Are Gut Health Tests Actually Worth It?
Experts discern whether at-home microbiome kits are science-backed or just full of sh*t.
Experts discern whether at-home microbiome kits are science-backed or just full of sh*t.
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If you’ve been dealing with mysterious, chronic digestive symptoms—like bloating, diarrhea, and constipation—you probably have an arsenal of probiotics and fiber supplements and a pantry full of gut health-supporting foods. But what if your symptoms persist, even when you keep a tight protocol? Enter at-home gut health tests, which some companies are now claiming to uncover the root cause of your discomfort.
But do these gut health tests really work? A registered dietitian and a gastroenterologist dissect the science.
Emily Spurlock, R.D.N., is a registered dietitian with the Institute for Digestive Wellbeing.
David Clarke, M.D., is board-certified in Internal Medicine and Gastroenterology and is the President of the Psychophysiologic Disorders Association.
Not to alarm you, but there’s a whole metropolis of tiny organisms—like bacteria, fungi, and viruses—in your digestive system, making up your gut microbiome (1). These microorganisms break down the food you eat and support your immune system, which keeps your digestion regular and healthy.
So, why would knowing what’s living in your gut improve your health?
Your gut microbiome is sensitive—anything from antibiotics and alcohol to a lack of sleep and stress can throw it out of balance.
When your microbiome is out of whack, the levels of beneficial or harmful bacteria aren’t in harmony. An unbalanced gut microbiome can lead to common but uncomfortable symptoms like diarrhea, bloating, GERD, or constipation. There’s also a link between an unhealthy microbiome and chronic conditions like IBS, IBD, and type 2 diabetes (2).
And here’s the kicker—research suggests that your gut microbiome doesn’t just help your digestion.
A 2021 study found that healthy aging is linked with having a diverse microbiome (3). On the other hand, less diverse microbiomes were associated with unhealthy aging—which comes along with a higher risk for diseases like diabetes, cancer, and heart disease (4).
Many at-home gut health tests claim to provide actionable recommendations to reverse or prevent both chronic and acute digestive issues. According to Emily Spurlock, R.D.N., the most common gut health test is a GI Map, which involves an at-home stool sample and tests for bacteria, viruses, yeast, and parasites. You can order it yourself or get a practitioner to order one for you.
“A lot of people suffer from digestive issues and can’t ever seem to get any answers or find relief,” Spurlock says. “A GI Map test can help give someone more answers.”
Other at-home gut health tests check for small intestinal bacterial overgrowth (SIBO) or food sensitivities, says Spurlock.
At-home GI Map tests can range from $129 to $600 a pop. Other well-known gut health brands, like Viome, offer a subscription service that includes an annual gut health test and custom probiotics based on your results for around $80 a month.
Most at-home tests follow the same instructions: go number two as usual, use a small scoop or swap to collect a stool sample, seal your sample in a small vial, and then ship it back to the company to be tested in a lab.
Weeks later, you’ll get a report detailing the type and number of certain microorganisms in your digestive system. Some companies also send you some diet and lifestyle recommendations, including your risk for certain conditions, based on your results.
But gastroenterologist David Clarke, M.D., notes that each company uses different methods to identify what’s in your microbial profile.
“This can give conflicting results,” warns Clarke. “[Many companies] analyze genetic material to identify what species of microbes are present. The challenge is that there are no widely agreed-upon standards for the best method.”
While your microbiome health will likely become a part of regular, preventative care at some point, according to a 2021 review, doctors have yet to agree on how to diagnose and treat microbiome issues (5). That’s why many experts are reluctant to recommend pricey at-home gut health tests.
“There is a wide range of microbiomes in people who are healthy and no scientific consensus on why one microbiome might be better than another,” Clarke explains. “So, in my opinion, these tests are not useful at this time and are unlikely to become helpful until we have a better understanding of what microbiomes are [considered] ‘healthy.’”
Plus, your microbiome is constantly changing (6). A gut health test may only give you a snapshot of what microorganisms are hanging out in your digestive system on a given day. Hence, these tests aren’t FDA-approved and aren’t meant to be diagnostic tools.
And when it comes to identifying exactly which tiny foes could be causing your digestive issues, the science simply isn’t there yet. Researchers have yet to uncover all of the species present in our guts—and 50 to 90 percent of these bacteria are “unculturable,” which makes it hard for scientists to identify them in a lab (7).
Just because at-home tests aren’t the Holy Grail for gut health doesn’t mean your doctor can’t help you out. Clarke says that many gut doctors will order tests for specific bacteria—like Giardia, Campylobacter, H.pylori—if they suspect an infection could be the cause of your symptoms.
And not all experts turn their noses up at at-home gut health tests. In fact, Spurlock regularly recommends GI Map or SIBO tests as part of her dietetics practice.
“If someone is suffering from digestive issues and can’t find relief, these tests can be beneficial in determining treatment options,” she says. However, she notes that not all gut health tests are helpful; you have to know what to do with the results.
“I always caution people to make sure they’re working with someone who can read [an at-home gut health test] and help interpret it,” Spurlock says. “These tests need to be taken with a grain of salt.”
If you’re interested in testing your microbiome, here are three popular gut health tests:
While a healthy microbiome is important to maintain tip-top digestive health and longevity, the science isn’t quite there for most doctors to get completely on board with at-home gut health tests—yet. However, if you want to give one a try, it’s best to work with a healthcare provider who can help explain your results, and potentially treat anything it uncovers.