How do fiber-supplemented formulas affect antroduodenal motility during enteral nutrition? A comparative study between mixed and insoluble fibers

Background: Fiber supplementation during enteral nutrition has been recomme nded but the effect of soluble compared with insoluble tiber supplements on antroduodenal motility is unknown. Objective: The objective of this study was to compare antroduodenal motor p atterns in 8 healthy volunteers during and after gastric infusion of 3 diff erent diets: a fiber-free diet, an insoluble-fiber diet, and a mixed-fiber diet (50% soluble fiber and 50% insoluble fiber). Design: Manometric studies with the 3 different dirts (2100 kJ) were perfor med in random order. Antroduodenal motility was monitored continuously for 6 h by using a pneumohydraulic system to calculate the number. amplitude, a nd duration of the pressure waves: the area under the curve (AUC); and the percentage of time occupied by motor activity before, during, and after eac h type of infusion. Variations in antral areas were measured by ultrasonogr aphy. Results: The gastric motor response was significantly higher, whatever the diet, in the distal antral recording site than in the 2 more proximal sites . In the proximal but not the distal antrum, the number of waver, the AUC, and the percentage of time occupied by motor activity were higher (P < 0.04 ) with the mixed-fiber than with the insoluble-fiber diet. No significant d ifferences in variations of antral area were observed among the 3 diets. Ln the duodenum, motor variables were not significantly different among the 3 diets. Conclusions: A gastric infusion induced a greater motor response in the dis tal than in the proximal antrum. A mixed-fiber diet was associated with sig nificantly greater proximal antral motility than was an insoluble-fiber die t. There was no significant difference among the 3 formulas in duodenal mot or variables or in variations in antral area as measured by ultrasound.