Oral microbiomes in children with asthma and dental caries

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.

Circulating microbiome analysis in patients with perioperative anaphylaxis

Background

Perioperative anaphylaxis is a rare and acute systemic manifestation of drug-induced hypersensitivity reactions that occurs following anesthesia induction; the two main classes of drugs responsible for these reactions being neuromuscular blocking agents (NMBA) and antibiotics. The sensitization mechanisms to the drugs are not precisely known, and few risk factors have been described. A growing body of evidence underlines a link between occurrence of allergy and microbiota composition. However, no data exist on microbiota in perioperative anaphylaxis. The aim of this study was to compare circulating microbiota richness and composition between perioperative anaphylaxis patients and matched controls.

Methods

Circulating 16s rDNA was quantified and sequenced in serum samples from 20 individuals with fully characterized IgE-mediated NMBA-related anaphylaxis and 20 controls matched on sex, age, NMBA received, type of surgery and infectious status. Microbiota composition was analyzed with a published bioinformatic pipeline and links with patients clinical and biological data investigated.

Results

Analysis of microbiota diversity showed that anaphylaxis patients seem to have a richer circulating microbiota than controls, but no major differences of composition could be detected with global diversity indexes. Pairwise comparison showed a difference in relative abundance between patients and controls for Saprospiraceae, Enterobacteriaceae, Veillonellaceae, Escherichia-Shigella, Pseudarcicella, Rhodoferax, and Lewinella. Some taxa were associated with concentrations of mast cell tryptase and specific IgE.

Conclusion

We did not find a global difference in terms of microbiota composition between anaphylaxis patient and controls. However, several taxa were associated with anaphylaxis patients and with their biological data. These findings must be further confirmed in different settings to broaden our understanding of drug anaphylaxis pathophysiology and identify predisposition markers.

Drugs Prescribed for Asthma and Their Adverse Effects on Dental Health

Asthma is a chronic, heterogeneous respiratory pathology characterized by reversible airway inflammation. Therapeutics focus on symptom reduction and control, aimed at preserving normal pulmonary function and inducing bronchodilatation. The objective of this review is to describe the adverse effects produced by anti-asthmatic drugs on dental health, according to the reported scientific evidence. A bibliographic review was carried out on databases, such as Web of science, Scopus, and ScienceDirect. Most anti-asthmatic medications are administered using inhalers or nebulizers, making it impossible to avoid contact of the drug with hard dental tissues and oral mucosa, and thus promoting a greater risk of oral alterations, mainly due to decreases in the salivary flow and pH. Such changes can cause diseases, such as dental caries, dental erosion, tooth loss, periodontal disease, bone resorption, as well as fungal infections, such as oral candidiasis.

Decreased salivary beta-defensin 2 in children with asthma after treatment with corticosteroid inhaler

PURPOSE

Asthma is the most common chronic disorder in childhood. Inhaled corticosteroid therapy is currently the most effective treatment for Asthma. The oral cavity complications related to this treatment may be in terms of the changes in the innate immune system of mouth. Salivary defensin has many immunomodulatory properties. The expression of beta-defensin 2 was measured before and after inhaled corticosteroid treatment in children with asthma to determine the potential impact of corticosteroids on defensin expression.

METHODS

The present study was a cohort study conducted on the patients referred to Children's Medical Center for whom a diagnosis of Asthma was confirmed, and inhaled corticosteroid therapy was prescribed. Saliva was sampled once at the stage of diagnosis and before receiving any treatment. Another salivary sample was collected 4 weeks after receiving corticosteroids. ELISA was performed to assess beta-defensin 2.

RESULTS

The beta-defensin 2 salivary level after inhaled corticosteroid therapy was significantly lower than before treatment. There is no significant difference in the salivary flow rate before and after treatment.

CONCLUSIONS

Considering the limitations of the present study, the following conclusions can be made salivary beta-defensin 2 is decreased in children with asthma after treatment with a corticosteroid inhaler. Regular dental and oral soft tissue examinations in Asthmatic children under corticosteroid therapy could be suggested.

