Gut microbiome tests are getting popular, and many companies claim that they can restore your gastrointestinal and overall health.
The proposition of using probiotics to balance the billions of microorganisms living in our gut may seem tempting. In this article, we will dig deeper and start by defining the gut microbiome, what tests are used for, and check if a simple stool sample can become the ultimate way to put back some order in our digestive system.
Finally, we will analyze the scientific basis of this new gut crave and check if at-home gut microbiome testings really bring any health value.
What is the gut microbiome?
Microbes are everywhere. Bacteria and microbes surround us. For example, it is estimated that the skin of any human being is the playground for more than 1.5 trillion bacterias. And it is only a tiny portion of the 1.5 Kg or 3.3 pounds of microbes that populate our body.
The microbes, especially, enjoy one part of our anatomy: our guts! For example, did you know that 50% of our feces are microbes and that more than 1,200 species of intestinal bacteria live in our intestines?
The microbiota will include all of the population of bacteria, yeast, viruses, and other types of microorganisms that proliferate happily in and on our bodies.
An unhealthy microbiota has been associated with many diseases, including inflammatory bowel disease (IBD), diabetes, liver diseases, obesity, some disorders of the immune system, or even allergic diseases in kids.
The microbiome corresponds to the genes related to the microscopic life we carry. These genes are unique and give us considerable versatility in the metabolic processes and biochemical pathways taking place in the human body.
Gut bacteria are essential for preserving our health, and the least we can do to ensure that they contribute to our well-being is a gut microbiome test. Isn’t it?
What are gut microbiome tests used for?
When suffering from chronic diarrhea, constipation, bloating, or gazes, a microbiome test can be helpful and potentially orient your doctor.
Depending on the test, various elements can be looked for, such as parasites, yeast, bacterial overgrowth, or cancerous markers that can orient the doctor’s treatment.
Interpreting a microbiome test can be confusing, and self-medication may carry the risks of exacerbating symptoms or even create new ones.
Therefore, when considering microbiome testing, always talk with your doctor first. He only will have the training and experience to orient you appropriately towards the treatment or diet changes that will bring you a healthy gut.
How is a gut microbiome test conducted?
Gut microbiome testing is very close to what you can expect from a DNA test, except for the sampling process, of course.
Analyzing the gut flora relies on two main types of analyses.
Everything starts with a stool test. The poo sample can be processed to grow the bacteria present in the feces. Some of these bacteria are not beneficial and can lead to diarrhea or other diseases related to gut infections. Your physician will mainly order these tests when looking for harmful bacteria such as the famous salmonella and E. coli.
Another method which is mainly the one used by at-home tests, is to extract the DNA and sequence it to fingerprint the bacteria present in the gut microbiota. The DNA test results will be compared to those of thousands of other individuals to tell you if your digestive tract microbiome diversity is in line with what can be expected.
One of the issues related to this type of genetic microbiome test is that you will not know if the bacteria are alive or dead, which dramatically decreases their diagnostic value.
Microbiome testing has to be seen as a snapshot of the gut microbiota as an instant time that poses the issue of the effects of certain medications or food on the population of gut bacteria.
Another potential problem is linked to the fact that the science of the microbiome is still in its infancy and that the healthy levels of various types of bacteria in the gut are still unknown.
Also, no solid scientific connections have still been made between specific bacteria levels and diseases like cancer or other chronic diseases. Thus, a critical question remains to know if the modification of the microbiota is the cause or the consequence of the disease. This point is critical as it can dramatically reduce the therapeutic potential of restoring balance in a microbiota still carrying so many unanswered questions?
Finally, there is currently no standard for reporting the levels of bacteria in healthy vs. unhealthy gut. Gut microbiome test kits fall more in the peace of mind type of tests, but it doesn’t mind that they are not valuable for those interested in quantifying all of the aspects of their life.
Can a gut microbiome test help you improve your health?
Contrary to tests ordered by your GI doctor, most of the at-home will analyze the DNA of your microbiota from a simple stool sample and provide dietary advice on how to maintain a healthy gut, even though, as we saw, no definitive scientific evidence has still been found on what is the ideal population of microorganisms to improve gut health.
Probiotics have been considered beneficial since the early nineteenth century when an association was made between the decreased levels of bifidobacteria and diarrheas in children suggesting that oral supplementation could be beneficial.
One of the first probiotics supplements available was composed of the Lactobacillus genera to prevent the appearance of infectious diarrhea.
Modern probiotics are usually selected for their capacity to resist the stomach acidic pH and contain up to 10 billion microorganisms, leading to issues in defining the benefits of individual strains.
