Faecal bile-acids and clostridia in patients with cancer of the large bowel.

Of 44 patients with cancer of the large bowel, 36 ( 82%) had high faecal bile-acid concentrations compared with only 15 (17%) out of 90 patients with other diseases. 31 (70%) of the 44 patients with large-bowel cancer had high faecal bile-acid concentrations in the presence of faecal clostridia able to dehydrogenate the bile-acid nucleus, compared with only 8 (9%) out of 90 patients with other diseases. Thes findings support the hypothesis that cancer of the large bowel is caused by high concentrations of bile-acid derivatives produced by certain anaerobic bacteria.