Periodontal Status and Microbiologic Pathogens in Patients with Chronic Obstructive Pulmonary Disease and Periodontitis: A Case-Control Study

Combined application of Er:YAG laser and low-level laser in non-surgical treatment of periodontitis

BACKGROUND

To compare the efficacy of combined treatment of Er:YAG laser (ERL) and low-level laser therapy (LLLT) with single laser applications, and scaling and root planing (SRP) for non-surgical periodontal treatment.

METHODS

In a randomized controlled trial, 25 non-smoking Stage II or Stage III periodontitis patients were recruited. The four intraoral quadrants were randomly assigned to four different treatments: (1) combined application with ERL plus SRP plus LLLT; (2) ERL plus SRP; (3) SRP plus LLLT; and (4) SRP. We assessed periodontal indexes, including probing depth (PD), clinical attachment level (CAL), bleeding index (BI), and plaque index (PLI), along with three cytokines (IL-1β, TNF-α, IL-10) from gingival crevicular fluid and red complex pathogens from subgingival dental plaque at baseline, 3 months, and 6 months.

RESULTS

For initial moderate pockets (4 mm ≤ PD ≤ 6 mm), quadrants treated with ERL+SRP+LLLT, ERL+SRP, and SRP+LLLT exhibited greater PD improvement compared to the control (SRP) quadrants at the 3-month follow-up (1.25 ± 1.06, 1.23 ± 1.12, 1.00 ± 1.21 vs. 0.98 ± 1.21 mm) and the 6-month follow-up (1.35 ± 1.06, 1.23 ± 1.17, 1.35 ± 0.98 vs. 0.98 ± 1.23 mm) (p = 0.002). Quadrants treated with ERL+SRP+LLLT and SRP+LLLT showed more CAL gain means than the control quadrants at the 3-month follow-up (0.96 ± 1.42, 0.61 ± 1.39 vs. 0.55 ± 1.57 mm) and the 6-month follow-up (0.84 ± 1.54, 0.89 ± 1.49 vs. 0.48 ± 1.68 mm) (p = 0.008). For initial deep pockets (PD ≥ 7 mm), the ERL+SRP+LLLT quadrants had more PD improvement and CAL gain compared to the control quadrants at follow-up. There were no significant differences in BI, PLI, inflammatory cytokines, and periodontal pathogens among the four groups.

CONCLUSION

The combined application of ERL and LLLT demonstrated potential efficacy in reducing PD, particularly for deep pockets.

PLAIN LANGUAGE SUMMARY

To compare the therapy effect of combined use of Er:YAG laser (ERL) and low level laser therapy (LLLT) with single laser applications, and traditional periodontal treatment (SRP). A total of 25 non smoking patients with periodontitis were involved, and their mouths were divided into four sections, each receiving a different treatment: ERL+SRP+LLLT, ERL+SRP, SRP+LLLT, and SRP. Clinical indexes and laboratory indicators were assessed at baseline, 3 months, and 6 months. After six months, for initial moderate pockets, combined laser group and single laser group showed better improvements than traditional group in reducing the depth of periodontal pockets and increasing attachment levels. But for initial deep pockets, only combined laser group showed better improvement than traditional group. There were no significant differences in bleeding, plaque, inflammation, or harmful bacterial levels among the groups. These findings suggest that the integration of Er:YAG laser and low level laser therapy into standard periodontal treatment may enhance the treatment's benefits in reducing pocket depth, especially for severe conditions.

Periodontal disease increases the severity of chronic obstructive pulmonary disease: a Mendelian randomization study

BACKGROUND

Recent research suggests that periodontitis can increase the risk of chronic obstructive pulmonary disease (COPD). In this study, we performed two-sample Mendelian randomization (MR) and investigated the causal effect of periodontitis (PD) on the genetic prediction of COPD. The study aimed to estimate how exposures affected outcomes.

METHODS

Published data from the Gene-Lifestyle Interaction in the Dental Endpoints (GLIDE) Consortium's genome-wide association studies (GWAS) for periodontitis (17,353 cases and 28,210 controls) and COPD (16,488 cases and 169,688 controls) from European ancestry were utilized. This study employed a two-sample MR analysis approach and applied several complementary methods, including weighted median, inverse variance weighted (IVW), and MR-Egger regression. Multivariable Mendelian randomization (MVMR) analysis was further conducted to mitigate the influence of smoking on COPD.

