD Complete Probiotics
For those who’re serious about taking the most potent probiotic, 1MD Complete Probiotics is the best you can get.
No other probiotic supplement can compete with the 51 billion cultures and 11 unique strains with each serving.
Dr. David Kahana, a renowned gastrointestinal doctor, says, “When my patients ask me what probiotic is best, I recommend 1MD’s Complete Probiotics Platinum. Complete Probiotics Platinum has 11 different strains and guarantees 50 billion live cultures per capsule. It also contains an effective dosage of Nutraflora prebiotic fiber that will ensure these cultures get the fuel they need to really make a difference in your gut.”
Why is this important?
Because several probiotic products only have 2-3 different strains, and consuming probiotics with a diverse collective of good bacteria strains offers a better bacterial balance for your gut.
From overall immune health to providing your body with better digestion and gut health, 1MD Complete Probiotics is one of the better daily habits you can have in the supplement space.
All natural, no artificial sweeteners, no artificial coloring, no artificial preservatives and 100% GMO-free.
This is important. When you’re taking a probiotic as a daily supplement, the last thing you want is “added stuff” to mess with your fatigue, oxidation, blood pressure and microbiome balance.
Made in the USA and in an FDA-approved facility.
Alpha XR‘s all-around probiotic supplement winner of 2021.
2. Probiotic 40 Gut Boost +
Nuzena is a brand-new supplement company known for their potent formulas.
Probiotic 40 Gut Boost + by Nuzena is shamelessly stacked and also one of the cheaper options on the list.
They are also one of the most robust probiotic formulas that we’ve reviewed. The formula contains 40 Billion probiotic bacteria made up of 4 individual strands for increased bioavailability.
When it comes to gut health we know that having multiple strands of probiotic bacteria your supplements is essential — as finding the correct match to your mitochondria can vary between different strands.
While some of the other probiotic supplements we’ve reviewed here have similar strands, Nuzena really stands out with the quality of their formula.
3. NOW Probiotic-10
Although this falls short of our winner, NOW Probiotic-10 contains ten different probiotic bacteria strains, which total to an eye-popping 25 billion colony forming units.
The bacteria are delivered via a vegetarian capsule, and NOW Probiotic-10 uses standard “unbranded” bacteria strains, which both saves you money and guarantees that you are getting the same specific strains that are used in scientific studies on the benefits of probiotics.
With a simple cellulose capsule, some of the bacteria might be lost to stomach acid, but the huge overall bacteria count should more than make up for this.
4. Garden of Life Primal Defense Ultra
Garden of Life always has an interesting take on supplements, and their Primal Defence Ultra probiotic is no exception. The thirteen strains of probiotic bacteria are supported by a matrix of organic oat grass processed with an enzymatic procedure to help bacteria growth, as well as a small amount of iron, which is known to massively boost bacteria growth inside the body.
They also include “ionic plant based minerals,” presumably to boost growth further. Garden of Life generally has a love it or hate it approach; if you want all the extras, it’s a great choice, but if you just want plain old bacteria in a pill, there are better options.
5. Nutrition Essentials Probiotic
If you want a “bacteria bomb,” look no further: Nutrition Essentials crams some 15 billion colony forming units into their tablets, along with half a gram of “pre-biotic” materials that foster the growth and reproduction of the bacteria. Nutrition essentials is different from some of its competitors in that it is comprised of just one probiotic bacteria, bacillus coagulans.
Fortunately, this is one of the better-researched probiotics, with research to date finding that it is a safe and effective treatment for irritable bowel syndrome and related gastrointestinal problems (1). The tablet is a pretty simple one, made of calcium carbonate, cellulose, and stearic acid, so it may face some problems getting the bulk of the probiotic bacteria into your intestines, but the high number of bacteria colony forming units to begin with should help offset that problem.
6. Hyperbiotics PRO-15
Hyperbiotics uses a formulation that packs fifteen different bacteria strains into their proprietary blend with a total of five billion CFUs.
Hyperbiotics also employs a proprietary “pearl capsule” technology which is intended to allow more of the bacteria to make it to your intestines to populate the gut flora. With Hyperbiotics’ allergen-free guarantee, this product is a big winner.
