Physiological effects of enteral and parenteral feeding on pancreaticobiliary secretion in humans

Abstract

In the nutritional management of digestive disorders, it is important to know the relative secretory and metabolic responses to enteral and parenteral feeding. Twenty-seven healthy volunteers were studied while receiving either oral drinks or duodenal infusions of a complex formula diet, duodenal or intravenous infusions of elemental (protein as free amino acids, low fat) formulae, or saline. Pancreaticobiliary secretory responses were measured by nasoduodenal polyethylene glycol perfusion and aspiration, while monitoring blood hormone and nutrient levels. Diets were matched for protein (1.5 g x kg(-1) x d(-1)) and energy (40 kcal x kg(-1) x d(-1)). Compared with placebo, all oroenteral diets stimulated amylase, lipase, trypsin, and bile acid secretion and increased plasma concentrations of gastrin and cholecystokinin, whereas intravenous feeding did not. The complex formula produced a similar response whether given as drinks or duodenal infusions. Changing the duodenal formula to elemental reduced enzyme secretion by 50%, independently of CCK. Higher increases in plasma insulin, glucose, and amino acids were noted with intravenous feeding. Delivering food directly to the intestine by a feeding tube does not reduce pancreaticobiliary secretion. Enteral "elemental" formulae diminish, but only intravenous feeding avoids pancreatic stimulation. Intravenous administration impairs metabolic clearance.

Immediate oral feeding in patients with mild acute pancreatitis is safe and may accelerate recovery—A randomized clinical study

“…The only form of feeding that avoids stimulation of pancreatic secretion is intravenous feeding and jejunal feeding with a mid-distal placement of the tube. [17][18][19] Although immediate oral feeding compared to fasting has not previously been investigated, several randomized clinical trials have been carried out that favours enteral feeding to parenteral feeding. 20 The tolerance for gastric feeding, might be explained by the hypothesis that pancreas is in a state of unresponsiveness during an attack of acute pancreatitis.…”

Practice Guidelines in Acute Pancreatitis

“…A major concern relates to stimulation of pancreatic secretion when feeding is introduced into the stomach or duodenum. There is evidence that intraduodenal feedings increase pancreatic enzyme synthesis (182) and secretion (183). The result may be an exacerbation of abdominal pain associated with a greater serum amylase (182).…”

Extending in vitro digestion models to specific human populations: Perspectives, practical tools and bio-relevant information

“…The brush border enzymes include glycosidases (dextrinase, glucoamylase), peptidases (aminopeptidase, carboxypeptidase, dipeptidase) and phophatases (Holmes & Lobley, 1989). Altogether, the functions of the auxiliary organs in the fasted and fed conditions are stimuli responsive and are mainly affected by the (Armand et al, 1996;O'Keefe et al, 2003). Further, there are inconsistencies in data on the pancreatic enzyme activities due to the differences in biochemical assays used to characterize these secretions: ranging from use of natural or synthetic standards such as casein, BAEE, TAME, BTEE, measurement modes (potentiometric, colorimetric, spectrophotometric), calculation methods up to the definition of enzymatic units of activity.…”