Findings on functional prediction of metagenome demonstrated more consistence than compositional profiles of bacteriome associated with Oral Squamous Cell Carcinomas (OSCC)s [1]. Moreover, speculations on functional capacity of the metagenome of polymicrobial, inflammatory diseases, using hypothetical models based on core community ecological theories, gained much attention in the recent past [2,3]. Evidently, keystone pathogen mediated polymicrobial synergy and dysbiosis (PSD) model developed for periodontitis provides the rationale on successful colonization of periodontal bacteria in the immunosuppressive OSCC tumour microenvironment [2]. This efficacious colonization seems to be more of a consequence of oral carcinogenesis than a cause in most instances with known aetiology. It has been demonstrated that the oral microbiome acts as a co-factor in the initiation and progression of oral cancer with well-known life style related modifiable risk factors [3,4]. However, those initial ‘apprentice’ might convert to ‘expert’ as they can enhance the carcinogenesis with their inflammophilic, carcinogenic, immunogenic and toxic attributes as the time progressed, according to the latest in-vitro an invivo experiments [5]. In light of these stirring findings, it is worthwhile to highlight the intrinsic factors which may facilitate the successful colonization of keystone periodontal pathogens in OSCC tumour microenvironment.

References

1. Perera M., et al. "Inflammatory bacteriome and oral squamous cell carcinoma”. Journal of Dental Research6 (2018): 725-732.
2. Perera Ml. “Possibility of polymicrobial synergy and dysbiosis of periodonto pathogens in the oral cell carcinoma tumour microenvironment”. Online Journal of Dentistry and Oral Health (2020).
3. Perera L and Perera I. “Revisiting for resolving: The ecological perspective of periodontal bacteriome for prevention and control of periodontitis in COVID-19 era”. Open Access Journal of Dental Science (2020).
4. PV) status on well-established risk profile of oral cancer in Sri Lanka”. Advances in Dentistry and Oral Health1 (2021).
5. Al-Hebshi NN., et al. “The microbiome of oral squamous cell carcinomas: a functional perspective”. Current Oral Health Reports2 (2019): 145-160.
6. Perera M., et al. “Emerging role of bacteria in oral carcinogenesis: a review with special reference to perio-pathogenic bacteria”. Journal of Oral Microbiology1 (2016): 32762.
7. Ai D., et al. “Integrated metagenomic data analysis demonstrates that a loss of diversity in oral microbiota is associated with periodontitis”. BMC Genomics1 (2017): 1-15.
8. Hajam IA., et al. "Bacterial flagellin-a potent immunomodulatory agent”. Experimental and Molecular Medicine9 (2017): e373-e373.
9. Hajishengallis G., et al. "The keystone-pathogen hypothesis”. Nature Reviews Microbiology10 (2012): 717-725.
10. Jenkinson HF and RJ Lamont. "Oral microbial communities in sickness and in health”. Trends in Microbiology12 (2005): 589-595.
11. Hajishengallis G and RJ Lamont. "Beyond the red complex and into more complexity: the polymicrobial synergy and dysbiosis (PSD) model of periodontal disease etiology”. Molecular Oral Microbiology6 (2012): 409-419.
12. De Lima PO., et al. "Hypoxic condition and prognosis in oral squamous cell carcinoma”. Anticancer Research2 (2014): 605-612.
13. Piau C., et al. "Capnocytophaga spp. involvement in bone infections: a review”. International Journal of Antimicrobial Agents6 (2013): 509-515.
14. Kendall JJ., et al. "Hemerythrins in the microaerophilic bacterium Campylobacter jejuni help protect key iron–sulphur cluster enzymes from oxidative damage”. Environmental Microbiology4 (2014): 1105-1121.
15. Lamont RJ and G Hajishengallis. "Polymicrobial synergy and dysbiosis in inflammatory disease”. Trends in Molecular Medicine3 (2015): 172-183.
16. Potempa J and RN Pike. "Bacterial peptidases”. Contributions to Microbiology 12 (2005): 132-180.
17. Perera ML. “The Microbiome Profile Of Oral Squamous Cell Carcinoma Tissues In A Group Of Sri Lankan Male Patients”. Griffith University, Queensland, Australia (2017).
18. Arjunan P., et al. "Oral pathobiont activates anti-apoptotic pathway, promoting both immune suppression and oncogenic cell proliferation”. Scientific Reports1 (2018): 1-15.
19. Manji F., et al. "Caries and periodontitis: contesting the conventional wisdom on their aetiology”. Caries Research6 (2018): 548-564.