RESULTS

We chose five single-nucleotide polymorphisms (SNPs) as instrumental variables for periodontitis. A strong genetically predicted causal link between periodontitis and COPD, that is, periodontitis as an independent risk factor for COPD was detected. PD (OR = 1.102951, 95% CI: 1.005-1.211, p = 0.039) MR-Egger regression and weighted median analysis results were coincident with those of the IVW method. According to the sensitivity analysis, horizontal pleiotropy's effect on causal estimations seemed unlikely. However, reverse MR analysis revealed no significant genetic causal association between COPD and periodontitis. IVW (OR = 1.048 > 1, 95%CI: 0.973-1.128, p = 0.2082) MR Egger (OR = 0.826, 95%CI:0.658-1.037, p = 0.1104) and weighted median (OR = 1.043, 95%CI: 0.941-1.156, p = 0.4239). The results of multivariable Mendelian randomization (MVMR) analysis, after adjusting for the confounding effect of smoking, suggest a potential causal relationship between periodontitis and COPD (P = 0.035).

CONCLUSION

In this study, periodontitis was found to be independent of COPD and a significant risk factor, providing new insights into periodontitis-mediated mechanisms underlying COPD development.

Association between periodontal diseases and chronic obstructive pulmonary disease: Evidence from sequential cross-sectional and prospective cohort studies based on UK Biobank

AIM

To investigate the association between periodontal diseases, airflow limitation and incident chronic obstructive pulmonary disease (COPD) in a large-scale prospective UK Biobank cohort.

MATERIALS AND METHODS

Our approach comprised a cross-sectional study and a prospective cohort. Periodontal diseases were determined based on the participants' self-reported dental symptoms, including painful gums, bleeding gums and loose teeth. Logistic regression and Cox proportional hazards models were used to evaluate the association of periodontal diseases with airflow limitation and incident COPD in the cross-sectional study and the prospective cohort, respectively.

RESULTS

The cross-sectional study involved 495,610 participants. Multivariable analysis found that periodontal diseases were significantly associated with airflow limitation (odds ratio = 1.036, 95% confidence interval [CI]: 1.015-1.059). The cohort study included 379,266 participants with a median follow-up period of 12.68 years. An elevated risk of incident COPD was associated with the presence of periodontal diseases (hazard ratio: 1.248, 95% CI: 1.174-1.326). The effect was consistent among subgroups, including baseline age (≤65 or >65 years), sex, smoking status and diabetes mellitus.

CONCLUSIONS

Periodontal diseases are associated with airflow limitation and elevated COPD incidence. Maintaining good periodontal health in patients with chronic bronchitis and emphysema may help prevent the onset of COPD.

Periodontitis is associated with airflow obstruction in the Malmö Offspring Dental Study

AIM

To investigate the association between periodontitis and lung function in the Malmö Offspring Dental Study.

MATERIALS AND METHODS

In all 1001 individuals (49.9% female, mean age: 44.6) from Malmö Offspring Dental Study were included. Periodontitis was assessed by a full-mouth examination protocol including bleeding on probing and classified according to the American Academy of Periodontology/Center for Disease Control definitions. Forced expiratory volume in 1 s (FEV1 ) and forced vital capacity (FVC) were expressed as absolute values and %predicted according to Global Lung Function Initiative reference values. FEV1 , FVC and FEV1 /FVC were analysed in relation to periodontal status using linear regression.

RESULTS

Severe periodontitis was found in 7% of the population. Adjusted regression models showed significant associations between lung function and severe periodontitis with 2.1 unit lower FEV1 /FVC ratio (95% CI: -3.91, -0.23) and odds ratio (adjusted) of 2.56 (95% CI: 1.40, 4.75, p = .003) for airflow obstruction (FEV1 /FVC less than the lower limit of normal) if having severe periodontitis. Lower values of %predicted FEV1 and %predicted FVC, but not FEV1 /FVC, were found in individuals with >25% bleeding on probing.

