Gut Biome Test?

Gut Biome Test- What, Why, and How

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Gut Biome Test?

The gut microbiome is a community of a large number of microorganisms, including bacteria and viruses, residing in our gut. These microbes are thought to influence body functioning and overall health. Microbes in our gut synthesize various vitamins and hormones, such as serotonin, influencing our physical and mental health. They are also thought to influence immunity and inflammation. 

Based on the concept, various tests have been introduced to study various types of microbes in an individual’s gut. These tests are referred to as "gut biome tests." The gut biome test is not a diagnostic test, and it only offers a screen for the risk of certain disease conditions. The test guides you for health care consultation and provides information regarding your dietary plan. However, there are also various debates in the scientific community regarding the test's usefulness. Tests can be done in specified centers as well as at home through home-based kits such as the AFIL premium test kits.

In this article, we intend to explain the gut biome test, how it's done, its uses, limitations, and whether you should undergo testing.

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What is Gut Biome Test?

The gut biome test is a test of your stool sample to identify the types and number of microbes in your digestive tract. The gut microbiome is the type and number of microorganisms, including bacteria, viruses, fungi, and protozoa, in your gastrointestinal tract. These can be good or bad organisms, playing an important role in your digestion, immunity, mood, and overall health. 

Gut imbalance can cause various gastrointestinal symptoms such as indigestion, bloating, heartburn, stool changes, mood-related issues such as depression and anxiety, obesity, skin conditions, liver disease, diabetes, and cancer.

Since the gut microbes' composition is considered as unique as fingerprints, it provides an individualized risk of disease. However, the test is not diagnostic and people should see their doctor if they have serious concerns regarding their health.

Why is the test done?

Why is the gut biome test done

A gut biome test is done to identify microorganisms in the digestive tract, including bacteria, viruses, fungi, and parasites. These tests measure the number and type of microorganisms to identify various digestive issues and other purposes. 

Research has identified that gut microbes are associated with processes regulating insulin resistance, obesity, and other metabolic conditions. It has also been found that a large variety of bacterial species in the gut is a good thing and the diversity decreases the risk of obesity, depression, diabetes, and inflammatory conditions

Similarly, gut microbiomes are considered to be associated with the following conditions: 

  • Mental health conditions such as depression and anxiety
  • Obesity
  • Skin disorders such as dermatitis
  • Cardiovascular diseases
  • Type 2 diabetes mellitus
  • Cancer such as colorectal cancer
  • Inflammatory conditions such as inflammatory bowel disease
  • Liver disease
  • Dental and oral health problems such as tooth decay and cavities.

Thus, a gut biome test guides you regarding the risk of certain health conditions for a healthcare consultation. Additionally, it also provides recommendations regarding lifestyle advice, such as dietary advice and physical activity.

How does the test works?

There are various companies offering the test at the doctor’s office or at home. However, the sample tested in most of the tests is generally a stool sample. The results of the test are usually provided within two to three weeks.

In some tests, bacteria are grown in the lab to identify specific microorganisms to identify types of bacteria causing certain symptoms such as diarrhea or indigestion. Other tests estimate several markers in the stool to be associated with various diseases and disorders. 

Most commercial tests analyze DNA by extracting it from the stool sample. DNA extraction can find out the types and numbers of bacteria in the stool.

Some tests measure other markers of gut health, such as calprotectin, which indicates inflammation of the gastrointestinal tract. Test reports usually include a comparison of your gut microbiome to a wide population and some pathogens are specifically looked for, such as Clostridium difficile, Escherichia/Shigella, and Vibrio cholerae.

Following the test, some companies also offer the solution to the problem in the form of dietary advice and prebiotics or probiotics intake. They usually offer a repeat test after some time of following their recommendation to look for improvements.

Who should undergo the test?

Who should undergo the test?

Anyone can take a gut biome test who wants to know about the composition of microorganisms in their digestive tract. However, it is usually advised if you have digestive symptoms such as diarrhea, bloating, or indigestion.

The test is not a diagnostic test. So, if you are at risk of a serious condition or have severe digestive symptoms, you should see your doctor. Some of these symptoms are:

  • Fever
  • Blood in the stool or black discoloration of the stool
  • Yellowish discoloration of eyes or skin
  • Weight changes
  • Vomiting for a prolonged period or severe vomiting
  • Severe abdominal pain
  • Difficulty swallowing food

How to choose a microbiome test?

