Alterations in the Fungal Microbiome in Ulcerative Colitis

Area of Science:

• Gastroenterology
• Microbiome research
• Immunology

Background:

• The role of gut fungi in inflammatory bowel disease (IBD) pathogenesis is increasingly recognized.
• However, a comprehensive understanding of the fungal microbiome in ulcerative colitis (UC), particularly concerning disease activity and treatment, remains limited.

Purpose of the Study:

• To investigate the fungal composition in ulcerative colitis (UC) patients.
• To analyze fungal diversity and abundance in relation to endoscopic and endohistologic activity.
• To explore the impact of biologic therapy on the UC fungal microbiome.

Main Methods:

• Analysis of fecal samples from 98 UC patients using data from the SPARC IBD registry.
• Assessment of fungal composition, diversity, and differential abundance across endoscopic activity, endohistologic activity, and biologic exposure.
• Identification of fungal amplicon sequence variants (ASVs).

Main Results:

• Over 500 unique fungal ASVs were identified, primarily from the phylum Ascomycota.
• Patients with endoscopic activity showed increased levels of Saccharomyces and Candida compared to those in remission.
• These fungal expansions persisted even after adjusting for age, sex, and biologic exposure.

Conclusions:

• Endoscopic inflammation in UC is associated with an increased abundance of Saccharomyces and Candida.
• These specific fungal taxa warrant further investigation as potential biomarkers for UC.
• The findings suggest a potential role for targeting these fungi in personalized UC therapeutic strategies.