Differential network analysis of oral microbiome metatranscriptomes identifies community scale metabolic restructuring in dental caries

Dental caries is a microbial disease and the most common chronic health condition, affecting nearly 3.5 billion people worldwide. In this study, we used a multiomics approach to characterize the supragingival plaque microbiome of 91 Australian children, generating 658 bacterial and 189 viral metagenome-assembled genomes with transcriptional profiling and gene-expression network analysis. We developed a reproducible pipeline for clustering sample-specific genomes to integrate metagenomics and metatranscriptomics analyses regardless of biosample overlap. We introduce novel feature engineering and compositionally-aware ensemble network frameworks while demonstrating their utility for investigating regime shifts associated with caries dysbiosis. These methods can be applied when differential abundance modeling does not capture statistical enrichments or the results from such analysis are not adequate for providing deeper insight into disease. We identified which organisms and metabolic pathways were central in a coexpression network as well as how these networks were rewired between caries and caries-free phenotypes. Our findings provide evidence of a core bacterial microbiome that was transcriptionally active in the supragingival plaque of all participants regardless of phenotype, but also show highly diagnostic changes in the ways that organisms interact. Specifically, many organisms exhibit high connectedness with central carbon metabolism to Cardiobacterium and this shift serves a bridge between phenotypes. Our evidence supports the hypothesis that caries is a multifactorial ecological disease.

Malocclusions in Pediatric Patients with Asthma: A Case-Control Study

Asthma is a public health problem that has been widely described, but little has been reported about its effects on dental occlusions. The aim of this study was to compare the alterations of normal occlusions in asthmatic children and those without the disease. The study included 186 patients between 5 and 12 years old, divided into two groups. The first group included patients with a previous diagnosis of asthma given by a specialist, which was confirmed by using the International Study of Asthma and Allergies in Childhood questionnaire. The second group included patients without the disease. All patients underwent a clinical examination to determine the presence of occlusion alterations in the sagittal, transverse, and vertical planes. Subsequently, chi-squared tests were performed to compare the variables between the groups. A significant association was found between asthma and the variables studied here: alterations in the sagittal plane (chi2 = 7.839, p = 0.005), alterations in the vertical plane (chi2 = 13.563, p < 0.001), alterations in the transverse plane (Fisher’s F p < 0.001), and oral habits (chi2 = 55.811, p < 0.001). The results suggest that asthmatic patients are more likely to develop malocclusions, especially anterior open bite and posterior crossbite. These conditions are typically related to mouth breathing, which is common in asthmatic patients.

Streptococcus mutans-associated bacteria in dental plaque of severe early childhood caries

Background

Streptococcus mutans (S. mutans) is a potential pathogenic bacteria of dental caries. However, the level of S. mutans is low in some children with severe early childhood caries (SECC)

Aim

To evaluate the effect of S. mutans level on dental microbiome and cariogenesis.

Methods

The oral microbiota was compared between caries-free group (CF) and SECC group.16S rRNA gene sequencing was used for S. mutans level bacterial community analysis. The candidate bacteria that were closely related with S. mutans abundance were identified and confirmed by absolute quantitative real-time PCR in clinical dental plaque samples from CF and SECC groups.

Results

Through in-depth analysis of dental plaque microorganism, Leptotrichia, Selenomonas and Prevotella_7 were found in the S. mutans-low group (p < 0.05) and Porphyromonas, Selenomonas_3 were found in the S. mutans-high group (p < 0.05). Through quantitative real-time PCR, Leptotrichia, Selenomonas and Prevotella_7 were identified as the potential biomarkers of SECC when S. mutans was at a low level.

Conclusion

Leptotrichia, Selenomonas and Prevotella_7 are identified as potential biomarkers in SECC with a low abundance or without S. mutans. Our study may shed light on the understanding of caries occurrence in SECC with low abundance of S. mutans.

Abbreviations

S. mutans, Streptococcus mutans; CF, caries-free; SECC, severe early childhood caries; ECC, early childhood caries; rRNA, ribosome RNA; qPCR, Quantitative real-time PCR; OTUs, operational taxonomic units; ANOVA, analysis of variance; LDA, Linear discriminant analysis; LEfSe, Linear discriminant analysis effect size; COG, Groups of proteins; NMDS, Non-MetricMulti-Dimensional Scaling; IL-1β, interleukin −1β; IL-6, interleukin-6; IL-8, interleukin-8; IL-10, interleukin-10.

