THE INFLUENCE OF COLLOIDAL BISMUTH SUBCITRATE ON FECAL AEROBES

The influence of colloidal bismuth subcitrate on the concentration of the aerobic faecal microorganisms in patients was investigated. Fiftee n patients with Helicobacter pylori related gastritis received colloid al bismuth subcitrate 120 mg four times a day for 2 wk and 14 other pa tients for 4 wk. A significant increase occurred in the median faecal concentrations of gram-negative bacilli (10(6)-10(7) CFU/g faeces; P<0 .001) and enterococci (10(5)-10(8) CFU/g faeces; P<0.001) following 2 wk colloidal bismuth subcitrate. There were no differences in median f aecal concentrations of aerobic microorganisms between weeks 2 and 4. Suppression of the indigenous microbiota with colloidal bismuth subcit rate did not cause an increase in the faecal concentration of yeasts. It is concluded that colloidal bismuth subcitrate impairs the autochth onous microbiota that limits the concentration of potentially pathogen ic microorganisms, but the resulting increase in the concentration of microorganisms seems too small to be of clinical relevance.