Note: The U.S. Food and Drug Administration (FDA) does not approve supplements for safety or effectiveness. Talk to a healthcare professional about whether a supplement is the right fit for your individual health, and about any potential drug interactions or safety concerns.
There’s a lot of buzz about
probiotics and their possible benefits. These living bacteria and yeasts naturally inhabit your
microbiome (your body’s community of microorganisms) and play many roles in your digestive health, including potentially boosting your immunity. Some people may benefit by taking a supplement to support these important microorganisms.
“There’s a lot of excitement around probiotics because there’s increasing attention being paid to the microbiome,” says Richard Maurice Peek Jr., MD, the vice president for the American Gastroenterological Association and a professor of medicine at the Vanderbilt University Medical Center in Nashville, Tennessee. “The issue is that a lot of the trials on probiotics have been fairly small, not all of them have been controlled, and many of them have used different probiotic formulations, so it’s hard to compare results.”
Probiotic supplements are generally considered safe for most healthy people and have
few risks and side effects, though it’s still
best to take probiotic supplements under the direction of your doctor, Dr. Peek says. Those who are immunocompromised have a small risk of side effects if supplements aren’t tested carefully for harmful microbes, which can cause serious infection in those individuals.
To choose a quality supplement, check the label for
USP,
NSF, or
ConsumerLab approval. This means the product has undergone third-party testing for quality and purity.
1. Probiotics May Help Irritable Bowel Conditions
If you have a digestive issue such as an irritable bowel condition, ask your doctor if they recommend probiotics. These supplements are widely recognized for potentially supporting overall digestive function, says Mai Nguyen, RDN, with Hoag's Mary and Dick Allen Diabetes Center in Newport Beach, California.
One systematic review and meta-analysis from England that evaluated 82 trials, including 10,332 people with IBS, established moderate certainty that
Escherichia strains may help overall symptoms. However, there were limitations in this study: There were inconsistent results across trials, and not all results from individual studies were published, so more research is needed.
Another systematic review that looked at 18 randomized, controlled trials and two observational studies, involving 2,675 adults with IBS or
inflammatory bowel disease (IBD), found that probiotics may help some people with IBS and IBD (particularly those with ulcerative colitis), but the results were inconsistent, so more research is needed.
More research is needed to establish both which strains work best and for which
digestive conditions. Because of the limited research, current major guidelines don’t broadly recommend probiotic supplements as part of standardized treatments for most digestive conditions.
“In most cases, we don't know specifically which of the probiotics are exuding this beneficial effect,” Peek says. “And we don't know how much people would have to take to gain these [possible] benefits.”
2. Certain Lactobacillus Strains May Help With Oral Health
The same probiotics that benefit your gut health may affect your mouth, Peek says. Specifically, those with poor gum health or oral infections may want to ask their doctor if probiotics could help.
A systematic review and meta-analysis from Portugal analyzed 33 randomized, controlled trials, involving 1,290 people, and found that adding probiotics to professional dental cleaning significantly improved gum health, with
Lactobacillus strains showing the most substantial benefit.
Another systematic review from China of 13 randomized, controlled trials, including a total of 898 participants, found that those who took probiotics were 62 percent less likely to develop the oral infection
thrush versus those who didn’t. However, 75 percent of the review’s studies used multistrain combinations of probiotics, so it’s unclear which strain works best. Most of these studies also recruited healthy people, so more research is needed, as thrush primarily affects immunocompromised people.
3. Probiotics May Help With Weight Loss
You may want to talk to your doctor about probiotics if you’re looking to
lose weight. One meta-analysis from China of eight randomized, controlled trials, involving 412 people with
obesity, found that people who took probiotics lost more weight, had greater reductions in waist circumference, and lost more visceral fat than control groups who didn’t take probiotic supplements.
“Probiotics help maintain a healthy gut microbiome, which plays a key role in nutrient absorption and fat storage,” Nguyen says. “However, while they can be helpful as part of a comprehensive, healthy lifestyle, they should not be considered a substitute for balanced nutrition, regular exercise, and overall healthy habits.”
4. Probiotics May Help Asthma and Allergies
You may want to ask your doctor about probiotics if you have
asthma or
allergies. The prevalence of autoimmune and allergic diseases is growing, Peek says.
“It’s speculated that certain bacteria are important to adequately train your immune system, and that beneficial bacteria like a probiotic could shape the microbiota to prevent or lessen the severity of autoimmune disease,” he says.
What’s more, a review from China analyzed 13 randomized, controlled trials, including 4,500 children with allergic diseases like asthma and allergic rhinitis. The researchers found that children who took probiotics had a roughly 25 percent lower risk of developing allergic symptoms, compared with those who took a placebo. The findings suggest use of probiotics as an adjunctive treatment, not a primary treatment.
Meanwhile, a randomized, placebo-controlled trial from China, including 99 adults with allergic rhinitis, asthma, or both, found that those who took
Lactobacillus reuteri showed improvements in certain rhinitis symptoms, better asthma control, and higher quality of life and
sleep.
5. Certain Lactobacillus and Bifidobacterium Strains May Help With Mental Health
“Emerging research suggests that gut health can influence mood and stress through the gut-brain axis,” Nguyen says. The gut-brain axis is the network of nerves that connects the brain to the gut.
Research shows that your digestive system’s bacteria can send signals to your brain through nerves in your gut, influencing how your mind and body work, Peek adds.
A systematic review and meta-analysis from Iran of 12 randomized, controlled trials, including 707 participants, found that probiotic strains such as
Lactobacillus acidophilus and
Bifidobacterium bifidum were linked to significant improvements in depression symptoms when measured with the Beck Depression Inventory (BDI) scale but not other scales. The BDI scale is a self-reported questionnaire that is known for its sensitivity to capturing depression symptoms, while the other scales used were based on observable symptoms of
depression or broader assessments that also include anxiety-related symptoms. The authors say that the discrepancy highlights the complexity of assessing these conditions.
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