Our guts operate on a quite separate nervous system. Learning more will help control gastrointestinal diseases Our huge gastrointestinal tracts operate their own nervous system, using neurons that follow different principles from those of brain neurons, according to recent findings: Our approximately seven-meter long gastrointestinal (GI) tract has its own functionally distinct neurons. Since this enteric nervous system (ENS) operates autonomously, it is sometimes referred to as the “second” or “abdominal” brain. While the ENS controls muscle movement (peristalsis) in the gut and its fluid balance and blood flow, it also communicates with the immune system and microbiome. Karolinska Institutet, “New fundamental knowledge of the ‘abdominal brain'” at Medical Xpress (December 7, 2020) Paper.