Before Trying Probiotics, Beware of These Potential Side Effects

Before trying probiotics, beware of these potential side effects

Is this "give it a try" supplement actually worth a shot?

YOU HAVE PROBABLY considered taking a probiotic supplement at some point in your life. Maybe a friend took one and said it worked for them. Or your doctor recommended it when you brought up some bloating issues.

Probiotic supplements been known as a “no harm, no foul” option to those seeking digestive relief. And with nearly 60 to 70 million Americans suffering with digestive issues according to the National Institute of Health, there’s a large population of people to market to.

The popularity of the supplement is growing exponentially. In 2021, the probiotic market was worth more than $48 billion, with an 8 percent increase from the previous year. While there’s no conclusive evidence that these supplements have any lasting benefit, they’re known as a “give it a try” supplement because the odds of side effects are so low, especially in healthy people.

Just because probability is low, however, doesn’t mean side effects can’t happen. So, what are the risks—and is it worth a try? We answer all your questions below.

What are the side effects of probiotics?

Since everyone’s microbiome is composed differently, probiotic supplements can react to the biome in different ways, causing different side effects.

While probiotic foods don’t inherently have side effects, they may cause some gas or bloating if you’re allergic or sensitive to certain foods. Probiotic supplements, on the other hand, may be a different story. And unfortunately, everyone’s experience is individualized.

“Every individual is different because every individual has a different system and has a different microbiome,” says Katherine Zeratsky, registered dietitian nutritionist at the Mayo Clinic.. “And so how their microbiome interacts with the newly introduced and dosage of what’s introduced could be different.”

Since there’s no way of knowing for sure what side effects you will experience, it’s important to familiarize yourself with them to be ready incase they do happen.

Digestive side effects

The most common side effects of probiotics include nausea, diarrhea, and bloating, according to Zeratsky. This happens as the bacteria of the probiotic settles in with your guts microbiome.

This happens initially upon starting the supplement, but usually fades after a few days, according to the Cleveland Clinic.

“For the average population, [taking a probiotic is] probably fairly safe. I think where you run into a cautionary tale is when you’re at kind of the ends of the age spectrums,” says Zeratsky. “So you have the very young who have a developing immune system, or at the other age spec where you, you have someone who’s aged and has maybe a more challenged immune system.”

Though incredibly rare, there are a few larger side effects that can happen.


Though unlikely, infections can happen when someone of immunocompromised status takes a probiotic supplement that has poor purity standards. Some microorganisms may be present that are not listed on the label because of lack of standardized regulation.

Since probiotics are considered a supplement, they’re not regulated by the Food and Drug Administration. Which basically means anyone can put anything into a pill vile and call it a probiotic— not great for the consumer.

This makes the market a bit sketchy. The best (and really, only) way to know you’re getting true, healthy cultures is through a third party certification company that tests supplement purity and potency. U.S. Pharmacopeia, or USP, or National Sanitation Federation, or NSF, are two of the most reputable companies, and have awarded certifications to big probiotic companies like Member’s Mark and TruNature.

Antibiotic resistance

Concern has been raised about some bacterial strains that are used for probiotic supplements having antibiotic resistance genes, according to a study published in Frontiers in Microbiology. These genes can then spread to the other bacteria in your gut.

This can be alarming, as it makes infections more difficult to treat, according to the World Health Organization. If the bacteria in our bodies are resistant to certain kinds of medicines, they’re going to be difficult to fight off if they’re making you sick.

Therefore, it’s important to make sure you are getting a probiotic supplement that has been tested for proper bacterial strains, like finding a USP or NSF certified brand.

The good news is that side effects are not common with well vetted supplements. In a 2019 study published in the peer-reviewed journal, Nutrients, the only statistically significant side effect of probiotics in IBS patients was abdominal pain.

Because of the low chance of these side effects, probiotics are often considered a “give it a try” supplement, according to the Cleveland Clinic. Regardless, Zeratsky recommends talking to a physician before trying any kind of supplement. She recommends starting with bettering your nutrition before introducing a probiotic.

“You have to eat good food,” says Zeratsky. “You have to eat your fruits, and you have to eat your vegetables. That promotes a healthy environment so you can have a set up to have a healthy gut and maintain a healthy gut. First things first.”

What are probiotics?

Let’s back it up for a second. What even are probiotics, anyway?

“Probiotics are bacteria that are sometimes naturally found in food that people might take with the intent that they may change their gut microflora, the bacteria that are present and living in their digestive tract,” says Zeratsky.

Believe it or not, our entire digestive tract is home to trillions of healthy bacteria, fungi, parasites, and viruses. Yes, they are supposed to be there, and we wouldn’t survive without them. We call this colony our microbiome.

Our microbiome consists of mostly healthy microorganisms, but can house some harmful ones. The healthy organisms assist in food breakdown, and even fight to protect us from the harmful ones that can make us sick.

So how do we ensure we have more healthy bacteria than bad?

Probiotics foods add healthy, living microorganisms to your microbiome. Fermented foods, such as kimchi, sauerkraut, kombucha, and yogurt, are packed with these healthy bacteria and can help improve the overall health of your microbiome.

But if you don’t get enough of probiotic-rich foods in your diet, probiotics supplements stuff billions of these little bacteria into a pill form.

When should you take probiotic supplements?

A doctor might recommend a probiotic supplement if you’re having digestive problems, such as constipation, diarrhea, or bloating. A study in the American Journal of Gastroenterology found that many with irritable bowel syndrome have seen great relief with these supplements.

These supplements may also be recommended by a doctor when you’re on antibiotics. Antibiotics are used to treat everything from strep throat to urinary tract infections by killing the bad bacteria that causes illness. However, sometimes the differentiation between the good and the bad bacteria is not so easy, and the ‘good’ gets taken out with the bad. By taking a probiotic supplement during this time, you ensure a new supply of good bacteria, keeping the microbiome in balance.

This article originally appeared on Men’s Health US.

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