CONCLUSIONS

Severe periodontitis was associated with lower FEV1 /FVC ratio and airflow obstruction in the present cohort. More large-scale prospective studies and intervention studies are required for a comprehensive evaluation.

Association between periodontal disease and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) and periodontal disease are chronic inflammatory conditions that significantly affect an individual's overall health and well-being. Generally, the prevalence of periodontitis is higher in patients with COPD than those without COPD, which may partly be attributed to common risk factors in COPD, such as smoking, respiratory infections, and inflammation. In particular, periodontitis may exacerbate the progression of COPD and further deteriorate the respiratory system by promoting inflammatory responses and bacterial infections. Immunocytes, including neutrophils, and microorganisms such as Fusobacterium nucleatum originating from oral biofilms are believed to be crucial factors influencing to COPD. Furthermore, the potential benefits of treating periodontal disease in COPD outcomes have been investigated. Although the relationship between COPD and periodontal disease has been preliminarily studied, there is currently a lack of large-scale clinical studies to validate this association. In addition to clinical examinations, investigating biomarkers and microbiology may contribute to explore the underlying mechanisms involved in the management of these conditions. This review aims to contribute to a better understanding of the clinical and basic research aspects of COPD and periodontitis, allowing for potential therapeutic approaches and interdisciplinary management strategies.

Periodontitis contributes to COPD progression via affecting ferroptosis

BACKGROUND

Periodontitis has emerged as a potential risk factor for chronic obstructive pulmonary disease (COPD). However, the precise mechanism through which periodontitis influences the progression of COPD requires further investigation. Ferroptosis is one of the crucial pathogenesis of COPD and recent researches suggested that periodontitis was associated with ferroptosis. Nonetheless, the relationship among periodontitis, COPD and ferroptosis remains unclear. This study aimed to elucidate whether periodontitis contributes to COPD exacerbation and to assess the potential impact of ferroptosis on periodontitis affecting COPD.

METHODS

The severity of COPD was assessed using Hematoxylin and eosin (H&E) staining and lung function tests. Iron assays, malondialdehyde (MDA) measurement and RT-qPCR were used to investigate the potential involvement of ferroptosis in the impact of periodontitis on COPD. Co-cultures of periodontitis associated pathogen Phophyromonas gingivalis (P. gingivalis) and lung tissue cells were used to evaluate the effect of P. gingivalis on inducing the ferroptosis of lung tissue via RT-qPCR analysis. Clinical Bronchoalveolar Lavage Fluid (BALF) samples from COPD patients were collected to further validate the role of ferroptosis in periodontal pathogen-associated COPD.

RESULTS

Periodontitis aggravated the COPD progression and the promotion was prolonged over time. For the first time, we demonstrated that periodontitis promoted the ferroptosis-associated iron accumulation, MDA contents and gene expressions in the COPD lung with a time-dependent manner. Moreover, periodontitis-associated pathogen P. gingivalis could promote the ferroptosis-associated gene expression in single lung tissue cell suspensions. Clinical BALF sample detection further indicated that ferroptosis played essential roles in the periodontal pathogen-associated COPD.

CONCLUSION

Periodontitis could contribute to the exacerbation of COPD through up-regulating the ferroptosis in the lung tissue.

Putative Bidirectionality of Chronic Obstructive Pulmonary Disease and Periodontal Disease: A Review of the Literature

The prevalence of chronic obstructive pulmonary disease (COPD) is increasing worldwide and is currently the third leading cause of death globally. The long-term inhalation of toxic substances, mainly cigarette smoke, deteriorates pulmonary function over time, resulting in the development of COPD in adulthood. Periodontal disease is an inflammatory condition that affects most adults and is caused by the bacteria within dental plaque. These bacteria dissolve the gums around the teeth and the bone that supports them, ultimately leading to tooth loss. Periodontal disease and COPD share common risk factors, such as aging and smoking. Other similarities include local chronic inflammation and links with the onset and progression of systemic diseases such as ischemic heart disease and diabetes mellitus. Understanding whether interventions for periodontal disease improve the disease trajectory of COPD (and vice versa) is important, given our rapidly aging society. This review focuses on the putative relationship between COPD and periodontal disease while exploring current evidence and future research directions.

