Mechanisms involved in the association between periodontal diseases and cardiovascular disease

Periodontal disease as a model to study chronic inflammation in aging

Periodontal disease is a chronic inflammatory condition that results in the destruction of the teeth supporting tissues, eventually leading to the loss of teeth and reduced quality of life. In severe cases, periodontal disease can limit proper nutritional intake, cause acute pain and infection, and cause a withdrawal from social situations due to esthetic and phonetic concerns. Similar to other chronic inflammatory conditions, periodontal disease increases in prevalence with age. Research into what drives periodontal disease pathogenesis in older adults is contributing to our general understanding of age-related chronic inflammation. This review will present periodontal disease as an age-related chronic inflammatory disease and as an effective geroscience model to study mechanisms of age-related inflammatory dysregulation. The current understanding of the cellular and molecular mechanisms that drive inflammatory dysregulation as a function of age will be discussed with a focus on the major pathogenic immune cells in periodontal disease, which include neutrophils, macrophages, and T cells. Research in the aging biology field has shown that the age-related changes in these immune cells result in the cells becoming less effective in the clearance of microbial pathogens, expansion of pathogenic subpopulations, or an increase in pro-inflammatory cytokine secretions. Such changes can be pathogenic and contribute to inflammatory dysregulation that is associated with a myriad of age-related disease including periodontal disease. An improved understanding is needed to develop better interventions that target the molecules or pathways that are perturbed with age in order to improve treatment of chronic inflammatory conditions, including periodontal disease, in older adult populations.

Moderate-intensity continuous training and high-intensity interval training modulate the composition of the oral microbiota of elderly adults: Randomized controlled trial

OBJECTIVE

We investigates the effects of 16-week high-intensity interval training and moderate-intensity continuous training on the composition of the oral microbiota. To the best of our knowledge, at the time of writing this paper no other scholars had described the oral metagenomic changes associated with prescribed exercise in older adults.

METHODS

Forty-three participants aged 60-74 years were randomized 1:1:1 to a control group, high-intensity interval training or moderate-intensity continuous training twice weekly for 16 weeks. Saliva samples were sequenced at baseline, week 8 and week 16 of intervention.

RESULTS

High-intensity interval training produced significant differences over time in Richness and a clear trend to decreased Simpson and Shannon diversity indices. In contrast, Simpson and Shannon indices showed an upward trend over time with moderate-intensity continuous training, which also decreased Firmicutes and increased Bacteroidetes levels. Significant differences in the abundance of pathogenic species were also observed after the participants completed the exercise interventions of either type.

CONCLUSIONS

Both types of exercise promoted subtle changes in the oral microbiota, confirming the modulatory effect of high-intensity interval training and moderate-intensity continuous training on the oral microbiome. Clinical trial registration NCT05220670.

Serum asprosin levels are increased in patients with periodontitis and ST-segment elevation myocardial infarction and correlated with periodontal parameters: A case-control study

OBJECTIVE

The study aims to investigate whether patients with ST-elevation myocardial infarction (STEMI)-related periodontitis will experience any changes in asprosin levels.

BACKGROUND

Periodontitis is a common, chronic infection of the periodontium that is epidemiologically associated with cardiovascular disease. Although asprosin, a hormone released from adipose tissue, is a protective role in cardiovascular diseases, its effectiveness in periodontitis is unknown.

METHODS

The study was conducted on a total of 120 patients, divided into four groups; the group of healthy control (n = 35), the group of periodontitis (n = 35), the group of periodontitis+STEMI (n = 25), and the group of STEMI (n = 25). In each patient, age, serum asprosin, CRP, troponin-I, and clinical periodontal parameters [plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL)] were evaluated. The results were analyzed statistically.

RESULTS

Serum asprosin, CRP, and troponin-I levels were statistically higher in the STEMI+periodontitis group compared to the other groups. In addition, as a result of the study, it was observed that there was a correlation between serum asprosin levels, clinical periodontal parameters, and CRP levels.

CONCLUSIONS

The results of this study show that STEMI and periodontitis are associated with high asprosin levels. Since the risk of periodontitis is high in STEMI patients, periodontitis should also be considered when evaluating asprosin levels in STEMI patients.

Dissecting the association between gut microbiota and hypertrophic scarring: a bidirectional Mendelian randomization study

Hypertrophic scars affect a significant number of individuals annually, giving rise to both cosmetic concerns and functional impairments. Prior research has established that an imbalance in the composition of gut microbes, termed microbial dysbiosis, can initiate the progression of various diseases through the intricate interplay between gut microbiota and the host. However, the precise nature of the causal link between gut microbiota and hypertrophic scarring remains uncertain. In this study, after compiling summary data from genome-wide association studies (GWAS) involving 418 instances of gut microbiota and hypertrophic scarring, we conducted a bidirectional Mendelian randomization (MR) to investigate the potential existence of a causal relationship between gut microbiota and the development of hypertrophic scar and to discern the directionality of causation. By utilizing MR analysis, we identified seven causal associations between gut microbiome and hypertrophic scarring, involving one positive and six negative causal directions. Among them, Intestinimonas, Ruminococcus2, Barnesiella, Dorea, Desulfovibrio piger, and Ruminococcus torques act as protective factors against hypertrophic scarring, while Eubacterium rectale suggests a potential role as a risk factor for hypertrophic scars. Additionally, sensitivity analyses of these results revealed no indications of heterogeneity or pleiotropy. The findings of our MR study suggest a potential causative link between gut microbiota and hypertrophic scarring, opening up new ways for future mechanistic research and the exploration of nanobiotechnology therapies for skin disorders.

A novel method for sampling subgingival microbiome: a comparative metatranscriptomic study

The subgingival microbiome has been implicated in oral and systemic diseases such as periodontitis and Alzheimer's disease. However, subgingival sampling is challenging. We developed a novel method of sampling the subgingival microbiome by rotationally swabbing the supragingival area, named subgingival-P (for proxy) samples. We sampled and metatranscriptomically analyzed subgingival and subgingival-P samples of three different teeth in 20 individuals. The subgingival-P samples were comparable to the subgingival samples in the relative abundances of microorganisms and microbial gene expression levels. Our data demonstrate that the novel method of collecting and analyzing the subgingival-P samples can act as a proxy for the subgingiva, paving the way for large and diverse studies investigating the role of the subgingival microbiome in health and disease.

Bone marrow inflammatory memory in cardiometabolic disease and inflammatory comorbidities

Cardiometabolic disorders are chief causes of morbidity and mortality, with chronic inflammation playing a crucial role in their pathogenesis. The release of differentiated myeloid cells with elevated pro-inflammatory potential, as a result of maladaptively trained myelopoiesis may be a crucial factor for the perpetuation of inflammation. Several cardiovascular risk factors, including sedentary lifestyle, unhealthy diet, hypercholesterolemia, and hyperglycemia, may modulate bone marrow hematopoietic progenitors, causing sustained functional changes that favour chronic metabolic and vascular inflammation. In the present review, we summarize recent studies that support the function of long-term inflammatory memory in progenitors of the bone marrow for the development and progression of cardiometabolic disease and related inflammatory comorbidities, including periodontitis and arthritis. We also discuss how maladaptive myelopoiesis associated with the presence of mutated hematopoietic clones, as present in clonal hematopoiesis, may accelerate atherosclerosis via increased inflammation.

