The Relationship Between the Human Gut and the Brain

Apr 3, 2023 | Teacher's Corner

Have you ever had a ‘gut feeling ‘about something or had ‘butterflies in your stomach ‘ .
These sensations emanating from your stomach suggest that your brain and stomach are connected.

Recent revolutionary studies show that there is a very close connection between your gut health and brain health – this communication system is now called the gut-brain axis and both organs are connected physically and biochemically.

Scientists now refer to the gut as your ‘second brain ‘. It contains the enteric nervous system – this consists of more than 100 million nerve cells lining your gastro-intestinal tract from oesophagus to rectum. The most important of those nerves is the Vagus nerve. Studies have shown that the Vagus nerve is important in controlling stress and depression.

The gut and brain are also connected by chemicals called neurotransmitters. One of our most important neurotransmitters is serotonin which contributes to feelings of happiness A large proportion of serotonin is produced by the gut and the trillions of microbes living there.

The trillions of bacteria, viruses and fungi that live in the gut are referred to as The Gut Microbiome – found predominantly in the large intestine. There are 40 trillion bacterial cells in the gut microbiome and there are only 30 trillion human cells – so you are more bacteria than human!!!

We must protect our gut microbiome, keep it healthy and prevent inflammation. A healthy gut can improve heart health, assist in weight reduction, control blood sugar and improve brain health. So, it is vital to eat a good diet.

The foods that are important are

  • Oily fish
  • High fibre foods – legumes, fruit, vegetables, beans, whole grains, nuts and seeds.
  • Fermented foods – yoghurt, kombucha
  • Polyphenols – almonds, blueberries, onions, dark chocolate, red wine, broccoli
  • Probiotics which are live bacteria. The use of probiotics has been shown to reduce levels of anxiety, stress and depression.



The gut and the brain are more closely linked than you think

The bottom line is that we can assist our bodies and particularly the gut to control digestion, build a good immune system, prevent inflammation and disease as well as improving cognitive and emotional well-being.

Just eat the right food and your ‘second brain ‘will stay healthy


– Healthline. The Gut- Brain Connection. Ruairi Robertson PhD
– Science Marches on- Emeritus Professor Anwar Mall UCT Summer school 2023

(Alison Lund)