When you hear about the gut microbiome, does it ever make you wonder what tiny creatures are teeming inside your own body? As a microbiologist who studies the microbiomes of plants, animals and people, I’ve watched public interest in gut microbes grow alongside research on their possible dramaticinfluence on human health. In the past several years, microbiome testing techniques used by researchers like me are now available to consumers at home. These personal gut microbiome testing kits claim to tell you what organisms live in your gut and how to improve your gut microbiome using that data.
I became very interested in how these home test kits work, what kind of information they provide and whether they can really help you change your gut microbiome. So I ordered a few kits from Viome, Biohm and Floré, tried them out and sifted through my own microbiome data. Here is what I learned.
How do gut microbiome kits work?
All gut microbiome kits require you to carefully collect fresh fecal material. You put it in the various tubes provided in the kit and mail the samples back to the company. Several weeks later, you’ll receive a report describing the types of microbes living in your gut and suggestions on how to change your diet or activities to potentially alter your gut microbiome.
What consumers don’t exactly know is how companies generate the microbial profile data from your fecal sample. A typical approach I and other microbiome researchers use is to extract and decode the microbial genetic material from a sample. We use that genetic material to identify what species of microbes are present. The challenge is that this process can be done in many different ways, and there are no widely agreed-upon standards for what is the best method.
Different home gut microbiome test kits can give conflicting results. Benjamin Wolfe, CC BY-NC-ND
For example, microbiome analyses can be done on two types of genetic material, RNA or DNA. If the profile is based on DNA, it can give you a snapshot only of what types of microbes are present, not what microbial genes are active or what activities they are doing in your body. On the other hand, if the profile is based on RNA, it can tell you not only what microbes are present, but also whether they’re playing a role in your digestion or producing metabolites that can reduce gut inflammation, among other functions. Viome generates its profiles by looking at RNA, while the other companies use DNA.
Other data analysis choices, such as how different types of genetic sequences are sorted or which databases are used to identify the microbes, can also affect the level of detail and utility of the final data. Microbiome scientists are usually very careful to point out these nuances when interpreting their own data in scientific papers, but these details are not clearly presented in home microbiome kits.
What I learned about my gut microbiome
Though I used the same fecal sample for each kit, mixed well to ensure uniformity, I was surprised that each of the three products I tried gave me different impressions of my gut microbiome.
Each company gives an overall “score” on how your microbiome compares with what they consider to be “good” or “healthy.” My scores ranged from 39% (not great) to 72% (good). Interestingly, Viome, which infers microbial activity by using RNA, gave the lowest score. It noted that certain microbial activities happening in my gut, such as methane production and digestion efficiency, were not optimal.
I was also surprised by the variation in total microbial diversity each company reported. While there was general agreement in the overall groups of microbes present at the phylum level, a more general biological grouping, there was a huge range of variation at the species level, the most specific grouping. One company reported 527 species of microbes in my microbiome, while another reported 312. One reported only 27.
Organisms like microbes can be classified into groups of relatedness, from highly specific (species) to very general (kingdom). VectorMine/iStock via Getty Images Plus
Perhaps the most surprising most surprising finding was that my gut may harbor a microbe that could (there are many caveats here!) pose a problem for me in the future if I experience certain medical situations. Even though all companies explicitly looked for this microbe in my gut microbiome sample, only two actually found it. While I won’t name the exact microbe to protect my health privacy, I am not too worried about this result because more information, such as full genome sequencing of the microbe, is needed to better understand if this is actually a concerning strain of this microbe. But this finding does point to some surprising variation in results across different testing kits.
Can this data really improve your gut microbiome?
Many microbiome scientists like me would probably argue that the data these kits provide are limited in terms of giving you the power to alter your health. This is partly because gut microbiome science is still a new field with many unanswered questions.
One challenge is that different people can have different proportions of microbes present in their gut. This variation has made it difficult for scientists and health professionals to agree on what type of microbial community makes a gut “healthy.” Some specific species, such as the bacterium C. diff, and some broad groups, like Proteobacteria, are usually considered undesirable in high amounts. But there is no clear consensus on why one microbiome might be better than another.
Even if you did try to improve your gut microbiome based on what your gut test told you, the results might not turn out as you hoped. Probiotics or diet changes can alter the diversity of your gut microbiome and how it functions, but studies often find that each person can have different responses to these interventions, possibly because of their own unique microbiome composition. The personalized ecology of gut microbial communities, combined with genetics, diet and other factors, makes it challenging to prescribe universal solutions.
So why bother getting a gut microbiome test? For me, it was illuminating to learn what microbes I carry around with me each day. When I eat my lunch, go for a run or get stressed out, the microbes in my gut respond to changes in my body. Researchers may not completely understand what those changes mean and how to manage our microbial partners, but getting to know who they are is a great first step.
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Benjamin Wolfe receives funding from the National Science Foundation and the United State Department of Agriculture.
