Today’s at-home microbiome testing industry is fraught with snake oil

The blue muffin challenge. Food sensitivity tests. Microbiome test kits.

Self-help gastrointestinal health is all the rage. Rightly so: One in four Americans is affected by digestive disorders. And we’re all eating worse, sleeping less, and experiencing more stress, leaving our guts feeling twisted.

Gastroenterologists like me often see patients who have spent hundreds, sometimes thousands, of dollars in out-of-pocket costs on microbiome kits, food sensitivity tests, black mold testing, and more. While appealing, these “tests” rarely provide actionable advice and usually lead to more questions than answers. Even worse, they can lead to a sense of complacency or a missed diagnosis because a patient chose not to pursue professional support.

Consumer-based microbiome tests are a particular concern for me. Some promise to identify the root causes of microbial imbalances and inflammation in your gut, and based on the results, inform personalized nutrition and supplements. So far, however, most are not evidenced-based and have over-promised and under-delivered.

Unfortunately, many patients come to my office having unnecessarily suffered for years while they tried to optimize their microbiome based on ambiguous test results. There is no replacement for working with a trained GI dietitian with the expertise to identify one among thousands of potential dietary triggers for bloating, constipation, or pain.

To be clear, scientists are certainly making progress in treatments based on population-based microbiome studies for certain GI infections and even early detection of oral cancers through microbiome testing. But there are no legitimate microbiome tests that doctors can recommend today. A rare group of consumer-based microbiome companies are approaching this field the right way, offering objective and unbiased evidence based on individual test results without promising to cure or alleviate symptoms. In the near- future, microbiome testing will likely give directional diagnostic/prognostic insight, as opposed to definitive answers.

But for people seeking answers today, most of the microbiome is still uncharted territory and has limited clinical value to help individual patients. The biggest concern from clinicians is that many companies are taking advantage of patient suffering to profit from selling these tests or using the results to sell the company’s own supplements.

To be clear, I am a proponent of empowering patients to learn more and access data about their body. My grave concern is the risk of companies using baseless claims to market these tests as a panacea to cure people’s symptoms.

There are three hurdles we need to overcome in consumer-based microbiome testing:

1) Defining “good” results

It is difficult for a microbiome test to provide meaningful direction because there is limited consensus among microbiologists on what constitutes the best bacterial strains or diversity. Microbiologists disagree on what defines a healthy gut microbiome. Some specific strains, like Clostridium difficile, can cause harm in high amounts, but no one knows whether one varied microbiome profile is necessarily better than another. Most microbiome testing companies create their own oversimplified scoring systems, but what do they mean by “healthy” or “unhealthy” when medical scientists don’t know what good means? I often see patients who place dangerous restrictions on their diets — avoiding dairy without replacing other sources of calcium or vitamin D, or eliminating foods that contain gluten without replacing fiber from other sources — in an attempt to “improve” their microbiome score.

2) Test-retest reliability

If you use different microbiome test kits on the same fecal sample, you may get different results as to your microbiome makeup. This variance in test results is an obvious indicator that many of today’s testing kits are imprecise. Tufts University microbiology specialist Benjamin Wolfe recently wrote a Fast Company article about his experience getting vastly different results using three different testing kits on the same fecal sample, ranging from a “not great” to “good” microbiome. It’s hard to consider yourself informed when test results conflict with one another. To be clear, this issue is more reflective of the testing available today, not the value of the underlying technology.

3) Your microbiome can change daily

Studies show that our microbiomes can change every single day based on the foods we eat and various other lifestyle factors, including exercise and stress. So, someone’s gut composition can change in the span between taking the test and receiving the results two weeks later, rendering results potentially outdated. Again, it is unclear how to account for these changes, how to make any recommendations based on a test result that can change daily, and whether these changes are clinically significant.

Unfortunately, these tests are a long way off in terms of delivering on claims to cure chronic illness and relieve suffering. Many companies are charging patients to beta-test their products, provide their data for research, and not doing anything to relieve symptoms. Some microbiome companies have already had meteoric rises and crashes, such as uBiome and more recently Evelo Bio.

Patients with GI conditions with persistent suffering will often look outside traditional medical care for a solution. Patients with irritable bowel syndrome report worse quality of life scores than patients on dialysis, and in a landmark study, 50% said that they would give up 15 years of life expectancy in exchange for an immediate cure today. These statistics speak to the immense degree of suffering that these patients face. It can be tempting for companies and self-described experts to capitalize on their pain and suffering for a bottom line, but that isn’t the way to do ethical business.

While the technology behind evidenced-based microbiome testing has potential, it is not ready for prime time.

The best way to support your microbiome for now? Eat 30 different plants per week — a variety of fruits, vegetables, legumes, nuts, seeds, whole grains, herbs, and spices. That of course, is no small feat. But if you’re worried about your gut, it’s the best way to spend your time, attention, and money.

Dr. Sameer Berry is chief medical officer at Oshi Health, clinical assistant professor of medicine in the Department of Medicine at New York University, and co-host of the “Healio’s Gut Talk” podcast with Dr. William Chey. He is active on Twitter @sameerkberry.