Enzymic determination of 3 alpha-, 7 alpha-, and 12 alpha-hydroxyl groups of fecal bile salts.

We used microbial 3 alpha, 7 alpha-, and 12 alpha-hydroxysteroid dehydrogenases to quantify 3 alpha-, 7 alpha-, and 12 alpha-hydroxyl groups in human feces. Samples collected over a 48-h period were lyophilized, extracted, and reconstituted by a modification of the method of DeWael et al. (clin. Chim. Acta 79: 465--470, 1977), then quantified enzymically by use of three group-specific hydroxysteroid dehydrogenase preparations. Total values for the three hydroxyl groups are given for 18 healthy humans. The ratio of 3 alpha-OH groups/7 alpha-OH groups/12 alpha-OH groups was 34.4 (SD 5.9)/25.2 (SD 6.4)/40.4 (SD 7.7) for the 18 samples.