In vivo measurement of colonic butyrate metabolism in patients with quiescent ulcerative colitis.
BACKGROUND
Butyrate, a short chain fatty acid produced by bacterial fermentation, is a major fuel source for the colonocyte. In vitro work has shown that ulcerative colitis may be characterised by a metabolic defect in colonocyte butyrate oxidation.


OBJECTIVE
To investigate the rate of metabolism of rectally administered butyrate in patients with quiescent colitis.


METHODS
[1-(13)C]-butyrate enemas were administered to 11 patients with long standing quiescent ulcerative colitis and to 10 control patients. The rate of production of (13)CO(2) in exhaled breath over four hours was measured by isotope ratio mass spectrometry combined with indirect calorimetry in order to measure CO(2) production. This allowed calculation of the patients' resting energy expenditure and respiratory quotient.


RESULTS
Over a four hour period, 325 (SEM 21) micromol (13)CO(2) was recovered in breath samples from the colitis group compared with 322 (17) micromol from the control group (NS). The respiratory quotient of the colitic group was significantly lower than that of the control group.


CONCLUSIONS
There was no difference in the rate of metabolism of butyrate between the two groups. It is unlikely that there is a primary metabolic defect of butyrate metabolism in patients with quiescent ulcerative colitis.
Simpson
E J
EJ
School of Biomedical Science, Nottingham University, UK.
Chapman
M A
MA
Dawson
J
J
Berry
D
D
Macdonald
I A
IA
Cole
A
A
D000328:Adult; D001944:Breath Tests / Q000379:methods; D002087:Butyrates / Q000378:metabolism*; D002245:Carbon Dioxide / Q000502:physiology; D002247:Carbon Isotopes; D003093:Colitis, Ulcerative / Q000378:metabolism*; D003106:Colon / Q000378:metabolism*; D004734:Energy Metabolism; D006801:Humans; D008875:Middle Aged; D010084:Oxidation-Reduction; D011659:Pulmonary Gas Exchange
D002087:Butyrates; D002247:Carbon Isotopes; D002245:Carbon Dioxide