Gastroenterologist explains why you get butterflies in your stomach, says gut-brain connection is real!

Butterflies in the stomach come from the gut-brain connection during stress responses. Adrenaline diverts blood from digestive organs, causing this feeling.

We’ve all felt it - that fluttery, almost nervous sensation in the pit of the stomach before a big date, an important presentation, or even a thrilling adventure. We call it “butterflies in the stomach", don't we? But is it just a poetic phrase or is there actual science behind it? According to a gastroenterologist, this feeling isn’t just in your head. It’s your body’s fight-or-flight response at work, triggered by adrenaline and your gut-brain connection.

Know why you get a fluttering feeling in your stomach when you are stressed or anxious.(Adobe Stock)

What really causes the “butterflies in your stomach” feeling?

The phrase "butterflies in your stomach" refers to the actual, scientific interaction between your nerve system, intestines, and brain, Dr K.S. Somasekhar Rao, Senior Consultant Gastroenterologist, Yashoda Hospitals, Hyderabad, tells Health Shots.

"Your body's stress response causes the physical reaction known as 'butterflies in your stomach'. Your brain triggers the response when you're nervous, excited, or anxious, which causes stress chemicals like adrenaline to be released. Your stomach feels fluttery and uneasy as a result of the blood being diverted from your digestive organs to your muscles. These sensations may also be intensified by gut microorganisms and nerve impulses along the gut-brain axis," explains Dr Rao.

Is that why some people get even nausea or loose motions before exams, interviews, or travel?

"Classic anxiety causes include travel and tests, which set off the 'fight or flight' reaction. Often referred to as upset stomach or anxiety-induced loose movements, this triggers your body to release stress chemicals that increase motility, or the movement of the gut, and can occasionally cause nausea or even diarrhea. Acute stress can quickly result in gastrointestinal symptoms because of the close relationship between the gut and the brain," Dr Rao adds.

How stress affects gut health

While the fluttering feeling may be short-lived, stress and anxiety may directly affect gut health in the long term.

"Anxiety and stress can interfere with the digestive tract's regular operation. The digestive system is disrupted by stress hormones, which also have an impact on gut flora—the microbes that help with digestion—and lower the synthesis of antibodies," adds the doctor.

He shares that this may result in symptoms such as indigestion, stomach cramps, nausea, either constipation or diarrhea, and appetite changes.

Long-term stress may even damage the gut microbiota by upsetting the delicate balance between beneficial and harmful gut microorganisms.

"It even increases gut permeability, or cause 'leaky gut', which makes it possible for poisons or bacteria to enter the bloodstream and can exacerbate disease and inflammation. Stress also increases the chance of developing gastrointestinal disorders such as IBS, and hinder the body's ability to heal," says Dr Rao.