10 Mar 2016

Are 'gut feelings' real?

1:35 pm on 10 March 2016

We asked an expert.



Image: 123rf

This Q&A is part of our two-week series on choices. Click here for more.  

It's Saturday night and you've been a bit reckless on Tinder, swiping right like your thumbs can do no wrong. It doesn't take long to get a match and within minutes you receive this, or something like it: "Wassup. Where are you??? Let's meet up now."

After taking a moment to inspect the copious amounts of camo and gun paraphernalia in your match's Tinder pictures, you get a sinking feeling in the bottom of your stomach. Maybe it's not a good idea. 

"Trust your gut," we're often told when struggling to make a decision. And we all know that churning sensation when something feels not quite right. But how much does our gut really have to do with intuition, and should we trust it? 

American neurogastroenterology expert Dr. Michael Gershon is the author of The Second Brain – meaning, of course, the gut. The gut is a pretty spectacular part of the body, capable of “thinking” for itself, he says. But when it comes to making tough choices, it's a bit more complicated than that. 

Hi Michael! First up, how long have you been a neurogastronl…? *trails off, hoping Michael won't notice the pronunciation failure* 

Neurogastroenterologist. Hmm, I’d say, probably since 1967?

You’re considered one of the founding fathers of the field - what’s it all about?

Let’s start with the gut. We have a tube inside of us that starts at the mouth and ends at the anus. Inside, that tube teems with life. There are more bacteria in there than you have cells in your body. The gut is essential to life; you can’t do without it because all your nutrients come in that way.

To do all that, it’s very, very complicated and it requires a tremendous amount of integration – a lot of computing – and that’s done by the nervous system it has inside. It’s the only part of the nervous system that can run an organ independently of any input from the brain or spinal cord. Because it can work on its own, I call it the second brain.

So essentially the gut is capable of “thinking” for itself?

There’s a two-way input between the brain and the guy. They talk to each other. For example, when I call the National Institute of Health in Washington to find out how my latest grant application has gone, I become painfully aware of the kind of effect the brain can have on the gut. That’s what you call “butterflies”.

What’s really happening when you feel butterflies in your stomach?

That’s information to do with anxiety coming from the central nervous system to the gut causing you to feel the contractions of the gut. That’s an effect from top down, but there are lots of effects that go from the gut up. In fact, when you look at the vagus nerve, a major nerve that connects the gut and the brain, you find that most of the fibres in it are carrying information from the gut to the brain, not from the brain to the gut. A huge amount of information is going upstairs and we don’t really know what all of it is but we know it can affect mood and well-being.

Dr. Michael D. Gershon

Dr. Michael D. Gershon Photo: Columbia University

So does our gut contribute to our mental health?

A decade ago I would’ve said to you “no way”. Now I would say, equally certainly, “absolutely”.

In fact, an interesting little titbit, if you stimulate the vagus nerve in a person, you can increase learning and memory and improve mood. It’s used to treat depression and vagus nerve stimulation is certainly better than electrocompulsive therapy.

We also now know that the little sensory cells in the gut can respond to bacteria and your bacteria can change your mood – that’s really wild.

How do we explain having a “gut feeling” about people or certain situations?

It came about because the gut is so central to the body. We feel so much there.  People can handle a lot more pain in their bones or muscles than they can in their gut. Having a 'gut instinct' about something is connected to the idea of butterflies in your stomach; a response to anxiety trigged by the brain.

But don’t take that too far because philosophy, religion, poetry, politics – god help us – is all in the head. The gut doesn’t contribute to politics other than getting butterflies when you listen to Donald Trump.

I get more than butterflies; I get queasy. How about feeling hangry (hungry + angry)? Is there something to be said about our emotional response to hunger based on the gut?

Hunger is associated with contractions in the stomach. The sensation, in part, has to do with the gut but a lot has to do with the brain and blood sugar. However, when you’re eating, the gut is very important in stopping you eating too much. A lot of the gut hormones promote satiety.

Do you think your research shows that people should trust gut instincts when they’re making choices? Is there a connection?


Not at all?

Remember, conscious thought and decision-making all happen in the brain. It can affect the gut, but the main choices, like should you vote for Hillary Clinton or Donald Trump, they happen in the brain.

Does that mean we don’t really have control over our “second brain”?

You do have control in the sense that the brain functions like a CEO that doesn’t like to micromanage; it can tell the gut to do more or less, but it can’t tell it specifically what movements to make. Those are intrinsic, hardwired into the bowel itself and that’s all the second brain doing that on its own. Actually, it was noted years ago that if you cut all the nerves to the gut, the gut works fine.

Woah. Am I drawing a longbow, then, when I say that if we focus on the health of our gut, we’re likely to be happier and healthier because our gut has a lot to do with mental health? In that way, we’re able to make better choices, right? 

That’s good. I like that. Absolutely.

Nailed it.