Salivary microbiota reflects local bacterial alterations and is influenced by diet, lifestyle, and oral and systemic health. Systemic diseases such as systemic autoimmune diseases, diabetes, cancer, and cardiovascular diseases influence the salivary levels of specific bacterial species and the overall diversity of the salivary microbiota. These changes can potentially mirror the general health status of individuals.

Simultaneously, it has been observed that in some cases treating periodontitis led to ameliorating systemic symptoms as well, suggesting that oral and general conditions are not only correlated, but there might exist a bidirectional causal relationship.

Exploring the associations between salivary bacteria and systemic conditions paves the way for a more holistic approach to patient care.

Periodontitis

Periodontitis, the 11th most common disease in the world 1, has been linked to various systemic conditions through microbial dysbiosis and impaired immune responses. This chronic inflammatory disease has abundant bacteria such as Eubacterium saphenum, Tannerella forsythia, Filifactor alocis, Streptococcus mitis/parasanguinis, Parvimonas micra, Prevotella sp., Phocaeicola sp., and Fretibacterium sp. Researchers have identified positive correlations between Treponema sp., Selenomas sp., and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6R, suggesting that these might serve as a potential biomarker role in diagnosing periodontitis.2

Salivary Microbiota and Systemic Diseases

Systemic Autoimmune Diseases (SADs)

Oral microbiome alterations have been correlated to SADs such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjögren’s syndrome (SS). Even though results regarding candidate bacterial pathogens were not consistent, Selenomonas and Veillonella were found significantly increased in these conditions, while Streptococcus was significantly decreased compared to control groups.3

Diabetes and Cardiovascular Diseases

Diabetic and cardiac patients exhibit a disrupted salivary environment with increased loads of cariogenic bacteria such as Streptococcus mutans. This microbial dysbiosis may underlie the progression of diabetes to cardiovascular disease.4

Cancer

Studies have shown the diversity of bacteria in oral squamous cell carcinomas, highlighting the abundance of Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis in tumor sites.5    Correlations between salivary microbiota dysbiosis and pancreatic cancer have also been noticed. Neisseria elongata and Streptococcus mitis have been identified as candidate biomarkers for pancreatic cancer.6 Simultaneously, increased risk of developing this type of cancer has been linked to high levels of Porphyromonas gingivalis antibodies.7

Increased levels of Firmicutes, Veillonella, and Streptococcus, and decreased levels of Fusobacterium and Prevotella, have been observed in non-small cell lung cancer patients as well.8

Alzheimer’s Disease

A retrospective study, conducted on a cohort of 18,672 patients, has concluded that patients with chronic periodontitis are 70% more likely to develop cognitive diseases, such as Alzheimer’s. These patients have been found to have a higher prevalence of periodontitis-associated bacteria such as Porphyromonas gingivalis, which may represent a factor in endothelial dysfunction and vascular disease.9

Treatment correlations

Associations between periodontitis and preterm deliveries, low birthweight, and pre-eclampsia have been observed. Research has shown that treatment of inflamed periodontal tissues can reduce the risk of preterm deliveries, highlighting its tentative benefits for maternal and fetal health.10

Periodontal treatment also reduces systemic inflammation which is a common underlying factor in multiple chronic diseases.

It has been associated with reductions in high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and plasma glucose levels, as well as improvements in flow-mediated dilation (FMD) and diastolic blood pressure, highlighting a positive impact on cardiovascular health and metabolic control.10

Also, it has been shown to reduce HbA1c levels (0.4%) in patients with type 2 diabetes, indicating better glycemic control. Simultaneously, controlling diabetes (i.e. improving glycaemic control) also reduces the risk and severity of periodontitis.11

Pathways of influence linking oral and systemic diseases  Oral infections, particularly periodontitis, may affect systemic diseases through three proposed mechanisms:

– metastatic spread of infection,

– metastatic injury from circulating microbial toxins, and

– metastatic inflammation caused by immunological injury.12

Furthermore, dysbiosis in the oral microbiota can lead to a dysregulated immune response, further promoting SADs, AD, carcinogenesis etc.3,13,14

The Oralis-1 oral microbiome test: a comprehensive tool for oral and systemic health

The Oral Microbiome Test (Oralis-1) is the latest comprehensive test I have encountered, offering an in-depth analysis of the oral microbiome to support both oral and systemic health conditions. By profiling bacterial diversity and pinpointing pathogenic microorganisms, it provides actionable insights for clinicians to tailor personalized interventions, making it a valuable tool for optimizing oral health and addressing its connection to overall well-being.15

Conclusion

In conclusion, the salivary microbiota serves as a dynamic biomarker, reflecting both oral and systemic health. Systemic diseases profoundly influence the composition and diversity of salivary bacteria, with these changes potentially mirroring an individual’s overall health status. Evidence highlights that treating periodontitis can improve systemic outcomes by reducing inflammation and enhancing markers of cardiometabolic health, glycemic control in diabetes, and pregnancy outcomes. These findings underscore the pivotal role of salivary microbiota in linking oral health to broader systemic conditions.

Companies like Norgen Biotek specialize in developing novel saliva-based diagnostic techniques. They show that saliva can be a non-invasive sample for analyzing the human microbiome, diagnosing respiratory illnesses, and mental health conditions like PTSD, and even COVID-19 detection.

The ADA recently invested in two innovative companies as part of its focus on improving oral health through strategic partnerships. One of these companies is Oral Genome, which developed a salivary diagnostic test to identify biomarkers related to several minor and major health conditions.

Nonetheless, further research is necessary to fully understand the long-term effects of these treatments and the complicated relationship between the microbiota and systemic conditions. Increased education on the role of oral health in managing systemic conditions is considered important for both clinicians and patients so that these diseases can be effectively prevented and managed.

Contributions of NamNR Pro – Global Dentists’ Pool in Shaping the Future of Companies Innovating and Implementing Salivary Biomarkers into Usable Devices

The Global Dentists’ PoolTM by NamNR Pro is an opportunity for dentists, dental researchers, scientists and innovative startups to collaborate more closely and build solutions to maximize the use of oral biomarkers in treating chronic systemic diseases and cancers.

For dental companies –

With more than 100 dentists spread across 24 countries, this Pool supports dental companies by helping them.

(1) validate their design ideas by running surveys in a large global cohort of practitioners and/or

(2) hire premium dental advisors and MedComms experts to support various clinical, regulatory, marketing and sales projects.

These are all dentists with specialized MedTech expertise in different domains. The core focus is to avoid hiring multiple ‘non-dental trained’ freelancers and consultants and hire premium dental advisors instead, who are the perfect single substitute for multiple human resources, in the form of one highly specialized advisor.

For dentists surgeons –

The Global Dentists’ Pool provides dentists, both general dentists and specialists, with opportunities to participate in dental projects without disrupting their clinical practice. The number of hours of engagement is flexible and dentists can upskill themselves by taking the “premium dental advisor program” which teaches how devices are made with medical device industry fundamentals.

If you would like to engage with us to support your project or advance your dental career, then reach out to us at contactus@namnrpro.org.

Disclaimer:

This article was not sponsored by or created in collaboration with any of the companies mentioned.

References

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Author information

With a solid foundation in dentistry and a passion for artificial intelligence, Dr. Vlada Levinta is a part of the Clinical Team at Overjet, a leading company that develops AI-powered software for dental care. She graduated with a Doctor of Dental Medicine (DMD) degree from Carol Davila University of Medicine and Pharmacy, where she conducts novel research on the integration of AI in dentistry, achieving a perfect score of 10/10.