The gut-brain axis mechanism of appetite regulation
Feeding is a fundamental requirement for the survival of host and gut microbiota.
The researchers discovered how gut microbiota influences feeding behavior through kynurenic acid (KYNA).
During fasting, increased KYNA levels stimulate food intake by inhibiting vagal afferent nerves and activating AgRP neurons, demonstrating a mechanism of microbiota-mediated appetite regulation.
KYNA effects were abolished by vagotomy, or modulating intestinal vagal afferent nerve signals.
The authors support the model in which KYNA acts through the GPR35 receptor to inhibit vagal afferent signaling and subsequently activate ARCAgRP neurons, which leads to increased food intake.
https://www.cell.com/cell-reports/fulltext/S2211-1247(25)00430-9
https://sciencemission.com/gut-brain-axis-mechanism-of-normal-appetite