7. Nature’s Bounty Ultra Probiotic 10
The ubiquitous and trusted Nature’s Bounty brand delivers when it comes to probiotics. Their Probiotic 10 supplement contains 20 billion colony forming units and, as the name suggests, ten different strains of bacteria.
The capsules are vegetarian, and there aren’t any extraneous ingredients included either, so this one’s a very solid choice.
8. Bio Schwartz Advanced Strength Probiotic
Though Bio Schwartz includes a huge amount of bacteria (40 billion colony forming units!) the choices of which ones to include are a little odd.
The staple bacteria lactobacillus acidophilus is there, but the other three are less common and less well-researched bacteria. The supplement also includes fructooligosaccharides to support the growth of the bacteria, but it doesn’t document how much it actually includes in the supplement.
9. Dr. Tobias Deep Immune Probiotics
The probiotic blend offered by Dr. Tobias includes five different types of bacteria which total to a bit under five billion colony-forming units.
The capsules are another major selling point; Dr. Tobias claims that their capsules resist the digestion of the stomach acid, making it so that more bacteria make their way into the intestinal tract instead of being destroyed by stomach acid.
10. Herrmann Health Products Advanced Probiotic
With a combination of seven different probiotic bacteria, including Lactobacillus, Bifidobacterium, and Bacillus strains, Hermann Health Products offers a solid combo of healthy bacteria, though only at a dose of 5.75 billion CFUs.
Best probiotic for women: 1MD Complete Probiotics
1MD Complete Probiotics comes out on top for women thanks to its huge variety of probiotic strains and the massive CFU count. This high-dose probiotic is great for women who want robust and healthy gut flora.
Best probiotic for men: 1MD Complete Probiotics
Yes, 1MD Complete Probiotics comes out on top for men, too—with strong variety in bacterial strains, plus the prebiotic fiber that allows these bacterial strains to grow and multiply, 1MD Complete Probiotics is a great pick, especially for men who want the gut health and immune system benefits of a probiotic supplement.
Best probiotic for weight loss: NOW Probiotic-10
NOW Probiotic-10 comes out on top for weight loss thanks to its high levels of bifidobacterium, a variety of probiotic bacteria strains that have been shown to be particularly effective in people who are overweight. These probiotic bacteria not only help with weight loss, but help accelerate the health gains associated with dropping weight too.
Best probiotic for irritable bowel syndrome: Nutrition Essentials Probiotic
If you have irritable bowel syndrome, or IBS, research shows your best shot is with a probiotic with only a few strains of probiotic bacteria. Nutrition Essentials Probiotic focuses only on bacillus coagulans, and delivers that strain at a potent dose, making it a great pick for IBS.
Best probiotic for constipation: Probiotic 40 Gut Boost +
Probiotics for constipation should include lactobacillus and bifidobacterium, which is why Probiotic 40 Gut Boost + comes out on top—it delivers high doses of bacterial strains of both of these varieties, which makes it our top choice for reducing constipation.
Who should buy probiotics?
Probiotics are most important for people who may have a disrupted or deficient gut microbiome. Probiotics are commonly recommended following a course of antibiotics, for example.
While antibiotic drugs can be very effective against infectious bacteria, they also lay waste to the healthy bacteria present in your stomach and intestines, paradoxically leaving you vulnerable to health disruptions in the future.
Taking a probiotic supplement after a course of antibiotics can help rectify this imbalance. Probiotics are also very helpful in many people who have intestinal problems like Crohn’s disease, ulcerative colitis, or irritable bowel syndrome (IBS).
The mechanisms behind many of these intestinal problems are unknown, but appear to be linked both to your immune system function and your levels of probiotic bacteria.
Not only are gut bacteria populations different between people with intestinal problems and health people, but modifying the gut bacteria in people with irritable bowel syndrome or Crohn’s disease can lead to improvements in symptoms, which strongly suggests gut bacteria is linked to the problem.
Beyond people with these health problems, there is increasing recognition that even healthy people can have a disrupted gut biome as a result of their diet.
Western diets, with their relatively low fiber content and high levels of sugar and refined carbohydrates, do not promote the kind of robust and diverse gut biome that you’d get on a diet high in fiber, fresh fruits, and vegetables.
