In an experiment,a researcher raises mice under completely germfree conditions so that colonization of their intestine with commensal bacteria cannot occur.In comparison with a conventionally raised animal,the concentration of which of the following would be expected to be increased in the colonic contents of such mice?
A)Butyrate B)Taurochenodeoxycholic acid C)Unconjugated bilirubin D)Immunoglobulin A (IgA) E)Lithocholic acid