Gut-brain axis.
OBJECTIVE
To summarize recent studies on the regulation and the functions of the gut-brain axis.


RESULTS
Visual cues of food and food intake interact with the gut-brain axis at the level of the hypothalamus. However, the hypothalamic response to glucose intake is considerably altered in patients with type 2 diabetes mellitus, indicating involvement of the hypothalamus in the pathophysiology of this disease in humans. A large number of studies have documented the functions of gut peptides with respect to the regulation of satiety. Gut peptides are involved in the regulation of insulin secretion and sensitivity. Recent data indicate that peptide YY is a gut hormone that also modulates bone metabolism. Increasing evidence is obtained on the role of afferent gastrointestinal nerves, especially the vagal nerve, in the modulation of the functions of the gut-brain axis.


CONCLUSIONS
The gut-brain axis is involved in a multitude of physiological processes including satiety, food intake, regulation of glucose and fat metabolism, insulin secretion and sensitivity and bone metabolism. It is likely, that more aspects of this system will be found the near future.
Romijn
Johannes A
JA
Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden, The Netherlands. j.a.romijn@lumc.nl
Corssmit
Eleonora P
EP
Havekes
Louis M
LM
Pijl
Hanno
H
D001069:Appetite Regulation / Q000502:physiology*; D004734:Energy Metabolism; D017615:Enteric Nervous System / Q000502:physiology; D005768:Gastrointestinal Hormones / Q000502:physiology; D041981:Gastrointestinal Tract / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007031:Hypothalamus / Q000502:physiology*; D009490:Neurosecretory Systems / Q000502:physiology*; D036361:Peptide Hormones / Q000502:physiology
D005768:Gastrointestinal Hormones; D036361:Peptide Hormones; D005947:Glucose