What Are Probiotics? 5 Things You Need to Know About Them
A registered dietitian nutritionist recently told me, “Probiotics are hot right now.” She’s not wrong: The number of adults in the U.S. taking probiotics or prebiotics—both of which are said to make your gut healthier—multiplied by four between 2007 and 2012, according to government data. Children use them too. A report from the National Institutes of Health says, “Probiotics or prebiotics were among the top three natural products used by children in 2012.”
So what are these pills so many people are taking? Probiotic pills are supplements that contain live organisms. Usually, these pills contain specific bacteria strains that contribute to the bacteria that live in your gut.
To understand how probiotics work, you might need a refresher on the purpose of your gut. “The lining of your gut, like every surface of your body, is covered in microscopic creatures, mostly bacteria," the Mayo Clinic explains. "These organisms create a micro-ecosystem called the microbiome. And though we don’t really notice it’s there, it plays an oversized role in your health and can even affect your mood and behavior.”
Therefore, your microbiome is pretty important; your overall health depends on the health of your microbiome. Given this, it’s not surprising that there’s a huge demand for pills that can supposedly make your microbiome healthier, which is what probiotics claim to do. But the reality is that probiotics benefit a very small number of people, according to science. Below, you’ll find five facts about probiotics that you need to understand before you start taking them.
Probiotics became popular as antibiotics became unpopular
It’s no coincidence that probiotics are so popular right now, Rabia De Latour, MD, a gastroenterologist and assistant professor of medicine at NYU Langone Health, tells Health. The current concerns about antibiotic resistance are partially responsible for the obsession with probiotics. Here’s why: Doctors have, until relatively recently, aggressively prescribed antibiotics. In the past, they were thought to be miracle drugs. From an efficiency standpoint, they are miracle drugs. But they don’t come without problems.
The more we take antibiotics, the more we become resistant to them. This means that if we continue to take antibiotics for anything and everything even when they’re unnecessary, they’ll stop working to cure us sooner rather than later. In fact, the World Health Organization (WHO) says that “antibiotic resistance is one of the biggest threats to global health, food security, and development today.”
There’s another problem with antibiotics: They mess with your microbiome. A 2016 report sums it up this way: “In addition to the development of resistance, the use of antibiotics heavily disrupts the ecology of the human microbiome.” When antibiotics disturb your gut, some of your body’s crucial processes go haywire, including your body’s ability to produce vitamins.
But this is still a relatively recent discovery: For years, doctors didn’t understand that antibiotics rob your gut of a healthy microbiome. “That’s a really big part of [the current probiotics obsession] because 100 years ago we didn’t know that the actual bugs in your colon played any role in your health," Dr. De Latour says. "We’ve been pushing hand sanitizer, antibiotics—and now [we] know those are wiping out something good for you.”
This partially explains why doctors and patients have been desperate for probiotics, which claim to be able to restore your microbiome to what it was before antibiotics took their toll. Once scientists figured out that antibiotics aren't problem-free, doctors understood the need for a pill that could restore the microbiome, and the probiotics boom was born.
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Not all probiotics are evaluated as medicinal and not all are the same
According to a 2018 report in Clinical Gastroenterology and Hepatology, unless a company claims that their probiotic can, for instance, cure a specific illness, their pill is evaluated as a food in the United States. “Regulation is focused on the legitimacy of any claims, rather than efficacy, safety, and quality,” the report says. This means probiotics aren’t necessarily evaluated in terms of what they can do to restore your microbiome—which is why people take them in the first place.
Dr. De Latour notes research has proven that most probiotics you can buy at your local drugstore are generally useless, explaining that we're resistant to many of them. If you're resistant to a pill you swallow, it won't do anything beneficial to your body. “Most of the things that are generically available—a lot of people are resistant to them. It’s kind of a waste of money,” she says.
Another fact about probiotics that you should keep in mind: Some probiotic properties are strain-specific. This means that the effects of one probiotic could be different than the effects of others. For example, Saccharomyces boulardii is a yeast that is marketed as able to treat diarrhea, while species that fall under the Bifidobacterium genus are said to be able to treat constipation. Both are considered to have probiotic properties.
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Probiotics don't have many downsides—and marketers know that
Probiotics might be useless for most of us, but they’re not necessarily unsafe. Dr. De Latour says some people might experience bloating, gas, or a change in bowel habits. “Not very common, but it can happen,” she says. She goes on to say that weak evidence has correlated headaches with taking probiotics.
The few and subtle downsides of probiotics are another reason Americans are so willing to take them. “Here are these pills that have very few side effects and very little downside. A lot of people see that as an opportunity for a little bit of cash,” Dr. De Latour explains, adding that the demand for probiotics propels a multi-billion dollar industry. “In 2013, the worldwide market for probiotics was worth $36 billion. In addition to their use in the management of a range of health conditions, probiotics are being aggressively promoted to consumers as a mean to increase or maintain health, fueled by media coverage,” the report in Clinical Gastroenterology and Hepatology says.
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They could be dangerous for immunocompromised people
For a very small number of people, probiotics can be dangerous. Don’t worry: We’re talking one in millions. Specifically, we’re talking about immunocompromised people. These are individuals living with weak immune systems who are less likely to fight off some illnesses. People with HIV/AIDS or certain inherited diseases have weak immune systems. Additionally, transplant and cancer patients taking some types of immunosuppressive drugs have weak immune systems.
For these people, probiotics can be dangerous, Dr. De Latour explains. She says that the risk of harm is small but present enough to warrant caution. Preliminary research presented at the American Association for Cancer Research meeting this year also supports the idea that probiotics might be dangerous if you’re being treated for cancer. “Based on our early results, cancer patients and doctors should carefully consider the use of over-the-counter probiotic supplements, especially before beginning immunotherapy treatment,” senior author of this new research Jennifer Wargo, MD, said in a statement. That said, you should consult a doctor about the risks associated with probiotics if you have reason to believe your immune system isn’t as strong as it should be.
You might want to take a specific probiotic if you have inflammatory bowel disease
Probiotics might not be all they’re hyped up to be, but they can help people with a condition called inflammatory bowel disease (IBD). IBD can cause diarrhea, abdominal pain, cramping, fever, blood in your stool, fatigue, a limited appetite, and unintended weight loss.
However, even if you have IBD, you shouldn’t just take any old probiotic you come across at the drugstore. Dr. De Latour says gastroenterologists prescribe a probiotic called VSL#3 for patients suffering from IBD. She adds that this is “really the only reason to prescribe a probiotic.”
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