The Impact of Oral Health on Respiratory Viral Infection

The impact of oral diseases on respiratory health and the influence of respiratory infections on the oral microbiome

OBJECTIVE

The objective of this review is to examine the relationship between oral diseases and respiratory health, investigating how oral microbiome disruptions contribute to respiratory tract infections. Additionally, it aims to explore the impact of respiratory disease symptoms and treatments on the oral microbiome.

DATA SOURCES

The literature utilized in this review was sourced from studies focusing on the correlation between oral health and respiratory infections, spanning a period of 40 years. Various databases and scholarly sources were likely consulted to gather relevant research articles, reviews, and clinical studies.

STUDY SELECTION

This review summarizes four decades-long research, providing insights into the intricate relationship between oral and respiratory health. It delves into how oral diseases influence respiratory tract conditions and vice versa. The selection process likely involved identifying studies that addressed the interaction between oral microbiome disruptions and respiratory complications.

CONCLUSION

Oral diseases or poor oral habits have been known to increase the risk of getting respiratory infections. Modern techniques have demonstrated the relationship between oral disease and respiratory tract infections like influenza, chronic obstructive pulmonary diseases, asthma, and Pneumonia. Apart from that, the medications used to treat respiratory diseases affect oral physiological factors like the pH of saliva, and saliva flow rate, which can cause significant changes in the oral microbiome. This review provides regular oral hygiene and care that can prevent respiratory health and respiratory infections.

CLINICAL SIGNIFICANCE

Understanding the intricate relationship between oral health and respiratory infections is crucial for healthcare providers. Implementing preventive measures and promoting good oral hygiene habits can reduce respiratory tract infections and improve overall respiratory health outcomes.

Effect of combined infection with Salmonella and influenza virus on their respective proliferation in chicken embryonated eggs

Background

Salmonella is a major food-borne bacterial pathogen that causes food poisoning related to the consumption of eggs, milk, and meat. Food safety in relation to Salmonella is particularly important for eggs because their shells as well as their contents can be a source of contamination. Chicken can also be infected with influenza virus, but it remains unclear how co-infection of Salmonella and influenza virus affect each other.

Aim

The potential influence of co-infection of Salmonella and influenza virus was examined.

Methods

Salmonella Abony and influenza virus were injected into chicken embryonated eggs. After incubation, proliferation of Salmonella and influenza virus was measured using a direct culture assay for bacteria and an enzyme-linked immunosorbent assay for influenza virus, respectively.

Results

Our findings indicate that the number of colony-forming units (CFUs) of Salmonella did not vary between chicken embryonated eggs co-infected with influenza A virus and Salmonella-only infected eggs. Furthermore, we found the proliferation of influenza A or B virus was not significantly influenced by co-infection of the eggs with Salmonella.

Conclusion

These results suggest that combined infection of Salmonella with influenza virus does not affect each other, at least in terms of their proliferation.

Oral Dysbiosis and Systemic Diseases: A Two-Way Relationship?

The human body consists of its own cells, but also of microorganisms that are found both inside and outside the human body [...].

Oral mucosa immunity: ultimate strategy to stop spreading of pandemic viruses

Global pandemics are most likely initiated via zoonotic transmission to humans in which respiratory viruses infect airways with relevance to mucosal systems. Out of the known pandemics, five were initiated by respiratory viruses including current ongoing coronavirus disease 2019 (COVID-19). Striking progress in vaccine development and therapeutics has helped ameliorate the mortality and morbidity by infectious agents. Yet, organism replication and virus spread through mucosal tissues cannot be directly controlled by parenteral vaccines. A novel mitigation strategy is needed to elicit robust mucosal protection and broadly neutralizing activities to hamper virus entry mechanisms and inhibit transmission. This review focuses on the oral mucosa, which is a critical site of viral transmission and promising target to elicit sterile immunity. In addition to reviewing historic pandemics initiated by the zoonotic respiratory RNA viruses and the oral mucosal tissues, we discuss unique features of the oral immune responses. We address barriers and new prospects related to developing novel therapeutics to elicit protective immunity at the mucosal level to ultimately control transmission.

