Studies have revealed a significant link—good oral health may play a key role in protecting patients from respiratory illnesses like the seasonal flu. This connection offers a unique chance to support patients beyond traditional care, helping them reduce their risk and lessen the impact of these infections.
As we enter the 2024 flu season, healthcare professionals are preparing for (what is expected to be) an active period for respiratory illnesses. The Centers for Disease Control and Prevention (CDC) anticipates this respiratory disease season will likely have a similar or lower number of combined peak hospitalizations due to COVID-19, influenza, and RSV compared to last season.
For dental practices, this presents a unique opportunity to support patient health by emphasizing the role of oral care in reducing respiratory infection risks. Research increasingly shows that a well-maintained oral microbiome, robust salivary defenses, and healthy periodontal tissues can play a critical role in minimizing flu severity and transmission. For instance, a study published in Frontiers in Microbiology found that dysbiosis of the oral microbiome is associated with increased symptom severity in respiratory infections, highlighting the importance of a healthy mouth.
In this article, we’ll explore how oral health interventions can help patients enhance their immune defenses and potentially mitigate the worst impacts of the flu.
The Oral Microbiome’s Role in Respiratory Health
The oral cavity hosts a complex microbiome that includes bacteria, fungi, viruses, and other microorganisms essential for oral and systemic health. The microbiome’s composition can impact inflammation, immunity, and overall disease susceptibility.
Research shows that poor oral health can significantly elevate the risk and severity of respiratory illnesses like pneumonia and COPD by promoting infection and inflammation in the respiratory tract. A systematic review published in BMC Oral Health found a strong association between poor periodontal health and increased COPD exacerbations, suggesting that oral bacteria can contribute to lung infections.
Pathogens such as Porphyromonas gingivalis and Fusobacterium nucleatum, both prominent in periodontal disease, can migrate to the respiratory tract through aspiration or bloodstream translocation, promoting infection. These bacteria may also influence respiratory viruses’ behavior, exacerbating their virulence.
Also notable, a study in PLOS One highlighted that increased colonization by Staphylococcus aureus and Streptococcus pneumoniae in the oral cavity correlates with higher flu severity.
How Oral Health Supports Respiratory Health
Poor oral health is often linked to reduced saliva production, which compromises the mouth's natural defenses and can increase infection risks. Periodontal disease, dental caries, and infections can impair salivary gland function, leading to dry mouth, reduced oral cleansing, and a buildup of harmful bacteria.
Here’s how effective oral health care can support patients’ respiratory and systemic health:
1. Saliva’s Immune Defense Mechanisms
Saliva isn’t just for digestion and oral lubrication—it is a frontline immune defense containing various antimicrobial proteins and immune molecules. Salivary proteins like gp340 and sialic acid are crucial in blocking pathogens, including influenza viruses, from binding to host cells. Importantly, secretory immunoglobulin A (SIgA) prevents pathogens from adhering to mucosal surfaces, protecting the respiratory tract from invasion. Clinical research shows that maintaining healthy saliva flow can help limit pathogen colonization in the respiratory tract (Clinical Oral Investigations).
2. Antiviral Properties of Saliva
Saliva also contains specific antiviral components—such as lactoferrin, lysozyme, and cathelicidin—that work to inhibit viral activity. Patients with reduced saliva levels may have a higher risk of pathogen retention, heightening the potential for infection. By naturally flushing away bacteria and viruses, adequate saliva production helps dilute viral loads and may reduce infection risk.
A study in the Journal of Clinical Periodontology also found that saliva produces virus-specific IgA following respiratory infections, enhancing immune protection.
3. Protective Molecules in Saliva
Research has emphasized that salivary components like gp340, sialic acid, and SIgA are natural barriers against respiratory viruses. Gp340 has been shown to bind viral particles, reducing infectivity, while sialic acid prevents virus attachment to epithelial cells. These protective mechanisms are particularly beneficial during flu season, as they mitigate risks and severity of respiratory infections.
4. Periodontal Health and Respiratory Infections, Including COVID-19
Recent findings illustrate a link between periodontal disease and more severe outcomes in respiratory infections, particularly with COVID-19. During SARS-CoV-2 infection, increased inflammatory cytokine production worsens periodontal conditions. Cytokine responses, including elevated IL-6 and TNF-α, exacerbate periodontitis while weakening immune response.
