Your gut microbiome is not fixed.
The community of microorganisms living in your gut can change throughout life. What you eat is one of the factors that can influence both which microorganisms are present and what they do.
How does diet affect the gut microbiome?
Different microorganisms use different nutrients and produce different substances as they process them.
This means that what regularly reaches the intestine can influence the environment in which these microorganisms live.
Your usual eating pattern may therefore help shape the composition and activity of your gut microbiome over time.
What else can influence your microbiome?
Diet is not the only factor.
Medications, health conditions, lifestyle and changes in the body that occur with age can also affect the gut microbiome.
These influences often occur together. This is one reason why two people can eat similar diets and still have different microbiome profiles.
Can you improve your microbiome?
The fact that the microbiome can change makes it particularly interesting for preventive health.
But changing the microbiome is not automatically the same as improving health.
There is no single bacterial profile that everyone should try to achieve. It is also too simple to assume that increasing one particular microorganism will necessarily make the microbiome healthier.
The more useful question is whether changes in diet and lifestyle can support microbial functions that are associated with better health.
What does this mean for healthy ageing?
The microbiome provides one possible biological pathway through which diet and lifestyle may interact with long-term health.
This makes it a potentially modifiable part of healthy ageing.
Dietary strategies, prebiotics and probiotics can all influence the gut microbiome, although their effects vary between people and should not be considered interchangeable.
The goal is therefore not simply to change the microbiome. It is to understand which changes may support health in a particular person.
