Bifidobacterium bifidum monoassociation of gnotobiotic mice: effect on enterocyte brush-border enzymes.

The effect of intestinal colonization with Bifidobacterium bifidum (Gram-positive anaerobic bacterium colonizing the intestine of healthy new-born mammals, exhibiting a probiotic effect, protecting the intestinal mucosa against colonization by pathogenic microflora) on enterocyte brush-border enzymes was examined in weaned 23-d- and in 2-month-old gnotobiotic inbred mice and compared with that in corresponding germ-free (GF) and conventional (CV) controls. The two groups of GF mice were associated with human B. bifidum 11 d before the end of the experiment. Specific activity of enterocyte brush-border enzymes--lactase, alkaline phosphatase and gamma-glutamyltranspeptidase was significantly higher in both age groups of GF mice in comparison with CV ones; on the other hand, sucrase and glucoamylase activities were higher in CV mice. Monoassociation with B. bifidum accelerates biochemical maturation of enterocytes resulting in a shift of specific activities of brush-border enzymes between the values found for GF and CV mice. This effect of B. bifidum supplementation was less pronounced for alkaline phosphatase, sucrase, glucoamylase and dipeptidyl peptidase i.v. in immature gut of weaned mice than of 2-month-old ones.