A lot of people have inquired about gut microbiome tests. This kind of test has gained a lot of popularity and is being marketed as a tool to help consumers find the best way to eat. But how useful is the microbiome test really?

Millions of microbes, including not only bacteria, but also viruses, or fungi colonize our bodies. Over the past years, research has reveled that our unique microbiomes play a vital role in digestion, immunity, inflammatory bowel disease, diabetes, or depression. While the microbiome is still being researched, some companies have taken early evidence and are now selling personalized nutrition plans, supplements, and more based on a microbiome test. The claim is that knowing one's gut microbiome could be the key to diagnosis and treatment of the conditions in question. This sounds promising, however there are a few problems with this approach.

Microbiome research is still a relatively new field. Currently there is no consensus regarding what defines a healthy microbiome. The microbiomes of healthy people vary vastly. Based on this data it is impossible to establish what would be considered optimal. Therefore, the understanding of the roles of the gut microbiome in health and disease is very limited.

With environmental influences such as diet, drugs, supplements, or chemicals, the microbiome changes rapidly. A test is only a snapshot and cannot determine how the microbiome might look when the lifestyle changes.

Approximately 20% of bacterial gene sequences have not been identified at all. We still don’t know what the function of about 40% of the 10 million genes we know is. From a clinical perspective, there are too many unknowns to make a recommendation solely on microbiome data.

The microbiome certainly is an exciting field of research and a promising tool to optimize nutrition. However, it is also a highly complex machinery, unique to the individual, that we just don’t know well enough yet. The research done on personalized diets based on the microbiome is still not solid enough.