β-Glucuronidase activity in germ-free, monoassociated and conventional mice.

The establishment of β-glucuronidase activity was investigated in intestinal contents from gnotobiotic mice monoassociated either with Lactobacillus rhamnosus ATCC 53103 (LGG) or with Escherichia coli X7 for different periods of time. Additionally, the enzyme activity was investigated after the animals had been conventionalized. Neither the monoassociated animals nor the conventionalized animals had reached normal levels of β-glucuronidase activity after the colonization period (3 and 7 days, or 7 and 14 days, respectively). A great inter-individual variation of the enzyme activity was observed in the group that was conventionalized for longer (14 days), mainly in the caecum. These results indicate a very slow establishment of the β-glucuronidase activity in the intestinal tract of mice after exposure to either individual bacterial strains or exclusively to the environment. [ABSTRACT FROM AUTHOR]