We Fact Checked Dr. Oz's Claims About Probiotic Supplements

In a March 6, 2024, post on Instagram, Dr. Mehmet Oz described the benefits of balancing the bacteria in your gut for your overall health, such as maintaining healthy blood sugar and cholesterol levels. Oz then said how important it is to supplement your gut with more of these good bacteria through probiotics sold at iHerb, a company where he serves as the global advisor. However, in December 2024, a consumer watchdog group called for a Federal Trade Commission investigation into whether he had properly disclosed his ties to the company, causing some to question the veracity of his health claims. Senate confirmation hearings in March 2024 for him to become the head of Medicare and Medicaid brought him under even more scrutiny. In light of this, we fact-checked Dr. Oz's claims regarding probiotics.

It is true that by eating prebiotics found in foods like legumes, whole grains, and bananas, you're feeding the good bacteria in your gut. You can also find probiotics in fermented foods such as sauerkraut, kimchi, kefir, and yogurt. If you don't typically eat these foods, it may sound simple to add a prebiotic or probiotic to your supplement regimen. However, the American Gastroenterological Association says it doesn't recommend taking a daily probiotic even if you have a digestive disorder because there isn't enough scientific evidence to warrant their use. There may be some times when a probiotic can help, however.

The problem with probiotics and other supplements is that they aren't regulated by the Food and Drug Administration in the same way as medications. Unless a specific laboratory analyzes the probiotic, there's no guarantee that the probiotic strains stated on the label are in that supplement. Although the Lactobacillus and Bifidobacterium bacteria are the most common in probiotics, specific strains can have different effects on your body, according to the National Institutes of Health. If a probiotic claims to address a specific condition, it must be tested for safety and effectiveness through clinical trials.

If you're generally healthy, you probably don't need a probiotic, according to a 2024 article in Advances in Nutrition. Probiotic strains Lactobacillus rhamnosus GG and Saccharomyces boulardii may help alleviate diarrhea and other gastrointestinal problems linked to taking antibiotics. Other strains of probiotics may prevent (not treat) recurring urinary and vaginal infections. The evidence is mixed about the effectiveness of probiotics in reducing respiratory tract infections or improving cardiovascular health.

The American Gastroenterological Association's 2020 article in Gastroenterology suggests finding specific probiotic strains to address your condition. People taking antibiotics may experience diarrhea due to a Clostridioides difficile (C. diff) infection. A probiotic with strains such as Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium bifidum, or Streptococcus thermophilus may prevent this infection while you're taking an antibiotic. People with irritable bowel syndrome or inflammatory bowel disease should not take a probiotic unless they're involved in a clinical trial.

If you decide to take a general probiotic, the AGA advises choosing a supplement brand that shows the probiotic has been independently tested. For example, the iHerb probiotic has been analyzed for microorganisms and heavy metals by Swift Laboratories. The National Institutes of Health says that probiotics are generally safe for healthy people, but they may be harmful for people with compromised immune systems or hospitalized for serious health conditions. Probiotics may be fatal for infants born prematurely. Probiotics that haven't been tested by a third party could have E. coli, mold, or other microorganisms that can make you sick. You may experience side effects such as gas, bloating, or diarrhea if you take too many probiotics.