Bacterial Microbiome in People With and Without Oral Carcinoma

Objectives: Comparison of bacterial microbiome from different oral-microenvironments in people with and without oral cancer.

Methods: A descriptive study was performed, prior informed consent, 30 samples were taken from people with oral squamous cell carcinoma (10 tumor tissue, 10 dental plaque and 10 saliva) and in 20 samples from healthy people (10 saliva and 10 dental plaque), the analyzes included DNA extraction, Miseq illumination sequencing, data cleaning, bioinformatics analysis, taxonomic assignment, profile construction, pathogenicity validation and discriminatory analysis using descriptive and analytical statistics between microenvironments.

Results: The average age of patients and controls was 56.4 and 56.5 years respectively, the most frequent sex was female (90%), the most frequent tumor location was tongue (50%), followed by cheek (30%) and lip (20 %). A 1: 1 ratio was found at the Phylum level, gender and species between patients and controls (on average 30, 419 and 842 respectively). Bacterial diversity was greater in plaque and saliva samples from patients and controls, while in tumor tissue it was lower. In patients, 5 genera were commonly identified in plaque and tissue, 289 genera in saliva and plaque. 436 bacterial species were identified in saliva plaque and tumor. In controls, 31 genera were plaque specific, 118 species were identified only in plaque and 18 in saliva. A core of 602 genera were identified in patients and controls. Interestingly, we found that bacterial dysbosis was higher in the microbiomes from controls, mainly in plaque and saliva samples, while in patients with OSC plaque, saliva and tumor dysbiosis was lower. Interestingly, a profile of bacterial species associated with health and disease was identified, 30 and 35 species respectively.

Conclusions: The oral bacterial microbiome diverse and abundant in dental plaque and saliva from controls than in patients.
A profile of bacterial species associated with healthy and pathogenic processes were identified