Lactobacilli and azoreductase activity in the murine cecum.

Azoreductase activity in the ceca of mice lacking lactobacilli as members of the normal microflora (reconstituted-lactobacillus-free RLF] mice) was compared with that of RLF mice whose gastrointestinal tracts were colonized by strains of Lactobacillus delbrueckii and Lactobacillus fermentum. Azoreductase activity was 31% lower in the ceca of mice colonized by lactobacilli.