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6 Science-Backed Benefits Of Probiotics & Who Should Take Them*

Marygrace Taylor
Author: Expert reviewer:
Updated on December 21, 2022
Marygrace Taylor
By Marygrace Taylor
mbg Contributor
Marygrace Taylor is a Philadelphia-based health and wellness writer.
Mario Roxas, N.D.
Expert review by
Mario Roxas, N.D.
Doctor of Naturopathic Medicine
Mario Roxas, N.D. received his doctorate in naturopathic medicine from the National University of Natural Medicine (NUNM) in Portland, Oregon.

Probiotics have garnered a lot of buzz over the past few years—and rightly so. These healthy bacteria, found in probiotic foods and supplements, help take care of your gut and give it the support it needs to run smoothly.*

Ready to learn more about these probiotic perks? We dialed up a few experts to answer some of the top-searched questions people have on the internet, and reveal exactly what taking probiotics can do for your total well-being.

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One of the most talked-about probiotic benefits is better digestion—but probiotics actually offer a number of incredible benefits, in addition to aiding digestion and bloat (think: supporting your mood and your immune system).* This is because your gut microbiome, the collection of bacteria living in the gut, actually plays an integral role in overall health.

Many people think about bacteria in terms of germs that make you sick. But probiotics are good bacteria that help support health, especially in the digestive tract.* These friendly bugs are key for maintaining the gut microbiome.* 

Where can you get them? Probiotic bacteria are found in fermented foods like yogurt, kefir, sauerkraut, kimchi, and tempeh. But you can also find them as supplements, including shelf-stable capsules, refrigerated capsules, powders, and liquid beverages.


Probiotics are beneficial bacteria, found in fermented foods and supplements, that help with digestion and support your immune system.
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Benefits of taking probiotics

Probiotic bacteria are involved in a wide range of functions from aiding in digestion and absorption to priming the immune system1 and producing neurotransmitters2.*

When you take a probiotic supplement, you add more of these good bugs to your gut.* As Robert Rountree, M.D., renowned integrative physician, explains it, "The probiotics are like good cops. We're putting in the good cops, and the good cops can keep watch over the bad guys."* Here's a closer look at how that can affect your health:


They're good for your gut* 

Probiotics are best known for their impact on gut health.* "Think of probiotics as your little helpers that restore order and help maintain harmony in your gut ecosystem,"* says gut health expert Vincent Pedre, M.D.

Research3 has shown that probiotics are beneficial for improving gut issues like irregularity (going too much or too little) due to gut imbalance.*

Science demonstrates their ability to support numerous functions of the upper and lower GI tract4, and promote abdominal comfort by helping reduce gas and bloating5.*


Probiotics help improve gut comfort and ensure order in your gut.*
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They can help support a healthy weight*

These good bugs might play a positive role in weight maintenance, too.* Gut bacteria play an important role in metabolism6, involved in everything from digestion to energy production and storage and even appetite regulation. 

Several studies have shown7 that the gut microbiomes of individuals who are overweight are different from the microbiomes of individuals who are a healthy weight. And the reason for that might have to do with how microbes help us break down food. 

"Certain bacteria are better at extracting energy from food than others," says Rountree. "It's that simple."

So, if you happen to have more of these desirable bacterial strains in your gut, then you could eat the same food as a friend and you end up turning it into energy, while your friend turns it into fat.*


Research shows probiotics can help with digestion, energy production and storage, and appetite regulation.*
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They support healthy digestion*

The friendly bacteria in your gut are key players in the breakdown and digestion of fiber-rich carbohydrates (sometimes called prebiotics).*

During the breakdown process, gut bacteria produce short-chain fatty acids (SCFAs), like butyrate, which serves as fuel8 for the cells that line and strengthen the barrier of the intestine. 

As gastroenterologist Will Bulsiewicz, M.D., MSCI, explains, "SCFAs are a real game-changer with the potential to legitimately transform the health of those who pursue it."