Some (though not all) researchers even suggest that children might benefit particularly from a probiotic supplement. One article in Current Opinions in Pediatrics argues that, due to the strong circumstantial evidence connecting a healthy gut bacteria population with decreased risks for asthma, allergies, and even type 2 diabetes and obesity, pediatricians should consider probiotic supplementation for children.
Even healthy adults are increasingly turning to probiotics to better their odds against these same chronic diseases, thanks to the circumstantial evidence that is continually piling up that indicates that gut bacteria composition is one of the cornerstones to overall health and wellness.
How we ranked
We started by aggregating all of the latest, most popular, and best-selling probiotic supplements. Among these probiotics, we specifically looked for the supplements that had a solid dosage of probiotics.
Unlike other supplements, probiotics don’t measure doses in milligrams or IUs: they use a special unit called colony forming units, or CFUs for short.
These colony forming units are defined by their ability to start a bacterial colony, or growth of bacteria. The more CFUs, the more live bacteria are contained in the supplement.
Clinical research indicates that you want at least one to five billion CFUs per day minimum to get the desired effects, so we dumped anything that had less than one billion CFUs, or that did not explicitly state its live bacterial colony content.
Secondly, we prioritized supplements that had higher doses. That’s why 1MD and Now Probiotic-10 rose to the top: their ultra-high doses of 50 and 25 CFUs made them top contenders, and on par with some of the most powerful probiotic supplements that have been tested in clinical research.
Next, we sought out brands that used specific strains of beneficial bacteria as opposed to general categories or species.
For example, despite its popularity, NewRythm Probiotics did not make our list for this reason: it merely lists the species of bacteria, such as lactobacillus acidophilus.
Compare that to Nature’s Bounty Probiotic 10, which lists the exact strain of bacteria used, such as Lactobacillus plantarum 299v. This level of specificity allowed us to compare the ingredients to what has been tested and proven beneficial in the scientific literature.
Finally, we prioritized probiotic supplements that provided a variety of probiotic strains known to be beneficial.
Brands that focused only on one type of probiotic, such as Klaire Labs Ther-Biotic Factor 4, didn’t make the cut since we were looking for a diverse range of proven probiotic bacteria, not just one type.
Some of the specific type of probiotic bacteria we looked for include lactobacillus, bifidobacterium, and streptococcus thermophilus—all of these probiotics have been specifically investigated for their health benefits in scientific research.
When possible, we matched up specific bacterial strains in commercial probiotics with the strains used in research to ensure the top-ranked probiotic supplements were the most effective ones on the market.
Probiotics can help you lose weight, bump up immune function, improve your digestion, and even cut your risk of chronic diseases.The importance of having a healthy gut doesn’t always get the attention it deserves, but research indicates it is just as vital as food choices, good sleep and exercise (1, 2).
We have ten times as many bacteria in our bodies as we do cells, and most of them live in the gut.
When these microorganisms are happy, we enjoy health benefits; when bacterial colonies aren’t thriving, we may suffer a range of negative effects. (3)
Certain types of yeast can also act as probiotics, but most of the conditioning required for keeping the gut healthy is performed by colonies of bacteria.
Probiotics can be taken in supplement form, and may also be ingested by eating probiotic foods prepared through fermentation processes that encourage the growth of friendly bacteria. Some popular fermented foods include kefir, kimchee, sauerkraut, tempeh and yogurt.
Bacterial communities work to maintain the integrity of gut wall. The gut wall is vital in preventing substances in the colon from leaking into other parts of the body and stimulating an immune response. (5, 6, 7)
Besides friendly bacteria, harmful gut flora also exist, and when the balance gets out of whack, it can lead to diseases like type 2 diabetes, metabolic syndrome, heart disease, depression, Alzheimer’s disease, colorectal cancer and many more. (8, 9, 10)
This is the area where the most research has been done on probiotics, especially in regard to diarrhea associated with taking antibiotics. (11)
Diarrhea often occurs after a course of antibiotics is taken to treat a medical condition, and can persist for long periods of time. Antibiotics eradicate many bacteria in the gut, and this can shift the balance so bad bacteria dominate and thrive.
