(P09-029-24) Impact of Waxy Corn Starch and Inulin on Appetite-Affecting Gut Hormones

Objectives: The 'Western diet' is associated with noncommunicable diseases (NCDs), particularly obesity and diabetes. Diet composition can modulate the risk factors that lead to NCDs by influencing appetite-affecting gut hormone secretion. This study aimed to compare the acute effects of waxy corn starch and inulin on plasma levels of glucagon-like peptide-1 (GLP-1), peptide YY (PYY), gastric inhibitory polypeptide (GIP), and insulin. Our hypothesis was that inulin, being a highly fermentable fiber, will promote a higher and extended release of GLP-1 and PYY than the commonly observed hormone secretion in the small intestine.

Methods: A mouse study was conducted with two treatments: gelatinized (rapidly digesting) waxy corn starch (WCS) and inulin (INU), administered via oral gavage after a 16-h fast. Euthanasia was done at specific time points, and blood samples were collected for plasma analysis. GLP-1, PYY, GIP, and insulin levels were measured using a Multiplex Luminex assay. Statistical analysis employed one-way ANOVA with post-hoc Tukey tests.

Results: Inulin administration led to a substantial and prolonged increase of plasma GLP-1 that was sustained between 60 and 180 min. WCS showed a much lower and shorter GLP-1 response compared to INU. Plasma PYY showed modest peaks with inulin at 60 and 180 min. WCS did cause an increase in PYY, however it significantly increased GIP levels at 40 min. Insulin levels peaked at 60 min for waxy corn starch and after 2 hours for inulin.

Conclusions: Highest acute responses were with INU increasing plasma GLP-1 and WCS for plasma GIP. This comparative study of highly digestible and fermentable carbohydrates shows potential applications in designing starch-fiber-based food products for controlling appetite-affecting gut hormones, particularly GLP-1 and GIP.

Funding Sources: None