When I was in medical school, we spoke of the gut as a “blind tube” whose entire purpose was to take in food, break it down, pass it on to the body, and eliminate it.
That negative view of the gut could not be further from the truth. Far from being a “blind tube,” your gut is really a second brain.
Consider the facts. There are more neurons in your gut than there are cells in your spinal column. You produce more serotonin — the “feel-good” biochemical that prevents depression and insomnia — in your gut than you do in your brain.
Your gut doesn’t simply “take orders” from your brain. Rather, communication between your gut and your brain is a bi-directional highway. Stress and anxiety in your brain can create indigestion in your gut. Bacterial imbalance in the gut can spark depression, anxiety, and “brain fog.” It’s definitely a two-way conversation, with each side having something to contribute.
Gut Feelings: Not Just a Metaphor
So guess what? All those expressions that we thought were just metaphors actually refer to a very real biological phenomenon.
I feel it in my gut.
Listen to your gut.
Go with your gut.
Modern science used to scoff at such thinking, treating it as a relic of the past. But what I have seen with thousands of patients is that these old expressions actually point our way to the medicine of the future. These so-called metaphors actually represent a deeper physiological understanding that there is a kind of intelligence in the gut.
Where do gut reactions come from?
Once we acknowledge the intelligence contained in our gut feelings, we transform our whole idea of what we consider “intelligent.” We also transform our understanding of our own bodies. Because where, finally, do gut reactions come from? Not solely from the human cells in our digestive tract, but also from the trillions of bacteria that live within our gut and elsewhere in our bodies.
Perhaps one individual little microbe doesn’t have much intelligence—but when you put trillions of bacteria together into a single system, that system exhibits a profound intelligence that goes far beyond anything that any one part of it could achieve. This is the power of emergent properties, the scientific term for what happens when something genuinely new emerges out of many individual pieces.
Recently I saw a remarkable video of a huge flock of birds that dipped and swirled in extraordinary patterns. Who knows what each individual bird would have done on its own. But from the collective action of all the birds together, an amazing intelligence emerged: a brilliantly organized display of aviational skill. Separately, each bird knew very little. Together, they knew how to create something awe-inspiring.
The Intelligence of Our Gut
In the same way, our individual microbes work as an extraordinary collective to create a new intelligence—the intelligence of our gut. This unique intelligence has the ability to create profound healing. Far from the mindless activity of a blind tube, the human and bacterial cells of your gut create a fusion of knowledge and emotion—the ultimate wisdom of a gut reaction.