New test kits promise information about your gut microbiome, but experts are dubious about their grandiose claims.
In recent years, gut health has become an increasingly hectic 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, combined with our newfound convenience with at-home testing for COVID-19, DNA, allergies and more, has led many consumers to consider purchasing home gut health tests. These test kits promise to give 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 you buy.
What is Gut Health?
Generally speaking, gut health refers to how well your digestive organs can perform their necessary functions. But more specifically, when these tests promise to scan “gut health,” what they’re really scanning is the diversity of bacteria in your gut.
According to a 2021 study in Nature’s Metabolism Of the gut microbiomes of more than 9,000 people, one of the keys to gut health is a diverse microbiome. In short, many different types of bacteria – a unique, individualized microbiome – support healthy aging.
What is a home gut health test?
Ranging from $50 to over $300, these test kits are available from a number of companies, including Biohm, Floré, Ombre, Thorne, Verisana, Viome, and Wellnicity. They typically include a spoon or swab, vial, solution, and instructions on how to ship the collected sample.
Its main appeal is convenience: You can collect your own stool sample, discreetly send it in, and receive a personalized report within weeks. This report includes a list of the bacteria in your personal biome, diet and lifestyle suggestions to improve the diversity of your microbiome, and a list of diseases or disorders you are at increased risk of developing. Companies may also introduce you to their own probiotics.
Are home gut health tests effective?
Experts in the field are highly skeptical, to say the least. There are a few main reasons for this: first, that a person’s gut microbiome is constantly changing; second, that testing information kits is partial and reductive; and third, that certain bacteria are not yet conclusively linked to certain health conditions. Let’s look at each question individually.
Constant changes in the gut microbiome
According with the doctor. Brian Lacy, a gastroenterologist and professor of medicine at the Mayo Clinic, “A change in diet can alter the gut microbiome within 24 to 48 hours.” Furthermore, “stress can alter bowel function and likely alter the gut microbiome… Thus, test results can change from week to week if exercise, diet, stress, and medications change.” This conceptualization of the gut microbiome as a “moving target” is supported by a 2019 study in Clinical Gastroenterology and Hepatology.
Unbiased data on the gut microbiome
Even if gut microbiome bacterial compositions were stable — which they are not — the lists provided by testing companies are woefully incomplete. This is because, according to Dr. Lacy,”[i]It is estimated that we can only accurately identify 10-15% 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 or more another bacteria. ” In short, most of your sample will not be identified.
Inconclusive links between bacteria and medical conditions
According to the study cited above, “microorganisms within the same genus can have a different effect on the same disease process; the same microorganism can also have different effects on different 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 agrees: “The best researchers in the most innovative labs at the best academic institutions in the world with the highest levels of funding cannot do what these companies are claiming. We have yet to identify which microbes are associated with which health outcomes.”
Should I buy an at-home gut health test?
We say save that hard-earned money; nor Dr. Lacy nor Dr. De Latour recommend them. And while we’re on the subject, think twice before buying probiotics too. Instead, talk to your primary care provider. Analyzing the gut microbiome individually is likely to become standard medical practice as we learn more about its particulars. Until then, the safest investment in health is still the boring but reliable advice: eat more vegetables, exercise and reduce stress. Your gut will thank you.