Abnormal intestinal permeability to sugars in villous atrophy

Area of Science:

• Gastroenterology
• Digestive Physiology
• Clinical Nutrition

Background:

• Intestinal permeability is crucial for nutrient absorption and barrier function.
• Villous atrophy, a condition affecting the small intestine, can impair these functions.
• Assessing permeability helps understand disease mechanisms and guide treatment.

Purpose of the Study:

• To compare intestinal permeability to a monosaccharide (L-rhamnose) and a disaccharide (lactulose) in patients with villous atrophy versus healthy controls.
• To investigate the relationship between sugar excretion patterns and the integrity of the small bowel mucosa.

Main Methods:

• Simultaneous oral administration of L-rhamnose and lactulose in a hypertonic solution.
• Measurement of urinary excretion of both sugars via quantitative thin-layer or paper chromatography.
• Comparison of results between 13 patients with untreated villous atrophy and 12 healthy volunteers.

Main Results:

• Urinary L-rhamnose excretion was significantly decreased (40%) in patients with villous atrophy.
• Urinary lactulose excretion was significantly increased (345%) in these patients.
• The lactulose/L-rhamnose urinary excretion ratio was sevenfold higher in patients, with no overlap between groups.

Conclusions:

• Reduced L-rhamnose excretion suggests a decreased absorptive surface area in villous atrophy.
• Increased lactulose excretion indicates increased mucosal permeability or 'leakiness' in the abnormal small bowel.
• The lactulose/L-rhamnose ratio serves as a sensitive marker for differentiating villous atrophy from healthy states.