Oral Microbiome and Inferred Functions Predict Kaposi's Sarcoma Progression

Area of Science:

• Microbiology
• Oncology
• Immunology

Background:

• Kaposi's sarcoma (KS), a cancer common in people with HIV, is linked to Kaposi's sarcoma-associated herpesvirus (KSHV).
• The oral microbiome's role in KS progression is not well understood, despite links to KSHV infection and KS development.
• Understanding oral microbiome alterations is crucial for managing KS progression in HIV patients.

Purpose of the Study:

• To investigate the association between oral microbiome composition and KS progression in patients with AIDS-associated KS.
• To identify specific microbial species and metabolic pathways in the oral cavity linked to progressive versus nonprogressive KS.
• To explore the potential of the oral microbiome as a prognostic marker for KS.

Main Methods:

• 16S rRNA gene sequencing was used to analyze the oral microbiome, peripheral blood, and tumor biopsies from 20 patients with AIDS-associated KS.
• Patients were divided into progressive (n=10) and nonprogressive (n=10) disease groups.
• Beta diversity and differential abundance analyses were performed to compare microbial communities between groups and sample sites.

Main Results:

• Significant differences in oral microbiome composition were observed between patients with progressive and nonprogressive KS (p=0.044).
• Sixteen oral microbial species were significantly associated with KS progression, compared to fewer species in blood and tumors.
• Prevotella pallens and Megasphaera micronuciformis, short-chain fatty acid producers, were enriched in progressive KS oral microbiomes.
• 39 differentially abundant microbial pathways were identified in the oral cavity, including those involved in denitrification, ubiquinone biosynthesis, and arginine metabolism.

Conclusions:

• Specific alterations in the oral microbiome are associated with the progression of Kaposi's sarcoma in HIV-infected individuals.
• Enriched short-chain fatty acid-producing bacteria and altered metabolic pathways in the oral cavity may drive KS pathogenesis.
• The oral microbiome presents potential novel prognostic markers for KS progression.