1. Introduction
satiety, meal on satiety, blood glucose, postprandial blood glucose, fullness
EVENT, TYPE 2 DIABETES MELLITUS, CHRONIC DISEASES
Background: Dietary fiber plays a potential role in regulating energy intake and stabilizing postprandial blood glucose levels. Soluble dietary fiber has become an important entry point for nutritional research on the regulation of satiety. Methods: this was a double-blind, randomized cross-over trial enrolling 12 healthy subjects to compare the effects of RPG (R+PolyGly) dietary fiber products (bread, powder, and capsule) and pectin administered with a standard meal on satiety, blood glucose, and serum insulin level. Results: Adding 3.8% RPG dietary fiber to bread significantly increased the volume, water content, hardness, and chewiness of bread compared to 3.8% pectin bread and white bread and significantly improved the sensory quality of bread. RPG bread had better appetite suppression effects at some time points than the other two groups and the best postprandial blood glucose lowering effects among the three groups. Administration of RPG capsules containing 5.6 g of RPG dietary fiber with meals improved satiety and reduced hunger compared to 6 g of RPG powder and 6 g of pectin, which had the greatest effect on suppressing appetite and reducing prospective food consumption. The peak level of serum glucagon-like peptide-1 (GLP-1) in the RPG capsule group (578.17 ± 19.93 pg/mL) was significantly higher than that in other groups at 0 min and 30 min after eating. RPG powder had the best effect in reducing postprandial blood glucose and increasing serum insulin levels; the total area under the curve (AUC) of serum insulin with RPG powder was higher than other groups (5960 ± 252.46 μU min/mL). Conclusion: RPG dietary fiber products can improve the sensory properties of food, reduce postprandial blood glucose, and enhance satiety, especially in capsule and powder forms. Further research on the physiological effects of RPG dietary fiber is required to facilitate its use as a functional ingredient in food products.Satiety refers to the feeling of fullness and satisfaction that occurs in response to an eating event and ends when the signals of food processing and absorption subside, inducing a feeling of hunger [Dietary fiber is closely linked to satiety. Consumption of soluble, viscous, gelatinous, and more fermentable fiber from fruits and certain vegetables has been shown to increase satiety and reduce hunger [Many different types of fiber have been reported to provide satiety benefits and lower blood glucose levels; however, there is limited research on the mechanisms of these responses and the extent of their health benefits [In our previous studies, high sugar and high acid were identified as necessary conditions for high methoxyl pectin to form a gel, and this phenomenon was due to the formation of hydrogen bonds between pectin molecules and its hydrophobic force. In contrast, the gel formation mechanism of low-methoxyl pectin (LMP) involved calcium and other divalent metals. Calcium pectate (CaP), a mixture of LMP and low-valence ions like calcium, has better gelation properties than LMP alone due to the egg-box-like model [Therefore, we conducted a double-blind, randomized cross-over trial to investigate the effect of RPG dietary fiber (a complex of LMP and calcium) products (bread, powder, and capsule) on human satiety and to explore the effect of RPG dietary fiber in lowering blood glucose and insulin response. Our findings may reveal the potential application of RPG dietary fiber products in the prevention and treatment of chronic diseases such as type 2 diabetes mellitus.