The oral microbiome: diversity, biogeography and human health

The human oral microbiota is highly diverse and has a complex ecology, comprising bacteria, microeukaryotes, archaea and viruses. These communities have elaborate and highly structured biogeography that shapes metabolic exchange on a local scale and results from the diverse microenvironments present in the oral cavity. The oral microbiota also interfaces with the immune system of the human host and has an important role in not only the health of the oral cavity but also systemic health. In this Review, we highlight recent advances including novel insights into the biogeography of several oral niches at the species level, as well as the ecological role of candidate phyla radiation bacteria and non-bacterial members of the oral microbiome. In addition, we summarize the relationship between the oral microbiota and the pathology of oral diseases and systemic diseases. Together, these advances move the field towards a more holistic understanding of the oral microbiota and its role in health, which in turn opens the door to the study of novel preventive and therapeutic strategies.

The effect of antipsychotic medication and the associated hyperprolactinemia as a risk factor for periodontal diseases in schizophrenic patients: a cohort retrospective study

BACKGROUND

Periodontal disease is a major health problem that results in tooth loss and thus affects oral health, which affects quality of life. In particular, schizophrenic patients are at higher risk for periodontal disease due to several factors, including the effect of antipsychotic medications received by those patients. Accordingly, the aim of the present cohort retrospective study is to explore the effect of antipsychotics on periodontal health and the possible effect of antipsychotic-induced hyperprolactinemia as a risk factor for periodontal disease progression in schizophrenic patients.

METHODS AND OUTCOMES

The study population consisted of three groups: Group A (n = 21): schizophrenic patients that have been taking "prolactin-inducing" antipsychotics for at least 1 year; Group B (n = 21): schizophrenic patients who have been taking "prolactin-sparing" antipsychotics for at least 1 year; and Group C (n = 22): newly diagnosed schizophrenic patients and/or patients who did not receive any psychiatric treatment for at least 1 year. The study groups underwent assessment of periodontal conditions in terms of pocket depth (PD), clinical attachment loss (CAL), gingival recession, tooth mobility, and bleeding on probing (BOP). Also, bone mineral density was evaluated using DEXA scans, and the serum prolactin level was measured by automated immunoassay.

RESULTS

Results revealed a statistically significant difference in PD, CAL, and serum prolactin levels (P ≤ 0.001, P = 0.001, and P ≤ 0.001, respectively) among the 3 study groups. For both PD and CAL measurements, group A has shown significantly higher values than both groups B and C, whereas there was no statistically significant difference between the values of groups C and B. Concerning serum prolactin levels, group A had significantly higher values than groups B and C (P ≤ 0.001 and P ≤ 0.001 respectively). There was a statistically significant difference (P ≤ 0.001) between the 3 study groups in terms of bone mineral density. Moreover, there was a statistically significant direct relation between serum prolactin level and other parameters including clinical attachment loss, pocket depth measurements and bone mineral density.

CONCLUSION

According to our results, it could be concluded that all antipsychotics contribute to the progression of periodontal disease, with a higher risk for prolactin-inducing antipsychotics. However, further long term, large sampled, interventional and controlled studies are required to reach definitive guidelines to allow clinicians properly manage this group of patients.

Unraveling the Link between Periodontitis and Coronavirus Disease 2019: Exploring Pathogenic Pathways and Clinical Implications

Periodontitis involves the inflammation of the periodontal tissue, leading to tissue loss, while coronavirus disease 2019 (COVID-19) is a highly transmissible respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is amplified by poor systemic health. Key facilitators of SARS-CoV-2's entry into host cells are angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). This review reveals that periodontal pockets can serve as a hotspot for virus accumulation, rendering surrounding epithelia more susceptible to infection. Given that ACE2 is expressed in oral mucosa, it is reasonable to suggest that poor periodontal health could increase the risk of COVID-19 infection. However, recent studies have not provided sufficient evidence to imply a significant effect of COVID-19 on periodontal health, necessitating further and more long-term investigations. Nevertheless, there are hypotheses linking the mechanisms of the two diseases, such as the involvement of interleukin-17 (IL-17). Elevated IL-17 levels are observed in both COVID-19 and periodontitis, leading to increased osteoclast activity and bone resorption. Lastly, bidirectional relationships between periodontitis and systemic diseases like diabetes are acknowledged. Given that COVID-19 symptoms may worsen with these conditions, maintaining good oral health and managing systemic diseases are suggested as potential ways to protect against COVID-19.

Association between androgenetic alopecia and periodontitis

AIM

Androgenic alopecia (AGA) is men's most common form of hair loss. It is affected by changes in the expression and activity of 5αR and the metabolism of testosterone and DHT. There is an association between AGA and systemic inflammatory diseases. We hypothesized that there is an association between AGA and periodontal disease, as inflamed gingiva and periodontal fibroblasts have been shown to express more 5αR. Thus, this study aimed to evaluate the relationship between periodontal disease and AGA and the potential effect of aging on this association.

MATERIALS AND METHODS

Out of a cohort of 1088 individuals, 385 white males aged 25-65 with similar socioeconomic levels and without systemic disease were included. Periodontitis was defined using NHANES data. AGA was evaluated using the Norwood-Hamilton scale. The relationship between AGA, periodontal disease severity, and age was assessed.

RESULTS

There was a correlation between age and baldness (r = .421, p < .001). There was a significant correlation between AGA and periodontal disease in younger patients aged 25-34 and 35-44. (p < .042 and p < .036, respectively). There was no significant correlation between AGA and periodontal disease in the 45-54 and 55-65 age groups (p > .05).

CONCLUSION

There may be a relationship between periodontal disease and AGA in the 25-44 age range, suggesting that this association starts at an early age in adulthood.

