Gut microbiome in primary sclerosing cholangitis: A review

Area of Science:

• Gastroenterology and Hepatology
• Microbiology
• Immunology

Background:

• Primary sclerosing cholangitis (PSC) is a chronic liver disease linked to inflammatory bowel disease (IBD).
• The gut-liver axis and gut microbiota's role in PSC pathogenesis are increasingly recognized.
• Dysbiosis and bacterial translocation are implicated in PSC development.

Purpose of the Study:

• To review current research on the gut microbiome in PSC and PSC-IBD.
• To explore potential mechanisms, including microbial metabolites like bile acids.
• To summarize microbe-altering therapeutic interventions for PSC.

Main Methods:

• Review of existing literature on PSC, IBD, and the gut microbiome.
• Analysis of studies identifying specific bacterial species in PSC patients.
• Examination of research on microbial metabolites and immune responses.

Main Results:

• Fecal microbiota studies show enriched levels of species like Veillonella, Streptococcus, and Enterococcus in PSC.
• Gut microbes influence host immune responses, with examples like Klebsiella pneumoniae inducing epithelial damage and Th17 responses.
• Bile acids (BAs) are key microbial metabolites with significant gut and hepatic signaling roles.

Conclusions:

• The gut microbiome plays a crucial role in PSC pathogenesis.
• Microbe-altering therapies, including antibiotics and fecal microbial transplantation, show preliminary benefit.
• Further research is needed on microbiome functional characterization and pediatric PSC.