The gut is often called "the second brain" because the 500 million gut neurons that form the enteric nervous system are capable of autonomous function.[1] [1]

The gut is often called "the second brain" because the 500 million gut neurons that form the enteric nervous system are capable of autonomous function.[1] [1] https://en.wikipedia.org/wiki/Enteric_nervous_system https://en.wikipedia.org/wiki/Enteric_nervous_system