Inulin propionate ester increases satiety and decreases appetite but does not affect gastric emptying in healthy humans

The short chain fatty acid (SCFA) propionate stimulates free fatty acid receptors 2 and 3 (FFAR2, FFAR3) found on enteroendocrine L-cells and increases the release of the anorectic gut hormones glucagon like-peptide-1(GLP-1) and peptide YY (PYY) in vitro (1). Dietary supplementation with an inulin propionate ester (propionate bound to inulin through an ester linkage) significantly increases the postprandial release of GLP-1 and PYY, whilst significantly decreasing food intake (unpublished findings). The time to 50% AUC excretion of 13C in breath (T1/2), a proxy for gastric emptying rate, was not significantly different between acute propionate ester and control trials (T1/2 180 min [95% CI, 163 to 198] control vs. 185 min [95% CI, 168 to 204] control, P = 0.51).These data demonstrate that acute ingestion of 10 g of inulin propionate ester increases satiety and reduces appetite in humans but this is not through an effect on gastric emptying, and it is most likely to be a centrally mediated action of GLP-1 and PYY. 1.