Influence of antibiotics on intestinal mucin in healthy subjects.

To determine the effect on microbial breakdown of intestinal mucin healthy volunteers were treated orally with ten different antibiotics. The most pronounced effects were seen after administration of bacitracin, clindamycin or vancomycin: the electrophoretic mucin pattern in faeces changed from a normal conventional pattern to a specific pattern similar to that found in germ-free rats. Disturbed patterns were also observed in some of the subjects treated with ampicillin, doxycycline, erythromycin, metronidazole or nalidixic acid. In most cases the electrophoretic mucin pattern normalized within five weeks after the end of treatment. There were no effects on the microbial breakdown of intestinal mucin in the groups treated with ofloxacin or trimethoprim/sulfamethoxazole. Thus, administration of antimicrobial drugs in clinically recommended doses may cause long-term disturbances in one microflora-associated characteristic, the breakdown of intestinal mucin.