Establishment of Lactobacillus and Bifidobacterium species in germfree mice and their influence on some microflora-associated characteristics.

Germfree mice were inoculated with both Lactobacillus acidophilus A10 and Bifidobacterium bifidum B11. Both strains were established and present in more than 10(8) cells per g of cecum and colon contents. Furthermore, L. acidophilus A10 was established in high numbers in stomach and small intestine. Contents from different parts of the intestine were investigated with regard to the following microflora-associated characteristics: degradation of mucin, beta-aspartylglycine and tryptic activity, conversion of cholesterol to coprostanol and bilirubin to urobilinogen, deconjugation of bilirubin glucuronides, and reduction of the cecum size. In spite of being established, the microbes were not able to mediate any alterations of the parameters investigated. All animals retained values as found in their germfree counterparts.