Comparison of the proportion of unconjugated to total serum cholic acid and the [14C]-xylose breath test in patients with suspected small intestinal bacterial overgrowth.
The proportion of unconjugated to total cholic acid in fasting serum and the 1-gram [14C]-xylose breath test were determined in 36 patients with suspected bacterial overgrowth of the small intestine. Twenty-two patients had an abnormal [14C]-xylose breath test, indicating bacterial overgrowth. The proportion of unconjugated to total cholic acid was significantly higher in the patients with an abnormal breath test compared with those displaying a normal breath test (47 +/- 5% vs 16 +/- 3%). A good correlation was obtained between the proportion of unconjugated to total cholic acid and the breath test (r = 0.63, n = 36). Provided the [14C]-xylose breath test is reliable as a test of bacterial overgrowth, determination of the proportion of unconjugated to total cholic acid in fasting serum had a sensitivity of 73% and a specificity of 94%. It is suggested that determination of the proportion of unconjugated to total cholic acid in peripheral venous blood may be useful as a simple screening test for detection of bacterial contamination of the upper small intestine provided the patients do not have bile acid malabsorption.
Einarsson
K
K
Department of Medicine, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
Bergström
M
M
Eklöf
R
R
Nord
C E
CE
Björkhem
I
I
D000328:Adult; D000368:Aged; D001944:Breath Tests; D002250:Carbon Radioisotopes; D019826:Cholic Acid; D002793:Cholic Acids / Q000097:blood*; D004755:Enterobacteriaceae / Q000254:growth & development*; D005260:Female; D005767:Gastrointestinal Diseases / Q000382:microbiology*; D006801:Humans; D007421:Intestine, Small / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D014994:Xylose
D002250:Carbon Radioisotopes; D002793:Cholic Acids; D014994:Xylose; D019826:Cholic Acid