Alterations of the bile microbiome in Primary Sclerosing Cholangitis

Jun 17, 2019 | Ethan McConkey, Moderator | @ethanmcconkey

microbiome

In a study published this month in Gut, T. Liwinski, et al., reports on the differences of the microbiome and bile acid composition seen in the bile fluid of patients with PSC compared with healthy controls. 43 patients with PSC and 22 controls were included and bile specimens were prospectively collected for microbiome and bile acid composition analysis. Additional biospecimens were obtained from the oral cavity and the duodenum of these patients. The authors found that the bile fluid contained a diverse microbiome that was different from the oral cavity and the duodenum of these participants. Moreover, the microbiome of the upper alimentary tract was altered between PSC patients and controls. The strongest difference of the two groups was seen in the bile fluid, including an decreased biodiversity of bacteria and an increase of pathogen Enterococcus faecalis among patients with PSC. Furthermore, Enterococcus abundance in bile fluid was strongly associated with the concentration of the noxious secondary bile acid: taurolithocholic acid.

This is a small, cross-sectional study with important findings. The authors have done a great work to enlighten us on the role of microbiome in PSC. We now know that patients with PSC have an altered microbiome of the upper alimentary tract and the bile fluid as well as an increased concentration of taurolithocholic acid, a proinflammatory molecule, in bile. Despite the study limitations, it brings forward the concept of microbiome contributions of the upper alimentary tract and bile fluid to the pathogenesis of PSC and its potential manipulation as a therapeutic modality for PSC. More studies are needed to further elaborate on the microbiome participation in PSC development. Yet, this study tells us that environmental elements, such as the microbiome, are important players in this disease.

The PDF of the published article can be found here.

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