The Best Probiotic Supplement

The 30-Second Review

The best probiotic supplements contain at least 1 billion bacteria cultures and are certified by an independent lab for purity and potency. Even better, they’re guaranteed to be viable; after all, we want those guys alive, not dead. To find the best, we enlisted the help of probiotic and health experts, dug into clinical trial findings, and examined the finalists ourselves. We chose four top picks that each target a specific health goal.

Best for General Digestive Health

Islands Miracle Ultra-30 Probiotics has a little bit of everything. It boasts nine of the 10 strains experts recommend for general gut health — more than any other supplement.

Best for Antibiotic Recovery

MegaFood MegaFlora helps your digestive system slowly replenish its natural flora after an antibiotic course wipes them out.

Best for Immune Health

Renew Life Ultimate Flora Extra Care uses bacteria strains that can improve upper-respiratory infections and aid in the treatment of autoimmune disorders. 

Best for IBS/IBD Relief

Dr. Formulas Nexabiotic Advanced Multi-Probiotic eases the symptoms of irritable bowel syndrome and acute infectious diarrhea.

  • July 25, 2017: After further research and expert input, we’ve updated this review with a revised methodology and arrived at a new set of top picks. This time around, we only looked at probiotics vetted by an independent third party. Because supplements aren’t regulated by the Food and Drug Administration (FDA), we wanted to make sure our top picks could live up to their label claims — and didn’t contain any questionable ingredients.

The Best Probiotic Supplement

In the humble human gut, there are hundreds of trillions of bacterial occupants, and they’re not just living there — they’re working for you. Gut flora makes up 70–80 percent of the human immune system. Adding good bacteria, called probiotics, protects the digestive tract from the harmful bacteria in sugars, pesticides, and saturated fats. Too much bad bacteria can inflame and destroy intestinal walls, enter the bloodstream, and trigger a multitude of health issues — constipation, depression, skin problems, autoimmune disease, and even bad breath. Incorporating probiotics can help.

If you’re new to the world of probiotics, start with our general health pick, Islands Miracle Ultra-30 Probiotics. It boasts over 30 billion bacteria cultures and more expert-recommended bacteria strains than any other probiotic on our list.

If you have a specific ailment or want to switch up your current probiotic routine, we chose products with bacteria strains will well-documented health benefits: MegaFood MegaFlora helps your system recover after taking antibiotics; Renew Life Ultimate Flora Extra Care strengthens your immune system; and Dr. Formulas Nexabiotic Advanced Multi-Probiotic eases IBS and IBD symptoms.

We also found strain combinations that address everything from weight loss to decreased anxiety — though that research is limited. Still, any probiotic supplement is going to make some improvement on your digestive health, so don’t be afraid to experiment.

Our Picks for the Best Probiotic Supplement

Best Probiotic for General Digestive Health

Islands Miracle Ultra-30 Probiotics This tiny capsule contains nine of the ten strains recommend for general gut health.

Maybe you don’t have a specific health goal in mind, but you do want to bolster the number of good bacteria floating around your system. Dr. Perlmutter recommends starting at a minimum of eight to 10 different bacterial species, including a core five: L. Plantarum, L. Acidophilus, L. Brevis, B. Lactis, and B. Longum. We included these five in a larger a list of the ten most researched and universally beneficial strains in a general digestive health pick — we wanted a probiotic that would work for everyone.

A 100% Vegan Option NOW Foods Probiotic-10 passed all of our criteria and contains a wide variety of strains like: L. Acidophilus, B. Lactis, L. Plantarum, and B. Longum. And since it contains no dairy or gelatin, it’s completely vegan.

Islands Miracle Ultra-30 Probiotics has 18 different strains total, and it includes nine of the ten we wanted in a general health probiotic. Each serving comes with 30 billion CFUs per serving; the label recommends you take two supplements per day. We also like that they’re also gluten and dairy-free — ideal if you already have a sensitive stomach.

When we opened the bottle, we noticed a slightly sour smell — common with all the probiotics we tested. But it’s subtle, and the individual capsules don’t have a noticeable scent.

Best Probiotic for Antibiotic Recovery

MegaFood MegaFlora This supplement fills your digestive tract with good bacteria until it's fully recovered from an antibiotic course.

Antibiotics wreak havoc on your microbiome by decimating both good and bad bacteria — an effective treatment if you have an infection, but without the gut good guys, you’ll come out the other side of any course of antibiotics with a weaker immune system. Potential side effects aren’t so pretty either: vomiting, diarrhea, and even susceptibility to a C. Diff infection. It’s tempting to think of probiotics as re-populating your post-apocalyptic gut with good bacteria after the fallout from antibiotics. Not quite.

Most of the bacteria native to the human microbiome aren’t in probiotics. To truly “repopulate” your system, you’d need a human fecal transplant (exactly what it sounds like) and you’re not going to find that in a jar.

Store your probiotics in the fridge. Probiotic bacteria are basically in hibernation. Keeping them cold slows down cell death and prolongs their shelf life.

Luckily, certain probiotic strains can help with antibiotic-associated symptoms in other ways. 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, S. Boulardii. Our antibiotic combatant MegaFood MegaFlora has six of these strains, as well as eight others. One serving contains 3 billion CFUs, a concentrated dose to replenish the good bacteria. You’ll want to keep the bottle in the fridge — this can sustain the life of the CFUs. The label clearly indicates it should be stored cold and was even shipped with an ice pack.

