Oral health's inextricable connection to systemic health: Special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions

Association of high-density lipoprotein cholesterol and periodontitis severity in Chinese elderly: a cross-sectional study

OBJECTIVES

Periodontitis is a local inflammatory disease of high prevalence worldwide. Increasing evidence has shown its association with cardiovascular diseases. While high-density lipoprotein is an important protective factor in preventing cardiovascular diseases, this study aims to examine whether high-density lipoprotein cholesterol (HDL-C) level is associated with different status of periodontitis.

MATERIALS AND METHODS

A total of 874 Chinese retirees (≥ 60 years of age) with different statuses of periodontitis were enrolled. Periodontal clinical data were collected to define periodontal disease severity (no, mild-moderate, severe). Peripheral blood was collected for serum lipid profile analysis. Linear and logistic regression analysis with adjustment for potential confounders (gender, age, BMI, alcohol intake, exercise frequency, smoking habits) were used to determine the association of periodontitis with HDL-C.

RESULTS

After adjustments for confounders, linear regression analyses revealed a significant relationship between the decreased HDL-C and periodontitis severity (p < 0.05). Although the multivariable-adjusted ORs of decreased HDL-C were not statistically significant, logistic regression analyses showed Chinese elderly with severe periodontitis had higher odds of exhibiting clinically abnormal HDL-C levels than those without periodontitis.

CONCLUSIONS

The elderly population with periodontitis showed HDL-C levels significantly lower than those without periodontitis. The severity of periodontitis was positively correlated with serum HDL-C levels.

CLINICAL RELEVANCE

Periodontitis reduces HDL-C level in the elderly population, indicating that oral health should be paid attention to in the prevention and treatment of dyslipidemia.

Associations between inflammation-related LL-37 with subgingival microbial dysbiosis in rheumatoid arthritis patients

OBJECTIVE

This study investigated the subgingival microbial profile of rheumatoid arthritis (RA) patients and its associations with disease parameters and the inflammation-related antimicrobial peptide, LL-37.

METHODS

RA and non-RA (NRA) patients were assessed for periodontal status and divided into periodontitis (CP), gingivitis (G), and healthy (H) groups. Subgingival plaque 16s rRNA gene sequencing data was processed and analyzed using the CLC Genomic Workbench (Qiagen). Bacterial diversity and co-occurrence patterns were examined. Differential abundance between groups was also investigated. Associations between bacterial genera with disease parameters and LL-37 levels were explored qualitatively using canonical correlation analysis.

RESULTS

Subgingival microbial community clustered in CP status. Co-occurrence network in NRA-H was dominated by health-associated genera, while the rest of the networks' key genera were both health- and disease-associated. RA-CP displayed highly inter-generic networks with a statistically significant increase in periodontal disease-associated genera (p<0.05). In NRA-H, disease parameters and LL-37 were correlated positively with disease-associated genera while negatively with health-associated genera. However, in the remaining groups, mixed positive and negative correlations were noted with genera.

CONCLUSION

RA patients demonstrated subgingival microbial dysbiosis where the bacteria networks were dominated by health- and disease-associated genera. Mixed correlations with disease parameters and LL-37 levels were noted.

CLINICAL RELEVANCE

The subgingival microbial dysbiosis in RA may predispose these patients to developing periodontal inflammation with an associated detrimental effect on host immune responses. Routine periodontal assessment may allow initiation of treatment strategies to minimize the effects of gingival inflammation on the existing heightened immune response present in RA patients.

Grafting Resveratrol onto Mesoporous Silica Nanoparticles towards Efficient Sustainable Immunoregulation and Insulin Resistance Alleviation for Diabetic Periodontitis Therapy

The treatment of diabetic periodontitis (DP) has become a tough challenge in dental clinic mainly due to the intrinsic drawbacks of conventional therapy strategy and currently unclear mechanisms to elucidate...