Relationships Between Oral Microecosystem and Respiratory Diseases

Oral microecosystem is a very complicated ecosystem that is located in the mouth and comprises oral microbiome, diverse anatomic structures of oral cavity, saliva and interactions between oral microbiota and between oral microbiota and the host. More and more evidence from studies of epidemiology, microbiology and molecular biology is establishing a significant link between oral microecosystem and respiratory diseases. Microbiota settling down in oral microecosystem is known as the main source of lung microbiome and has been associated with the occurrence and development of respiratory diseases like pneumonia, chronic obstructive pulmonary disease, lung cancer, cystic fibrosis lung disease and asthma. In fact, it is not only indigenous oral microbes promote or directly cause respiratory infection and inflammation when inhaled into the lower respiratory tract, but also internal environment of oral microecosystem serves as a reservoir for opportunistic respiratory pathogens. Moreover, poor oral health and oral diseases caused by oral microecological dysbiosis (especially periodontal disease) are related with risk of multiple respiratory diseases. Here, we review the research status on the respiratory diseases related with oral microecosystem. Potential mechanisms on how respiratory pathogens colonize oral microecosystem and the role of indigenous oral microbes in pathogenesis of respiratory diseases are also summarized and analyzed. Given the importance of oral plaque control and oral health interventions in controlling or preventing respiratory infection and diseases, we also summarize the oral health management measures and attentions, not only for populations susceptible to respiratory infection like the elderly and hospitalized patients, but also for dentist or oral hygienists who undertake oral health care. In conclusion, the relationship between respiratory diseases and oral microecosystem has been established and supported by growing body of literature. However, etiological evidence on the role of oral microecosystem in the development of respiratory diseases is still insufficient. Further detailed studies focusing on specific mechanisms on how oral microecosystem participate in the pathogenesis of respiratory diseases could be helpful to prevent and treat respiratory diseases.

Gut microbiota in a population highly affected by obesity and type 2 diabetes and susceptibility to COVID-19

Coronavirus disease 2019 (COVID-19) is a disease produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is currently causing a catastrophic pandemic affecting humans worldwide. This disease has been lethal for approximately 3.12 million people around the world since January 2020. Globally, among the most affected countries, Mexico ranks third in deaths after the United States of America and Brazil. Although the high number of deceased people might also be explained by social aspects and lifestyle customs in Mexico, there is a relationship between this high proportion of deaths and comorbidities such as high blood pressure (HBP), type 2 diabetes, obesity, and metabolic syndrome. The official epidemiological figures reported by the Mexican government have indicated that 18.4% of the population suffers from HBP, close to 10.3% of adults suffer from type 2 diabetes, and approximately 36.1% of the population suffers from obesity. Disbalances in the gut microbiota (GM) have been associated with these diseases and with COVID-19 severity, presumably due to inflammatory dysfunction. Recent data about the association between GM dysbiosis and metabolic diseases could suggest that the high levels of susceptibility to SARS-CoV-2 infection and COVID-19 morbidity in the Mexican population are primarily due to the prevalence of type 2 diabetes, obesity, and metabolic syndrome.

Associations between dental caries and systemic diseases: a scoping review

BACKGROUND

The objective of this study was to evaluate and present evidence from animal and human clinical studies on associations between dental caries and systemic diseases, and to suggest potential mechanisms that might explain such associations.

METHODS

An electronic search was conducted of PubMed, Embase and Cochrane Central Register of Controlled Trials for articles published from 2010 to 2020 in the English language. From the initial search, 404 full-text studies were assessed for eligibility. After excluding studies for technical and study limitations, a total of 67 studies were included in the summary tables and additional studies were included in the review to support evidence.

RESULTS

Few systemic disease and conditions were found to be clinically meaningfully associated with caries experience. Best evidence from human and animal studies described association between metabolic diseases and dental caries. Several interesting animal studies were noted that could generate clinical hypotheses and further investigations in rodent models for cardiovascular injury and hyperglycemia. Inadequate data was found to suggest any modifications to current clinical practice or prevention guidelines.

CONCLUSIONS

Limited clinical evidence was found connecting several systemic diseases and dental caries. Inadequate data was found to suggest any modifications to current clinical practice or prevention guidelines.

CLINICAL SIGNIFICANCE

Understanding of associations between dental caries and systemic diseases play a crucial role in the treatment planning and education of the dental patient.

