The gut-brain connection or ‘axis’ refers to the connection and communication network between your gut and brain. The two organs are connected both physically and biochemically through various mechanisms.

The Digestive System

The Vagus Nerve

There are approximately 100 billion neurons in the human brain. Similarly, your gut contains 500 million neurons, which are connected to your brain through nerves in your nervous system

The vagus nerve is one of the biggest nerves connecting your gut and brain., a major nerve that sends signals in both directions. This nerve plays a crucial role in the communication between the gut and brain, influencing various functions including stress response and gastrointestinal health. This is because stress inhibits the signals sent through the vagus nerve and so causes gastrointestinal problems.

Neurotransmitters in the Gut-Brain axix

Neurotransmitters produced in the brain control feelings and emotions.

Neurotransmitters, such as serotonin and gamma-aminobutyric acid (GABA), play a role in connecting the gut and brain. These chemicals produced in both the brain and gut affect feelings, emotions, and even processes like controlling the body clock.

GABA – helps control feelings of fear and anxiety

Serotonin – contributes to feelings of happiness and also helps control your body clock


Untitled-design-85 The Gut-Brain Connection

Your body is full of trillions of bacteria, viruses and fungi. They are collectively known as the microbiome.

Most of the microbes in your intestines are found in a “pocket” of your large intestine called the cecum, and they are referred to as the gut microbiome.

The trillions of microbes living in your gut produce various chemicals that can influence brain function. Short-chain fatty acids (SCFA), neurotransmitters, and other compounds produced by gut microbes can have an impact on appetite, mood, and even brain barrier functions.

Gut microbiota are essential to immune system development and immune function. 

The immune system also plays a role in the gut-brain axis, with gut health and inflammation affecting brain disorders like depression and Alzheimer’s disease.

How to Improve the Gut Brain Connection

Improving gut health through probiotics, prebiotics, and a healthy diet can positively impact brain health. Foods like omega-3 fats, fermented foods, high-fiber foods, polyphenol-rich foods, and tryptophan-rich foods can help support the gut-brain axis by promoting a healthy gut microbiome and potentially improving brain function.