Determination of 14CO2 in breath and 14C in stool after oral administration of cholyl-1-[14C]glycine: Clinical application

Abstract

Twenty patients with intestinal bacterial overgrowth and 20 control subjects were investigated for bile acid deconjugation, by measuring 14CO2 in the breath after cholyl-1-[14C]glycine administration. 14CO2 output/24 h was 11.0±5.2% (mean±SD) in controls and 54.2±14.0% (mean±SD) in bacterial-overgrowth patients (P < .001). 14CO2 excretion rate in 12 h, when normalized to 100% of the dose at the 12th hour, gave an even finer discrimination between the two groups (no false responses). 14C in stool, analyzed in 20 malabsorption patients and 20 controls by two different techniques, was 6.6 ± 4% and 31.38 ± 21.7% (mean±SD), respectively. Results by the two different techniques described here correlated well (r=.99). Bile acid malabsorption was in reasonable agreement (r=.67) with percentage of 'chenoid' (chenodeoxycholic acid plus ursodeoxycholic acid) in the stool by gas-liquid chromatography; a poorer correlation was observed when 'chenoid' plus 'choloid' (cholic acid plus its epimers) were plotted vs. 14C in stool (r=.57, n=15).