Can take-home microbiome kits really predict disease?
Our bodies are filled with trillions of microorganisms including bacteria, fungi, parasites and viruses. These bugs coexist with each other and our own cells throughout our body, but most of them are found in our gut. The gut microbiome plays an important role in our digestive system and immune system, and is relevant to some chronic diseases like Crohn’s disease and irritable bowel syndrome (IBS).
Home microbiome kits claim that your microbiome is a ‘mirror of your health’, and using their kits could predict your likelihood of developing certain diseases. Is it true that we can predict disease from our microbiome? And are commercially available home kits sensitive enough to do this? We asked 5 experts in microbiomes, microbiology and immunology ‘Can take-home microbiome kits really predict disease?’, here is what they said…
Can take-home microbiome kits really predict disease?
5 experts say ‘No’
What are take-home microbiome kits?
Each person has a unique microbiome, influenced by our genetics and lifestyle. As most of the microbes live in our gut, we can find out which species we host by running tests on our poo. Faecal analysis has found that over 50% of human faeces is made of bacteria! Take-home microbiome kits require you to send off some poo samples to be analysed. The analysis can be done in many ways but often it is by sequencing genetic material in the poo to identify which microbes are present. The resulting report includes which types of microbes are present, and often suggestions as to what this might mean in terms of your health or disease risk. Interestingly, the kits from different companies can give different results even if you send them the same sample!
What can microbiome kits tell us?
Dr Kate Secombe, an expert in microbiomes from Adelaide University in Australia, says “Take-home microbiome kits can be interesting to get an overall snapshot of the types of bacteria that live in your gut, and how that may differ from others in the population.”
She adds that “we currently don't have enough information about how your gut microbiome may specifically relate to disease, and whether it can predict occurrence of certain diseases, and therefore it is unlikely that a take-home kit will be able to do this.”
Dr Hannah Wardill, an expert in microbiomes and gastroeneterology from Adelaide University, agrees, saying “These tests a well designed marketing ploy leveraging on peoples' interest in the microbiome and gut health. Whilst these tests will certainly tell you about the types of bacteria that inhabit your gut, they are not able to diagnose disease. They may be able to give you some insight into the types of diseases with which certain microbial compositions are linked or associated, but based on current evidence, there are no universally accepted microbial ‘biomarkers’ for diseases linked with the microbiome. What people can realistically expect to learn from these new commercial tests is more along the lines of a snapshot of how a person’s microbiome compares to others, and the presence of specific gut infections.”
Why is it difficult to predict disease from microbiomes?
Dr Secombe says “As the gut microbiome can differ so much between different people, we do not understand if certain species of bacteria make developing a certain disease more likely, or whether it is more important what products are produced by the microbiome. How this relates to disease could differ depending on your age, diet, where you live or many other factors. Some diseases may not even have a microbial role at all! There is still so much to learn about our microbiome that I think accurate prediction of disease will be a long way off.”
Dr Bella Van Sebille, an expert in oncology from South Australia University, agrees saying “While there is mounting evidence that the microbiome influences diseases, there isn't currently enough evidence to show HOW this occurs, or what microbial profiles are associated with different pathologies. There is much promise in this area, but it's still in its infancy. More research in the area is urgently required.”
Dr Matthew Koci, an expert in microbiomes and immunology from North Carolina State University in the USA, says “The issue is so many factors affect what they might find in your poo from month to month, day to day, even between breakfast, lunch and dinner. There is so much more noise in one person's microbiome sample on one random day, so much more than is in the relatively stable human genome that it is going to take a lot longer for these kits to catch up to just what 23 and Me is today.”
Will these kits be more informative in the future?
Most experts agreed that more research is needed in the microbiome space, and this would make these take-home tests more informative. Dr Koci says “The home genetics [like 23 and Me] kits are still largely more entertainment than really informing health decisions, but as more people contribute and fill out their surveys they are hoping to find predictive power. The home microbiome testing companies are hoping for the same thing. The idea is if they get enough people's poo, with enough additional health data from, one day they'll know what to do with that information.”
Currently, take-home microbiome kits cannot predict disease accurately.
May the facts be with you!
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