This gastroenterologist says probiotics are ‘a waste of money.’ Here’s what you should be doing instead

While fans of probiotics—including physicians, health influencers, and what Pasricha calls self-proclaimed “gut health experts”—purport that probiotic supplements can boost your gut microbiome and treat everything from digestive issues to mental health, Pasricha is skeptical.

“The marketing claims about over-the-counter probiotics largely do not match the evidence,” Pasricha wrote. As a gastroenterologist, Pasricha said, she rarely advises her patients to take probiotics—which often surprises them.

“They’re even more surprised when I tell them that’s part of the evidence-based guidelines: The American Gastroenterological Association does not recommend probiotics for most digestive conditions,” she said.

So as we learn how pivotal the gut microbiome is for our overall health, what should we do instead? Pasricha’s recommendation is in line with what many dietitians and doctors are focusing on nowadays: a high-fiber diet.

Pasricha points out that studies show low-fiber diets can lead to the permanent loss of certain gut bacteria, leading to a less diverse gut that can worsen your health. She encourages people to focus on a diet with a variety of plants, nuts, and fermented foods to feed your microbiome the diverse nutrients it needs.

“This time-tested recommendation remains one of the strongest-studied ways to promote and preserve a healthy microbiome and improve your overall health,” Pasricha wrote.

Probiotic confusion

Pasricha pointed out that the research on probiotics is hard to rely on—with over 1,000 clinical trials of probiotics completed, there are too many different bacterial strains, doses, and outcomes being measured for scientists to come to a consensus.

Additionally, Pasricha said that probiotics, like other supplements, don’t go through rigorous clinical trials and testing by the Food and Drug Administration, like prescription drugs do. That means consumers can’t know for sure if the probiotics are as effective as manufacturers claim.

“Probiotics…have incredible potential,” she wrote, “but realizing that potential is still a nascent scientific field in many ways. Each of our microbiomes, medical history and diets is unique. We still need rigorous studies that would allow us to personalize such treatments for individuals.”

Misinformation both from marketing campaigns and social media also fuels the confusion around probiotics, Pasricha said. Marketers will sometimes extract data about the benefits of one probiotic and use that to sell their product, even if the probiotics are different, she said, “as if all probiotic types fall neatly under one big umbrella.”

Meanwhile on social media, one 2023 study found that the majority of YouTube videos about probiotics were not only positively endorsing them—but most of the content was produced by amateurs, not experts, Pasricha said. 

Focus on a high-fiber diet instead

As experts have told Fortune, fiber is your frontline diet defense against cancer—especially colorectal cancer, which is on the rise among millennials and Gen Xers. Nutrition experts have also found that people who fixate too much on protein intake are often missing out on the numerous benefits of fiber, and could be worsening their health in the process.

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The U.S. Department of Agriculture’s Dietary Guidelines for Americans recommend that women eat 22 to 28 grams of fiber per day, while men should aim for 28 to 34 grams of fiber per day. 

Yet Americans eat about 10 to 15 grams of fiber per day on average, according to Harvard Medical School. 

While fiber supplements might seem like the easy way out, registered dietitians like Abbey Sharp have previously told Fortune that whole-food sources of fiber are your best option, as they will offer vital micronutrients, vitamins, and minerals in addition to fiber.

Here are some high-fiber foods to start incorporating into your diet:

• Beans
• Lentils
• Nuts
• Fresh fruits like raspberries, blueberries, apples, and pears with skin
• Fresh vegetables like broccoli, Brussels sprouts, green peas, and potatoes with skin
• Popcorn
• Avocados
• Whole grains like oatmeal, farro, and barley
• Split peas
• Chia seeds and flax seeds

If you’re not sure where to start, nutritionist Federica Amati told Fortune this trick for building filling, high-fiber meals: Fill half your plate with some plant source—a salad, broccoli, sautéed zucchini. Next, fill a quarter of the plate with your favorite lean protein like salmon, chicken breast, edamame, or tofu. The last quarter is for a high-fiber complex carbohydrate like brown rice, barley, or sweet potatoes.

Who should take probiotics

Pasricha wrote that there are few cases in which clinical guidelines advise the use of probiotics. Those include:

• To decrease possible risk of infection with C. difficile, a bacteria that causes severe diarrhea, while taking a course of antibiotics.
• When patients with inflammatory bowel disease who have undergone surgery resecting a portion of the bowel develop a condition called pouchitis.

“It should be noted that the guidelines do not recommend even these indications very strongly—and that the quality of evidence upon which they’re based was rated ‘low’ or ‘very low,’” Pasricha said.

She added that some people’s positive experiences using probiotics is still valid, however, as a small fraction of people can experience benefits from taking them.

“In these cases, I tell my patients I’m glad they’ve found something that has helped them and feel reassured if they’ve bought a probiotic from a company vetted by a third party,” she wrote.

However, Pasricha warns that people looking to take probiotics to alleviate belly pain or bloating may be disappointed when those symptoms do not improve—and find they wasted money in the process.

“That’s a good moment for us to pause and consider the data together,” she said.

For more on nutrition:

• Nutritionists offer these 6 ways to get back to a healthy diet
• Coca-Cola is Olipop’s and Poppi’s latest prebiotic soda competitor. But are ‘healthy’ sodas actually good for you?
• New dietary guidelines warn Americans to limit these 4 food types—and eat more of this instead
• Keto vs. paleo diet: which one is better? Experts weigh in