Understanding the Gut

The Gut-Brain Axis

Your brain is connected to every part of your body, so what is so special about the connection between your gut and your brain? It turns out that your gut enjoys a particularly intimate relationship with your brain, compared to the other organs in your body, so much so, that your gut has been called your ‘second brain’.


We now know that there is a constant and complex two-way conversation and flow of information taking place between your gut and your brain. This means that what is happening in your brain (if you are happy, sad, anxious or tired for example) can have a big effect on what is happening in your gut. And, importantly, what is happening in your gut can also affect what is happening in your brain. Think of the feeling of ‘butterflies in your stomach’ you may have got before an exam, or the need to dash to the bathroom when something nerve racking is about to happen. All those feelings are due to the Gut-Brain axis.

Gut-brain connection. Vector illustration

Two-way Conversation
In addition to brain factors affecting gut function, there is also evidence that events happening within the gut can affect the pain sensors and pathways in the gut itself and that this is relayed back to the brain.

It is easy to see how this can lead to a vicious cycle: Psychological stressors → changes in gut function → increased pain in the gut → increased sensitivity of pain pathways → reduced pain threshold → increased stress and anxiety in the brain, etc.

In addition we now know that the GM also has a two-way conversation with the enteric neurones in the gut, such that people now refer to the Gut-Brain-microbiota axis.