Interactions between the endocrine system and the gastrointestinal tract

It is well-known that the gastrointestinal tract (GIT) is not a mere site for the absorption of nutrients. Several peptides are synthesized and released from neurons and endocrine cells from the stomach and intestines, which makes the gut the largest endocrine organ in the body (1). These substances interact with different systems, and regulate a variety of processes, such as food intake, energy metabolism, and endocrine balance. The relationship between the GIT and the endocrine system is multidirectional, and hormones released by traditional endocrine organs can also regulate GIT function.