Are Gut Microbiome Home Test Kits a Scam?
HHuman bodies are mysterious. They are full of wonders (brains, kidneys) and horrors (earwax). We spend our entire lives inside these meat bags, and yet we don’t fully understand how they work, or how jeans fit into them from one day to the next
And the gut microbiome is perhaps one of the most confusing aspects.
Gut health has become something of a wellness buzzword. Part of this is due to legitimate advances in microbiome research, which boomed over the past two decades, thanks to advances in DNA sequencing methods. And part of it is thanks to social media hype and new products promising quick fixes to the intractable problem of the human condition.
Among those products: home microbiome testing kits, which customers can order and use to take a stool sample and send it in for analysis. The company then sends back a report on the customer’s gut health, along with dietary advice. According to a video Paris Hilton posted on InstagramWhen she sent her stool sample to Viome, a company that makes home testing kits and in which Hilton has invested, she learned that her “superfoods” are avocados and apples, but that she should avoid broccoli.
Thousands of TikTok and Instagram posts claim that these kits can help with conditions as diverse as bloating, joint pain, anxiety and “leaky gut” – a vague term that encompasses conditions such as bloating, diarrhea and low energy. According to the Mayo Clinicit is a “hypothetical condition that is not currently recognized as a medical diagnosis.”
Experts agree that the microbiome is important to human health. But many are skeptical about how useful these kits are—at least for now.
We asked experts what the gut microbiome is, how it affects our health, and whether home tests actually help.
What is a microbiome?
Microbiome is a general term used to describe a community of microorganisms – organisms that you can’t see without a microscope, such as bacteria, fungi and viruses – explains Dr. Jonathan Eisen, a professor and microbiologist at the University of California, Davis.
We have microbiomes on our skin, in our mouths, and in our reproductive tracts. There are also ocean microbiomes, soil microbiomes, and air microbiomes.
What is the gut microbiome?
The term “gut” refers to the human gastrointestinal tract – the organs that make up our digestive system. These include the stomach, large intestine, and small intestine. These organs are teeming with trillions of microorganisms, which make up the gut microbiome. (Whether the gut microbiome itself qualifies as an organ is a matter of debate.) for discussion.)
What is a healthy gut and what influence does the microbiome have on gut health?
There is no single definition of healthy gut flora, says Dr. Kira L. Newman, clinical assistant professor of gastroenterology and hepatology at the University of Michigan.
Every person’s microbiome is different. And unlike, say, our genes, which are largely fixed throughout our lives, our microbiomes are constantly evolving and changing based on factors like age, diet, lifestyle and hormonal changes. “It’s terribly complex and unstable,” Eisen says.
In general, Newman describes a healthy gut as “one that allows for the digestion of food, the absorption of nutrients, and the removal of waste.”
The microbiome also helps protect our bodies from bad bacteria, explains Dr Nicholas Ilot, a senior researcher and lead bioinformatician at the Oxford Centre for Microbiome Studies. It does this in several ways. “By taking up space in the gut, it acts like a blanket, creating a barrier between our gut tissue and any opportunistic invaders,” he says. The microorganisms in the microbiome can also compete for nutrients that certain harmful bacteria need to survive. And some of the bacteria produce molecules that can help our immune system.
How does the gut microbiome influence overall health?
“It is clear that the microbial community in the gut has a major impact on mammalian health,” says Eisen.
But how the gut’s microbial balance affects specific health conditions is still largely unclear. Wellness influencers and companies selling at-home testing kits claim that learning your microbiome balance and adjusting your diet accordingly can increase a person’s energy, improve their skin, and help with anxiety.
But most of these claims are based on studies that showed correlations rather than causation, Eisen says, adding that many such studies “probably haven’t been done in large enough populations to be convincing.”
Indeed, according to Dr. Vijaya Surampudi, a nutritionist at UCLA Health, imbalances in the gut microbiome have been linked to a range of chronic diseases, including gastrointestinal, inflammatory and metabolic diseases, as well as neurological, cardiovascular and respiratory disorders.
What is a gut microbiome test? Do I need one?
At-home microbiome testing kits range in price from $120 to $400. In addition to a gut health report that breaks down the types of bacteria and yeast in your microbiome at the time you collected your stool sample, many companies also offer personalized dietary recommendations based on your results. Some also offer personalized probiotics to correct perceived microbiome imbalances.
It’s hard to talk broadly about gut microbiome testing because the process isn’t standardized. “Every company uses a different methodology,” Surampudi explains. And these tests haven’t been scientifically validated for their usefulness in assessing gut health, she adds.
Normally, Surampudi says, the tests use DNA or RNA sequencing to evaluate the microorganisms in a stool sample.
This process can take several weeks. By then, the balance of a person’s microbiome may have shifted somewhat. As Ilot notes, a microbiome test serves as a snapshot of your gut at a specific point in time, reflecting the foods you ate in the days before. “Will it look the same tomorrow? Or a week, a month?” he says. “It’s going to look similar, but not exactly the same.”
Does leaky gut really exist?
On platforms like TikTok and Instagram, “leaky gut” is being cited as a possible reason for gastrointestinal complaints, brain fog and fatigue in people. According to the Mayo ClinicThe theory behind the hypothetical condition is that intestinal permeability is both a cause and a symptom of gastrointestinal disease. If too many bacteria and nutrients from our intestines pass through the intestinal walls, the thinking goes, toxins can enter the bloodstream and cause inflammation.
“The ‘leaky gut’ hypothesis of how gut bacteria influence metabolic conditions and liver disease is an area of active research,” Ilot says, and there is still much we don’t know.
Gut permeability can vary across different health and disease states, Newman says, but there is no technical definition of leaky gut. Plus, the gut is always expected to be a little “leaky,” she explains, because the gut naturally absorbs water and nutrients.
Are Home Microbiome Tests Effective or a Scam?
Currently, microbiome testing is a useful diagnostic tool for a “limited number of conditions,” Eisen says, including Crohn’s disease and type 2 diabetes.
But Newman says “there is no clinical utility for direct-to-consumer microbiome testing at this time,” adding that these tests are not reliable or regulated in the same way as FDA-approved lab tests.
With these home kits, there’s often a lot of variability in the results, she says. “Someone can get two very different results from two different companies, even if they send the same sample.”
Identifying the species within the gut microbiome is fairly straightforward, says Dr. Justin Sonnenburg, a professor of microbiology and immunology at Stanford University, but drawing meaningful conclusions from this data is still difficult. Using these microbiome profiles to “recommend foods or predict disease is extraordinarily difficult and only done well by a small number of groups,” he says.
Experts agree that it is currently difficult to draw meaningful conclusions from people’s microbiome profiles, but that it could be a valuable tool in the future.
“(Microbiome testing) could be part of our clinical trials,” Dr. Surampudi says. Potential applications include assessing how a person responds to a particular drug or food. “But we’re not there yet.”