How to choose a microbiome test?

There are various tests regarding gut biome offered by various companies, and the results provided by the companies also vary. So, you need to consider various factors before ordering the tests.

  • Depth of interpretation: The analysis done by the test can differ. So, you should choose your test according to the information they provide and what is the reason you are undergoing the test for.
  • Explanation of results: The tests are better if they explain the test in a way easy to understand and apply. The explanation should also be comprehensive for doctors to interpret results to get more information. Some tests also provide advice regarding lifestyle habits and diet to be adopted. 
  • Confidentiality: If you consider privacy to be important, you also need to consider the privacy of the test results and choose a test based on the confidentiality provided by the company.
  • Affordability: You should also find a suitable test according to the cost of the test. The average test usually costs below $200 but can be expensive. There is also a provision of mostly installment service.
  • Home-based test: If you cannot go to the test center due to certain reasons you can order tests at home for your ease. However, you need to share the test results with your doctor for health care advice.

Limitations of Gut Biome Test

Although the gut biome test seems promising regarding the simplicity and usability of the test in various conditions, there are certain limitations of the tests to be considered.

It has been argued against the gut biome test that the test is not able to identify all the microorganisms in our gut with a small sample of stool, as a result of which there is a variation of results with different samples of the same person. Additionally, some bacteria are attached to the gut wall and not present in the stool, which means they could not be studied.

Furthermore, only 20% of bacterial gene sequences have been identified, and the function of those bacteria is also unknown. Also, microorganisms may act differently during interaction with other organisms, which has also not been studied properly. There might also be variations regarding bacterial function in different human bodies. Similarly, tests using DNA extraction do not tell you whether the bacteria are dead or alive.

Hence, these limitations of the test, along with the cost of the test, make it debatable to undergo the test regularly, despite its benefits. Moreover, these tests are not FDA-approved. So, there are these limitations of the test to consider before undergoing it and the value of the test might increase in the future as the research associated with the gut microbiome increases and its association with different diseases becomes more concrete.


Microbiomes play an important role in our body's regulation of physical and mental health by producing metabolic compounds and hormones. Thus, finding out the type and number of bacteria to identify the health situation in our body is beneficial. This can be done by a gut biome test by taking a sample of stool.

There are multiple tests offered by various companies for this purpose, and they also offer other services like advice on lifestyle habits and healthcare consultation. However, there are certain limitations to the test, which you should consider and understand that the test is not diagnostic. So, if you have symptoms suggesting some disease, it is best to seek help from professionals. Additionally, you should share the results of the gut biome test with your doctor.

In general understanding, your gut biome can be interesting and might provide you with some hints regarding your dietary changes. However, you can always rely on healthy eating habits such as including fruits and vegetables in your diet, reducing your intake of processed foods, reducing foods high in fat and sugar, and being physically active, with or without gut biome tests.

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  2. Shreiner, A. B., Kao, J. Y., & Young, V. B. (2015). The gut microbiome in health and in disease. Current opinion in gastroenterology, 31(1), 69.
  3. Cresci, G. A., & Bawden, E. (2015). Gut microbiome: what we do and don't know. Nutrition in Clinical Practice, 30(6), 734-746.
  4. Ahn, J., Sinha, R., Pei, Z., Dominianni, C., Wu, J., Shi, J., ... & Yang, L. (2013). Human gut microbiome and risk for colorectal cancer. Journal of the National Cancer Institute, 105(24), 1907-1911.
  5. Staley, C., Kaiser, T., & Khoruts, A. (2018). Clinician guide to microbiome testing. Digestive Diseases and Sciences, 63(12), 3167-3177.

Author: Dr. Sony S. | Panel Expert, Medical Doctor Dr. Sony is known for her medical articles, written with in-depth detail and accuracy owing to her vast medical knowledge and thorough research of each article. She completed her degree with multiple scholarships from Guangzhou Medical University and is a board-certified Clinical Doctor. She is currently working as a Medical Officer in the emergency department of a renowned hospital and continues to publish numerous medical papers and articles. Dr. Sony continues to lead the way in medical breakthroughs, unparalleled by her high level of detail, knowledge and passion for discovering new sciences and innovative healthcare treatments.

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