Microbiome of Saliva and Plaque in Children According to Age and Dental Caries Experience

Dental caries are one of the chronic diseases caused by organic acids made from oral microbes. However, there was a lack of knowledge about the oral microbiome of Korean children. The aim of this study was to analyze the metagenome data of the oral microbiome obtained from Korean children and to discover bacteria highly related to dental caries with machine learning models. Saliva and plaque samples from 120 Korean children aged below 12 years were collected. Bacterial composition was identified using Illumina HiSeq sequencing based on the V3–V4 hypervariable region of the 16S rRNA gene. Ten major genera accounted for approximately 70% of the samples on average, including Streptococcus, Neisseria, Corynebacterium, and Fusobacterium. Differential abundant analyses revealed that Scardovia wiggsiae and Leptotrichia wadei were enriched in the caries samples, while Neisseria oralis was abundant in the non-caries samples of children aged below 6 years. The caries and non-caries samples of children aged 6–12 years were enriched in Streptococcus mutans and Corynebacterium durum, respectively. The machine learning models based on these differentially enriched taxa showed accuracies of up to 83%. These results confirmed significant alterations in the oral microbiome according to dental caries and age, and these differences can be used as diagnostic biomarkers.

The role of oral microbiome in respiratory health and diseases

The oral cavity (mouth) has various microbial habitats, including, teeth, gingival sulcus, gingiva, tongue, inner cheek, hard palate, and soft palate. The human oral cavity houses the second most diverse microbiome in the body harboring over 700 bacterial species. The fine-tuned equilibrium of the oral microbiome ecosystem maintains oral health. Oral dysbiosis caused by food habits and poor oral hygiene leads to various oral diseases such as periodontitis, caries, gingivitis, and oral cancer. Recent advances in technology have revealed the correlation between the oral microbiome and systemic diseases such as pulmonary diseases, cardiovascular diseases, rheumatoid arthritis, Alzheimer's disease, and other metabolic diseases. Since the oral cavity directly connects with the upper respiratory tract, the oral microbiome has easier access to the respiratory system compared to other organ systems. Direct aspiration of oral microflora in the respiratory system and oral dysbiosis-induced host immune reaction and inflammation are mainly responsible for various pulmonary complications. Numbers of literature have reported the correlation between oral diseases and pulmonary diseases, suggesting the possible role of the oral microbiome in respiratory diseases such as chronic obstructive pulmonary diseases, pneumonia, lung cancer, etc. This paper reviews the current evidence in establishing a link between the oral microbiome and pulmonary diseases. We also discuss future research directions focusing on the oral microbiome to unravel novel therapeutic approaches that could prevent or treat the various pulmonary complications.

Microbiomes of colored dental biofilms in children with or without severe caries experience

BACKGROUND

Biofilm coloration can compromise maturation and increase the risk of oral disease in adulthood, though children with colored biofilm do not always demonstrate a poor oral health status.

AIM

The microbial compositions of colored and white biofilms in children were compared.

DESIGN

Thirty-two dental biofilm samples from 16 children (age < 13 years) were analyzed using 16S rRNA pyrosequencing, then the subjects were divided into severe caries and healthy (caries-free) groups. Correlations between microbiomes and oral health status were also examined.

RESULTS

Phylogenetic analysis revealed no distinctly different patterns between colored and white biofilms. In the severe caries group, genus Actinomyces, Cardiobacterium, Kingella, Lautropia, and Veillonella, and family Neisseriaceae were detected, though abundance was significantly different between colored and white biofilm specimens, in contrast to the healthy group. In addition, five colored biofilm samples from the severe caries group contained greater than 15% Actinomyces, which led us to consider that genus to be possibly associated with formation of colored biofilm in children.

CONCLUSIONS

Our findings indicate that differences in bacterial composition between colored and white biofilms are higher in individuals with severe caries. Additional research may reveal the significance of colored dental biofilm in children.

Bacterial salivary microbiome associates with asthma among african american children and young adults

Several studies have shown that the airways of asthma patients contain higher diversity of bacteria and are enriched in pathogenic species. However, sampling the airways in children is challenging. Here we aimed to identify differences in the salivary bacterial composition between African Americans children with and without asthma. Saliva samples from 57 asthma cases and 57 healthy controls were analyzed by means of 16S ribosomal RNA amplicon profiling. Measurements of bacterial diversity and genus relative abundance were compared between cases and controls using the nonparametric Wilcoxon test and multivariate regression models. A total of five phyla and a mean of 56 genera were identified. Among them, 15 genera had a relative abundance greater than 1%, being Prevotella, Haemophilus, Streptococcus, and Veillonella the most abundant genera. Differences between cases and controls were found in terms of diversity, as well as in relative abundance for Streptococcus genus (13.0% in cases vs 18.3% in controls; P = .003) and Veillonella genus (11.1% in cases vs 8.0% in controls; P = .002). These differences remained significant after correction for multiple comparisons and when potential confounders were taken into account in logistic regression models. In conclusion, we identified changes in the salivary microbiota associated with asthma among African Americans.