Block the Spread: Barriers to Transmission of Influenza Viruses

Respiratory viruses, such as influenza viruses, cause significant morbidity and mortality worldwide through seasonal epidemics and sporadic pandemics. Influenza viruses transmit through multiple modes including contact (either direct or through a contaminated surface) and inhalation of expelled aerosols. Successful human to human transmission requires an infected donor who expels virus into the environment, a susceptible recipient, and persistence of the expelled virus within the environment. The relative efficiency of each mode can be altered by viral features, environmental parameters, donor and recipient host characteristics, and viral persistence. Interventions to mitigate transmission of influenza viruses can target any of these factors. In this review, we discuss many aspects of influenza virus transmission, including the systems to study it, as well as the impact of natural barriers and various nonpharmaceutical and pharmaceutical interventions.

Long-term systemic and mucosal SARS-CoV-2 IgA response and its association with persistent smell and taste disorders

Introduction

Current approved COVID-19 vaccines, notably mRNA and adenoviral vectored technologies, still fail to fully protect against infection and transmission of various SARS-CoV-2 variants. The mucosal immunity at the upper respiratory tract represents the first line of defense against respiratory viruses such as SARS-CoV-2 and is thus critical to develop vaccine blocking human-to-human transmission.

Methods

We measured systemic and mucosal Immunoglobulin A (IgA) response in serum and saliva from 133 healthcare workers from Percy teaching military hospital following a mild infection (SARS-CoV-2 Wuhan strain, n=58) or not infected (n=75), and after SARS-CoV-2 vaccination (Vaxzevria®/Astrazeneca and/or Comirnaty®/Pfizer).

Results

While serum anti-SARS-CoV-2 Spike IgA response lasted up to 16 months post-infection, IgA response in saliva had mostly fallen to baseline level at 6 months post-infection. Vaccination could reactivate the mucosal response generated by prior infection, but failed to induce a significant mucosal IgA response by itself. Early post-COVID-19 serum anti-Spike-NTD IgA titer correlated with seroneutralization titers. Interestingly, its saliva counterpart positively correlated with persistent smell and taste disorders more than one year after mild COVID-19.

Discussion

As breakthrough infections have been correlated with IgA levels, other vaccine platforms inducing a better mucosal immunity are needed to control COVID-19 infection in the future. Our results encourage further studies to explore the prognosis potential of anti-Spike-NTD IgA in saliva at predicting persistent smell and taste disorders.

Progress in salivary glands: Endocrine glands with immune functions

The production and secretion of saliva is an essential function of the salivary glands. Saliva is a complicated liquid with different functions, including moistening, digestion, mineralization, lubrication, and mucosal protection. This review focuses on the mechanism and neural regulation of salivary secretion, and saliva is secreted in response to various stimuli, including odor, taste, vision, and mastication. The chemical and physical properties of saliva change dynamically during physiological and pathophysiological processes. Moreover, the central nervous system modulates salivary secretion and function via various neurotransmitters and neuroreceptors. Smell, vision, and taste have been investigated for the connection between salivation and brain function. The immune and endocrine functions of the salivary glands have been explored recently. Salivary glands play an essential role in innate and adaptive immunity and protection. Various immune cells such as B cells, T cells, macrophages, and dendritic cells, as well as immunoglobins like IgA and IgG have been found in salivary glands. Evidence supports the synthesis of corticosterone, testosterone, and melatonin in salivary glands. Saliva contains many potential biomarkers derived from epithelial cells, gingival crevicular fluid, and serum. High level of matrix metalloproteinases and cytokines are potential markers for oral carcinoma, infectious disease in the oral cavity, and systemic disease. Further research is required to monitor and predict potential salivary biomarkers for health and disease in clinical practice and precision medicine.

Leisure Time Physical Activity and SARS-CoV-2 Infection among ELSA-Brasil Participants

The regular practice of physical activity (PA) can reduce the chance of aggravation of the disease and lower rates of hospitalization and mortality from COVID-19, but few studies have analyzed the association of PA with the risk of infection by SARS-CoV-2. The aim of the study was to analyze the association between PA and self-reported SARS-CoV-2 infection. A longitudinal study was conducted with data from 4476 ELSA-Brasil participants who had their PA analyzed twice, once in 2016-2018 and again in 2020. PA was identified using the IPAQ at both follow-up moments and categorized into four groups: (a) remained physically inactive (reference); (b) remained physically active; (c) became physically active in the second moment; and (d) became physically inactive in the second moment. The variables of age, sex, obesity, hypertension, diabetes and specific protective practices against COVID-19 were tested as possible confounders. Data were analyzed by logistic regression. A 95% confidence interval (CI) was used. Remaining physically active was associated with a 43% reduction in the risk of SARS-CoV-2 infection only among those who used specific practices to protect against COVID-19, OR = 0.57 and CI = 0.32-0.99. The results suggested that regular practice of PA can reduce the risk of SARS-CoV-2 infection, especially among those who have used specific practices to protect against COVID-19 during the pandemic.

