Postprandial effects of polydextrose on satiety hormone responses and subjective feelings of appetite in obese participants

Abstract

Background: Dietary fibers are associated with enhanced satiety. However, the mechanism of different dietary fibers contributing to satiety-related gastrointestinal (GI) peptide release, especially in an obese population, is still poorly understood. Polydextrose (PDX), a water-soluble glucose polymer, has demonstrated its ability to reduce energy intake at a subsequent meal, but its mechanism of action requires further research. Also, there is limited evidence on its capacity to regulate subjective feelings of appetite. This study examines the effects of PDX on postprandial secretion of satiety-related GI peptides, short chain fatty acids (SCFAs), lactic acid, and subjective appetite ratings in obese participants.

Methods: 18 non-diabetic, obese participants (42.0 y, 33.6 kg/m2) consumed a high-fat meal (4293 kJ, 36% from fat) with or without PDX (15 g) in an acute, multicenter, randomized, double-blind, placebo-controlled and crossover trial. Postprandial plasma concentrations of satiety-related peptides, namely ghrelin, cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY), as well as SCFAs and lactic acid were assessed. GI peptide, SCFA and lactate concentrations were then modeled using a linear mixed-effects model.The subjective feelings of hunger, satisfaction, and desire to eat were evaluated using visual analogue scales (VAS), which were analyzed as incremental areas under the curve (iAUC) during the satiation and satiety periods.

Results: We found that PDX supplementation increased plasma GLP-1 levels more than the placebo treatment (P = 0.02). In the whole group, GLP-1 concentrations found in participants older than 40 years old were significantly lower (P = 0.01) as compared to those aged 40 years or less. There were no statistically significant differences in postprandial ghrelin, CCK, or PYY responses. The lactic acid concentrations were significantly (P = 0.01) decreased in the PDX group, while no significant changes in SCFAs were found. PDX reduced iAUC for hunger by 40% (P = 0.03) and marginally increased satisfaction by 22.5% (P = 0.08) during the post-meal satiety period.

Conclusion: Polydextrose increased the postprandial secretion of the satiety hormone GLP-1 and reduced hunger after a high-fat meal. PDX also reduced the elevated postprandial lactic acid levels in plasma. Therefore, PDX may offer an additional means to regulate inter-meal satiety and improve postprandial metabolism in obese participants.

Figure 1

Changes in the concentrations of gastrointestinal peptides in plasma. Changes in ghrelin (A), CCK (B), GLP-1 (C) and PYY (D) after the ingestion of the study meal supplemented with the placebo or polydextrose (PDX) presented as box plots and analyzed by a linear mixed-effects model. The GLP-1 response was increased significantly (P = 0.02) with PDX when compared to the placebo. The concentrations of ghrelin, CCK, and PYY were not significantly altered by the treatments. The median of all values at the first time point (0 min) has been subtracted from the parameter values presented in the box plots. CCK, cholecystokinin; GLP-1, glucagon-like peptide 1; PYY, peptide YY.

Figure 2

Changes in the concentrations of acetic acid and lactic acid in plasma. Changes in postprandial acetic acid (A) and lactic acid (B) in plasma after the ingestion of the study meal supplemented with the placebo or polydextrose (PDX) presented as box plots and analyzed by a linear mixed-effects model. The decrease (11.9%) in the concentration of lactic acid after the consumption of PDX was statistically significant when compared to the placebo (P = 0.01). The curves are adjusted to zero by subtracting the median of all values at the first time point (0 min) from the parameter values presented in the box plots.

Figure 3

VAS results for the subjective feelings of hunger. A) The VAS curves of the placebo and polydextrose (PDX) adjusted to zero intensity at 40 min (after the meal). B) The incremental areas under the curve (iAUC) for the placebo and PDX during the satiation period, i.e. between 0 min and 40 min (1176 ± 135 min.mm and 794 ± 179 min.mm, respectively, P > 0.05). C) The iAUC for the placebo and PDX during the satiety period, i.e. between 40 min and 280 min, differed statistically (5487 ± 700 min.mm and 3272 ± 923 min.mm, respectively, P < 0.05*). VAS, visual analogue scales.

Figure 4

VAS results for the subjective feelings of satisfaction. A) The VAS curves of the placebo and polydextrose (PDX) adjusted to zero intensity at 40 min (after the meal). B) The incremental areas under the curve (iAUC) for the placebo and PDX during the satiation period, i.e. between 0 min and 40 min (-1409 ± 95 min.mm and -1144 ± 143 min.mm, respectively, P > 0.05). C) The iAUC for the placebo and PDX during the satiety period, i.e. between 40 min and 280 min (-6944 ± 1095 min.mm and -5385 ± 735 min.mm, respectively, P = 0.08). VAS, visual analogue scales.

Figure 5

VAS results for the subjective feelings of desire to eat. A) The VAS curves of the placebo and polydextrose (PDX) adjusted to zero intensity at 40 min (after the meal). B) The incremental areas under the curve (iAUC) for the placebo and PDX during the satiation period, i.e. between 0 min and 40 min (1218 ± 134 min.mm and 1034 ± 153 min.mm, respectively, P > 0.05). C) The iAUC for the placebo and PDX during the satiety period, i.e. between 40 min and 280 min (6167 ± 1052 min.mm and 4939 ± 814 min.mm, respectively, P > 0.05). VAS, visual analogue scales.