Meet Your Second Brain

Decision-making, mood, disease… scientists are discovering that the network of neurons in our gut is involved in a lot more than just digestion

- Robert Matthews

You’re facing a big decision – whether that’s to go into a business partnership with a friend, say, or put money into a promising new idea. It’s a tough call, as there are very few hard facts to go on. So it’s time to use your second brain. Don’t worry, you’ve probably used your second brain countless times before; it’s just that when you did, you more likely referred to it as ‘gut instinct’.

New research is showing that this age-old phrase is surprisingly accurate. We really do have a second brain that influences our judgment, and much else besides. Known as the Enteric Nervous System (ENS) – enteric meaning ‘to do with intestines’ – it’s an extensive network of brain-like neurons and neurotransmitters wrapped in and around our gut.

Most of the time, we’re unaware of its existence, as its prime function is what one would expect: managing digestion. Yet the presence of all that brain-like complexity is no coincidence. The ENS is in constant communication with the brain in our skull via the body’s own information superhighway – the vagus nerve. And it’s now becoming clear that all those signals flowing back and forth can influence our decisions, mood and general well-being.

“Your gut has capabilities that surpass all your other organs, and even rival your brain,” says ENS specialist Dr Emeran Mayer of the University of California, Los Angeles, who is author of a new account of the science of the ENS, The Mind-Gut Connection. “This second brain is made up of 50-100 million nerve cells, as many as are contained in your spinal cord.”