The effect of continuous enteral feeding on cholic acid kinetics in a child.

Continuous enteral feeding is utilized for nutritional support and specific therapy for several pediatric diseases, including protracted infantile diarrhea. Its effects on the enterohepatic circulation of bile acids were studied in a boy during continuous intragastric feeding of a high fat diet at age 42 months and after recovery while on bolus feedings at age 51 months. Cholic acid kinetics measured by the isotopic dilution technique using cholic-COOH-14C acid and meal stimulated intraluminal bile acid concentrations were measured. Cholic acid pool size was unaltered (1294 mg/m(2)) during continuous feeding compared to 999 mg/m(2) during bolus feeds and 1072 plus or minus 243 mg/m(2) (mean plus or minus SE) in nine control children. However, the cholic acid fractional turnover rate was increased 3-fold (0.912 days(-1)) during continuous feeds compared to 0.309 days(-1) during bolus feeding and 0.365 plus or minus 0.163 in controls. Similarly, synthesis rate was increased 3-4 fold during continuous feeds (1180 mg/m(2)/day) compared to controls (363 plus or minus 193 mg/m(2)/day) and the patient during bolus feeding (309 mg/m(2)/day). The intraluminal bile salt concentration was apparently reduced both during treatment (3.86 mM) and when bolus fed (3.85 mM) but were significantly different from controls (7.12 plus or minus 1.74 mM). During continuous enteral feeding with a high fat diet, effective homeostatic mechanisms in the enterohepatic circulation of bile salts ensured intraluminal bile salt concentrations adequate for normal fat solubilization and, consequently, normal fat absorption.