The capsules are quite tiny, about the length of a pinky fingernail. These could be super easy to drop and misplace, but also easy to take if you have trouble swallowing pills — and you only have to take one a day.

Best Probiotic for Immune Health

Renew Life Ultimate Flora Extra Care 30 Billion This option uses bacteria that can improve upper respiratory infections and aid in the treatment of autoimmune disorders.

In addition to the prophylactic effect of stocking your gut with good bacteria, there are some probiotic strains that can even improve immune function, and some have even shown promise in treating symptoms of certain autoimmune disorders.

L. Planatarum and L. Paracasei in particular can improve immune function with as little as 500 million CFUs daily, and a combination of L. Acidophilus and B. Lactis at 2.5 billion CFUs twice daily has been shown to improve upper respiratory infections.

Renew Life Flora Extra Care has all four targeted bacteria strains, at 30 billion CFUs per serving. The capsules are a bit bigger than the penny-sized Islands Miracle probiotic, but you only have to take one a day, and it’s still no horse pill. Renew Life also earned the highest Label Accuracy score from our picks tested by Labdoor (87 out of 100). Impressively, this means you’re more likely to get the bacteria and CFUs that the product is advertising — a difficult feat for sensitive bacteria that die off.

It’s worth noting that, like MegaFoods MegaFlora, the Renew Life label recommends cold storage. But that recommendation is printed so small we nearly missed it (and it didn’t ship with a cold pack).

Best Probiotic for IBS/IBD Relief

Dr. Formulas Nexabiotic Advanced Multi-Probiotic Research suggests its bacteria can ease the symptoms of irritable bowel syndrome and acute infectious diarrhea.

There has been a lot of research on treating IBS and IBD symptoms with probiotics, much more than on most other pathologies. There are many strains proven to alleviate symptoms — L. Acidophilus, and E. Faecium came up again and again in our research.

Dr. Formulas Nexabiotic Advanced Multi-Probiotic has both of these and five other relevant species (with 23 strains total) in its 34.5 billion CFU serving. This product also had the highest overall Labdoor score of our picks at 92.4 out of 100. It’s a normal-sized capsule, slightly smaller than the Renew Life Flora Extra Care, and has a faint peanut butter smell — less sour than the other probiotics we looked at.

Other Probiotics to Consider

The research on probiotics is still in its infancy, but it seems that probiotics can do a lot more than just keep you regular. We put together our top picks based on which strains had substantial evidence backing up a concrete health benefit, but we also came across some studies that surfaced some lesser-known benefits of taking probiotic supplements, like decreased anxiety.

While there’s not as much research to support their claims, these probiotics still have plenty good-for-your-gut bacteria. Not all of these supplements contain every relevant strain, but they checked off the most boxes where it counts.

Did You Know?

There is still a surprisingly small amount of research on probiotics.

Although the idea of beneficial bacteria has been around since the late 1800s, and probiotic supplements have been around since the 1930s, there haven’t been many human clinical trials.

We do know that probiotics produce enzymes that help break down chemicals that the average human gut has a hard time with, such as the oligosaccharides in legumes. That digestive assistance results in less gastrointestinal distress and better absorption of nutrients.

Probiotics also elicit an immune response in the intestines that can help your body deal with certain harmful pathogens and other GI problems. There is actually a mechanism we learned about called cross-talk where, through chemical signals, the bacteria communicate with your body, and your body communicates back.

The hard research, especially on recommended CFU dosages, is minimal but expanding as interest in the product does.

You can get probiotics (and prebiotics) from certain foods.

Some foods are made by the addition of bacteria — yogurt, pickles, cottage cheese, kombucha, and sauerkraut for example. And those foods work to provide the same probiotic benefits as supplements. However, most foods are so processed and pasteurized that it’s unlikely you’d be able to get enough to see the same benefits as you would with a supplement, let along the right strains. Regardless, it certainly can’t hurt to be getting extra probiotics through your diet.

You’ll also want to get enough prebiotics too. Prebiotics are complex sugars ingested as fuel for gastrointestinal bacteria. Some probiotics include them in the supplement, but the amount is usually too small to make an impact, and you’re likely already getting enough in your regular diet.

There are tons of prebiotics that probiotics love in whole fruits and vegetables, including onions, garlic, bananas, asparagus, unpasteurized apple cider vinegar, and artichokes. If you’re worried you might not be getting between five to 20 grams per day (a bowl of onion soup), consider taking a prebiotic supplement, usually a powder or drink mix. Dr. Perlmutter recommends acacia gum.

Keep up your probiotic routine and mix it up.

The benefits you gain from your probiotic will cycle through your body if you don’t take them regularly. Probiotics stick around for a while, though for how long isn’t precisely clear. You have to keep taking them to continue to reap the benefits. Further, getting a wide variety of strains into your system is beneficial. “Periodically mixing up your probiotic supplement is also a good way to ensure that you get different health-building strains in your health regime,” says Dr. Cook.

The Best Probiotic Supplement: Summed Up

The Best
Islands Miracle Ultra-30 Probiotics
For General Digestive Health
MegaFood MegaFlora
For Antibiotic Recovery
Renew Life Ultimate Flora Extra Care
For Immune Health
Dr. Formulas Nexabiotic Advanced Multi-Probiotic
For IBS/IBD Relief