Another Look at the Contribution of Oral Microbiota to the Pathogenesis of Rheumatoid Arthritis: A Narrative Review

Although autoimmunity contributes to rheumatoid arthritis (RA), several lines of evidence challenge the dogma that it is mainly an autoimmune disorder. As RA-associated human leukocyte antigens shape microbiomes and increase the risk of dysbiosis in mucosae, RA might rather be induced by epigenetic changes in long-lived synovial presenting cells, stressed by excessive translocations into joints of bacteria from the poorly cultivable gut, lung, or oral microbiota (in the same way as more pathogenic bacteria can lead to "reactive arthritis"). This narrative review (i) lists evidence supporting this scenario, including the identification of DNA from oral and gut microbiota in the RA synovium (but in also healthy synovia), and the possibility of translocation through blood, from mucosae to joints, of microbiota, either directly from the oral cavity or from the gut, following an increase of gut permeability worsened by migration within the gut of oral bacteria such as Porphyromonas gingivalis; (ii) suggests other methodologies for future works other than cross-sectional studies of periodontal microbiota in cohorts of patients with RA versus controls, namely, longitudinal studies of oral, gut, blood, and synovial microbiota combined with transcriptomic analyses of immune cells in individual patients at risk of RA, and in overt RA, before, during, and following flares of RA.

Association between liver cirrhosis and peri-implant diseases: a case-control study on implant- and patient-related risk factors

OBJECTIVE

The objective of this study was to evaluate the potential association between liver cirrhosis and peri-implant diseases, as well as the influence of different risk indicators on this association.

METHODS

This case-control study included 64 cases with liver cirrhosis and 128 controls without liver diseases that presented the same socio-demographic and economic profile. The specific inclusion criteria were the following: aged group of 35-55 years and presenting at least one osseointegrated implant functioning for >5 years. A full-mouth peri-implant and periodontal examination was performed and risk variables were recorded. The association between risk variables and the occurrence of peri-implant diseases was tested through univariate analysis and multivariate logistic regression, stratified by alcohol status. Additionally, a mediation analysis was performed to examine the mediating effect of age with peri-implantitis.

RESULTS

A high prevalence of peri-implantitis (29.7%) was observed among cases when compared to controls (18.0%). Individuals with cirrhosis presented ~2.5 higher chance of having peri-implantitis than controls (p<0.001). Significant variables associated with the occurrence of peri-implantitis in the final logistic model were the following: cirrhosis, alcohol use, age (>55 years), male sex, smoking, periodontitis, and number of ≤14.

CONCLUSIONS

An important risk association between liver cirrhosis and peri-implantitis was reported. Future studies with a larger sample size controlling for the patient- and implant-related confounders are needed to better understand the link between peri-implantitis and liver cirrhosis.

CLINICAL RELEVANCE

Cirrhosis individuals, age, and periodontitis, as well as alcohol use and smoking interaction, should be considered as potential risk indicators for peri-implantitis.

Oral health's inextricable connection to systemic health: Special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions

The landscape in dentistry is changing as emerging studies continue to reveal that periodontal health impacts systemic health, and vice versa. Population studies, clinical studies, and in vitro animal studies underscore the critical importance of oral health to systemic health. These inextricable relationships come to the forefront as oral diseases, such as periodontal disease, take root. Special populations bring to bear the multimodal relationships between oral and systemic health. Specifically, periodontal disease has been associated with diabetes, metabolic syndrome, obesity, eating disorders, liver disease, cardiovascular disease, Alzheimer disease, rheumatoid arthritis, adverse pregnancy outcomes, and cancer. Although bidirectional relationships are recognized, the potential for multiple comorbidities, relationships, and connections (multimodal relationships) also exists. Proposed mechanisms that mediate this connection between oral and systemic health include predisposing and precipitating factors, such as genetic factors (gene polymorphisms), environmental factors (stress, habits-such as smoking and high-fat diets/consumption of highly processed foods), medications, microbial dysbiosis and bacteremias/viremias/microbemias, and an altered host immune response. Thus, in a susceptible host, these predisposing and precipitating factors trigger the onset of periodontal disease and systemic disease/conditions. Further, high-throughput sequencing technologies are shedding light on the dark matter that comprises the oral microbiome. This has resulted in better characterization of the oral microbial dysbiosis, including putative bacterial periodontopathogens and shifts in oral virome composition during disease. Multiple laboratory and clinical studies have illustrated that both eukaryotic and prokaryotic viruses within subgingival plaque and periodontal tissues affect periodontal inflammation, putative periodontopathogens, and the host immune response. Although the association between herpesviruses and periodontitis and the degree to which these viruses directly aggravate periodontal tissue damage remain unclear, the benefits to periodontal health found from prolonged administration of antivirals in immunocompromised or immunodeficient individuals demonstrates that specific populations are possibly more susceptible to viral periodontopathogens. Thus, it may be important to further examine the implications of viral pathogen involvement in periodontitis and perhaps it is time to embrace the viral dark matter within the periodontal environment to fully comprehend the pathogenesis and systemic implications of periodontitis. Emerging data from the coronavirus disease 2019 pandemic further underscores the inextricable connection between oral and systemic health, with high levels of the severe acute respiratory syndrome coronavirus 2 angiotensin-converting enzyme 2 receptor noted on oral tissues (tongue) and an allostatic load or overload paradigm of chronic stress likely contributing to rapid breakdown of oral/dental, periodontal, and peri-implant tissues. These associations exist within a framework of viremias/bacteremias/microbemias, systemic inflammation, and/or disturbances of the immune system in a susceptible host. A thorough review of systemic and oral diseases and conditions and their mechanistic, predisposing, and precipitating factors are paramount to better addressing the oral and systemic health and needs of our patients.

