# A Narrative Review on Oral Microbiome Dysbiosis in Benign and Malignant Oral Lesions: Mechanistic Insights and Clinical Implications

## TL;DR

This review explores how changes in the mouth's microbial balance are linked to both non-cancerous and cancerous oral conditions, and their potential for diagnosis and treatment.

## Contribution

The paper provides mechanistic insights and clinical implications of oral microbiome dysbiosis in benign and malignant oral lesions.

## Key findings

- Malignant tumors like OSCC show dysbiosis with pathogenic bacteria such as Porphyromonas gingivalis.
- Benign lesions exhibit localized microbial changes, unlike the broader dysbiosis in cancerous tumors.
- Microbial dysbiosis may offer diagnostic and therapeutic opportunities for oral diseases.

## Abstract

Maintaining oral and systemic health depends heavily on the dynamic and varied microbial environment found in the human mouth cavity. There is growing evidence that the oral microbiota plays a role in the pathophysiology of both benign and malignant oral cancers by producing carcinogenic chemicals, modifying host immune responses, and causing chronic inflammation. Malignant tumors like oral squamous cell carcinoma (OSCC) show profound dysbiosis marked by enrichment of pathogenic taxa such as Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum, whereas benign lesions like papillomas, fibromas, and odontogenic tumors show localized microbial alterations. This review examines the molecular processes connecting microbial dysbiosis to carcinogenesis, summarizes current understanding of the oral microbiome across several oral cancers, and emphasizes potential diagnostic, prognostic, and therapeutic applications.