Are At-Home Gut Health Tests Worth It?

In recent years, gut health has become an increasingly buzzy wellness topic. A variety of new studies illustrate the role our gut bacteria—also known as gut flora—play in our overall health, influencing conditions like diabetes, irritable bowel syndrome, depression, obesity, cardiovascular disease, fatty liver disease and even hepatocellular carcinoma.

This interest, paired with our newfound comfortability with at-home testing for COVID-19, DNA, allergies and more, has led many consumers to consider purchasing at-home gut health tests. These testing kits promise to offer the user a window into their gut microbiome as well as tangible ways to improve it. But can they live up to their promises? Here’s what you need to know before buying.

What Is Gut Health?

Broadly speaking, gut health refers to how well your digestive organs can perform their requisite functions. But more specifically, when these tests promise to scan for “gut health,” what they are really scanning for is the diversity of the bacteria in your gut.

According to a 2021 study in Nature Metabolism of more than 9,000 peoples’ gut microbiomes, one of the keys to gut health is a diverse microbiome. In short, many different types of bacteria—a unique, individualized microbiome—supports healthy aging.

What Is an At-Home Gut Health Test?

Ranging from $50 to over $300, these testing kits are available from a variety of companies, including Biohm, Floré, Ombre, Thorne, Verisana, Viome, and Wellnicity. They typically include a scoop or swab, vial, solution and instructions on how to mail in the collected sample.

Their primary appeal is their convenience: you can collect your own stool sample, ship it discreetly and receive a personalized report in a few weeks. This report includes a list of the bacteria in your personal biome, diet and lifestyle suggestions for improving the diversity of your microbiome, and a list of diseases or disorders you are at higher risk for developing. Companies may also pitch you their own probiotics.

Are At-Home Gut Health Tests Effective?

Experts in the field are highly skeptical, to put it mildly. There are a few main reasons for this: first, that a person’s gut microbiome is changing constantly; second, that the information kits test for is partial and reductive; and third, that certain bacteria are not yet conclusively tied to certain health conditions. Let’s examine each issue individually.

Constant Changes in the Gut Microbiome

According to Dr. Brian Lacy, gastroenterologist and professor of medicine at the Mayo Clinic, “a change in diet can change the gut microbiome within 24 to 48 hours.” Furthermore, “stress can change gut function and likely change the gut microbiome… Thus, results of testing could change from week to week, if exercise, diet, stress and medications all change.” This conceptualization of the gut microbiome as a “moving target” is further backed by a 2019 study in Clinical Gastroenterology and Hepatology.

Impartial Data on the Gut Microbiome

Even if the gut microbiome’s bacterial compositions were stable—which they’re not—the lists testing companies provide are woefully incomplete. This is because, according to Dr. Lacy, “[i]t is estimated that we can accurately identify only 10 to 15% of all gut bacteria…Even in a research setting, it is difficult to provide more than a broad overview of gut health and where there is a predominant species of one bacteria or another.” In short, most of your sample will be unidentified.

Inconclusive Links Between Bacteria and Medical Conditions

According to the study cited above, “microorganisms within the same genus might have a differing effect on the same disease process; the same microorganism might also have different effects on separate disease processes.” In layman’s terms, any specific microorganism cannot easily be defined as “healthy” based on composition alone.

Dr. Rabia De Latour, gastroenterologist and associate professor of medicine at NYU Langone Health concurs: “The top researchers at the most innovative laboratories at the world’s best academic institutions with the highest levels of funding can’t do what these companies are claiming. We still cannot pinpoint which microbes are associated with which health outcomes.”

Should I Buy an At-Home Gut Health Test?

We say save that hard-earned money; neither Dr. Lacy nor Dr. De Latour recommends them. And while we’re on the subject, think twice about purchasing probiotics as well. Instead, talk to your primary care provider. Analyzing the gut microbiome individually will likely become standard medical practice as we learn more about its particularities. Until then, the safest health investment is still the usual boring but reliable advice: eat more veggies, exercise and reduce stress. Your gut will thank you.