If you’d asked me when I was a teenager if I knew what it meant to have two brains, I’d have said the one in my head and the one zippered in my fly. As I got older, I learned to pay more attention to another brain . . . the one in my gut.

The body actually does have more than one brain: there is the central nervous system and another called the enteric nervous system. When I got to medical school, I learned the biological explanations for the butterflies in my stomach when I looked down from the railings of high bridges. Research in the new field of neural gastroenterology is further clarifying the power of this hidden brain. The nervous system in your gut and the central nervous system both use the same hardware to run their programs: the neurotransmitter, serotonin. It turns out that 95% of the body’s serotonin is housed in the gut.

Having two brains makes literal and evolutionary sense. What two brains do is weave their neural networks to control your behavioral programs. The brain in your gut is a library of information that tells you what foods don’t mix in your intestine, if it’s rotten, or if you’re eating too fast. What you feel in your gut is an accurate assessment of what you need to be paying attention to, and it doesn’t get much help from the central nervous system. The gut knows things the brain hasn’t even considered.

Pay attention to what your belly is telling you; this is ancient wisdom for which we have new explanations. Trust your gut feeling. It is the voice of your intuitive soul, and it will teach you at least as much as your brain (or, perhaps, penis) once did.