How gut health affects physical and mental health; experts explain the gut-brain link and offer tips to optimise your microbiome

Your gut is your ‘second brain’. What happens there can directly and indirectly affect your mood and stress levels, as well as your physical health

Experts on the gut microbiome explain the gut-brain axis, how diet affects mood and stress disrupts the gut, and offer tips on keeping your microbiome healthy

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The nerves in your stomach act as a “second brain”, and your gut microbiome can affect your mental and physical health, so it is vital to eat the right food and keep your gut healthy. Photo: Shutterstock

Published: 4:15pm, 12 Jun 2023Updated: 11:21am, 5 Jul 2023

Almost 25 years ago, Michael Gershon, a professor of pathology and cell biology at Columbia University in New York, published his groundbreaking book, The Second Brain.

His 30 years of research had led to the discovery that nerve cells in the gut act as a ‘brain’ that controls the stomach.

Our two brains, he wrote, must cooperate, otherwise there is chaos in the gut and misery in the head, everything from “butterflies” to cramps, diarrhoea and constipation.

More research over the years has helped us understand the function of ‘the second brain’ and the interdependence of the gut microbiota and the brain, the so-called gut-brain axis.

Professor of pathology and cell biology Michael Gershon has been studying the gut and microbiome for decades. Photo: Columbia University

Kara Holmes, nurse and author of The Gut Health Reset, says it’s helpful to think of it as a phone line that’s always open – a signalling system supported by immune cells, the enteric nervous system (ENS), gut bacteria and the vagus nerve, the largest nerve in the autonomic nervous system, which extends from the brain to the colon and plays a key role in heart, lung and digestive function.

The enteric nervous system is the focus of University of Melbourne professor Joel Bornstein’s research.