Gut and oral microbial profile associations to oral cancer.

The human microbiome is widely known to be associated with health and disease. The oral microbiome has been linked with oral diseases and infections, though not many studies have explored the relation between oral and gut microbiome with oral cancer based on lesion histology METHODS: This study uniquely explores the oral and gut microbiota in 30 participants (n = 30) divided into three groups based on histology; Benign (B) (n = 15), Potentially Malignant (PM) (n = 8), and Malignant (M) (n = 7) oral lesions. Using shotgun metagenomic sequencing, we analysed microbiota profiles to determine their potential as biomarkers for oral malignancy RESULTS: Distinct gut microbial profiles were observed between Benign and Malignant groups and the association of specific microbes in oral saliva, such as Haemophilus parainfluenzae, Veillonella parvula, Fusobacterium nucleatum and Rothia mucilaginosa were strongly associated with malignancy CONCLUSION: The data from this exploratory study suggest that oral and gut microbiomes could act as possible biomarkers and aid in early detection and assessment of oral cancer risk. With regard to potentially malignant lesions, future research could study individual Oral Potentially Malignant Disorders (OPMDs) as distinct entities due to the wide variation in clinical and histological presentation. Further research is required to develop definitive biomarkers in both potentially malignant and malignant oral lesions CLINICAL SIGNIFICANCE: While smoking and alcohol are known risk factors for oral cancer, a biomarker such as the saliva/stool microbiome profile could help identify a risk indicator or a potential risk factor. Additionally such a biomarker could help identify patients with OPMDs that are likely to undergo malignant transformation.