Excretion of bile acids in healthy children and children with cystic fibrosis

Abstract

Urinary bile acid excretion was investigated in twenty-two patients with cystic fibrosis (CF) and in seven healthy children. CF patients with and without antibiotic treatment were compared. Bile acids were determined in 24-h samples after separation into unconjugated, glycine conjugated, taurine conjugated and sulphate conjugated bile acids. In total twenty bile acids were identified of which cholic, chenodeoxycholic, 3β-hydroxy-5-cholenoic acid and 24-nor-5β-cholan-23-oic acid were routinely present in samples collected from both CF patients and healthy children. None of the other bile acids were preferentially excreted by CF patients. When compared with the normal group, no statistical significance could be attached to the increased total urinary bile acids excreted by the CF patients (due to the large individual variations). The CF patients excreted increased amounts of cholic acid, 3α, 7β, 12α-and 3β, 7β, 12α-trihydroxy-5β-cholanoic acids mainly in the unconjugated state. After administration of 24-[¹⁴C]cholic acid to thirteen CF patients the isotope excretion in faeces and urine was studied. Most of the patients had a high faecal excretion indicating great losses of bile acids from enterohepatic circulation. Compared to normal adults CF children excreted isotope in increased amounts in the urine.

Key Words:

• bile acids
• bile acid conjugates
• cholic acid
• cystic fibrosis