Most of us have experienced the fluttery feeling in our stomachs, known as “butterflies,” before we go up on stage or on a first date. This thought and emotion is actually dictated by our digestive system, which actually does more than just digest food. The gastrointestinal (GI) tract acts as a “second brain” with a network of neurons that influence behavior, mood, and stress levels, according to BrainCraft’s video: “The Strange Location of Your Second Brain.”

The trillions of bacteria in our gut have more of a relationship with our brain than we would like to think. BrainCraft host Vanessa Hill spills the guts on the surprising ways our digestive system exerts control over our taste buds and mood. For example, the phrase “grumpy hungry” is used to explain the overwhelming irritability that overcomes us when we’ve gone too long without food. This is because our gut — the second brain — contains a network of neurons that allow it to keep in close contact with the brain in the skull via vagus nerves, which influences our emotional state.

The microbiota in our gut are influenced by what we eat, our genes, age, stress levels, and even where we live. Certain bacteria can thrive depending on what we eat, and they can communicate with our central nervous system and behavior.

A 2011 study published in the journal Communicative & Integrative Biology found prebiotics — little fiber compounds that stimulate the growth of gut bacteria, have an anti-anxiety effect on people. The participants who took prebiotics every day had lower levels of cortisol — the stress hormone — and were more likely to pay attention to positive information compared to the placebo group after three weeks.

It seems the function of the gastrointestinal tract goes far beyond just processing what we eat. Although our second brain, the enteric nervous system isn’t capable of conscious thought, it can influence our behavior, mood, and stress levels.

Remember, it’s more than just a gut feeling.