And a healthy butyrate level, a type of SCFA, is believed to promote good health9 and a healthy weight—perhaps by helping to support the body's healthy inflammatory response10.* 


Probiotics can help with the digestion of fiber-rich carbohydrates, also called prebiotics.*
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They have skin benefits*

Probiotics don't just work wonders inside your body; they can actually affect the outside as well.*

"You have bacteria on your skin and all over your body. Probiotics on the skin affect the microbiome that's present on your skin, as opposed to the one in your gut," says integrative medicine expert Amy Shah, M.D. In this case, both oral and topical probiotics can help, but are certainly not one and the same. 


Both oral and topical probiotics contain skin care benefits.*

They can affect emotional health, too*

Several studies11 have found that probiotics seem to ease the body's stress response and positively affect cognitive function.*

How? The mechanisms are complex, but good bacteria in the gut are capable of producing mood-stabilizing neurotransmitters, like serotonin and dopamine12.*

And because these bugs have a direct link13 to the central nervous system, via a pathway called the vagus nerve, they play a key role in regulating mood.*

And that can have real effects: In one study14, when women were shown pictures of angry faces, those who ate probiotic yogurt twice a day for four weeks before seeing the pictures felt calmer compared to those women who didn't eat the yogurt.


Research shows that probiotics can reduce the body's stress response and positively affect cognitive function.*

They're heart-healthy*

Believe it or not, the benefits of probiotics can even extend to your ticker.* Case in point: A review15 of more than 30 randomized clinical trials found that taking probiotic supplements can significantly and positively affect total cholesterol levels.* 

There are also benefits to blood pressure. Consuming probiotics can have positive effects on both systolic (the top number) and diastolic (the bottom number) blood pressure about the same as from eating a low-salt diet, a recent analysis16 determined.*  


Research shows that probiotic supplements can help support healthy cholesterol levels and blood pressure.* 

Probiotics for women.

Can getting more probiotics also help your vaginal microbiome? Yes, it turns out that facilitating microbial balance (i.e., more good bugs than bad) is critical for your vagina and urogenital tract health.*

With that in mind, it might follow that getting more good bacteria in the form of food and targeted probiotic supplements could help.*

And indeed, a few small studies have shown that taking an oral probiotic17 or a probiotic combo18 (all Lactobacillus strains) can help facilitate this delicate microbial balance and promote vaginal health.*

Regular yogurt consumption, a probiotic-rich food, is tied to19 healthier levels of vaginal bacteria as well.*  

Probiotics could also prove beneficial during pregnancy20, but of course, pregnant women should work with their doctor to determine a personalized plan right for them.*


Research shows that probiotic supplements can support vaginal health. Eating probiotic-rich foods, like yogurt, can lead to healthier levels of vaginal bacteria as well.*

Probiotics for men.

Is what's good for the gut also good for the gonads? When it comes to couples who are trying to get pregnant, the science is promising.*

A handful of studies21 have found that supplementing with a blend of probiotics and prebiotics (fibers that act as food for probiotics) can promote fertility by supporting sperm quality and healthy testosterone levels in men.* For a more detailed look at what probiotics can do for men, check out our top probiotics for men.


Research shows that supplementing with a blend of probiotics and prebiotics can promote fertility by supporting sperm quality and healthy testosterone levels in men.*

Picking a probiotic: What to look for

There are loads of different bacteria strains that fall under the probiotic category.

And while many probiotic supplement products take the "kitchen sink" approach of throwing a lot of different strains into one capsule, "different strains can be tied to different benefits," explains functional dietitian Krista King, M.S., RDN, LDN.

So if you're thinking about taking a probiotic, then it makes sense to seek out a supplement with a strain or strains for your unique needs.

Experts are still studying and learning how different types of probiotics deliver their unique health benefits.* Here's a brief look at what the research has uncovered so far:

  • For general health support: Lactobacillus, Bifidobacterium, and Saccharomyces boulardii.*
  • For regularity22: Lactobacillus rhamnosus GG, Lactobacillus acidophilus, Lactobacillus bulgaricus, and Saccharomyces boulardii.*
  • For weight maintenance23: Lactobacillus gasseri, Lactobacillus rhamnosus, and Bifidobacterium lactis.*
  • For mood support24: Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Lactobacillus helveticus, and Lactobacillus rhamnosus.* 
  • For heart health15: Lactobacillus acidophilus, Lactobacillus plantarum, and Bifidobacterium lactis.*
  • For bloat25: Lactobacillus acidophilus and Bifidobacterium lactis. *

Aside from the probiotic strains themselves, also pay attention to the number of colony-forming units (CFUs) listed on the product label. (A typical probiotic supplement contains anywhere from 1 to 50 billion CFUs per serving.)