Glipizide Alleviates Periodontitis Pathogenicity via Inhibition of Angiogenesis, Osteoclastogenesis and M1/M2 Macrophage Ratio in Periodontal Tissue

New consensus indicates type 2 diabetes mellitus (T2DM) and periodontitis as comorbidity and may share common pathways of disease progression. Sulfonylureas have been reported to improve the periodontal status in periodontitis patients. Glipizide, a sulfonylurea widely used in the treatment of T2DM, has also been reported to inhibit inflammation and angiogenesis. The effect of glipizide on the pathogenicity of periodontitis, however, has not been studied. We developed ligature-induced periodontitis in mice and treated them with different concentrations of glipizide and then analyzed the level of periodontal tissue inflammation, alveolar bone resorption, and osteoclast differentiation. Inflammatory cell infiltration and angiogenesis were analyzed using immunohistochemistry, RT-qPCR, and ELISA. Transwell assay and Western bolt analyzed macrophage migration and polarization. 16S rRNA sequencing analyzed the effect of glipizide on the oral microbial flora. mRNA sequencing of bone marrow-derived macrophages (BMMs) stimulated by P. gingivalis lipopolysaccharide (Pg-LPS) after treatment with glipizide was analyzed. Glipizide decreases alveolar bone resorption, periodontal tissue degradation, and the number of osteoclasts in periodontal tissue affected by periodontitis (PAPT). Glipizide-treated periodontitis mice showed reduced micro-vessel density and leukocyte/macrophage infiltration in PAPT. Glipizide significantly inhibited osteoclast differentiation in vitro experiments. Glipizide treatment did not affect the oral microbiome of periodontitis mice. mRNA sequencing and KEGG analysis showed that glipizide activated PI3K/AKT signaling in LPS-stimulated BMMs. Glipizide inhibited the LPS-induced migration of BMMs but promoted M2/M1 macrophage ratio in LPS-induced BMMs via activation of PI3K/AKT signaling. In conclusion, glipizide inhibits angiogenesis, macrophage inflammatory phenotype, and osteoclastogenesis to alleviate periodontitis pathogenicity suggesting its' possible application in the treatment of periodontitis and diabetes comorbidity.

Effect of scaling and root planing with and without minocycline HCl microspheres on periodontal pathogens and clinical outcomes: A randomized clinical trial

BACKGROUND

This study tests the effects of scaling and root planing (SRP) versus SRP plus minocycline hydrochloride microspheres (SRP+MM) on 11 periodontal pathogens and clinical outcomes in Stage II-IV Grade B periodontitis participants.

METHODS

Seventy participants were randomized to receive SRP (n = 35) or SRP+MM (n = 35). Saliva and clinical outcomes were collected for both groups at baseline before SRP, 1-month reevaluation, and at 3- and 6-month periodontal recall. MM were delivered to pockets ≥5 mm immediately after SRP and immediately after the 3-month periodontal maintenance in the SRP+MM group. A proprietary saliva test* was utilized to quantitate 11 putative periodontal pathogens. Microorganisms and clinical outcomes were compared between groups using generalized linear mixed-effects models with fixed effects and random effects terms. Mean changes from baseline were compared between groups via group-by-visit interaction tests.

RESULTS

Significant reduction in Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Parvimonas micra, and Eikenella corrodens were identified at the 1-month reevaluation after SRP+MM. Six months after SRP with a re-application of MM 3 months after SRP, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens were significantly reduced. SRP+MM participants had significant clinical outcome reductions in pockets ≥5 mm at the reevaluation, 3- and 6-month periodontal maintenance, and clinical attachment loss gains at the 6-month periodontal maintenance.

CONCLUSION

MM delivered immediately after SRP and reapplication at 3 months appeared to contribute to improved clinical outcomes and sustained decreased numbers of Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens at 6 months.

Oral microbiome variations related to ageing: possible implications beyond oral health

The global population is getting older due to a combination of longer life expectancy and declining birth rates. Growing evidence suggests that the oral microbiota composition and distribution may have a profound effect on how well we age. The purpose of this study was to investigate age-related oral microbiome variations of supragingival plaque and buccal mucosa samples in the general population in Latvia. Our results indicated significant difference between supragingival plaque bacterial profiles of three age groups (20-40; 40-60; 60 + years). Within supragingival plaque samples, age group 20-40 showed the highest bacterial diversity with a decline during the 40-60 age period and uprise again after the age of 60. Among other differences, the important oral commensal Neisseria had declined after the age of 40. Additionally, prevalence of two well-documented opportunistic pathogens Streptococcus anginosus and Gemella sanguinis gradually rose with age within our samples. Furthermore, supragingival plaque and buccal mucosa samples significantly differed in overall bacterial composition.

The Role of the Oral Microbiome in the Development of Diseases

Periodontal disease (PD) is a complex and infectious illness that begins with a disruption of bacterial homeostasis. This disease induces a host inflammatory response, leading to damage of the soft and connective tooth-supporting tissues. Moreover, in advanced cases, it can contribute to tooth loss. The aetiological factors of PDs have been widely researched, but the pathogenesis of PD has still not been totally clarified. There are a number of factors that have an effect on the aetiology and pathogenesis of PD. It is purported that microbiological, genetic susceptibility and lifestyle can determine the development and severity of the disease. The human body’s defence response to the accumulation of plaque and its enzymes is known to be a major factor for PD. The oral cavity is colonised by a characteristic and complex microbiota that grows as diverse biofilms on all mucosal and dental surfaces. The aim of this review was to provide the latest updates in the literature regarding still-existing problems with PD and to highlight the role of the oral microbiome in periodontal health and disease. Better awareness and knowledge of the causes of dysbiosis, environmental risk factors and periodontal therapy can reduce the growing worldwide prevalence of PDs. The promotion of good oral hygiene, limiting smoking, alcohol consumption and exposure to stress and comprehensive treatment to decrease the pathogenicity of oral biofilm can help reduce PD as well as other diseases. Evidence linking disorders of the oral microbiome to various systemic diseases has increased the understanding of the importance of the oral microbiome in regulating many processes in the human body and, thus, its impact on the development of many diseases.

Periodontal disease is associated with the risk of cardiovascular disease independent of sex: A meta-analysis

Objectives

Studies have established a link between periodontal disease and cardiovascular disease (CVD), but it is unclear whether there is a sex difference in their association.

Methods

The PubMed, Embase, and Cochrane databases were searched until June, 21 2022. Cardiovascular outcomes included any CVD, myocardial infarction (MI), coronary heart disease (CHD), or stroke. Studies reported the prevalence of CVD in patients with periodontal disease and the relationship between periodontal disease and CVD. The study is registered with PROSPERO (CRD42022333663). The level of evidence and recommendations is assessed by the Grading of Recommendations for Assessment, Development and Evaluation (GRADE).

Results

Twenty-six studies were included. In patients with periodontal disease, the prevalence of CVD was 7.2% [9 studies; 95% confidence interval (CI): 2.7-13.6%], and prevalence for CHD, hypertension, stroke, and heart failure was 6.6, 25.3, 1, and 1.1%, respectively. There was a significant association between periodontal disease and CVD in men [odds ratio (OR) = 1.22; 95% CI: 1.12-1.34] and women (OR = 1.11; 95% CI: 1.05-1.17), with no significant sex difference (P > 0.05).

Conclusion

Cardiovascular disease is relatively common in patients with periodontal disease, and an increased risk of CVD is associated with periodontal disease independent of sex. Interventions targeting periodontal disease may be beneficial for CVD.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022333663.

