The gut microbiome and immune system are closely connected.
Gut microorganisms and the substances they produce interact continuously with immune cells. These interactions can influence inflammatory activity throughout the body.
But inflammation and inflammaging are not the same.
What is inflammation?
Inflammation is part of the body’s normal immune response.
It helps protect us from infection and supports tissue repair after injury. This response is usually temporary and decreases when it is no longer needed.
Inflammation becomes different when it persists.
Chronic inflammation can continue for months or years. It can occur at different ages and is associated with many chronic diseases.
What is inflammaging?
Inflammaging describes persistent, low-grade inflammatory activity associated with ageing.
It develops alongside changes in the immune system and other biological processes that occur as we age.
Inflammaging is therefore a specific concept in ageing research. It is not simply another name for all chronic inflammation.
How does the gut microbiome fit in?
The gut contains microorganisms that can influence immune activity.
During ageing, the composition and activity of the microbiome can change. Some beneficial commensal bacteria may decrease. Potentially pro-inflammatory bacterial groups may become more prominent.
Microbial products can also interact with the intestinal barrier and immune cells. These interactions may influence inflammatory signalling.
The relationship also works in the opposite direction. Inflammation can change the intestinal environment and alter the gut microbiome.
Diet, medications, disease and other age-related changes can affect both systems.
Why does this matter for longevity?
Inflammaging is associated with biological ageing and many age-related diseases.
The gut microbiome may be one factor involved in this process. It is not the only one, and current evidence does not show that changing the microbiome can prevent inflammaging.
Understanding the two-way relationship between the microbiome and inflammatory ageing may help us better understand why ageing follows different biological trajectories.
