Correlation between Peptacetobacter hiranonis, the baiCD Gene, and Secondary Bile Acids in Dogs

Bruna Correa Lopes; Chih-Chun Chen; Chi-Hsuan Sung; Patricia Eri Ishii; Luis Fernando da Costa Medina; Frederic P Gaschen; Jan S Suchodolski; Rachel Pilla

doi:10.3390/ani14020216

Correlation between Peptacetobacter hiranonis, the baiCD Gene, and Secondary Bile Acids in Dogs

Animals (Basel). 2024 Jan 9;14(2):216. doi: 10.3390/ani14020216.

Authors

Bruna Correa Lopes¹, Chih-Chun Chen¹, Chi-Hsuan Sung¹, Patricia Eri Ishii¹, Luis Fernando da Costa Medina¹, Frederic P Gaschen², Jan S Suchodolski¹, Rachel Pilla¹

Affiliations

¹ Gastrointestinal Laboratory, Department of Small Animal Clinical Sciences, Texas A&M University, College Station, TX 77840, USA.
² Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.

Abstract

Bile acid metabolism is a key pathway modulated by intestinal microbiota. Peptacetobacter (Clostridium) hiranonis has been described as the main species responsible for the conversion of primary into secondary fecal unconjugated bile acids (fUBA) in dogs. This multi-step biochemical pathway is encoded by the bile acid-inducible (bai) operon. We aimed to assess the correlation between P. hiranonis abundance, the abundance of one specific gene of the bai operon (baiCD), and secondary fUBA concentrations. In this retrospective study, 133 fecal samples were analyzed from 24 dogs. The abundances of P. hiranonis and baiCD were determined using qPCR. The concentration of fUBA was measured by gas chromatography-mass spectrometry. The baiCD abundance exhibited a strong positive correlation with secondary fUBA (ρ = 0.7377, 95% CI (0.6461, 0.8084), p < 0.0001). Similarly, there was a strong correlation between P. hiranonis and secondary fUBA (ρ = 0.6658, 95% CI (0.5555, 0.7532), p < 0.0001). Animals displaying conversion of fUBA and lacking P. hiranonis were not observed. These results suggest P. hiranonis is the main converter of primary to secondary bile acids in dogs.

Keywords: Clostridium hiranonis; bai operon; bile acid metabolism; canine; conversion of bile acids; fecal unconjugated bile acids; primary bile acids.

Grants and funding

This research received no specific funding. The microbiome research at the Gastrointestinal Laboratory is supported in part through the Purina PetCare Research Excellence Fund.