Are home microbiome test kits worth it?
Probably not.
TL;DR: Right now, these tests don’t provide actionable information to diagnose health conditions, guide medical treatments, or tailor our diets.
When you order an at-home microbiome stool kit, you collect a tiny stool sample and send it to a lab that uses DNA sequencing to analyze the bacteria in that sample. The report describes dozens of bacterial species living in your colon, grouped into families.
Here are some reasons why this Nerdy Girl wouldn’t use a home stool test kit right now:
1. These tests don’t provide information that guides medical or behavioural decisions. They give you a snapshot of what’s going on inside your gut, but the value of that snapshot is very limited because scientists don’t fully understand what a “normal” ,”healthy” or “unhealthy” microbiome looks like. This is a very new, and rapidly evolving field. We need much more research to more deeply understand the role of each bacteria, and how they interact with each other. In short, we don’t know what to do with our test results once we get them.
2. Your microbiome can change from day to day. Factors like your diet, medications you take, and bowel habits all have an impact on your microbiome (even on the day-to-day). For example, research has shown that the make-up of our microbiome can change within days of a change in our diet when we overindulge during the holiday or festive season.
Another example that drives this point is a comparison of the microbiome of vegans versus meat eaters. Vegans tend to have a microbiome enriched with bacteria more equipped at breaking down plant-based fiber and complex carbohydrates. Meat eaters have more bacteria types that are better at digesting animal proteins and fats. Both microbiomes are adapted to their respective diets, and even though there’s probably a health advantage to eating more plant-based foods and less meat, neither of these microbiomes inherently signal “healthy” or “unhealthy.” Context matters – this simply shows us that the microbiome adapts to changes in our diet, and could be shifted in one direction or the other. Scientists are learning more each day about how particular microbiome signatures may be predictors or causes of specific diseases, but it’s very early days and not yet worth shelling out a lot of money.
Also, the gut microbiome differs at various locations throughout your digestive system. So, testing your stool only shows what’s happening at the end of the gut at that particular day and time. It does not, however, give you the big picture of your gut microbiome, and if it’s healthy or unhealthy.
3. These tests lack reliability. You will notice, for example, that if you test the same stool sample with various stool kits, you may get different results. This is because there’s no single, standardized way to analyze the data—different tests use different methods, which can lead to inconsistent findings. Note that the FDA has not approved these tests [archived link].
4. These tests do not provide information that can personalize your diet and make you healthier, despite marketing claims that suggest otherwise. It’s true that each of us can respond differently to the same food, and that our microbiome contributes to this response, but the scientific evidence is not mature enough to be making dietary “prescriptions”. Unfortunately, these tests can lead people to over-restrict their diets or try expensive supplements to quick-fix their gut microbiome. More research is needed before we can rely on these results to make decisions about diet or medications.
The gut microbiome is a community of beneficial microorganisms living in your gut that have shown to be important for health and well-being. Disturbances in the gut microbiome have been linked to the development of various chronic conditions. There is hope that this kind of testing will have significance in the future. But for now, Those Nerdy Girls suggest holding off on these expensive tests, and instead support your gut microbiome via eating lots of plant diversity, regular exercise, good hydration, good quality sleep, and stress management techniques.
Sources:
STAT News – microbiome gut tests at home
UMB News – Researchers Call for Regulation of Microbiome Tests [archived link]
Frontiers in Microbiology – Assessing the Influence of Vegan, Vegetarian and Omnivore Diets on Human Gut Microbiota
The Guardian – Are at-home gut microbiome testing kits a scam?