Many studies indicate probiotics can cure this problem (12, 13), as well as being effective in reducing bloating, gas, constipation, and other intestinal problems, including symptoms associated with irritable bowel syndrome (IBS). (14, 15)
Probiotics can assist in treating ulcerative colitis and Crohn’s disease , and may also help fight helicobactor pylori infections. These infections are caused by the bacteria that leads to ulcers and raises the risk of stomach cancer. (16,17)
Anyone who has digestive issues that have been difficult to resolve might consider taking a probiotic supplement.
Probiotic bacteria could even help you lose weight. If you’re carrying around a significant amount of extra weight, chances are your gut flora are different than someone who is thin or of normal weight. (15)
Researchers playing with this concept transplanted gut flora from thin animals into obese animals, and the result was dramatic: fat animals began to lose weight. (16)
Data from a study conducted in 2013 with more than 200 people suffering from central obesity (large amounts of belly fat) offered encouraging results: over three months, participants taking the probiotic lactobacillus gasseri had an average decrease of 8.5% in belly fat mass. (19)
It took only a month for test subjects to gain back the belly fat they lost after they stopped taking the probiotic.
Another study indicated that Bifidobacterium and lactobacillus ramnosis may help in preventing obesity and supporting weight loss. (20)
Potential health benefits resulting from these effects may include a decreased risk of developing chronic Western diseases like autoimmune diseases, mental disorders, arthritis and heart disease. Further research is likely to reveal even more health advantages associated with healthy gut flora.
The use of probiotics has been associated with improvements in a range of other health conditions, including dropping blood pressure for patients with hypertension, reducing inflammation (21), enhancing immune system function (22), lowering cholesterol and LDL cholesterol, improving skin conditions such as rosacea, acne and eczema (23) and reducing symptoms in patients suffering from depression and anxiety (treated with these strains: bifidobacterium longum and lactobacillus helveticus) .
Taking probiotics is completely safe for most people, though some experience digestive side effects during the first few days; abdominal discomfort, bloating and gas are the most common problems. (24) Improved digestion usually follows these initial symptoms.
Those with compromised immune systems, such as patients diagnosed with AIDS or HIV, have had issues with infection after taking probiotics, and anyone with a medical condition should talk with a doctor before making a decision about supplementing. (25)
If you’re looking to treat a specific health issue, it’s important to do your homework and find out which strains of probiotics have been successful in specific applications; always purchase probiotics from a trusted manufacturer.
Probiotic bacteria have been researched intensively in the last few years, and we now have much more detailed information on the appropriate dosage for a probiotic supplement (though there’s still plenty of work to be done on the scientific front).
For starters, virtually no clinical studies have demonstrated efficacy with probiotic doses of less than one billion CFUs, and most use at least five billion CFUs per day. Beyond this, the picture gets a little murky because the appropriate dose seems to depend on the exact health condition that is being treated.
For instance, one study on using probiotics to improve immune function in older adults found that five billion CFUs per day was equally effective compared to a dosage of 50 billion CFUs per day (38).
On the other hand, a review article highlighted a strong dose-response relationship in using probiotics to treat diarrhea that occurs after taking antibiotics (39). In these cases, doses of over 100 billion CFUs per day were definitievely more effective than lower doses.
The takeaway from this research is that a baseline dosage of five billion CFUs per day is a good place to start, but for some conditions—particularly those linked to the digestive tract—much higher doses, in the range of 50-100 CFUs per day, might be a good idea.
Q: What are probiotics?
A: Probiotics aren’t just any type of bacteria—they are good bacteria that live in your intestine and which have been associated with positive health benefits.
Often, these bacteria are found in fermented foods, like the lactobacillus and bifidobacterium found in cheese and yogurt. To get probiotic bacteria in higher doses, a probiotic supplement is the way to go.
Q: Can a probiotic supplement work as a thermogenic for weight loss?
A: The relationship between gut bacteria and weight loss is complex, but clearly connected: obese people have substantially different gut bacteria profiles compared to healthy people, even after controlling for things like dietary intake.
On the other hand, the agricultural industry has long used specific bacterial strains to induce weight gain in cattle and other stock animals.
The weight loss or weight gain effects of a probiotic depends on the specific strain being used; some research suggests that certain strains of probiotics will consume some of the calories that you eat, which would (in theory) prevent weight gain.
However, if you are overweight or obese, certain probiotics do have other benefits, such as potentially being able to reduce your risk for type 2 diabetes, even independent of any weight loss that may occur.
