https://medicalxpress.com/news/2018-09-gut-hardwired-hormonal.html People have debated whether we have a sixth sense or not for a long time, and it looks like science is finally poised to recognize one existing in our stomach. Other research has indicated that the microflora in our guts acts as a sort of primitive computer that helps to determine what we eat and avoid, very much like a colony animal. My own belief is we should have four rudimentary brains, and the stomach is merely the most obvious and important to study for the thermodynamics of the overall system. Note that our stomach, skin, eyes, and other senses all have the most intimate contact with the outside world and all of our senses use the same actions to both detect and process what they are detecting. Doing it that way makes them simultaneously outrageously fast and efficient and makes the system scalable.