Research on the Association Between Periodontitis and COPD

Periodontitis is a common chronic bacteria-initiated inflammatory disease that is closely associated with various systemic diseases, including chronic obstructive pulmonary disease (COPD). Periodontitis and COPD share similar risk factors, pathology and microorganisms. Epidemiological and clinical research have shown positive correlation between the two diseases. Individuals with severe periodontitis had a higher risk of developing COPD. Moreover, the relative risk of COPD in severe periodontitis was much higher compared to people without periodontal disease and patients with mild to moderate periodontitis. COPD patients with periodontitis had a higher frequency of COPD exacerbation and periodontal treatment demonstrated some control of COPD. However, the nature of periodontitis affecting COPD still needs further exploration. Periodontitis caused microbial and immune imbalances of the lung through several aspects: (I) under periodontitis status, periodontal pathogens directly caused the lung inflammatory reaction after inhalation and colonization on the lung, (II) periodontitis status promoted the oral colonization of pneumonia-associated pathogens, (III) periodontitis status affected the respiratory epithelium structure and (IV) periodontitis status caused imbalances in neutrophils, macrophages and inflammatory cytokines. In this review, we conclude the association between periodontitis and COPD through several aspects and further discuss the potential mechanism by which periodontitis affects COPD.

Periodontopathogens Porphyromonas gingivalis and Fusobacterium nucleatum and Their Roles in the Progression of Respiratory Diseases

The intricate interplay between oral microbiota and the human host extends beyond the confines of the oral cavity, profoundly impacting the general health status. Both periodontal diseases and respiratory diseases show high prevalence worldwide and have a marked influence on the quality of life for the patients. Accumulating studies are establishing a compelling association between periodontal diseases and respiratory diseases. Here, in this review, we specifically focus on the key periodontal pathogenic bacteria Porphyromonas gingivalis and Fusobacterium nucleatum and dissect their roles in the onset and course of respiratory diseases, mainly pneumonia, chronic obstructive pulmonary disease, lung cancer, and asthma. The mechanistic underpinnings and molecular processes on how P. gingivalis and F. nucleatum contribute to the progression of related respiratory diseases are further summarized and analyzed, including: induction of mucus hypersecretion and chronic airway inflammation; cytotoxic effects to disrupt the morphology and function of respiratory epithelial cells; synergistic pathogenic effects with respiratory pathogens like Streptococcus pneumoniae and Pseudomonas aeruginosa. By delving into the complex relationship to periodontal diseases and periodontopathogens, this review helps unearth novel insights into the etiopathogenesis of respiratory diseases and inspires the development of potential therapeutic avenues and preventive strategies.

Characterization of the upper respiratory tract microbiota in Chilean asthmatic children reveals compositional, functional, and structural differences

Around 155 million people worldwide suffer from asthma. In Chile, the prevalence of this disease in children is around 15% and has a high impact in the health system. Studies suggest that asthma is caused by multiple factors, including host genetics, antibiotic use, and the development of the airway microbiota. Here, we used 16S rRNA high-throughput sequencing to characterize the nasal and oral mucosae of 63 asthmatic and 89 healthy children (152 samples) from Santiago, Chile. We found that the nasal mucosa was dominated by a high abundance of Moraxella, Dolosigranulum, Haemophilus, Corynebacterium, Streptococcus, and Staphylococcus. In turn, the oral mucosa was characterized by a high abundance of Streptococcus, Haemophilus, Gemella, Veillonella, Neisseria, and Porphyromonas. Our results showed significantly (P < 0.001) lower alpha diversity and an over-abundance of Streptococcus (P < 0.01) in nasal samples from asthmatics compared to samples from healthy subjects. Community structure, as revealed by co-occurrence networks, showed different microbial interactions in asthmatic and healthy subjects, particularly in the nasal microbiota. The networks revealed keystone genera in each body site, including Prevotella, Leptotrichia, and Porphyromonas in the nasal microbiota, and Streptococcus, Granulicatella, and Veillonella in the oral microbiota. We also detected 51 functional pathways differentially abundant on the nasal mucosa of asthmatic subjects, although only 13 pathways were overrepresented in the asthmatic subjects (P < 0.05). We did not find any significant differences in microbial taxonomic (composition and structure) and functional diversity between the oral mucosa of asthmatic and healthy subjects. This study explores for the first time the relationships between the upper respiratory airways bacteriome and asthma in Chile. It demonstrates that the nasal cavity of children from Santiago harbors unique bacterial communities and identifies potential taxonomic and functional biomarkers of pediatric asthma.

