What is the Origin of Gut-Brain Axis Hormones?

The concept of the Gut-Brain Axis evolved from the initial recognition of the enteric nervous system, the "second brain," to a more integrated view of hormonal and neural signaling. The discovery of various gut peptides with central effects, particularly on feeding behavior, cemented the hormonal component of this axis. This framework acknowledges the gut as a primary endocrine organ with a direct influence on behavior and metabolism.

What is the Mechanism of Gut-Brain Axis Hormones?

Upon food ingestion, enteroendocrine cells release a cocktail of hormones into the bloodstream in a pattern dictated by the type and quantity of nutrients consumed. These hormones act on specific receptors in the brain, either directly crossing the blood-brain barrier or, more commonly, activating vagal afferent nerves that relay the signal to the brainstem. For instance, ghrelin stimulates hunger pathways, while GLP-1 and PYY stimulate anorexigenic neurons in the hypothalamus, collectively fine-tuning the homeostatic control of energy balance.

Gut-Brain Axis Hormones ∞ Area

Gut-Brain Axis Hormones

Meaning

Gut-Brain Axis Hormones are the bioactive peptides secreted by enteroendocrine cells lining the gastrointestinal tract that serve as chemical messengers to the central nervous system. These hormones facilitate the rapid, bi-directional communication between the gut and the brain, which is essential for coordinating digestion, nutrient absorption, and the regulation of appetite and satiety. Key examples include ghrelin, cholecystokinin (CCK), Glucagon-like Peptide-1 (GLP-1), and Peptide YY (PYY). Their collective signaling provides the brain with real-time information about nutrient status and caloric load.