Origin of intestinal beta-glucuronidase in germfree, monocontaminated and conventional rats.

The intestinal beta-glucoronidase was studied in germfree, monocontaminated and conventional rats. The greater part of the beta-glucuronidase of the caecum and the large intestine of the contaminated animals was of bacterial origin. No bacterial beta-glucuronidase was found in the small intestine. Monocontamination with Escherichia coli gave activities corresponding to those of the conventional rats, whereas content from the caecum and the large intestine of the rats monocontaminated with Streptococcus pyogenes showed an activity approximately 10 per cent of that of the conventional rats.