Association between chronic obstructive pulmonary disease and periodontal disease: a systematic review and meta-analysis

Objectives

Studies have suggested contradictory results on the relationship between chronic obstructive pulmonary disease (COPD) and periodontal disease (PD). The aim of this study was to determine whether PD increased the risk of COPD and COPD-related clinical events.

Design

A systematic review and meta-analysis.

Data sources

PubMed, Ovid EMBASE and Ovid CENTRAL were searched from inception to 22 February 2023.

Eligibility criteria for studies

We included trials and observational studies evaluating association of PD with the risk of COPD or COPD-related events (exacerbation and mortality), with statistical adjustment for smoking.

Data extraction and synthesis

Two investigators independently extracted data from selected studies using a standardised Excel file. Quality of studies was evaluated using the Newcastle-Ottawa Scale. OR with 95% CI was pooled in a random-effect model with inverse variance method.

Results

22 observational studies with 51 704 participants were included. Pooled analysis of 18 studies suggested that PD was weakly associated with the risk of COPD (OR: 1.20, 95% CI 1.09 to 1.32). However, in stratified and subgroup analyses, with strict adjustment for smoking, PD no longer related to the risk of COPD (adjusting for smoking intensity: OR: 1.14, 95% CI 0.86 to 1.51; smokers only: OR: 1.46, 95% CI 0.92 to 2.31; never smokers only: OR: 0.93, 95% CI 0.72 to 1.21). Moreover, PD did not increase the risk of COPD-related exacerbation or mortality (OR: 1.18, 95% CI 0.71 to 1.97) in the pooled result of four studies.

Conclusions

This study demonstrates PD confers no risk for COPD and COPD-related events when strictly adjusted by smoking. Large-scale prospective cohort studies with control of potential confounding factors are warranted to validate the present findings.

Sputum Microbiome and Chronic Obstructive Pulmonary Disease in a Rural Ugandan Cohort of Well-Controlled HIV Infection

Sub-Saharan Africa has increased morbidity and mortality related to chronic obstructive pulmonary disease (COPD). COPD among people living with HIV (PLWH) has not been well studied in this region, where HIV/AIDS is endemic. Increasing evidence suggests that respiratory microbial composition plays a role in COPD severity. Therefore, we aimed to investigate microbiome patterns and associations among PLWH with COPD in Sub-Saharan Africa. We conducted a cross-sectional study of 200 adults stratified by HIV and COPD in rural Uganda. Induced sputum samples were collected as an easy-to-obtain proxy for the lower respiratory tract microbiota. We performed 16S rRNA gene sequencing and used PICRUSt2 (version 2.2.3) to infer the functional profiles of the microbial community. We used a statistical tool to detect changes in specific taxa that searches and adjusts for confounding factors such as antiretroviral therapy (ART), age, sex, and other participant characteristics. We could cluster the microbial community into three community types whose distribution was shown to be significantly impacted by HIV. Some genera, e.g., Veillonella, Actinomyces, Atopobium, and Filifactor, were significantly enriched in HIV-infected individuals, while the COPD status was significantly associated with Gammaproteobacteria and Selenomonas abundance. Furthermore, reduced bacterial richness and significant enrichment in Campylobacter were associated with HIV-COPD comorbidity. Functional prediction using PICRUSt2 revealed a significant depletion in glutamate degradation capacity pathways in HIV-positive patients. A comparison of our findings with an HIV cohort from the United Kingdom revealed significant differences in the sputum microbiome composition, irrespective of viral suppression. IMPORTANCE Even with ART available, HIV-infected individuals are at high risk of suffering comorbidities, as shown by the high prevalence of noninfectious lung diseases in the HIV population. Recent studies have suggested a role for the respiratory microbiota in driving chronic lung inflammation. The respiratory microbiota was significantly altered among PLWH, with disease persisting up to 3 years post-ART initiation and HIV suppression. The community structure and diversity of the sputum microbiota in COPD are associated with disease severity and clinical outcomes, both in stable COPD and during exacerbations. Therefore, a better understanding of the sputum microbiome among PLWH could improve COPD prognostic and risk stratification strategies. In this study, we observed that in a virologically suppressed HIV cohort in rural Uganda, we could show differences in sputum microbiota stratified by HIV and COPD, reduced bacterial richness, and significant enrichment in Campylobacter associated with HIV-COPD comorbidity.

