A noninvasive stable-isotope method to simultaneously assess pancreatic exocrine function and small bowel absorption

Area of Science:

• Gastroenterology
• Diagnostic Medicine
• Biochemistry

Background:

• Assessing digestive function is crucial for diagnosing conditions like maldigestion and malabsorption.
• Current diagnostic methods can be invasive or time-consuming.
• A rapid, noninvasive test is needed to differentiate between pancreatic insufficiency and small bowel dysfunction.

Purpose of the Study:

• To evaluate a novel, single-step, noninvasive stable isotope method for assessing digestive function.
• To determine if this method can differentiate normal individuals from those with maldigestion or malabsorption.
• To assess the test's ability to distinguish between maldigestion and malabsorption.

Main Methods:

• The PABAX test was administered to 40 healthy volunteers, 18 adults with cystic fibrosis (representing maldigestion), and 4 adults with celiac sprue (representing malabsorption).
• Subjects ingested a liquid meal containing bentiromide, [13C6]PABA, and xylose.
• Serum samples were collected after 1 hour and analyzed using gas chromatography-mass spectrometry with stable isotope dilution methods.

Main Results:

• The PABAX test successfully differentiated between normal subjects, those with maldigestion (cystic fibrosis), and those with malabsorption (celiac sprue).
• Subjects with cystic fibrosis demonstrated abnormal pancreatic function, consistent with maldigestion.
• Subjects with celiac sprue showed abnormal small bowel absorption, consistent with malabsorption.

Conclusions:

• The one-hour PABAX test is a reliable and noninvasive method for assessing digestive function.
• It effectively separates normal individuals from those with maldigestion or malabsorption.
• The test can also distinguish between maldigestion and malabsorption, aiding in differential diagnosis.