Two healthy people can have very different gut microbiomes.
The microorganisms living in the intestine are influenced by many factors, including diet, medications, age, health, lifestyle and environment.
This natural variation makes the gut microbiome highly individual.
Is there one ideal gut microbiome?
There is currently no single microbiome profile that can be considered ideal for everyone.
Some microorganisms and microbial functions are associated with better health. Others are more frequently associated with disease or declining health.
But the meaning of an individual microorganism depends on the wider microbial community and the person in whom it is found.
For this reason, a microbiome cannot be assessed reliably by looking at one bacterium in isolation.
Why can two healthy people have different results?
People eat differently, use different medications and have different health histories and environmental exposures.
Age also matters. The microbiome can change throughout life without those changes necessarily indicating poorer health.
A result that differs from another person’s microbiome is therefore not automatically abnormal.
What should we look at instead?
Microbiome assessment can consider the overall microbial community rather than searching for one ideal list of bacteria.
The functions of these microorganisms also matter. Gut microorganisms produce and transform substances that can interact with metabolism, immune function and other processes in the body.
The individual microbiome profile is therefore most useful when considered together with other information about the person’s health, diet, medications and lifestyle.