Most clinical studies relative to probiotics are not conducted independently and are sponsored mainly by the industry, leading to doubts about their actual efficacy and benefits.
In addition, research on the effects of specific strains of probiotics and their interaction with the gut flora is still needed to efficiently translate this innovative approach into a clinically relevant treatment to improve the gut microbiome.
We are what we eat, so the best way to stay healthy and enjoy an overall healthy gut is to eat healthy products. Of course, we all know what they are: fruits, vegetables, fermented milk, and dairy products. However, probiotics supplements’ real value may reside in the realization that we intend to take care of ourselves, microbiota included.
Could analyzing the gut microbiome help manage food allergies?
Microbiome tests can somehow lead to therapeutic pathways and approaches that are highly innovative and would not have been suspected without the development of microbiome science. In a study published in 2020 by the team of Pr. Boyd, from the Stanford University School of Medicine, the gastrointestinal tract was found as a reservoir for antibodies responsible for food allergies. Peanut allergies in the present study.
Hence, the gut microbiome could play a critical role in the development of food allergies. In an article published in the prestigious review Nature, a connection was found between the different types of gut bacteria found in children suffering or not from milk allergies.
One approach is to transplant fecal bacteria from a non-allergic population to individuals to patients suffering from allergies in the hope of providing beneficial bacteria and decrease allergic reactions. A clinical trial sponsored by the Boston Children’s Hospital is currently being conducted to assess if Fecal Microbiota Capsules can decrease the allergic reaction to peanuts. This first study only includes 15 participants but could open the way to new treatments to cure allergies.
More than a healthy gut, gut microbiome analyses could lead to a disruptive approach to treat allergies and food intolerance—all starting with a simple stool sample and microbiome test.
Are at-home gut microbiome tests worth it?
Gut health is a critical component of the overall health of an individual. Numerous companies now offer the possibility to have your microbiome analyzed, but as we mention, the results will need to be seen with a critical eye.
Not that the tests are useless, but they may lack the necessary predictive value. As for at-home DNA tests that provide results based on percentiles, a microbiome test kit will mostly tell you how your microbiota compare to the rest of the population and what potential imbalance in the gut flora may need to be restored.
As we mentioned, dealing with pathogenic bacteria will require more than an at-home microbiome analysis test. Only clinically predictive tests prescribed by a GI doctor and stool sample cultures will provide the necessary information to cure any potential disease linked to the microbiota.
Even if scientists are often dubious about the actual value of at-home gut microbiome tests, gut health has been the subject of numerous studies and debates in recent years. The ultimate goal is to find the missing link between the bacterium or microbe present and the health status.
In 2020, the team of Pr. Sung from the Center for Individualized Medicine of the Mayo Clinic in Rochester published an article in the prestigious review Nature about developing “a predictive index for health status using species-level gut microbiome profiling.”
They introduced a Gut Microbiome Health Index (GMHI) based on the analysis of 50 microbial species found in the guts of healthy individuals.
Thirty-four studies dealing with 12 health conditions and representing the results of the analyses of 4347 human stool genomes were used to identify still unidentified links and develop a mathematical algorithm to bring a real predictive value to microbiome tests.
When testing their algorithm on 679 samples from 9 additional studies, the model successfully distinguished healthy vs. non-healthy with an accuracy of 73.9%. An amazing achievement!
Despite the limitations of their study, the GMHI appears as the first scientifically robust indicator of what can be the predictive value of a gut health test.
At-home gut microbiome tests may still not have achieved this level of scientific robustness. However, they can still be of interest more from an educational perspective than a purely clinical one.
To wrap up
Now that you know the microbiota and hopefully understand the open questions that still need to be solved, you may wonder if you need to check your microbiome biodiversity.
There is no straight answer. Asking yourself this question is already proof that you are on a path to improve your lifestyle and health. As we mentioned, we all know what to eat or not. Using a gut microbiome test kit will have little value if you spend most of the days eating snacks and drinking sodas.
For the health-conscious individual, such a test may be a motivation factor and a way to better care for the trillions of microorganisms that depend on you to stay healthy and reciprocally.
Probiotics and supplements are only as good as you believe they are, but they have the virtue of making you take care of yourself.
In a nutshell, a microbiome test should probably not be your top priority. Still, if you suffer from chronic GI disorders, the best option may be at first to visit your doctor and follow his nutritional recommendation.
If a test is needed, your doctor will certainly recommend one and will use the results as part of a global therapeutic approach that will not only benefit your gut.