Should you test your gut microbiome?

At-home kits promise results, but don’t always deliver.

At-home testing kits have disrupted healthcare in recent years. You can now map your ancestry, check for allergies, and learn about your genes in the comfort of your own home.

One of the newest tests aims to tell you about one of the most talked-about parts of the body: the gut microbiome. This dynamic and ever-changing ecosystem in the intestine is teeming with trillions of microorganisms that play a role in mental health, weight loss, Alzheimer’s disease, and how well certain cancer treatments work.

The DIY kits from companies like Viome, Biohm, and uBiome claim their tests will help you optimize your microbiome (and your health). Since the science is still evolving, Furthermore tapped the experts to see what the kits can and can’t tell you.

How it works:
You’ll need to swab a used piece of toilet paper to get a stool sample, then ship it off to a lab. Within a few weeks, you’ll get a report about the microorganisms in your gut.

What they can tell you:
This depends on which company you decide to use. Some companies use science-backed approaches like 16S sequencing and metagenomic analysis to give you an accurate snapshot of what’s happening inside our gut at a particular time, says Emanuelle Bellaguarda, MD, assistant professor of gastroenterology and hepatology at Northwestern University’s Feinberg School of Medicine in Chicago.

The specificity of what you’ll find out varies. Some brands, like Biohm, send you information about bacteria and fungi. Viome uses a method called metatranscriptomics, which apparently also identifies viruses, parasites, bacteriophages, and yeast down to the specific strains, but their method hasn’t been backed up by peer-reviewed research just yet.

Where they fall short:
With any kit, your results could be inconsistent for a few reasons. First, there’s no standard testing method and no quality control, Bellaguarda says. She’s had patients show her reports from two different brands, with different results. “That’s one of the downsides.”

Plus, your gut microbes shift in response to diet, sleep, stress, travel, and exercise. The kits say they can give you a snapshot of your “core” microbes, but those might still change if you’re in the middle of a stressful work week or you just got back from vacation. To really see how your lifestyle affects your gut, you’d need to take a test nearly every day, says Justin Mager, MD, a San Francisco-based internist and a member of the Equinox Health Advisory Board.

Companies like Viome use your results to recommend which foods would produce beneficial or harmful metabolites in your gut, but there’s not enough science to back them up. “Some of these suggestions are based on experimental data,” says Jeffrey Bland, Ph.D., an Equinox Health Advisory Board member and president of the Personalized Lifestyle Medicine Institute in Bainbridge Island, Washington. “That means what the company is giving you is more like a hypothesis of which foods they think are compatible or not with your microbiome, but we need more data to know if this approach works.”

A firsthand experience:
In some cases, test results may not reflect how you feel. That’s what happened when Katzie Guy-Hamilton, Equinox’s food and beverage director and a certified health coach based in New York City, took an at-home test last year. “It showed that my microbiome looked great for the most part,” she says, but in reality, her digestion at the time was subpar. “For me, it was confusing and strange to think that my results were good, but I didn’t feel good.”

She’d like to see companies link their clients up with practitioners who could walk them through their results, good or bad, especially if they include dietary suggestions. “I wouldn’t want someone to cut foods or entire food groups out of their diet by themselves,” she says. “That’s something you’d want to discuss with a professional who could guide you through the process.”

The final word:
There’s still a lot to learn about the microbiome, and until then, the tests can only tell you so much. “Even if we can find out what’s in the gut, we don’t yet know what a healthy microbiome actually looks like,” Bellaguarda says, adding that the definition of a healthy microbiome would vary from person to person.

Mager says an at-home test is one way you can see what’s going on if you’re suffering from gut issues like bloating, but you’d also want to check in with a physician or integrative practitioner.

If you do decide to get a snapshot of your microbiome, be cautious about how you interpret and apply the results. “We’re very much in the discovery process,” Bland says, so don’t use a single microbiome test as the definitive roadmap to health.

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