Dietary lactitol fermentation increases circulating peptide YY and glucagon-like peptide-1 in rats and humans.
OBJECTIVE
Recently peptide YY (PYY) has attracted interest as a possible regulator of food intake. Release of PYY by nutrients in the distal small intestine is thought to contribute to the so-called ileal brake by inhibiting motility and secretion in the foregut. Our objective was to establish whether plasma concentrations of the gut peptides PYY and glucagon-like peptide-1 in rats and humans change in response to intake of a non-absorbable but fermentable carbohydrate.


METHODS
The acute response was determined in rats by killing animals 0, 5, 10, and 24 h after a single meal with or without lactitol (100 g/kg of semisynthetic diet) and measuring PYY and glucan-like peptide-1 concentrations in plasma. Food intake, body mass, and plasma peptide levels were also determined in rats fed the same diet for 10 d. Healthy human volunteers consumed lactitol or sucrose as a fruit-flavored drink. Breath hydrogen levels were measured at 45-min intervals over the next 7.5 h and plasma peptide concentrations were assessed after 0 and 5 h. Volunteers were also asked to complete a questionnaire to record satiety and well-being.


RESULTS
Ingestion of lactitol significantly increased the acute postprandial PYY response in rats, and prolonged consumption decreased weight gain in growing rats. In humans given a single dose of lactitol, the effects on PYY were much less marked but the postprandial decrease in circulating concentrations of PYY was attenuated. There was no effect on plasma glucan-like peptide-1.


CONCLUSIONS
Our observations are consistent with a role for fermentation products in the release of gastrointestinal peptides in the rat and, to a lesser extent, in humans.
Gee
Jennifer M
JM
Nutrition Division, Institute of Food Research, Norwich, United Kingdom.
Johnson
Ian T
IT
D000704:Analysis of Variance; D000818:Animals; D001944:Breath Tests; D005285:Fermentation; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D006859:Hydrogen / Q000032:analysis; D008297:Male; D019894:Peptide YY / Q000097:blood*; D019518:Postprandial Period; D051381:Rats; D017208:Rats, Wistar; D012528:Satiety Response / Q000187:drug effects / Q000502:physiology; D013402:Sugar Alcohols / Q000008:administration & dosage / Q000378:metabolism*; D015430:Weight Gain
D013402:Sugar Alcohols; D019894:Peptide YY; D006859:Hydrogen; D052216:Glucagon-Like Peptide 1; C014635:lactitol