The human microbiome is the total complement of microorganisms in all or a part of a person’s body. Examples are the microbiomes on the skin, in the saliva and in the gut. The human gut microbiome is the most studied and this type of testing is what commercial organizations are offering to Australian consumers.
There are already a number of companies offering gut microbiome testing to people in Australia. Testing is not cheap - $300 upwards depending on the company and the testing.
There have been several recent articles about microbiome testing:
Medscape Pathology and Lab Medicine (you will have to set up a login to read this) - Microbiome Profiling: Big Business, but What About the Data?
The Scientist - Companies Pursue Diagnostics that Mine the Microbiome
Australian Family Practitioner - The gut microbiome
Consumer testing will usually provide results showing a table or a graph comparing the range of common types of bacteria in your gut compared to the average and other subgroups of people. Some companies will use these results to try to sell you various probiotics to remedy any “imbalances” in your microbiome. The important question is whether there is any evidence that taking steps such as changing your diet or taking probiotics will do you any good? If you read the articles above you will see that the commercialization of this testing is way ahead of the scientific evidence needed to support it.
There are many studies showing differences between the gut microbiomes of people with a large range of conditions, especially gut disorders such as inflammatory bowel disease. However, an interesting thing is that gut microbiomes may also differ between people with a range on non-gut disorders as well. It is clear that there are interactions between the gut microbiome, the immune system, the nervous system and more. What is not clear at all is whether these differences are causes or effects of the conditions and whether any interventions to alter the gut microbiome have any effect on the conditions.
The Human Gut Microbiome Project and The International Human Microbiome Consortium are large collaborative research projects to further research in this area and to accumulate the huge amounts of data required to answer these questions.
There are still other problems associated with commercial consumer microbiome testing. It is already known that there is huge variation between the gut microbiomes of apparently healthy people so the range of what is “normal” is still unknown. Different labs use different sequencing methods, different software for analysis, different databases for comparison and different methods for sample stabilization during transport from you to the lab. All of these things have a potential to cause variation in the results and one or more may be responsible for the large difference in results this journalist for Science News found when having the same sample tested at different labs.
Medscape Pathology and Laboratory Medicine finish their article with a quote from Dr. David A. Johnson, Professor of Medicine and Chief of Gastroenterology at Eastern VA Medical School in Virginia, USA and author of the book; The GUT Microbiome: New Understanding and Potential Translational Applications for Disease Management. Dr. Johnson says; “At this point, it still seems premature to say that [an individual's microbiome profile] is something we can then use to determine strategies for managing disease or improving health. It's incredibly promising, but it needs to be done in a programmatic way, with science leading it rather than commercialization”.