Gut mucosal virome alterations in ulcerative colitis.

Area of Science:

• Gastroenterology
• Virology
• Microbiome research

Background:

• Gut microbiota dysbiosis is implicated in ulcerative colitis (UC) pathogenesis.
• The role of the intestinal viral community (virome) in UC remains largely unexplored.

Purpose of the Study:

• To characterize the mucosal virome and its functions in individuals with and without UC.
• To investigate the potential role of viral alterations in UC pathogenesis.

Main Methods:

• Deep metagenomics sequencing of virus-like particles and 16S rRNA sequencing were performed on rectal mucosa samples from 167 Chinese subjects (91 UC, 76 healthy controls).
• Viral and bacterial communities were analyzed, and alterations were correlated with clinical data.
• A partition around medoids clustering algorithm classified viral communities into two metacommunities.

Main Results:

• UC mucosa showed an expansion and decreased diversity of Caudovirales bacteriophages compared to healthy controls.
• Specific phages like Escherichia phage and Enterobacteria phage were more abundant in UC patients.
• UC patients exhibited a significant loss of diverse viral functions, with enrichment of bacteriophage functions related to bacterial fitness and pathogenicity.
• Transkingdom correlations between mucosal viruses and bacteria were significantly reduced in UC.

Conclusions:

• Ulcerative colitis is characterized by significant alterations in the mucosal virobiota and functional distortions.
• The enrichment of Caudovirales bacteriophages, increased phage/bacteria virulence functions, and reduced viral-bacterial correlations suggest a key role for the mucosal virome in UC pathogenesis.