Oral Hygiene: A Preventive Strategy for Respiratory Health
Maintaining good oral hygiene is essential to reduce the pathogenic load in the mouth, which may also decrease aspiration risks and bacterial migration to the respiratory tract. Rigorous oral care practices, including brushing, flossing, and professional cleanings, can help reduce pneumonia incidence, especially in high-risk groups.
Scientific Support for Oral Health in Preventing Flu
Recent research reveals that individuals with inadequate oral care face a relative risk of 1.31 for influenza compared to those with strong oral hygiene practices. This connection suggests that preventive oral health can be an added layer of defense during flu season. Here are a few impactful ways dental professionals can support their patients:
- Focus on Salivary Flow as a Barrier: For patients at risk of dry mouth, which can reduce natural antimicrobial defenses, consider suggesting saliva-stimulating solutions or even in-office fluoride treatments to support the mouth’s innate pathogen defenses.
- Highlight the Inflammation Link: Discuss how inflammation from periodontal disease can amplify respiratory risks. By focusing on reducing inflammation—such as using adjunctive therapies like chlorhexidine rinses or recommending anti-inflammatory diets—dentists can help patients maintain a healthier immune profile.
- Leverage Oral Health and Immune Support: Take advantage of preventive visits to discuss immune-supportive practices that can optimize oral and respiratory health. For instance, suggesting nutrient-dense foods that support gum health is valuable to patients' preventive care routines.
In Conclusion
As flu season approaches, oral health's role in bolstering respiratory and immune defenses takes on heightened significance. Research shows that a healthy oral microbiome and effective salivary defenses can reduce the severity of respiratory infections, including seasonal flu. This connection underscores a vital opportunity for dental professionals to protect patient health by encouraging patients to be mindful of hygiene practices, especially during flu season.
By prioritizing preventive oral health strategies—like periodontal care, regular cleanings, and patient education—dental teams can play a pivotal role in strengthening immune resilience against viral infections. Integrating oral health into broader public health initiatives improves individual outcomes and supports community health during flu season and beyond.
About DOCS Education
DOCS Education is the premier provider of dental sedation education in the United States. During their 25-year history, they have trained more than 30,000 dental professionals in safe and effective sedation protocols. They offer online, in-person, and Interactive (((LIVE))) Streaming education. To learn more, visit their website at DOCSEducation.com.
References
- Kelly, N., Winning, L., Irwin, C. et al. Periodontal status and chronic obstructive pulmonary disease (COPD) exacerbations: a systematic review. BMC Oral Health 21, 425 (2021). https://doi.org/10.1186/s12903-021-01757-z
- Marsh, P. D., Zaura, E., & Willems, H. M. E. (2021). The oral microbiome in health and disease: An ecological perspective. Frontiers in Microbiology, 12, 687513. https://doi.org/10.3389/fmicb.2021.687513
- Chen Y, Zhou R, Yi Z, Li Y, Fu Y, Zhang Y, Li P, Li X, Pan Y. Porphyromonas gingivalis induced inflammatory responses and promoted apoptosis in lung epithelial cells infected with H1N1 via the Bcl‑2/Bax/Caspase‑3 signaling pathway. Mol Med Rep. 2018 Jul;18(1):97-104. doi: 10.3892/mmr.2018.8983. Epub 2018 May 7. PMID: 29750299; PMCID: PMC6059728.
- Kawamoto M, Tanaka H, Sakurai A, Otagiri H, Karasawa I, Yamada S-i, et al. (2021) Exploration of correlation of oral hygiene and condition with influenza infection. PLoS ONE 16(8): e0254981. https://doi.org/10.1371/journal.pone.0254981
- Cunha, A.S., dos Santos, L.V., Marañón-Vásquez, G.A. et al. Genetic variants in tooth agenesis–related genes might be also involved in tooth size variations. Clin Oral Invest 25, 1307–1318 (2021). https://link.springer.com/article/10.1007/s00784-020-03437-8
- Pathak, J. L., Yan, Y., Zhang, Q., Wang, L., & Ge, L. (2021). The role of oral microbiome in respiratory health and diseases. Respiratory Medicine, 185, 106475. https://doi.org/10.1016/j.rmed.2021.106475
- Zhou, X., Han, J., & Liu, Z. (2017). Role of oral health in reducing respiratory infection risk. International Journal of Oral Science. Retrieved from https://www.nature.com/articles/ijos2017117