It was recently disclosed that CYP3A is responsible for the tertiary stereoselective oxidations of deoxycholic acid (DCA), which becomes a continuum mechanism of the host-gut microbial co-metabolism of bile acids (BAs) in human. This work aims to investigate the species difference of BA redox metabolism and clarify whether the tertiary metabolism of DCA is a conserved pathway in preclinical animals. With quantitative determination of the total unconjugated BAs in urine and fecal samples of human, dogs, rats and mice, it was confirmed that the tertiary oxidized metabolites of DCA were found in all tested animals while DCA and its oxidized metabolites disappeared in germ-free mice. The in vitro metabolism data of DCA and the other unconjugated BAs in liver microsomes of human, monkeys, dogs, rats and mice showed consistencies with the BA profiling data, confirming that the tertiary oxidation of DCA is a conserved pathway. In liver microsomes of all tested animals, however, the oxidation activities toward DCA were far below the murine-specific 6β-oxidation activities toward chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA) and lithocholic acid (LCA), and 7-oxidation activities toward murideoxycholic acid (MDCA) and hyodeoxycholic acid (HDCA) came from the 6-hydroxylation of LCA. These findings provided further explanations for why murine animals have significantly enhanced downstream metabolism of CDCA compared to human. In conclusion, the species differences of BA redox metabolism disclosed in this work will be useful for the inter-species extrapolation of BA biology and toxicology in translational researches.