Ecology, Not Host Phylogeny, Shapes the Oral Microbiome in Closely Related Species

Host-associated microbiomes are essential for a multitude of biological processes. Placed at the contact zone between external and internal environments, the little-studied oral microbiome has important roles in host physiology and health. Here, we investigate the roles of host evolutionary relationships and ecology in shaping the oral microbiome in three closely related gorilla subspecies (mountain, Grauer's, and western lowland gorillas) using shotgun metagenomics of 46 museum-preserved dental calculus samples. We find that the oral microbiomes of mountain gorillas are functionally and taxonomically distinct from the other two subspecies, despite close evolutionary relationships and geographic proximity with Grauer's gorillas. Grauer's gorillas show intermediate bacterial taxonomic and functional, and dietary profiles. Altitudinal differences in gorilla subspecies ranges appear to explain these patterns, suggesting a close connection between dental calculus microbiomes and the environment, likely mediated through diet. This is further supported by the presence of gorilla subspecies-specific phyllosphere/rhizosphere taxa in the oral microbiome. Mountain gorillas show a high abundance of nitrate-reducing oral taxa, which may promote adaptation to a high-altitude lifestyle by modulating blood pressure. Our results suggest that ecology, rather than evolutionary relationships and geographic distribution, shape the oral microbiome in these closely related species.

Potential Roles of Selectins in Periodontal Diseases and Associated Systemic Diseases: Could They Be Targets for Immunotherapy?

Periodontal diseases are predisposing factors to the development of many systemic disorders, which is often initiated via leukocyte infiltration and vascular inflammation. These diseases could significantly affect human health and quality of life. Hence, it is vital to explore effective therapies to prevent disease progression. Periodontitis, which is characterized by gingival bleeding, disruption of the gingival capillary's integrity, and irreversible destruction of the periodontal supporting bone, appears to be caused by overexpression of selectins in periodontal tissues. Selectins (P-, L-, and E-selectins) are vital members of adhesion molecules regulating inflammatory and immune responses. They are mainly located in platelets, leukocytes, and endothelial cells. Furthermore, selectins are involved in the immunopathogenesis of vascular inflammatory diseases, such as cardiovascular disease, diabetes, cancers, and so on, by mediating leukocyte recruitment, platelet activation, and alteration of endothelial barrier permeability. Therefore, selectins could be new immunotherapeutic targets for periodontal disorders and their associated systemic diseases since they play a crucial role in immune regulation and endothelium dysfunction. However, the research on selectins and their association with periodontal and systemic diseases remains limited. This review aims to discuss the critical roles of selectins in periodontitis and associated systemic disorders and highlights the potential of selectins as therapeutic targets.

The Role of Inflammation in Cardiovascular Disease

Atherosclerosis is a chronic inflammatory disease, in which the immune system has a prominent role in its development and progression. Inflammation-induced endothelial dysfunction results in an increased permeability to lipoproteins and their subendothelial accumulation, leukocyte recruitment, and platelets activation. Recruited monocytes differentiate into macrophages which develop pro- or anti-inflammatory properties according to their microenvironment. Atheroma progression or healing is determined by the balance between these functional phenotypes. Macrophages and smooth muscle cells secrete inflammatory cytokines including interleukins IL-1β, IL-12, and IL-6. Within the arterial wall, low-density lipoprotein cholesterol undergoes an oxidation. Additionally, triglyceride-rich lipoproteins and remnant lipoproteins exert pro-inflammatory effects. Macrophages catabolize the oxidized lipoproteins and coalesce into a lipid-rich necrotic core, encapsulated by a collagen fibrous cap, leading to the formation of fibro-atheroma. In the conditions of chronic inflammation, macrophages exert a catabolic effect on the fibrous cap, resulting in a thin-cap fibro-atheroma which makes the plaque vulnerable. However, their morphology may change over time, shifting from high-risk lesions to more stable calcified plaques. In addition to conventional cardiovascular risk factors, an exposure to acute and chronic psychological stress may increase the risk of cardiovascular disease through inflammation mediated by an increased sympathetic output which results in the release of inflammatory cytokines. Inflammation is also the link between ageing and cardiovascular disease through increased clones of leukocytes in peripheral blood. Anti-inflammatory interventions specifically blocking the cytokine pathways reduce the risk of myocardial infarction and stroke, although they increase the risk of infections.

Citizen-science reveals changes in the oral microbiome in Spain through age and lifestyle factors

The relevance of the human oral microbiome to our understanding of human health has grown in recent years as microbiome studies continue to develop. Given the links of the oral cavity with the digestive, respiratory and circulatory systems, the composition of the oral microbiome is relevant beyond just oral health, impacting systemic processes across the body. However, we still have a very limited understanding about intrinsic and extrinsic factors that shape the composition of the healthy oral microbiome. Here, we followed a citizen-science approach to assess the relative impact on the oral microbiome of selected biological, social, and lifestyle factors in 1648 Spanish individuals. We found that the oral microbiome changes across age, with middle ages showing a more homogeneous composition, and older ages showing more diverse microbiomes with increased representation of typically low abundance taxa. By measuring differences within and between groups of individuals sharing a given parameter, we were able to assess the relative impact of different factors in driving specific microbial compositions. Chronic health disorders present in the analyzed population were the most impactful factors, followed by smoking and the presence of yeasts in the oral cavity. Finally, we corroborate findings in the literature that relatives tend to have more similar oral microbiomes, and show for the first time a similar effect for classmates. Multiple intrinsic and extrinsic factors jointly shape the oral microbiome. Comparative analysis of metabarcoding data from a large sample set allows us to disentangle the individual effects.

Regular dental visits, periodontitis, tooth loss, and atherosclerosis: The Ohasama study

Objective

We aimed to explore the association between regular dental visits and atherosclerosis and between periodontitis, number of remaining teeth, and atherosclerosis among community dwellers in Japan.

Background

Few studies have examined the association between regular dental visits, periodontitis, tooth loss, and atherosclerosis in community dwellers in Japan.

Methods

The participants of this cross‐sectional study included community dwellers aged ≥55 years and residing in Ohasama. Exposure variables were regular dental visits; periodontitis, defined as radiographic alveolar bone loss (BL); the Centers for Disease Control/American Academy of Periodontology (CDC/AAP) classification; and number of remaining teeth. The primary outcome was atherosclerosis, defined as maximum carotid intima‐media thickness ≥1.1 mm or confirmation of atheromatous plaque.

Results

Of 602 participants, 117 had atherosclerosis. In the multivariate model, compared to those with regular dental visits, the odds ratio (OR) (95% confidence intervals [CIs]) of atherosclerosis among those with the absence of regular dental visits was 2.16 (1.03–4.49). Regarding BL‐max, compared with those in the first quartile, ORs (95% CIs) of those in the second, third, and fourth quartiles were 1.15 (0.65–2.30), 0.65 (0.32–1.35), and 1.57 (0.81–3.01), respectively. Regarding CDC/AAP classification, compared to those with no or mild periodontitis, ORs (95% CIs) for those with moderate and severe periodontitis were 2.48 (0.61–10.1) and 4.26 (1.01–17.5), respectively. Regarding the number of remaining teeth, compared to those with ≥20 teeth, ORs (95%CIs) for those with 10–19 and 1–9 teeth were 1.77 (1.004–3.12) and 0.96 (0.52–1.80), respectively.

Conclusion

The absence of regular dental visits and presence of periodontitis are associated with atherosclerosis among community dwellers in Japan.