Physical Activity, Empowerment of the Immune System and Public Health: What We Learned from the COVID-19 Pandemic

The importance of physical activity for the cardiovascular, metabolic and mental health systems with its repercussions for public health has been studied for some time, although further studies are needed due to the depletion of health services observed during the COVID-19 pandemic [...].

Oral microbial taxa associated with risk for SARS-CoV-2 infection

Hypothesis and objective

The oral and digestive tract microbial ecosystem has sparked interest because of its impact on various systemic diseases and conditions. The oral cavity serves not only as a reservoir for many potentially virulent microbiota but also as an important entry point and portal to the human body system. This is especially significant in the transmissibility of the virulent current pandemic virus SARS-CoV-2. The oral and digestive microbiome influences the inflammatory burden and effectiveness of the immune system and serves as a marker of activity of these host processes. The host immune response plays a role in infection susceptibility, including SARS-CoV-2. The purpose of this study is to investigate the role of specific salivary oral microbiome in susceptibility to SARS-CoV-2 infection.

Methods and results

One hundred six subjects of known medical and dental history who consented to provide saliva samples between January 2017 and December 2019 were included in this study. Sixteen had become COVID-19 positive based on the PCR test by 3/01/2021. A comparison of oral microbiome bacteria taxa profiles based on 16S rRNA sequencing revealed differences between the two groups in this pilot study.

Conclusions

These bacteria taxa may be markers of increased susceptibility to SARS-CoV-2 infection in the unvaccinated population.

High Expression Level of α2-3-Linked Sialic Acids on Salivary Glycoproteins of Breastfeeding Women May Help to Protect Them from Avian Influenza Virus Infection

Terminal sialic acids (Sia) on soluble glycoprotein of saliva play an important role in the clearance of influenza virus. The aim of this study is to investigate the alteration of sialylation on the salivary proteins of women during the lactation period and its effect on the saliva binding ability to virus. In total, 210 saliva samples from postpartum women with and without breastfeeding were collected, and the expression level of α2-3/6-linked Sia on the whole salivary proteins and specific glycoproteins of IgA and MUC5B from different groups were tested and verified using lectin microarray, blotting analysis and ELISA based method. The H1N1 vaccine and three strains of Avian influenza virus (AIV) were used for the saliva binding assay. Results showed that the variation in salivary expression level of α2-3-linked Sia was much more obvious than the α2-6-linked Sia, which was up-regulated significantly in the breastfeeding groups compared to the non-breastfeeding groups at the same postpartum stage. Furthermore, the binding abilities of salivary glycoproteins to AIV strains and H1N1 vaccine were increased in breastfeeding groups accordingly. This finding adds new evidence for the maternal benefit of breastfeeding and provides new thinking to protect postpartum women from AIV infection.

Relationship between Oral Health Knowledge and Maternal Oral Health with Obstetric Risk and Breastfeeding

The relationship between maternal gingival health status and low birth weight or preterm delivery is controversial. The aim of this study was to analyze the association between maternal oral knowledge and the level of oral health during pregnancy with the risk of obstetric complications and breastfeeding. A descriptive cross-sectional study was conducted after an oral health educational intervention in a consecutive sample of 97 pregnant women. Data collection consisted of a validated questionnaire, oral examination, the Caries Index (CAOD) and the Simplified Oral Hygiene Index (IHOS). The participants had a mean age of 32.5 ± 5.19 years and a predominantly university education (57.1%). The level of knowledge regarding oral health was fair (12.5 ± 3.56 correct answers). Older pregnant women (33.0 ± 4.80 years) practiced breastfeeding and had a higher number of correct answers to the questionnaire. Adequate IHOS was associated with higher birth-weight newborns (3333 ± 0.3), whereas poor oral hygiene control was associated with lower birth-weight newborns (2960 ± 0.1) (p < 0.05). A lower level of academic education was associated with worse oral hygiene (p < 0.05). In addition, the greater the number of children, the higher the CAOD. Finally, among non-smoking women, the weight of infants was 437 mg higher. Maternal oral hygiene and the week of delivery were associated with newborn weight (p < 0.05) in a multiple linear regression model. Smoking was also related to low birth weight (p < 0.05). Educational interventions in pregnancy are necessary to decrease the incidence of obstetric adverse effects and improve the oral health of mothers and their children.

