4 All-Too-Common Misconceptions About Probiotics, Fact-Checked by a Dietitian

These days, digestive supplements and toilet footstools are nearly as ubiquitous as avocado toast and matcha lattes. Moreover, conversations around poop (or a lack thereof) are more mainstream than ever. With the growing normalization around all things digestion and gut health—and a booming industry to support growing interest and needs—you’re probably no stranger to probiotic supplements. But how much do you *really* know about probiotics—including how effective they are, how to choose the right one, and if you even need them at all?

To separate fact from fiction, we asked Brooklyn–based dietitian Maddie Pasquariello, MS, RDN to share the key facts about probiotics to know before you buy to ensure you’re getting the most bang for your buck.

Myth #1: Any probiotic will work for anyone

The reality: Not all probiotic supplements offer the same benefits.

You might think that you’re doing your gut and greater health a solid by popping any old probiotic supplement on the daily…but there’s a lot more nuance to it than that.

That’s because there are different types of probiotics, such as Lactobacillus and Bifidobacterium, which have potential to support different aspects of health. “Some probiotic strains inhibit specific pathogens, while others help restore normal microflora or can regulate immune response,” Pasquariello says. Moreover, she says a single strain, or combination thereof, could help with one condition or issue but be completely ineffective for another. “There are even levels of probiotic specificity to consider when treating diseases that share similar mechanisms of action, e.g., IBD and IBS,” she continues. In sum, the potential benefits of any probiotic supplement, for any given goal, will be strain-specific.

If you’re interested in taking probiotics, hone in on your key concern(s) and investigate from there. Probiotics exist for everything from digestive irregularity and acne to vaginal health and beyond. Once you have a goal in mind, a little bit of research on which strains are effective—from peer-reviewed journals, reputable news outlets, and/or a trusted health-care practitioner, rather than supplement brands themselves—can help you narrow down your probiotic search and inch you closer to the results you want.

Myth #2: The more strains, the merrier

The reality: More probiotic per dose doesn’t always equal more effective.

The amount of strains in a serving of probiotics also has implications for potential benefits. “The effect of any given probiotic depends on both the combination of bacteria used as well as the dose, typically indicated as colony forming units or CFU,” says Pasquariello. “This is usually in the range of 500 million to 100 billion CFU per dose, and varies depending on the strain in question, [with] 100 million being the minimum effective dose.”

However, despite what some marketing claims will lead you to believe, a higher CFU count in a given probiotic supplement doesn’t automatically mean it’s superior to a product with a lower CFU count or fewer strains. “More isn’t always better. In fact, results for certain conditions treated with probiotics can plateau at a certain CFU dosage,” the dietitian clarifies. “A slightly lower dosage is sometimes just as effective, if not more so.” That’s why it’s important to understand not just the specific strain(s) you want, but also how much of it is truly needed to help benefit the issues you’re trying to manage, she says. (Another great moment for talking to a health-care provider if you can to help you sort out everything.)

Myth #3: Everyone needs to take probiotics

The reality: Not all people may benefit from probiotics—and that’s okay.

Since a balanced gut is crucial for everything from digestive regularity and clear skin, to mental health and immunity, you might think that probiotic supplements are an essential part of a wellness toolkit. Yet Pasquariello says that not everyone needs to take probiotics, especially if you’re in generally good health and adhere to a diverse and well-rounded diet.

“[Probiotics] are often most helpful for those with more serious conditions, so those with mild symptoms or no symptoms at all may not see major changes while taking them,” she explains. In addition, while high-quality probiotics are most known for addressing a myriad of GI issues, not every person dealing with such conditions is guaranteed relief with supplementation. Plus, Pasquariello says that people in some higher-risk groups—such as those who are immunocompromised—may be advised against taking probiotics to begin with.

Myth #4: Probiotics can “fix” or “undo” dietary gaps

The reality: Probiotics should supplement, not replace, a healthy diet and lifestyle.

“As with any supplement, probiotics should be seen as just that: supplemental to an already balanced and nutrient-dense diet,” says Pasquariello. Even the most impressive probiotic supplements won’t do much if you lack necessary foods and nutrients in your greater dietary routine.

It’s also worth remembering that probiotics—whether from supplements or probiotic-rich foods—need prebiotics to thrive—because prebiotics are food for gut bacteria. “It’s important that while you’re replenishing your gut microflora, they have prebiotic foods to feed off of,” says Pasquariello. “These include many different grains along with certain fruits and veggies.”

The takeaway

While probiotics can be an effective, worthy part of your wellness regimen, it pays to get clear about your specific goals, investigate the strain(s) and counts demonstrated to achieve said goals, and incorporate any supplements into a healthy diet. (Of course, if you have any health conditions or are on medications, consult your physician and/or work with a dietitian before adding any supplements into your routine—including probiotics.)

Things can get tricky in a highly saturated market abundant with compelling (but sometimes misleading) claims. But being a curious, mindful consumer will help you combat myths and find the actual facts about probiotics to help you make the right choice. “Each consumer should do his or her own research about any brands they’re thinking of buying,” Pasquariello concludes.

Deep dives, fact-checks, and meticulous label-readings aside, she suggests prioritizing brands that are third-party tested, tested for contaminants like pesticide and herbicides, and vegan-friendly, as well as have a certificate of analysis (COA) available for every product.