Alterations in subgingival microbiota during full-fixed appliance orthodontic treatment-A prospective study

BACKGROUND

Full-fixed appliance orthodontic treatment (commonly called braces) increases plaque accumulation and the risk of gingivitis and periodontitis. However, little consensus exists on changes to subgingival microbiota and specific periodontopathogens during treatment with braces. Prior studies have been hampered by selection biases due to dependence on culture conditions, candidate-based PCR and shallow sequencing methods.

OBJECTIVE

The objective was to provide the first longitudinal, culture-free and deep-sequence profiling of subgingival bacteria in subjects during early stages of full-fixed orthodontic treatment.

METHODS

We performed 16S rRNA next-generation sequencing (NGS) on 168 subgingival samples collected at 4 distinct mandibular tooth sites per subject before (0 weeks) and during (6 and 12 weeks) orthodontic intervention in 9 experimental and 5 control subjects not undergoing treatment.

RESULTS

Overall, we noted that orthodontic intervention led to increased microbial richness, accompanied by an increased incidence of localized gingivitis/mild periodontitis in subjects requiring orthodontic treatment compared to controls, as well as significant baseline variations in subgingival microbiomes in all subjects. Moreover, we confirmed individual- and site-dependent microbiome variability (in particular, the lingual site harboured higher microbiome diversity than buccal sites) that orthodontic bands may lead to more prolonged shifts in microbial changes compared to brackets, and evidence of adaptive enrichment of consensus bacteria with orthodontic intervention (12 novel, consensus bacterial species were identified).

CONCLUSION

Our study, along with evolving global profiling methods and data analyses, builds a strong foundation for further analyses of subgingival microbiomes during full-fixed orthodontic treatment.

The Complex Molecular Picture of Gut and Oral Microbiota-Brain-Depression System: What We Know and What We Need to Know

Major depressive disorder (MDD) is a complex mental disorder where the neurochemical, neuroendocrine, immune, and metabolic systems are impaired. The microbiota-gut-brain axis is a bidirectional network where the central and enteric nervous systems are linked through the same endocrine, immune, neural, and metabolic routes dysregulated in MDD. Thus, gut-brain axis abnormalities in MDD patients may, at least in part, account for the symptomatic features associated with MDD. Recent investigations have suggested that the oral microbiome also plays a key role in this complex molecular picture of relationships. As on one hand there is a lot of what we know and on the other hand little of what we still need to know, we structured this review focusing, in the first place, on putting all pieces of this complex puzzle together, underlying the endocrine, immune, oxidative stress, neural, microbial neurotransmitters, and metabolites molecular interactions and systems lying at the base of gut microbiota (GM)-brain-depression interphase. Then, we focused on promising but still under-explored areas of research strictly linked to the GM and potentially involved in MDD development: (i) the interconnection of GM with oral microbiome that can influence the neuroinflammation-related processes and (ii) gut phageome (bacteria-infecting viruses). As conclusions and future directions, we discussed potentiality but also pitfalls, roadblocks, and the gaps to be bridged in this exciting field of research. By the development of a broader knowledge of the biology associated with MDD, with the inclusion of the gut/oral microbiome, we can accelerate the growth toward a better global health based on precision medicine.