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. 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. 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: 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.* 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.* 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.* “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. 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. 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.* 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.* 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. 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: 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. 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.
