The microorganisms living in your gut interact continuously with your body.
They use nutrients and other substances that reach the intestine. During these processes, they produce and transform many different substances. Some of these can interact with human cells or enter the circulation.
This is one of the ways the gut microbiome can influence processes beyond the intestine.
What do gut microorganisms produce?
Gut microorganisms produce many substances known as microbial metabolites.
Some are produced when microorganisms break down components of food. Others result from interactions between different microorganisms and substances already present in the intestine.
These metabolites can interact with biological processes in the body.
Which parts of the body can be affected?
The gut microbiome can interact with several important systems.
Microbial substances can influence metabolism and immune responses. They can also participate in communication between the intestine and other organs.
The effects depend on the microorganisms present, what they are doing and the environment in which they live.
This is why simply knowing which bacteria are present does not provide all the information about a microbiome.
Why does this matter as we age?
Both the composition and activity of the gut microbiome can change with age.
Some of these changes are associated with health, while others are associated with poorer health or disease.
For healthy ageing, understanding the microbiome therefore involves two questions: which microorganisms are present and what are they doing?
These two types of information can help us understand how the gut microbiome interacts with the body throughout life.
