“Butterflies in the stomach” is that fluttering, nervous feeling you might have before a job interview, giving a speech, or at the beginning of a romance.
It’s a cute description for part of the fight-or-flight response that can be triggered if you’re excited or scared.
But what exactly are these butterflies? Why can we feel them in our stomach? And can we do anything about them?
Threat alert
These “butterflies” – along with increased heart rate, sweating and a “jumpy” feeling – are part of your survival mode. That’s when the part of your body known as the autonomic nervous system gets involved.
When you sense a potential threat—whether physical or social, real or imagined—the information is sent to the amygdala region of the brain for emotional processing. If the amygdala senses danger, it sends a danger signal to another part of the brain, the hypothalamus, which starts a cascade of changes to help the body prepare.
The adrenal glands above each kidney send the chemical messengers adrenaline and noradrenaline into the bloodstream, activating receptors in the blood vessels, muscles, lungs, and heart. Heart rate and blood flow increase, blood sugar levels increase, and muscles prepare for strength (fight) and speed (flight).
Digestion can wait
Digestion can wait until you escape the tiger (or the job interview). So, while all of this is happening, your body reduces blood flow to your stomach and intestines and stops the constant digestive pulse of the gut (known as peristalsis).
The autonomic nervous system also stimulates the stomach (and other organs) via the vagus nerve, the nerve that runs from the brainstem parallel to the vertebra, sending signals back and forth between the brain, heart, and digestive system.
There is no direct evidence to explain which part of this cascade leads to the sensation of butterflies. But it’s likely related to how the autonomic nervous system stops the gut from pulsating, and the vagus nerve sends signals about this change up to the brain.
The feeling of butterflies is technically a “gut feeling,” but it’s just one of the gut signals that communicates back and forth with the brain, along the so-called gut-brain axis. This is the communication pathway system that shares signals about stress and mood, as well as digestion and appetite.
Read more: The vagus nerves help us rest, digest and restore. Can you really reset them to feel better?
Could our gut microbes be involved?
Gut microbes are a part of this complex communication system. It is tempting to think that the action of microbes it’s what causes the butterfly sensation, but it’s unlikely to be that simple.
Germs, then, are microscopic, and so are the actions and changes that take place from moment to moment. There should be coordinated microbial movements en masse to explain the sudden onset of this anxious feeling, like a flock of geese in formation, and there is no evidence that germs work that way.
However the germs have has been shown to influence the stress response, with more research up to here was conducted in mice.
In humans, there is moderate evidence of a small study linking microbes to the stress response. This showed that following a microbiome-targeted diet—a prebiotic fiber-rich diet designed to feed fiber-loving members of the gut microbiome—could reduce perceived stress compared to a standard healthy diet.
But this single study isn’t enough on its own to definitively tell us exactly how this would work or if this diet would work for everyone.
What can I do about butterflies?
How can we manage these nervous physical feelings?
The first thing to consider is whether you need to manage them at all. If it’s a high stress situation in a blue moon situation, you may be able to just say “hello” to those butterflies and get on with your day until your body’s rest and assimilation response kicks in to bring your body back to its original state.
Self-guided techniques can also help.
Paying close attention to your fluttering butterflies can help you notice subtle cues in your body about how you’re feeling before you get overwhelmed.
By then taking whatever actions are under your control – from noticing your breathing to taking the next steps toward the dive you fear most – you show your brain that you can overcome the threat.
Sometimes it can be worth turning to the cause of the stressful situation itself. Could some extra interview preparation (for example) help you feel more in control? Or is it more about reminding yourself how overcoming these situations aligns with your values? Sometimes a change in perspective makes all the difference.
If stress is more frequent or gets in the way of doing the things you care about, try this documented method of “breaking down the fight”.
This means sitting, rather than trying to fight or resist, with anxiety and any other troublesome feelings. You can even thank your mind (and your body) for trying to help you and for reminding you of what is important to you.
Or you can seek help from a psychologist to ease anxiety (as well as other common mental health struggles) using an evidence-based approach commonly known as ACT or acceptance and commitment therapy. That entails skill development for a meaningful life despite difficult feelings and situations. It helps people work with, rather than control, difficult thoughts and feelings.
In addition to her academic role, Amy Loughman provides therapies including ACT (Acceptance and Commitment Therapy) as a psychologist in private practice.
