Dr. Trisha Pasricha

That's the vagus nerve.

Yeah.

We've known that the gut and the brain have been in communications for over a century.

If you go back to the 1890s, 1890s, you'll see in doctor's journals, they were talking about how it seemed like things like emotional stress seemed to cause this response of all places inside the gut.

And there was a famous set of experiments that was done in the 1950s at Cornell.

And the researchers had participants

talk about really stressful emotional experiences.

So they would talk about an argument they had with their spouse or the financial troubles they were having.

And while they were discussing these psychologically stressful events, the researchers used a prototype of a colonoscope.

So they looked directly at the colon from the inside.

And as these people were talking, they would see the colon start to spasm and squeeze and move.

And these people would experience stomach cramps and gut cramps.

And I think that tracks with what

Certainly what I experienced in real life, if I'm having an argument with my husband, which doesn't happen that often, but if I'm having that, I sometimes feel cramps in my stomach.

It's like a very unpleasant feeling.

The problem is that for several decades, that was the way we framed the gut-brain connection entirely.

We thought about that gut-brain connection as the brain talking down to the gut.

It wasn't until the 1980s, 1990s, that my field, which is neurogastroenterology, the study of the gut-brain connection, really crystallized.

And that's when people said, wait a minute, this vagus nerve, this large nerve that's the conduit between the brain in the head and the brain in the gut,

Most of the signals, 80% of those signals, they're not going from the brain in the head down to the gut.