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DEAR MAYO CLINIC: As a woman in my 40s, I've experienced a wide variety of diet fads come and go. One week I read it’s bad to eat carbs. The next week, it’s full-fat dairy products. I’ve seen articles that say I should only eat between certain hours of the day. There is a lot of contradictory information. How do I distinguish between nutrition myth and fact?
ANSWER: Among the sea of information about nutrition is a tide of inaccuracies. It can seem challenging to know what is good for you.
Here are 10 nutrition myths debunked:
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DEAR MAYO CLINIC: As a woman in my 40s, I've experienced a wide variety of diet fads come and go. One week I read it’s bad to eat carbs. The next week, it’s full-fat dairy products. I’ve seen articles that say I should only eat between certain hours of the day. There is a lot of contradictory information. How do I distinguish between nutrition myth and fact?
ANSWER: Among the sea of information about nutrition is a tide of inaccuracies. It can seem challenging to know what is good for you.
It may take some planning and time in the kitchen, but eating healthy on a budget is possible.
Some helpful hints include planning meals and snacks around sales and creating a shopping list. Stock up on seasonal vegetables and fruits as well as staples, such as brown rice, whole-wheat pasta, dried beans and lentils, especially when there is a sale. Consider purchasing frozen or canned fruits and vegetables as an alternative to fresh products. Be sure to check the ingredient list to avoid items with added sugars or salt.
It may take some planning and time in the kitchen, but eating healthy on a budget is possible.
Some helpful hints include planning meals and snacks around sales and creating a shopping list. Stock up on seasonal vegetables and fruits as well as staples, such as brown rice, whole-wheat pasta, dried beans and lentils, especially when there is a sale. Consider purchasing frozen or canned fruits and vegetables as an alternative to fresh products. Be sure to check the ingredient list to avoid items with added sugars or salt.
Unless you have celiac disease or gluten intolerance, you don't need to avoid gluten.
Gluten is the protein found in wheat, barley and rye. Whole-wheat products have great nutritional benefits, including essential B vitamins and fiber. Be mindful when manufacturers remove gluten, as additional sugar, salt or refined starches often are added to make up the difference in flavor and texture. If you follow a gluten-free diet for medical reasons, check the ingredient list and Nutrition Facts label to make sure you choose a healthy option.
Unless you have celiac disease or gluten intolerance, you don't need to avoid gluten.
Gluten is the protein found in wheat, barley and rye. Whole-wheat products have great nutritional benefits, including essential B vitamins and fiber. Be mindful when manufacturers remove gluten, as additional sugar, salt or refined starches often are added to make up the difference in flavor and texture. If you follow a gluten-free diet for medical reasons, check the ingredient list and Nutrition Facts label to make sure you choose a healthy option.
Although unrefined sugar options may contain a small number of vitamins and minerals, the advantage is minimal. They are still considered added sugar and contribute to the recommended daily limit on added sugar in the diet.
Although unrefined sugar options may contain a small number of vitamins and minerals, the advantage is minimal. They are still considered added sugar and contribute to the recommended daily limit on added sugar in the diet.
The fat-free and low-fat diet trend is a thing of the past — the ’80s and ’90s to be exact. Yet, some people are still scared of fat.
This shouldn't be the case, as fat has beneficial functions, like protecting our organs, maintaining cell membranes, promoting growth and development, and absorbing essential vitamins. Be aware that fats aren't created equal, though. Choose heart-healthy unsaturated fats, such as olive and canola oil, nuts, nut butters, and avocados over those that are high in saturated and transfats, such as fatty meats and high-fat dairy products.
The fat-free and low-fat diet trend is a thing of the past — the ’80s and ’90s to be exact. Yet, some people are still scared of fat.
This shouldn't be the case, as fat has beneficial functions, like protecting our organs, maintaining cell membranes, promoting growth and development, and absorbing essential vitamins. Be aware that fats aren't created equal, though. Choose heart-healthy unsaturated fats, such as olive and canola oil, nuts, nut butters, and avocados over those that are high in saturated and transfats, such as fatty meats and high-fat dairy products.
The low-carb diet is a fad diet that has continued to make an appearance over the years. It gives carbohydrates — fruit and whole grains included — a bad reputation.
People who followed this diet have had success with weight loss, but anytime someone eliminates highly processed carbohydrates foods, such as chips, cookies, white bread and potatoes smothered in butter and gravy, they would be expected to have the same results. Any diet or eating program that eliminates an entire food group gets a red flag, as one is likely to miss out on vital nutrients.
The low-carb diet is a fad diet that has continued to make an appearance over the years. It gives carbohydrates — fruit and whole grains included — a bad reputation.
People who followed this diet have had success with weight loss, but anytime someone eliminates highly processed carbohydrates foods, such as chips, cookies, white bread and potatoes smothered in butter and gravy, they would be expected to have the same results. Any diet or eating program that eliminates an entire food group gets a red flag, as one is likely to miss out on vital nutrients.
