There have been some scientific approaches recently. I just read an article in GEO (much like National Geographic Explorer but with lots of scientific topics) about what they called "stomach brain".
The title was "The second brain". I couldn't find an English version so I try to sum it up.
In every culture the stomach is viewed or said to be the region where our emotions, our health, intuition etc are located. Our bowels are surrounded by more than 100 million neurons, more than in the whole spinal cord. This second brain works like the one in our heads, using the same neurotransmitter, cell types and communication units. It has a big influence on our psyche. It is some kind of survival guaranty for body and soul and produces lots of chemicals that control our emotions like serotonine, dopamine and benzodiazepines.
The diversion in the two brains is during the fetal development-simply because we can't store everything in our heads. A newborn child has to be able to drink and digest right from his birth so it is better to avoid long wires and to give this survival abilities some independence.
In adults psyche and digestive system are very closely linked. E.g the digestive organs are often the first to get sick, even without obvious medical reasons when someone gets under pressure. Our intestines are also the first line of combat against intruders, organize the first answer of the immune system, and keepn our symbionts under control. It has more than 70% of all immune cells of our body.
Intestines can kept alive and reactive in nutrition liquids without any connections to brain and spinal chord-one more hint towards a brain of its own.
This brain has quite a lot of power: it controlls other organs, a whole set of reactions of its own and can process data of its own sensors. It has everything an integrative nervous system needs including a capable memory.
Our "stomach brain" guides us through our decisions by feelings stored in chemical codes and based on our experience of life. Intuition and intuitive decisions are the results of two brains working closely together. Our decisions are not only based on intellectual calculations but also on a giant catalogue of body feelings and emotional reactions of the "gut memory".
Among the scientists cited are
Michael Gershon, Columbia University, New York
Emeran Mayer, University of California, L.A.
so maybe you can look up the original papers.
Hope this helps,