Q: What do probiotics do?
A: Once inside your digestive tract, the bacterial spores in the colony forming units start multiplying. Of course, they don’t multiply forever, because they have to coexist in an ecosystem of other bacteria in your stomach and intestines which have access to a limited amount of food.
However, they do have a lasting effect on the composition of your gut bacteria. These changes can be especially helpful to jump-start the benefits of a healthy diet: scientific research suggests that, while your diet is by far the largest determinant of your gut biome, short-term dietary changes have little effect on gut bacteria composition (40).
To boost the beneficial changes in gut bacteria composition, a probiotic supplement could be just the trick.
Q: How long does it take for probiotics to work?
A: Clinical research suggests that you need at least eight to nine weeks, and perhaps up to 12 weeks, for probiotics to have a statistically detectable effect.
That being said, you may start to feel the benefits of probiotics much sooner, since these clinical studies have to detect the effect among large populations with a lot of inter-individual variability.
Still, probiotics do take time to have an effect—don’t expect amazing results overnight. At least eight weeks is necessary to assess whether your probiotic supplement is having a measurable effect on your gut bacteria.
Q: What is the difference between prebiotics and probiotics?
A: Probiotics, as described earlier, are living bacterial cells that reproduce inside your body and definitively change the makeup of your gut bacteria.
There are many different kinds of probiotic bacteria, but they all share the fact that they are, fundamentally, living creatures that multiply inside your body.
Conversely, prebiotics are like functional foods for bacteria: prebiotics are nutrients that facilitate the growth of beneficial bacteria inside your digestive tract.
Even something as simple as psyllium husk or other kinds of fiber supplements can be a prebiotic, because probiotic bacteria can consume this fiber for energy. Likewise, you’ll also see prebiotics that contain inulin, a plant-derived fiber that’s incredibly useful as energy for probiotic bacteria, as well as fructooligosaccharides, which are carbohydrates similarly useful for probiotic bacteria.
Prebiotics are often used as a “booster” to either augment your natural levels of probiotic bacteria, or in combination with a probiotic supplement to accelerate the growth of the probiotics that you are taking.
You’ll find prebiotic ingredients in several of our top-ranked probiotic supplements, and we have also specifically ranked and reviewed the best prebiotic supplements separately.
Q: How should you take probiotics and antibiotics at the same time?
A: Though it sounds counterintuitive, the scientific literature suggests that taking probiotics at the same time as antibiotics is the best way to prevent some of the the negative side effects of an antibiotic.
Of course, as with any prescription medication, you should talk to your doctor to make sure there aren’t any special reasons not to mix prebiotics and probiotics, but large meta-analysis studies of clinical research has found that probiotic supplements are extremely effective at preventing side effects like diarrhea, but might not be as helpful if you wait until side effects have already developed (41).
In other words, they are a better prevention than treatment. In clinical research, probiotics and antibiotics are usually taken at the same time: the probiotic bacteria seem resilient enough not to get totally destroyed by the antibiotics. Keep in mind that not all antibiotics work on all bacteria, so a broad-spectrum probiotic supplement may have a better chance of surviving during the course of an antibiotic treatment.
While common sense might indicate that it would be wasteful to take probiotics and antibiotics at the same time, the scientific research actually suggests precisely the opposite: it’s better to start taking probiotics right away instead of waiting to finish your course of antibiotics.
- Probiotics for women
- Probiotic foods
- Probiotic yogurt
- Digestive enzyme
- Complete Probiotics Platinum Review
Probiotics are supplements that contain beneficial bacteria that improve the health of your digestive system and boost your immune function.
They provide assistance to your body for cultivating friendly gut bacteria, which can be helpful in improving a range of health conditions, including immune system function, weight management, depression and systemic inflammation.
Shoot for a dosage of at least five billion CFUs per day, and higher if you are specifically taking probiotics for a digestive tract issue.
If you are taking probiotics to help prevent side effects from a course of antibiotics, don’t delay taking a probiotic supplement until you are done with your antibiotic prescription—the scientific research shows that taking them at the same time is actually far more effective than waiting until digestive side effects from antibiotics appear.
While there is still plenty more research to do on probiotics, the results so far are already very promising.
For Alpha XR‘s #1 probiotic supplement recommendation, click here.