The Brain Inside Your Tummy

The story

Here is a strange and wonderful fact about you. You have a brain in your head, thinking your thoughts right now. And winding through your middle, wrapped around your gut like a soft net, you have something rather like a second one.

It is not a round grey brain in a bony shell. It is a web of nerve cells, hundreds of millions of them, lining the long winding tube that carries your food. Scientists call it the enteric nervous system, which means the gut's very own nervous system. And it is such a busy, clever web that many scientists fondly call it the little brain in the gut.

What does it do all day? It runs your food factory. It senses what you have eaten, squeezes the tube in slow gentle waves to push each meal along, calls for the right juices at the right moments, and keeps everything moving in the proper order. And here is the remarkable part. It can do much of this work on its own. The brain in your head does not have to think about your lunch even once. The little brain handles it, hour after hour, like a quiet worker who never needs to be reminded.

The two brains do talk to each other, though. A thick bundle of nerves called the vagus nerve runs between them like a telephone cable. And when scientists studied that cable, they found something surprising. A great many of its fibres carry news UPWARD, from the tummy to the head. Your gut is not just taking orders from above. It is reporting, all day long. All is well down here. Or, something is not right, be careful.

You have felt those reports yourself. Before something big, a show, a race, a first day at a new place, your tummy flutters, as if butterflies were loose inside it. That is your two brains talking. The head brain notices that something important is coming. The body gets ready. And the gut feels all that getting-ready and sends the news straight back up.

People seemed to know about this long before science proved it. In English and in many other languages, people say things like, I have a gut feeling, or, I just felt it in my stomach. Those old sayings turn out to point at something real. There truly is a web of nerves down there, hard at work, sending its reports.

So be kind to your hard-working middle. Feed it well and give it time to do its quiet job. And when your tummy flutters before something big, you can smile, because now you know what that flutter is part of. Your head and your gut are talking it over together, and the message between them says, get ready, this matters.