Interconnection of periodontal disease and comorbidities: Evidence, mechanisms, and implications

Periodontitis, a microbiome-driven inflammatory disease of the tooth-attachment apparatus, is epidemiologically linked with other disorders, including cardio-metabolic, cognitive neurodegenerative and autoimmune diseases, respiratory infections, and certain cancers. These associations may, in part, be causal, as suggested by interventional studies showing that local treatment of periodontitis reduces systemic inflammation and surrogate markers of comorbid diseases. The potential cause-and-effect connection between periodontitis and comorbidities is corroborated by studies in preclinical models of disease, which additionally provided mechanistic insights into these associations. This overview discusses recent advances in our understanding of the periodontitis-systemic disease connection, which may potentially lead to innovative therapeutic options to reduce the risk of periodontitis-linked comorbidities.

Armed to the Teeth-The Oral Mucosa Immunity System and Microbiota

The oral cavity is inhabited by a wide spectrum of microbial species, and their colonization is mostly based on commensalism. These microbes are part of the normal oral flora, but there are also opportunistic species that can cause oral and systemic diseases. Although there is a strong exposure to various microorganisms, the oral mucosa reduces the colonization of microorganisms with high rotation and secretion of various types of cytokines and antimicrobial proteins such as defensins. In some circumstances, the imbalance between normal oral flora and pathogenic flora may lead to a change in the ratio of commensalism to parasitism. Healthy oral mucosa has many important functions. Thanks to its integrity, it is impermeable to most microorganisms and constitutes a mechanical barrier against their penetration into tissues. Our study aims to present the role and composition of the oral cavity microbiota as well as defense mechanisms within the oral mucosa which allow for maintaining a balance between such numerous species of microorganisms. We highlight the specific aspects of the oral mucosa protecting barrier and discuss up-to-date information on the immune cell system that ensures microbiota balance. This study presents the latest data on specific tissue stimuli in the regulation of the immune system with particular emphasis on the resistance of the gingival barrier. Despite advances in understanding the mechanisms regulating the balance on the microorganism/host axis, more research is still needed on how the combination of these diverse signals is involved in the regulation of immunity at the oral mucosa barrier.

The traditional and modifiable risk factors of coronary artery disease - a community-based cross-sectional study among 2 populations

A community-based cross-sectional study was undertaken by the Cardiology Society of India (Kerala Chapter) to determine the prevalence of coronary artery disease (CAD) and its risk factors. The periodontal health status of the rural and urban participants in the Thiruvananthapuram district of Kerala was evaluated to document any association between periodontal disease (PD) and CAD and to describe any shared risk factors.The participants were selected using a multistage cluster random sampling method. Socio-demographic data and personal histories were collected using a structured interview schedule and validated tools. Body mass index, blood pressure, electrocardiogram, and biochemical investigations were recorded and analyzed using standard protocols. A modification of the Ramfjord periodontal disease index was used to assess periodontal health.PD was more frequent among rural (61.4%) than in the urban population (35.5%). The frequencies of CAD associated with PD in the rural and urban populations were 82.6% and 40.5%, respectively. PD was not found to be a significant risk factor for CAD in the univariate regression analysis of urban populations. In the rural population, the odds of PD as a risk factor for CAD were found to be 3.08 (95% CI [1.38-8.38]) and significant (P = .043) in univariate regression analysis and 1.54 (95% CI: 0.44-5.4) and non-significant (P = .503) in the multivariate regression analysis.In rural areas, male sex and dyslipidemia demonstrated borderline significance as risk factors for CAD. PD was not found to be an independent risk factor after adjusting for age, sex, tobacco use, hypertension, sedentary lifestyle, and dyslipidemia. Male sex and dyslipidemia were identified as shared risk factors between PD and CAD, which could have confounded the significant association between the latter. In urban areas, age, male sex, and dyslipidemia demonstrated an independent association with CAD. This study could not establish an independent association between PD and CAD in either community. Future epidemiological studies should identify and recruit novel environmental factors to understand the interrelationships between PD and CAD and focus on the role of effect modifiers that may have a protective role against PD colluding with CAD.

Sulfonylureas for Treatment of Periodontitis-Diabetes Comorbidity-Related Complications: Killing Two Birds With One Stone

Periodontitis is one of the most prevalent oral inflammatory diseases leading to teeth loss and oral health problems in adults. Periodontitis mainly affects periodontal tissue by affecting the host immune system and bone homeostasis. Moreover, periodontitis is associated with various systemic diseases. Diabetes is a metabolic disease with systemic effects. Both periodontitis and diabetes are common inflammatory diseases, and comorbidity of two diseases is linked to exacerbation of the pathophysiology of both diseases. Since bacterial dysbiosis is mainly responsible for periodontitis, antibiotics are widely used drugs to treat periodontitis in clinics. However, the outcomes of antibiotic treatments in periodontitis are not satisfactory. Therefore, the application of anti-inflammatory drugs in combination with antibiotics could be a treatment option for periodontitis-diabetes comorbidity. Anti-diabetic drugs usually have anti-inflammatory properties and have shown beneficial effects on periodontitis. Sulfonylureas, insulin secretagogues, are the earliest and most widely used oral hypoglycemic drugs used for type-2 diabetes. Studies have found that sulfonylurea drugs can play a certain role in the mitigation of periodontitis and inflammation. This article reviews the effects of sulfonylurea drugs on the mitigation of periodontitis-diabetes comorbidity-related inflammation, bone loss, and vascular growth as well as the involved molecular mechanisms. We discuss the possibility of a new application of sulfonylureas (old drug) to treat periodontitis-diabetes comorbidity.

The levels of soluble urokinase plasminogen activator receptor (suPAR) in saliva are influenced by acute stress

Although elevations in systemic suPAR levels have been associated with inflammatory conditions and with exposure to life stress and adversity, it is not yet clear whether acute psychological stress influences suPAR levels, either systemically and/or in saliva. The aim of this study was to investigate whether salivary suPAR levels are increased following exposure to acute psychological stress. Healthy subjects, aged 18-40 years, completed a laboratory psychological stressor and provided saliva samples before and after the stress test (60 min apart). Levels of suPAR as well as those of cytokines increased in the post-stress samples (all ps < .001). Baseline and post-stress IL-1β and TNF-α as well as post-stress IL-6 correlated significantly with suPAR (all ps < .01), but IL-10 and baseline IL-6 did not. These results show that suPAR levels in saliva are stress-reactive and suggest a potential application as stress biomarkers in saliva, particularly given the advantage of easily detectable concentrations.

An Explorative Study on Monocyte Reprogramming in the Context of Periodontitis In Vitro and In Vivo

Aims

Periodontitis is an independent risk factor for cardiovascular disease, but the mechanistic link is not fully understood. In atherosclerotic cardiovascular disease, monocytes can adopt a persistent hyperresponsive phenotype, termed trained immunity. We hypothesized that periodontitis-associated bacteria can induce trained immunity in monocytes, which subsequently accelerate atherosclerosis development.