It Takes Two to Tango: A Review of Oncogenic Virus and Host Microbiome Associated Inflammation in Head and Neck Cancer

Simple Summary

Certain viruses, specifically, human papillomavirus (HPV) and Epstein–Barr virus (EBV), have been linked with the development of head and neck cancer. In this study, we review the mechanisms by which (these) viruses lead to cellular transformation and a chronic inflammatory state. Given that the head and neck host a rich microbiome (which itself is intrinsically linked to inflammation), we scrutinize the literature to highlight the interplay between viruses, cellular transformation, inflammation, and the local host microbiome in head and neck cancer.

Abstract

While the two primary risk factors for head and neck squamous cell carcinoma (HNSCC) are alcohol and tobacco, viruses account for an important and significant upward trend in HNSCC incidence. Human papillomavirus (HPV) is the causative agent for a subset of oropharyngeal squamous cell carcinoma (OPSCC)—a cancer that is impacting a rapidly growing group of typically middle-aged non-smoking white males. While HPV is a ubiquitously present (with about 1% of the population having high-risk oral HPV infection at any one time), less than 1% of those infected with high-risk strains develop OPSCC—suggesting that additional cofactors or coinfections may be required. Epstein–Barr virus (EBV) is a similarly ubiquitous virus that is strongly linked to nasopharyngeal carcinoma (NPC). Both of these viruses cause cellular transformation and chronic inflammation. While dysbiosis of the human microbiome has been associated with similar chronic inflammation and the pathogenesis of mucosal diseases (including OPSCC and NPC), a significant knowledge gap remains in understanding the role of bacterial-viral interactions in the initiation, development, and progression of head and neck cancers. In this review, we utilize the known associations of HPV with OPSCC and EBV with NPC to investigate these interactions. We thoroughly review the literature and highlight how perturbations of the pharyngeal microbiome may impact host-microbiome-tumor-viral interactions—leading to tumor growth.

Pulsed blue light, saliva and curcumin significantly inactivate human coronavirus

In a recent study, we showed that pulsed blue light (PBL) inactivates as much as 52.3% of human beta coronavirus HCoV-OC43, a surrogate of SARS-CoV-2, and one of the major strains of viruses responsible for the annual epidemic of the common cold. Since curcumin and saliva are similarly antiviral and curcumin acts as blue light photosensitizer, we used Qubit fluorometry and WarmStart RT-LAMP assays to study the effect of combining 405 nm, 410 nm, 425 nm or 450 nm wavelengths of PBL with curcumin, saliva or a combination of curcumin and saliva against human beta coronavirus HCoV-OC43. The results showed that PBL, curcumin and saliva independently and collectively inactivate HCoV-OC43. Without saliva or curcumin supplementation 21.6 J/cm2 PBL reduced HCoV-OC43 RNA concentration a maximum of 32.8% (log10 = 2.13). Saliva supplementation alone inactivated the virus, reducing its RNA concentration by 61% (log10 = 2.23); with irradiation the reduction was as much as 79.1%. Curcumin supplementation alone decreased viral RNA 71.1%, and a maximum of 87.8% with irradiation. The combination of saliva and curcumin reduced viral RNA to 83.1% and decreased the RNA up to 90.2% with irradiation. The reduced levels could not be detected with qPCR. These findings show that PBL in the range of 405 nm to 450 nm wavelength is antiviral against human coronavirus HCoV-OC43, a surrogate of the COVID-19 virus. Further, it shows that with curcumin as a photosensitizer, it is possible to photodynamically inactivate the virus beyond qPCR detectable level using PBL. Since HCoV-OC43 is of the same beta coronavirus family as SARS-CoV-2, has the same genomic size, and is often used as its surrogate, these findings heighten the prospect of similarly inactivating novel coronavirus SARS-CoV-2, the virus responsible for COVID-19 pandemic.