By Kate Hakala
This week I had a job interview for a position that I so badly desired. Because I actually gave a crap, I had what many know to be anticipatory butterflies in the tummy. Only, these butterflies seemed to have taken some amphetamines and enrolled in jazzercise lessons, because there was some weapons-grade fluttering. This is an unpleasantry that we all have experienced–whether it’s before a job interview, on the first day of school, or when we’re reaching the door to our partner’s parent’s home for the first time. It’s a sickening feeling that can even lead to unlucky trips to the bathroom where these restless nerves work their way out of whatever end your body so chooses.
But it can also be a good feeling. Conventional wisdom has it that if you don’t feel winged insects in your GI tract when you meet your girlfriend or boyfriend, they’re probably not the love of your life. So whether it’s your heart swelling or just plain old trepidation, butterflies happen. Why? What good does it to have our body feel so poisonous before landmark life events?
The simple answer is that the butterflies in your stomach come from a reaction to your body’s fight-or-flight response. But that’s just the SparkNotes version.
When you’re faced with some ungodly fear, anxiety, or even dizzying infatuation, your body triggers the fight-or-flight response, which is basically your body’s way of getting you more alert. Your heart rate increases and you start to breath faster. The nervous system sends out your adrenal glands to battle, releasing cortisol and adrenaline. Adrenaline raises your metabolism, increases your heart rate and blood pressure. You’ll notice now that there is a lot of tension in your belly. This is what we might call the “tied in knots” sensation we groan about. Your stomach muscles contract with more frequency to keep you awake and ready. Since our tummies are so sensitive, these surging chemicals and tightened muscles can feel sort of, well, like a muddy swimming pool of terrible.
Thousands of years ago, our fight-or-flight response system developed as a reaction to stresses like lions, tigers, and bears charging at us. Though the SATs and a first date are not comparable to these issues of yore, biology hasn’t caught up with us yet. So, for some, these minute, non-life-threatening situations still feel rather apocalyptic. When our body is telling us to run like a bat out of hell, the adrenaline rush can also halt digestion–because a fleeing animal need not be a pooping animal. With that, blood moves away from the stomach to parts of the body where it is supposedly needed more, like our arms and legs. This flow of blood away from the digestive system creates that swirling, flutter like quality we are so familiar with.
The tied in knots and butterflies in the stomach effect seems to almost come from a hidden, prescient knowledge within us. When we say we have a “gut instinct” about something, whether it is positive or negative, what we mean is that there’s an odd feeling we have in our middles that is guiding us in a certain direction, towards a specific choice. Is it just a turn of phrase? No. Science says our stomach might actually be more aptly called a “second brain”.
This second brain’s proper name is the enteric nervous system (ENS). The ENS is part of the peripheral nervous system, meaning the network made up of the nerves and the ganglia that are found outside of the brain. It works within the tissue lining in the esophagus, stomach, small intestine, and colon. Think of the ENS as your own personal Miss Cleo, but with less turban and more intestine. The ENS helps with digestion, but it also responds to impulses, has a bit of a memory, and can get quite emotional. That’s because estimates say there are oh, only 200 to 600 million neurons in the ENS, equal to (or greater than!) the amount in the spinal cord. Their job is to chaperone the bowels, the gall bladder, and the pancreas as they go about their business.
Both the head-brain and gut-brain start out as an embryonic clump known as the neural crest, but as species evolved, they learned to separate as you develop inside the womb. They’ve remained independent since, though still pass notes all the time through the vagus nerve, which serves as the brain-gut axis. Vagus nerve stimulation can help you memorize, learn, and reduce depression. Yes, your tummy can guide your mood, make judgements, and is a lot more attuned to your inner needs than you may want to acknowledge.
Our gut-feeling control centers are remarkable. The ENS can operate without the brain’s go-ahead, it can signal the brain, and it can remember reflexes without prompting from the brain or spinal cord. How can the belly do its own bidding? The ENS hosts neurotransmitters we fondly know from the central nervous system such as serotonin, dopamine, glutamine, norepinephrine, and nitric oxide. It also boasts proteins called neuropeptides and psychoactive chemicals like enkephalins and benzodiazepines. This is the enteric nervous system’s chemical equivalent of earning almost every Girl Scout badge the lead scout, the brain, has.
The downside is, most times when the ENS has to exercise its reflexes, you’re doomed for the porcelain throne. Here are some prime examples of how the ENS really works stuff out for you. When you encounter something you are allergic to for the first time, your mast cells in your stomach become sensitized to the antigens. The next time you dare eat that food, your gut’s brain remembers the antigens and immediately starts to cramp so you can eliminate the threat. While having diarrhea after you eat one of your favorite meals is not ideal, your gut is doing you a favor thanks to this recollection.
Next, often during bouts of stress, the stomach lining becomes curiously inflamed. This is the big brain telling your gut brain to protect itself against outside attack. You cramp, have diarrhea, and balloon out as a result. Finally, when we are nervous, serotonin circuits in the gut also work overtime, and all that excitement can also lead to a trip to the water closet. When the ENS is put to task, it tells your stomach to shut down or have the lodgers evacuate the premises. If your gut brain is on the fritz, it can even lead to uncomfortable and chronic conditions like colitis and irritable bowel syndrome.
So, how do we combat the critters playing capture the flag in your abdomen when they’re getting out of hand? The answer is irritatingly simple. Try to relax. Breath deeply. But see a therapist or doctor if your lepidopteral playmates are getting in the way of your pursuit of happiness.
All this information puts me at ease, leaving me butterfly-free. I always had a sneaking suspicion that it was my gut leading me down the right streets, to the right jobs, and the right kind of people my entire life, and, as it turns, I’ve been absolutely correct. Now that we know we have two “brains” and that’s why we have a gut instinct, what will science think of next? Perhaps a second heart? It would sure explain a lot of our dating history…
ExpliKate is a column running on Kate-book.com every other Monday at noon. It is written by the hyper-inquisitive Kate Hakala, who seeks to answer questions ranging from “What is kombucha?” to what you read above. Follow her on Twitter here.