It turns out those gut feelings or pits in your stomach may actually come from your second brain.

According to a CBS Los Angeles report, scientists from Australia discovered that human beings have a second brain and it is located in the butt. The gastrointestinal tract houses millions of neurons. Called the enteric nervous system (ENS), it controls the muscle movement in the colon independently of the central nervous system, according to a Uproxx report. The enteric nervous system lines the digestive tract with a mesh-like neuron network.

“These findings identify a previously unknown pattern of neuronal activity in the peripheral nervous system. Until this new study, no one had any idea exactly how large populations of neurons in the ENS lead to contraction of the intestine,” Prof. Nick Spencer from Flinders University in Australia said in a press release.

These neurons coordinate to fire together and help propel waste out of the body. Although scientists discovered the second brain in mice, they believe that they exist in other mammals, including human beings.

Interestingly, this so-called “second brain” is actually the first brain and very likely developed before the central nervous system. The ultimate goal of the research is to help treat things like constipation and irritable bowel syndrome, once scientists discover precisely how everything works. Additionally, there is a possibility that learning the way this second brain works could help lead to new treatments for depression and anxiety.

Your Body Has A "Second Brain" And It's Even Cooler Than We Thoughthttps://t.co/IJCoL6Awju pic.twitter.com/5Wj833orRH — IFLScience (@IFLScience) May 31, 2018

While the gut-brain doesn’t think the same way the brain in your head thinks, it could end up affecting your mood anyway. A report in Psychology Today pointed out that mounting evidence claims that gut health can change mood. In fact, it may be as or more influential in your moods than the brain in your head, which makes sense.

“One of the great mysteries of the gastrointestinal tract is how such large populations of enteric neurons (that lie within the gut wall) actually fire action potentials to generate contractions of the smooth muscle cells, enabling propulsion of colonic content,” Spencer said.

Who knew those butterflies in your stomach actually came from an entirely separate brain? Although the gut-brain communicates mostly with the bacterial biome in the gut and sends messages to the central nervous system instead of receiving lots of signals from it, it can profoundly affect the quality of life. Scientists are just now figuring out how all of it works together to run a human body effectively.