Oral microbial dysbiosis in patients with periodontitis and chronic obstructive pulmonary disease

Background

Oral microbiota is closely related to the homeostasis of the oral cavity and lungs. To provide potential information for the prediction, screening, and treatment strategies of individuals, this study compared and investigated the bacterial signatures in periodontitis and chronic obstructive pulmonary disease (COPD).

Materials and methods

We collected subgingival plaque and gingival crevicular fluid samples from 112 individuals (31 healthy controls, 24 patients with periodontitis, 28 patients with COPD, and 29 patients with both periodontitis and COPD). The oral microbiota was analyzed using 16S rRNA gene sequencing and diversity and functional prediction analysis were performed.

Results

We observed higher bacterial richness in individuals with periodontitis in both types of oral samples. Using LEfSe and DESeq2 analyses, we found differentially abundant genera that may be potential biomarkers for each group. Mogibacterium is the predominant genus in COPD. Ten genera, including Desulfovibrio, Filifactor, Fretibacterium, Moraxella, Odoribacter, Pseudoramibacter Pyramidobacter, Scardovia, Shuttleworthia and Treponema were predominant in periodontitis. Bergeyella, Lautropia, Rothia, Propionibacterium and Cardiobacterium were the signature of the healthy controls. The significantly different pathways in the Kyoto Encyclopedia of Genes and Genomes (KEGG) between healthy controls and other groups were concentrated in genetic information processing, translation, replication and repair, and metabolism of cofactors and vitamins.

Conclusions

We found the significant differences in the bacterial community and functional characterization of oral microbiota in periodontitis, COPD and comorbid diseases. Compared to gingival crevicular fluid, subgingival plaque may be more appropriate for reflecting the difference of subgingival microbiota in periodontitis patients with COPD. These results may provide potentials for predicting, screening, and treatment strategies for individuals with periodontitis and COPD.

[Salivary Peptide Profiling Analysis of Patients with Periodontitis and Chronic Obstructive Pulmonary Disease]

Objective

To analyze the salivary peptide profiles of patients with periodontitis (PD) and chronic obstructive pulmonary disease (COPD), to identify differentially expressed peptides that are associated with diseases, to explore for biomarkers with potential diagnostic significance, and to probe for new perspectives for the early prevention and treatment of COPD.

Methods

A total of 10 PD patients (the PD group), 10 PD patients with COPD (the PD plus COPD group), and 8 healthy controls (the Control group) were selected for the study. The clinical data and saliva samples of the subjects were collected. Salivary supernatant samples were separated and purified with weak-cation-exchange magnetic bead-based (WCX-MB). With matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS), the biodata of the samples were obtained and differential salivary peptide profiling was conducted to screen for peptides exhibiting inter-group differences. In addition, all the differentially expressed peptides were examined and verified with liquid chromatography tandem mass spectrometry (LC-MS/MS).

Result

An average of 77 peptide mass peaks were detected among three groups, the peaks intensities differed significantly for 10 peptides between PD patients and PD patients with COPD. Among them, eight peptides (1193.5, 1836.2, 1735.1, 1321.3, 1356.8, 2086.8, 1863.6, and 2230.9) showed increased expression and two peptides (1067.3 and 1124.4) showed decreased expression in the PD plus COPD group, in comparison with the PD group. Among the 10 differential peptides, 1193.5 and 1356.8 were identified as histidine-rich protein-1, submaxillary gland androgen-regulated protein 3B, and salivary acidic proline-rich protein 1/2.

Conclusion

With WCX-MB and MALDI-TOF-MS, we have identified, from the saliva of patients with concomitant PD and COPD, differentially expressed salivary peptides that were associated with diseases. The differentially expressed peptides thus screened out show promises for being used as auxiliary biomarkers for early diagnosis of COPD.