There’s little evidence that dietary cleanses do any of the things they promise.
The fact is you don't need to purchase a product to cleanse your body. Your liver, kidneys and gastrointestinal tract do a good job of detoxing it every day. If you're looking to rejuvenate your body, focus on eating more whole foods, drinking water and removing highly processed foods from your diet.
There’s little evidence that dietary cleanses do any of the things they promise.
The fact is you don't need to purchase a product to cleanse your body. Your liver, kidneys and gastrointestinal tract do a good job of detoxing it every day. If you're looking to rejuvenate your body, focus on eating more whole foods, drinking water and removing highly processed foods from your diet.
While late-night snacking can lead to weight gain or prevent weight loss, it's not because of the time on the clock. Instead, it’s about why you're eating.
It is common to reach for food for reasons other than physical hunger in the evening, whether it be a habit, boredom or craving. Be mindful about what you eat more so than when.
While late-night snacking can lead to weight gain or prevent weight loss, it's not because of the time on the clock. Instead, it’s about why you're eating.
It is common to reach for food for reasons other than physical hunger in the evening, whether it be a habit, boredom or craving. Be mindful about what you eat more so than when.
Unfortunately, no foods burn fat, make you lose weight more quickly or increase your metabolism enough to affect weight loss.
Diets that focus on single foods, like those mentioned above, are restrictive and lack nutrients the body needs. They’re also unsustainable, and any weight loss that may occur is a result of calorie restriction and will likely come back once you discontinue.
Unfortunately, no foods burn fat, make you lose weight more quickly or increase your metabolism enough to affect weight loss.
Diets that focus on single foods, like those mentioned above, are restrictive and lack nutrients the body needs. They’re also unsustainable, and any weight loss that may occur is a result of calorie restriction and will likely come back once you discontinue.
The 2020-2025 Dietary Guidelines for Americans recommends having no more than 2,300 milligrams of sodium per day. The average American consumes 3,400 milligrams of sodium per day. The problem isn't as easy as taking the salt shaker off the table, though.
Much of the excess sodium that Americans consume from their diet comes from the salts added to processed, ready-to-eat foods and restaurant meals. Limit the processed foods and enjoy more fresh, home-cooked meals.
The 2020-2025 Dietary Guidelines for Americans recommends having no more than 2,300 milligrams of sodium per day. The average American consumes 3,400 milligrams of sodium per day. The problem isn't as easy as taking the salt shaker off the table, though.
Much of the excess sodium that Americans consume from their diet comes from the salts added to processed, ready-to-eat foods and restaurant meals. Limit the processed foods and enjoy more fresh, home-cooked meals.
Many products labeled low-fat or fat-free contain added sugar or sodium to make up for the loss of flavor when removing or reducing fat.
In addition, fat helps with satiety — making you feel fuller longer. Choosing a fat-free product to reduce calories can backfire, as you may find yourself snacking soon after.
My best advice if you want to eat healthy is to always look at the Nutrition Facts label when choosing among fat-free, low-fat and regular. Pay attention to sugar and sodium content. Choose whole foods versus processed, and make sure you are drinking enough water. If you feel you need a more specific menu, ask your health care professional for a referral to a dietitian or nutritionist. — Allyn Wergin, R.D.N., Clinical Nutrition Services, Mayo Clinic Health System, New Prague and Le Suer, Minnesota
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(Mayo Clinic Q & A is an educational resource and doesn’t replace regular medical care. E-mail a question to MayoClinicQ&A@mayo.edu. For more information, visit www.mayoclinic.org.)
Many products labeled low-fat or fat-free contain added sugar or sodium to make up for the loss of flavor when removing or reducing fat.
In addition, fat helps with satiety — making you feel fuller longer. Choosing a fat-free product to reduce calories can backfire, as you may find yourself snacking soon after.
My best advice if you want to eat healthy is to always look at the Nutrition Facts label when choosing among fat-free, low-fat and regular. Pay attention to sugar and sodium content. Choose whole foods versus processed, and make sure you are drinking enough water. If you feel you need a more specific menu, ask your health care professional for a referral to a dietitian or nutritionist. — Allyn Wergin, R.D.N., Clinical Nutrition Services, Mayo Clinic Health System, New Prague and Le Suer, Minnesota
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(Mayo Clinic Q & A is an educational resource and doesn’t replace regular medical care. E-mail a question to MayoClinicQ&A@mayo.edu. For more information, visit www.mayoclinic.org.)
You and the trillions of microbes in your gut can live in harmony. Kateryna Kon/Science Photo Library via Getty Images
Different home gut microbiome test kits can give conflicting results. Benjamin Wolfe, CC BY-NC-ND
Organisms like microbes can be classified into groups of relatedness, from highly specific (species) to very general (kingdom). VectorMine/iStock via Getty Images Plus