Gut feelings: the emerging biology of gut–brain communication

The importance of interactions between the brain and the digestive system in health and disease has been recognized for centuries. Mayer reviews the neuroanatomy and signalling mechanisms that underlie this bidirectional communication system in health and disease, as well as possible consequences for higher-level executive functions and emotional states. The concept that the gut and the brain are closely connected, and that this interaction plays an important part not only in gastrointestinal function but also in certain feeling states and in intuitive decision making, is deeply rooted in our language. Recent neurobiological insights into this gut–brain crosstalk have revealed a complex, bidirectional communication system that not only ensures the proper maintenance of gastrointestinal homeostasis and digestion but is likely to have multiple effects on affect, motivation and higher cognitive functions, including intuitive decision making. Moreover, disturbances of this system have been implicated in a wide range of disorders, including functional and inflammatory gastrointestinal disorders, obesity and eating disorders.