Materials and Methods

We combined in vitro experiments on human primary monocytes and in vivo techniques in patients with periodontitis to test this hypothesis. Adherent peripheral blood mononuclear cells (PBMCs) were transiently exposed in vitro to Porphyromonas gingivalis for 24 hours, and restimulated with lipopolysaccharide (LPS) or Pam3CysK4 (P3C) six days later, to measure interleukin-6 (IL-6) and tumor necrosis factor α (TNFα) production. In an exploratory observational study, patients with severe periodontitis (63 ± 6 years, n=14) and control subjects with no-to-mild periodontitis (54 ± 10 years, n=14) underwent venipuncture and 2’-deoxy-2’-[¹⁸F]fluoro-D-glucose positron-emission-tomography ([¹⁸F]FDG PET/CT) scanning.

Results

When adherent peripheral blood mononuclear cells (PBMCs) were transiently exposed in vitro to Porphyromonas gingivalis for 24 hours, and restimulated with LPS or P3C six days later, IL-6 and TNFα production was significantly increased (TNFα/P3C, p<0.01). Circulating leukocytes, IL-6 and interleukin-1 receptor antagonist (IL-1Ra) concentrations were generally higher in patients compared to controls (leukocytes: p<0.01; IL-6: p=0.08; IL-1Ra: p=0.10). Cytokine production capacity in PBMCs after 24h stimulation revealed no differences between groups. [¹⁸F]FDG PET/CT imaging showed a trend for increased [¹⁸F]FDG-uptake in the periodontium [mean standard uptake value (SUV_mean), p=0.11] and in femur bone marrow (SUV_mean, p=0.06), but no differences were observed for vascular inflammation. Positive correlations between severity of periodontitis, measured by The Dutch Periodontal Screening Index and pocket depth, with circulating inflammatory markers and tissue inflammation were found.

Conclusions

P. gingivalis induces long-term activation of human monocytes in vitro (trained immunity). Patients with severe periodontitis did have signs of increased systemic inflammation and hematopoietic tissue activation. However, their circulating monocytes did not show a hyperresponsive phenotype. Together we suggest that trained immunity might contribute to local periodontal inflammation which warrants further investigation.

Experimental Periodontal Disease Triggers Coronary Endothelial Dysfunction in Middle-Aged Rats: Preventive Effect of a Prebiotic β-Glucan

This study was aimed to verify the hypothesis that periodontal disease contributes to endothelial dysfunction in the coronary arteries of middle-aged rats. Besides we evaluated the effects of a prebiotic (β-glucan isolated from Saccharomyces cerevisiae) in preventing vascular dysfunction. The sample comprised young (sham and induced to periodontal disease) and middle-aged rats (sham, periodontal disease, sham-treated and periodontal disease-treated), at 12 and 57 weeks, respectively. The treated-groups received daily doses of β-glucan (50 mg/kg) orally (gavage) for 4 weeks, and periodontal disease was induced in the last 2 weeks by ligature. A myograph system assessed vascular reactivity. The expression of endothelial nitric oxide synthase (eNOS), cyclooxygenase 1 (COX-1), COX-2, p47phox, gp91phox, NF-KB p65, p53, p21, and p16 was quantified by western blotting. Serum hydroperoxide production was measured by the ferrous oxidation-xylenol orange (FOX-2) assay method. Interleukin-1 beta (IL-1β), IL-10, and tumor necrosis factor-alpha (TNF-α) levels were evaluated by spectroscopic ultraviolet-visible analysis. Periodontal disease in middle-aged rats was associated with reduced acetylcholine-induced relaxations of coronary artery rings affecting the endothelium-dependent hyperpolarization- and the nitric oxide-mediated relaxations. The endothelial dysfunction was related to eNOS downregulation, pronounced impairment of the EDH-mediated relaxation, increased IL-1β and TNF-α proinflammatory cytokines, and also upregulation of NADPH oxidase and COXs, starting accumulate aging markers such as p53/p21 and the p16. Treatment with β-glucan effectively reduced bone loss in periodontal disease and delayed endothelial dysfunction in the coronary artery. Our data show that yeast β-glucan ingestion prevented oxidative stress and synthesis of proinflammatory marker and prevented eNOS reduction induced by periodontal disease in middle-aged rats. These results suggest that β-glucan has a beneficial effect on the coronary vascular bed.

Emerging Role of Epigenetics in Explaining Relationship of Periodontitis and Cardiovascular Diseases

Cardiovascular diseases such as ischemic heart diseases or stroke are among the leading cause of deaths globally, and evidence suggests that these diseases are modulated by a multifactorial and complex interplay of genetic, environmental, and lifestyle factors. Genetic predisposition and chronic exposure to modifiable risk factors have been explored to be involved in the pathophysiology of CVD. Environmental factors contribute to an individual's propensity to develop major cardiovascular risk factors through epigenetic modifications of DNA and histones via miRNA regulation of protein translation that are types of epigenetic mechanisms and participate in disease development. Periodontal disease (PD) is one of the most common oral diseases in humans that is characterized by low-grade inflammation and has been shown to increase the risk of CVDs. Risk factors involved in PD and CVD are determined both genetically and behaviorally. Periodontal diseases such as chronic inflammation promote DNA methylation. Epigenetic modifications involved in the initiation and progression of atherosclerosis play an essential role in plaque development and vulnerability. Epigenetics has opened a new world to understand and manage human diseases, including CVDs and periodontal diseases. Genetic medicine has started a new era of epigenetics to overcome human diseases with various new methodology. Epigenetic profiling may aid in better diagnosis and stratification of patients showing potential predisposed states for disease. A better understanding of the exact regulatory mechanisms of epigenetic pathways driving inflammation is slowly emerging and will aid in developing novel tools for the treatment of disease.

A 16S rRNA gene sequencing based study of oral microbiota in migraine patients in China

Migraine is a primary headache characterized by moderate or severe headache attacks, accompanied with reversible neurological and systemic symptoms. There are rare biomarkers for the disease. While emerging evidence has indicated the connection between gut microbiota and migraine, the relation between oral microbiota and migraine is barely known. Thus, the objective of the current study was to explore a possible correlation between oral microbiota and migraine. We compared the oral microbiota communities of migraine patients (26) with healthy subjects (29) via 16S rRNA gene sequencing. Alpha diversity indices were higher in migraine group compared with control group, whereas beta diversity indices also showed significant difference. A total of 23 genera were found differentially abundant between migraine and control groups. To conclude, there was a significant compositional difference in oral microbiota in migraine patients compared with healthy subjects.

Remote Ischemic Preconditioning Protects Against Endothelial Dysfunction in a Human Model of Systemic Inflammation: A Randomized Clinical Trial

[Figure: see text].

Correlation of periodontal diseases with intracranial aneurysm formation: novel predictive indicators

Background

We investigated whether periodontal diseases, specifically, periodontitis and gingivitis, could be risk factors of the incidence of intracranial aneurysms (IAs).

Methods

We performed a case–control study to compare the differences in the periodontal disease parameters of 281 cases that were divided into the IAs group and non-IAs group. All cases underwent complete radiographic examination for IAs and examination for periodontal health.