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.

The association between periodontitis and lung function: results from NHANES 2009-2012

BACKGROUND

We aimed to explore the association between periodontitis and lung function in the United States of America.

METHODS

The data was based on the National Health and Nutrition Examination Survey (NHANES) 2009-2012. Periodontitis was defined following the CDC/AAP (Centers for Disease Control and Prevention/American Academy of periodontology) classification. Lung function measurements included forced expiratory volume in one second (FEV1) , forced vital capacity (FVC) , and FEV1/FVC ratio. Linear regression and binary logistic regression were used to explore the association between periodontitis and lung function measurements. Restricted cubic spline was used to assess the dose-response relationships between the mean attachment loss, the mean probing depth and spirometry-defined airflow obstruction (FEV1/FVC < 0.7) .

RESULTS

A total of 6313 adults aged 30 years or older were included. Compared to those with non-periodontitis, the multivariate-adjusted odds ratios (ORs) of airflow obstruction for moderate and severe periodontitis were 1.38 (95%CI: 1.01-1.75) and 1.47 (95%CI: 1.06-2.01) , the β coefficients of FEV1 for moderate and severe periodontitis were -130.16 (95%CI: -172.30 to -88.01) and -160.46 (95%CI: -249.94 to -70.97) , the β coefficients of FVC for moderate and severe periodontitis were -100.96 (95%CI: -155.08 to -46.85) and -89.89 (95%CI: -178.45 to -1.33) , the β coefficients of FEV1/FVC for moderate and severe periodontitis were -0.01 (95%CI: -0.02 to -0.01) and -0.02 (95%CI: -0.03 to -0.01) . In stratified analyses, the multivariate-adjusted odds ratios of airflow obstruction for the moderate and severe periodontitis were 1.27 (95%CI: 0.84-1.93) and 2.31 (95%CI: 1.10-4.83) in former smokers, 1.84 (95%CI: 1.03-3.30) and 1.79 (95%CI: 1.02-3.16) in current smokers, with no significant association observed in never smokers. Mean clinical attachment loss and mean probing depth were negatively associated with FEV1, FVC and FEV1/FVC in never, former and current smokers. Dose-response relationship analysis showed that the risk of airflow obstruction increased with increasing mean clinical attachment loss and mean probing depth, and showed a non-linear dose-response relationship.

CONCLUSION

Our study suggested that moderate and severe periodontitis might be associated with the decline of lung function in the United States of America. This article is protected by copyright. All rights reserved.

Effect of periodontal therapy on COPD outcomes: a systematic review

Background

Latest evidence suggests that periodontitis is prevalent among patients with chronic obstructive pulmonary disease (COPD), while recent studies have also reported a potential benefit of periodontal treatment on several COPD outcomes. This systematic review aims to determine the impact of periodontal treatment on exacerbation rate, lung function and quality of life of COPD patients.

Methods

A systematic search of electronic databases of PubMed, Scopus, Virtual Health Library, ScienceDirect, Wiley Online Library, Web of Science, ProQuest Dissertation and Theses Global and Google Scholar was conducted. Search restricted to studies involving human subjects which were published from January 2000 to March 2020 in English language. Distiller Systematic Review software was used for data management. Risk of bias was assessed using Risk of Bias 2 (RoB2) and Risk of Bias for non-randomized studies of intervention (ROBINS-I) tools. Overall quality of evidence was judged based on Grading of Recommendations Assessment, Development and Evaluation working group methodology.

Results

Out of 1442 articles retrieved, 7 full text articles were included in the review. Limited evidence suggests that periodontal treatment in patients with COPD and periodontitis is associated with reduced exacerbation frequency and a slower lung function decline rate, while its effects on quality of life remain unclear. In addition, periodontal treatment in COPD is associated with lower hospitalization rates and reduced all-cause mortality. Significant methodological differences were noted amongst included studies, while very low-to-moderate overall quality of evidence was demonstrated.

Conclusions

Although it is reasonable to advise COPD patients not to neglect their dental health, further studies are warranted to determine the role of periodontal therapy on COPD clinical outcomes.

Trial Registration: PROSPERO 2020 (CRD42020158481). https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020158481

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01429-2.