Active and passive sugar absorption in pancreatic insufficiency

Area of Science:

• Gastroenterology
• Pediatric Medicine
• Biochemistry

Background:

• Intestinal permeability is a key factor in nutrient absorption.
• Cystic Fibrosis (CF) is a genetic disorder affecting multiple organs, including the pancreas and intestines.
• Previous studies suggested altered intestinal permeability in CF, but specific markers and comparisons with other pancreatic insufficiency disorders were needed.

Purpose of the Study:

• To investigate and compare intestinal permeability in cystic fibrosis (CF) and other pancreatic insufficiency (PI) disorders.
• To assess the urinary excretion of specific sugar probes (lactulose, mannitol, 3-O-methylglucose) as indicators of intestinal absorption.
• To differentiate the mucosal barrier abnormalities in CF from those in other forms of PI.

Main Methods:

• Oral administration of lactulose (5 g), mannitol (5 g), and 3-O-methylglucose (2 g) to subjects with CF, other PI disorders, and healthy controls.
• Measurement of urinary excretion of these sugar probes over a defined period.
• Statistical analysis to compare excretion levels and ratios between different subject groups.

Main Results:

• Mean lactulose excretion was 10-fold higher in CF and 2-fold higher in other PI disorders.
• Mean mannitol excretion was 1.6 times greater in CF but reduced in other PI disorders.
• The lactulose/mannitol excretion ratio was elevated in all PI types, indicating increased permeability.

Conclusions:

• CF exhibits a distinct pattern of increased intestinal absorption of lactulose and mannitol compared to other PI disorders.
• These findings support a specific abnormality in the intestinal mucosal barrier in CF.
• The differential absorption patterns highlight unique pathophysiological mechanisms in CF-related intestinal dysfunction.