Results

Comparing with those in the non-IAs group, the cases in the IAs group were older (53.95 ± 8.56 vs 47.79 ± 12.33, p < 0.001) and had a higher incidence of hypertension (76 vs 34, p = 0.006). Univariate logistic regression analysis revealed that age (> 50 years) and hypertension were predictive risk factors of aneurysm formation (odds ratio [OR] 1.047, 95% confidence interval [95% CI] 1.022–1.073, p < 0.001 and OR 2.047, 95% CI 1.232–3.401, p = 0.006). In addition, univariate and multivariate logistic regression analyses showed that the parameters of periodontal diseases, including gingival index, plaque index, clinical attachment loss, and alveolar bone loss, were significantly associated with the occurrence of IAs (all p < 0.05). For further statistical investigation, the parameters of periodontal diseases were divided into four layers based on the quartered data. Poorer periodontal health condition (especially gingival index > 1.1 and plaque index > 1.5) had the correlation with IAs formation (p = 0.007 and p < 0.001).

Conclusion

Severe gingivitis or periodontitis, combining with hypertension, is significantly associated with the incidence of IAs.

Antioxidant Ascorbic Acid Modulates NLRP3 Inflammasome in LPS-G Treated Oral Stem Cells through NFκB/Caspase-1/IL-1β Pathway

Human gingival mesenchymal stem cells (hGMSCs) and endothelial committed hGMSCs (e-hGMSCs) have considerable potential to serve as an in vitro model to replicate the inflammation sustained by Porphyromonas gingivalis in periodontal and cardiovascular diseases. The present study aimed to investigate the effect of ascorbic acid (AA) on the inflammatory reverting action of lipopolysaccharide (LPS-G) on the cell metabolic activity, inflammation pathway and reactive oxygen species (ROS) generation in hGMSCs and e-hGMSCs. Cells were treated with LPS-G (5 μg mL⁻¹) or AA (50 μg mL⁻¹) and analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, immunofluorescence and Western blot methods. The rate of cell metabolic activity was decreased significantly in LPS-G-treated groups, while groups co-treated with LPS-G and AA showed a logarithmic cell metabolic activity rate similar to untreated cells. AA treatment attenuated the inflammatory effect of LPS-G by reducing the expression of TLR4/MyD88/NFκB/NLRP3/Caspase-1/IL-1β, as demonstrated by Western blot analysis and immunofluorescence acquisition. LPS-G-induced cells displayed an increase in ROS production, while AA co-treated cells showed a protective effect. In summary, our work suggests that AA attenuated LPS-G-mediated inflammation and ROS generation in hGMSCs and e-hGMSCs via suppressing the NFκB/Caspase-1/IL-1β pathway. These findings indicate that AA may be considered as a potential factor involved in the modulation of the inflammatory pathway triggered by LPS-G in an vitro cellular model.

Fermented milk with Lactobacillus curvatus SMFM2016-NK alleviates periodontal and gut inflammation, and alters oral and gut microbiota

This study aimed to analyze the effect of milk fermented with Lactobacillus curvatus SMFM2016-NK on periodontal diseases and gut health in a rat model. To improve the effect of Lb. curvatus SMFM2016-NK-fermented milk administration for relieving periodontitis, the periodontitis rat models were treated with the following for 4 wk: 10% skim milk (normal), periodontitis + 10% skim milk (negative control), periodontitis + Lactobacillus rhamnosus GG-fermented milk (positive control), and periodontitis + Lb. curvatus SMFM2016-NK-fermented milk (PD+LCFM). Transcriptional analysis of inflammatory cytokines [tumor necrosis factor α (TNF-α), IL-1β, IL-6, and IL-10] was performed via quantitative reverse-transcription PCR. The changes in the oral and gut microbiomes after administering Lb. curvatus SMFM2016-NK-fermented milk were analyzed with metagenomics sequencing using DNA extracted from the oral gingival tissues and feces from the cecum of the rat models. After treatment with Lb. curvatus SMFM2016-NK-fermented milk, the relative gene expression levels of TNFA and IL1B in the gingiva decreased in the PD+LCFM group compared with those in the negative control group. In the oral microbiome, the proportion of the phylum Proteobacteria in the PD+LCFM group was lower than that in the negative control after treatment with Lb. curvatus SMFM2016-NK-fermented milk. For the effect in the gut, the relative gene expression levels of inflammatory cytokines in the colon between the normal and negative control groups were not different; however, the expression levels of TNFA and IL1B in the PD+LCFM and positive control groups, respectively, were lower than those in the negative control group. The composition and diversity of the gut microbiome differed among normal, periodontitis, and Lb. curvatus SMFM2016-NK-fermented milk treatment groups. These results indicate that Lb. curvatus SMFM2016-NK-fermented milk could alleviate periodontal and gut inflammation and change oral and gut microbiota.

Periodontal Pathogens and Neuropsychiatric Health

Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.

Age and sex-associated variation in the multi-site microbiome of an entire social group of free-ranging rhesus macaques

BACKGROUND

An individual's microbiome changes over the course of its lifetime, especially during infancy, and again in old age. Confounding factors such as diet and healthcare make it difficult to disentangle the interactions between age, health, and microbial changes in humans. Animal models present an excellent opportunity to study age- and sex-linked variation in the microbiome, but captivity is known to influence animal microbial abundance and composition, while studies of free-ranging animals are typically limited to studies of the fecal microbiome using samples collected non-invasively. Here, we analyze a large dataset of oral, rectal, and genital swabs collected from 105 free-ranging rhesus macaques (Macaca mulatta, aged 1 month-26 years), comprising one entire social group, from the island of Cayo Santiago, Puerto Rico. We sequenced 16S V4 rRNA amplicons for all samples.

RESULTS

Infant gut microbial communities had significantly higher relative abundances of Bifidobacterium and Bacteroides and lower abundances of Ruminococcus, Fibrobacter, and Treponema compared to older age groups, consistent with a diet high in milk rather than solid foods. The genital microbiome varied widely between males and females in beta-diversity, taxonomic composition, and predicted functional profiles. Interestingly, only penile, but not vaginal, microbiomes exhibited distinct age-related changes in microbial beta-diversity, taxonomic composition, and predicted functions. Oral microbiome composition was associated with age, and was most distinctive between infants and other age classes.

CONCLUSIONS

Across all three body regions, with notable exceptions in the penile microbiome, while infants were distinctly different from other age groups, microbiomes of adults were relatively invariant, even in advanced age. While vaginal microbiomes were exceptionally stable, penile microbiomes were quite variable, especially at the onset of reproductive age. Relative invariance among adults, including elderly individuals, is contrary to findings in humans and mice. We discuss potential explanations for this observation, including that age-related microbiome variation seen in humans may be related to changes in diet and lifestyle. Video abstract.

