Short-chain fatty acid absorption in patients with cystic fibrosis.

Patients with cystic fibrosis (CF) often exhibit malabsorption despite the use of supplemental pancreatic enzymes. Unabsorbed carbohydrates and amino acids can serve as substrates for large intestine anaerobic fermentation, thus increasing excretion of short-chain fatty acids (SCFA) in the feces. Nine patients with CF on regular pancreatic enzyme supplementations in the age range of 5-11 years and one older patient were studied. Three-day stool samples were collected, as were 72-h food records. Stools were analyzed for gross energy, total nitrogen, fat content, and SCFA concentration. A significant difference was found between CF and normal controls in total caloric excretion due to fat malabsorption. No significant difference was found between CF and normal controls in protein or SCFA excretion. Fat excretion as percentage of fat intake was significantly increased in CF patients: 35.3 +/- 10.2% versus 8.0 +/- 3.0%, respectively. These data suggest that carbohydrate supplementation could be more widely used to increase caloric intake in CF patients without causing secondary osmotic diarrhea.