Differences in enterocyte brush border enzyme activities in ageing rats reared in germ-free and conventional conditions.

The aim of this study was to evaluate the levels of disaccharidase and dipeptidyl peptidase i.v. activities in rat jejunal enterocytes under the influence of long-term germ-free conditions. We found that the brush-border lactase and dipeptidyl peptidase i.v. activities were two to three times higher in 2-month-old germ-free rats in comparison with their conventional counterparts. The highest effect of germ-free condition was observed on lactase activity in 6-month-old and dipeptidyl peptidase i.v. in 2-month-old rats. No difference between germ-free and conventional rats in sucrase and glucoamylase activities was found in 2-month-old rats. The difference develops with increasing age, sucrase activity becoming significantly higher in 6- and 12-month-old rats and glucoamylase in 12-month-old germ-free rats.