Fecal steroids and bacterial flora in patients with polyposis coli.

Fecal neutral and acid steroids and bacterial flora have been studied in a series of patients with polyposis coli and normal controls. The patients with polyposis coli showed a higher concentration of cholesterol and primary bile acids, which increased still more after ileorectostomy. The bacterial flora of the patients with polyposis coli showed an anaerobe/aerobe ratio of 2.7/1 with a relative increase in clostridia and bifidobacteria and decrease in eubacteria and bacteroides. After ileorectostomy clostridia disappear, as do rumenococcus, peptostreptococcus, and fusobacteria, whereas eubacteria and lactobacilli decrease and bifidobacteria and bacteroides increase. Eubacteria showed a decrease from normal in the pre- and postoperative patients with polyposis coli and paralleled the reduction of cholesterol to coprostanol.