Faecal bile acid and dietary residue excretion in cystic fibrosis: age group variations.

BACKGROUND

Earlier studies report the excessive faecal excretions of bile acids and dietary residues in cystic fibrosis (CF). However, few of these investigated large groups of patients using modern pancreatin preparations and little data exists reporting carbohydrate excretion. We therefore aimed to characterise the general levels of malabsorption within age groups of 132 patients attending a regional CF centre.

METHODS

The faecal excretions of bile acids, fat, nitrogen and carbohydrate were measured. Most of these patients were treated with either (Creon) (n = 58) or Pancrease (n = 51) and prophylactic antibiotics. The patients were grouped in age ranges 0.5 to 5 years, 6 to 10 years, 11 to 15 years and >16 years. Carbohydrate excretion was determined in the 11 to 15 year group.

RESULTS

Increased excretions with increment in age group were found which, for bile acids, was twice that of age matched controls. Modest relationships were found between the overall excretion of bile acids and fat, and between the excretion of bile acids and nitrogen. Primary bile acids were a feature of cystic fibrosis stools but the patterns of individual bile acid excretion revealed a trend towards a normal bile acid types with increment in age group. Faecal carbohydrate was significantly increased to levels which may significantly alter large bowel microflora.

CONCLUSIONS

The data adds to the evidence that maldigestion initiates bile acid sequestration and consequently, the predominance of primary bile acids.