Impacto de diferentes fibras dietéticas no esvaziamento gástrico e trânsito do intestino delgado de voluntários saudáveis: estudo clínico randomizado.

Abstract

Dietary fibers are undigested compounds from enzymes of the gastrointestinal tract that reaches the colon intact. Several functions are attributed to dietary fibers, highlighting the impact on gastrointestinal motility. However, studies aiming to evaluate this effect are scarce and with controversial results. Thus, this study aims to evaluate the impact of partially hydrolyzed guar gum and fructooligosaccharide on the percentage of gastric emptying and on the percentage of transited material through the small intestine. This is a randomized, placebo controlled, double masked crossover study. Healthy volunteers of both sexes with ≥ 18 years of age without diagnoses of diseases that alter gastrointestinal motility were included. On three separate occasions, with a washout of at least seven days, after a fasting of 8 hours, the volunteers ingested a standardized test meal for the analysis of gastric emptying of solids, consisting of: two slices of bread, omelet made with two egg whites and 10 grams of strawberry jam. One milicurie of 99m-technetium-colloidal tin and 20 grams of one of the modules to be studied were incorporated into the omelet: (i) fructooligosaccharide, (ii) partially hydrolyzed guar gum or (iii) maltodextrin (placebo). To obtain the percentage of gastric emptying and the percentage of material transited through the small intestine, abdominal imaging scintigraphy was used immediately after ingestion of the test meal and every hour during the 6-hour period. Blood samples were collected using dipeptidyl peptidase inhibitor tubes at fasting, 1 and 3 hours after ingestion of each test meal for gastrointestinal hormone analysis: Glucagon-like peptide-1, gastric inhibitor peptide and pancreatic polypeptide. The sensations of hunger, satiety and desire to eat were assessed by 100 mm visual analog scales applied in the fasting and after the test meal ingestion at the following times: 30 minutes and every hour between 1-6 hours. Statistical analyzes were performed using the Statistical Package for Social Sciences program (version 25) and p values ≤ 0.05 were considered statistically significant. Twenty-four healthy volunteers were included, with average age of 25.00 ± 3.90 years. Results show that ingestion of fructooligosaccharide or partially hydrolyzed guar gum did not influence the percentage of gastric emptying when compared to maltodextrin (p> 0.05). For the percentage of transited material through the small intestine in 3 hours, lower values (p ≤ 0.05) were observed for meals containing partially hydrolyzed guar gum and fructooligosaccharide (24.26 ± 13.76% and 28.57 ± 15.56%, respectively) in relation to maltodextrin (41.20 ± 15.41%). Significant elevation of glucagon-like peptide-1 was noted at 1 and 3 hours for fructooligosaccharide and partially hydrolyzed guar gum, respectively (p ≤ 0.05). For sensations of hunger, satiety and desire to eat, no significant differences were observed between the groups (p> 0.05). It was concluded that the dietary fibers used in the study increased the concentrations of glucagon-like peptide-1 hormone and slowed the small intestine transit reducing the percentage of transited material through the small intestine.