The CFU count of each probiotic strain should meet or exceed the level it was studied via clinical research. The more strains, typically the higher the CFU count as a result. Higher CFU counts aren't necessarily more potent than lower ones, though, says the National Institutes of Health26.

As Rountree sums it up, "More doesn't necessarily equal better." Adding, "You want something that's got a good stability, got a good shelf life, and then you want to have strains that have actually been well researched."

If a product has an expiration date, the CFU count is good up until that date. If a probiotic supplement includes a manufacturing date, then the potency (CFU count) is typically good through two years, but you can ask the manufacturer if you want to be sure. 

No matter what product you end up choosing, you'll want to follow the storage directions to keep your product as potent and stable as possible.

"Some probiotics will need to be refrigerated while others may just need to be stored in a cool, dry place," King says.


Seek out a supplement with a strain or strains that have been shown to have potential in supporting your specific needs. Also pay attention to the number of colony-forming units (CFUs) listed on the product label. (A typical probiotic supplement contains anywhere from 1 to 50 billion CFUs per serving.)

Probiotic-rich foods

Fermented foods are a delicious way to reap some of the same benefits as probiotic supplements27. They also have the added benefit of providing a natural source of vitamin K. Here's a list of some of our favorites:

Safety & side effects.

Probiotics are generally regarded as safe to take and won't cause any side effects if you're healthy, according to The National Center for Complementary and Integrative Health (NCCIH).

But if you have an illness or compromised immune system, then you'll want to first get the green light from your doctor. 

As for how much you should take—and how often? If you're generally healthy, it's fine to take a probiotic supplement every day, King says. It's also worth incorporating probiotic foods into your diet—think yogurt, kefir, sauerkraut, kimchi, or tempeh.

There's no standard dosage that's right for everyone, though, so consider talking with your doctor or a registered dietitian who specializes in functional eating. They will be able to offer more specific guidance based on the health area you're trying to support.

Finally, pay attention to how your probiotic supplement makes you feel. If your gut health seems to get worse instead of better, then that could be a sign that the particular probiotic strain doesn't agree with you, King says.

In that case, you should take a break, work with your healthcare provider, and consider trying another strain.  


Probiotics are generally regarded as safe to take if you're healthy. Be sure to consult with your doctor, however, if you have an illness or compromised immune system.

Frequently Asked Questions

What are signs a probiotic is working?

You may experience less bloating, improved regularity, and more gut comfort overall.* Learn more about how to tell if your probiotic is working here.

How long do probiotics take to work?

Results and time vary from person to person, but in general most people see benefits in two weeks.

Should I take probiotics after antibiotics?

It’s best to take a probiotic for at least six months after a course of antibiotics. Add probiotic-rich foods, like kimchi and kefir, to your diet too.

What are the signs you need probiotics?

While supporting your gut is good for almost anyone, probiotics can help alleviate some GI discomfort like bloating and gas. Read more about what the experts say here.

The takeaway.

The gut microbiome is made up of trillions of bacteria living in your small intestine. These bacteria are involved in a wide range of functions in the body, supporting the digestive tract, immune system, and more. Consuming probiotic foods and supplements can help support good bacteria in the gut and can be greatly beneficial for overall health.* 

If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.
Marygrace Taylor author page.
Marygrace Taylor

Marygrace Taylor is a Philadelphia-based health writer for the Amerisleep blog, as well as other health and lifestyle websites. She has a bachelor's in english from The College of New Jersey and has written freelance for a variety of publications for over six years. Taylor specializes in healthy eating and nutrition, natural health, weight loss, women’s health, pregnancy and parenting.