Linking the oral microbiome and salivary cytokine abundance to circadian oscillations

Saliva has immense potential as a diagnostic fluid for identification and monitoring of several systemic diseases. Composition of the microbiome and inflammation has been associated and reflective of oral and overall health. In addition, the relative ease of collection of saliva further strengthens large-scale diagnostic purposes. However, the future clinical utility of saliva cannot be fully determined without a detailed examination of daily fluctuations that may occur within the oral microbiome and inflammation due to circadian rhythm. In this study, we explored the association between the salivary microbiome and the concentration of IL-1β, IL-6 and IL-8 in the saliva of 12 healthy adults over a period of 24 h by studying the 16S rRNA gene followed by negative binomial mixed model regression analysis. To determine the periodicity and oscillation patterns of both the oral microbiome and inflammation (represented by the cytokine levels), two of the twelve subjects were studied for three consecutive days. Our results indicate that the Operational Taxonomic Units (OTUs) belonging to Prevotella, SR1 and Ruminococcaceae are significantly associated to IL-1β while Prevotella and Granulicatella were associated with IL-8. Our findings have also revealed a periodicity of both the oral microbiome (OTUs) and inflammation (cytokine levels) with identifiable patterns between IL-1β and Prevotella, and IL-6 with Prevotella, Neisseria and Porphyromonas. We believe that this study represents the first measure and demonstration of simultaneous periodic fluctuations of cytokine levels and specific populations of the oral microbiome.

Local and systemic mechanisms linking periodontal disease and inflammatory comorbidities

Periodontitis, a major inflammatory disease of the oral mucosa, is epidemiologically associated with other chronic inflammation-driven disorders, including cardio-metabolic, neurodegenerative and autoimmune diseases and cancer. Emerging evidence from interventional studies indicates that local treatment of periodontitis ameliorates surrogate markers of comorbid conditions. The potential causal link between periodontitis and its comorbidities is further strengthened by recent experimental animal studies establishing biologically plausible and clinically consistent mechanisms whereby periodontitis could initiate or aggravate a comorbid condition. This multi-faceted ‘mechanistic causality’ aspect of the link between periodontitis and comorbidities is the focus of this Review. Understanding how certain extra-oral pathologies are affected by disseminated periodontal pathogens and periodontitis-associated systemic inflammation, including adaptation of bone marrow haematopoietic progenitors, may provide new therapeutic options to reduce the risk of periodontitis-associated comorbidities.

Periodontitis has been causally linked to the development of other chronic inflammatory diseases outside the oral mucosa. In this Review, George Hajishengallis and Triantafyllos Chavakis consider the molecular basis of these links.

Local destruction from distant action

Discussion on the identification of an osteoclast precursor population, which emerges in the bone marrow after systemic infection with a periodontal pathogen.

Introducing Standardized Assessment and Management of Oral Cares in a Rehabilitation Unit: Patient Outcomes and Experiences

PURPOSE

The aim of this study was to improve patient oral hygiene outcomes in a rehabilitation unit by implementing a nursing education package and oral hygiene assessment tool.

DESIGN

A case-control design with 50 rehabilitation patients was performed.

METHODS

Nursing staff received education and training in applying the Modified Oral Health Assessment Tool. Clinician assessment of patient oral hygiene occurred on admission and at days 5-7. Each patient reported their perceptions of oral hygiene and comfort prior to hospitalization, while in the hospital, and after transfer to the rehabilitation unit.

FINDINGS

Oral hygiene rating scores improved significantly from admission to the rehabilitation unit to days 5-7 (p = .00). The mean score of patient perceived cleanliness improved from hospital admission to admission to the rehabilitation unit.

CONCLUSION

Oral hygiene was improved following admission to a rehabilitation unit with a consistent and individualized approach to oral hygiene.

CLINICAL RELEVANCE

The introduction of a consistent and individualized approach to oral hygiene demonstrates positive patient outcomes and high patient acceptance.

The severity and extent of periodontitis is associated with cardio-ankle vascular index, a novel arterial stiffness parameter

OBJECTIVES

To evaluate the association between the severity and extent of periodontitis and arterial stiffness using the cardio-ankle vascular index (CAVI).

MATERIALS AND METHODS

A cross-sectional study of 2888 Electricity Generation Authority of Thailand (EGAT) employees aged 44-78 years was conducted. The severity of periodontitis was evaluated based on mean clinical attachment level (CAL). The percentage of sites with CAL ≥ 5 mm was used to divide the extent of periodontitis into healthy (0%), localized (> 0-< 30%), and generalized (≥ 30%). The CAVI value, a novel blood pressure-independent arterial stiffness parameter, was analyzed as both continuous and categorical data (low: < 9 or high: ≥ 9). Regression analysis was used to estimate the level of association.

RESULTS

The participants demonstrated a mean CAL, % sites with CAL ≥ 5 mm, and a CAVI value of 3.2 ± 1.2 mm, 16.0 ± 20.8%, and 8.24 ± 1.12, respectively. Higher mean CAVI was observed with greater mean CAL and % sites with CAL ≥ 5 mm. The mean CAVI of the healthy, localized, and generalized periodontitis groups were 8.01 ± 1.11, 8.22 ± 1.12, and 8.51 ± 1.04, respectively (p < 0.01). Linear and logistic regression analysis demonstrated a significant relationship between CAVI and all periodontal variables with β = 0.004-0.17 and OR = 1.01-1.58, respectively.

CONCLUSIONS

There is a significant dose-dependent association between the severity and extent of periodontitis and arterial stiffness measured by CAVI in Thai adults.

CLINICAL RELEVANCE

Preventing arterial stiffness, an early sign of cardiovascular events, by controlling the emerging risk factors, such as periodontitis, might have a high impact on health promotion.

Interleukin-10 Prevents Pathological Microglia Hyperactivation following Peripheral Endotoxin Challenge

Microglia, the resident macrophages of the brain parenchyma, are key players in central nervous system (CNS) development, homeostasis, and disorders. Distinct brain pathologies seem associated with discrete microglia activation modules. How microglia regain quiescence following challenges remains less understood. Here, we explored the role of the interleukin-10 (IL-10) axis in restoring murine microglia homeostasis following a peripheral endotoxin challenge. Specifically, we show that lipopolysaccharide (LPS)-challenged mice harboring IL-10 receptor-deficient microglia displayed neuronal impairment and succumbed to fatal sickness. Addition of a microglial tumor necrosis factor (TNF) deficiency rescued these animals, suggesting a microglia-based circuit driving pathology. Single cell transcriptome analysis revealed various IL-10 producing immune cells in the CNS, including most prominently Ly49D⁺ NK cells and neutrophils, but not microglia. Collectively, we define kinetics of the microglia response to peripheral endotoxin challenge, including their activation and robust silencing, and highlight the critical role of non-microglial IL-10 in preventing deleterious microglia hyperactivation.

Barriers and Predictors Associated With Accessing Oral Healthcare Among Patients With Cardiovascular Disease in Australia

BACKGROUND

Periodontal disease is associated with cardiovascular disease, and patients should be aware of this risk and seek dental care.

OBJECTIVE

In this study, the authors sought to identify the barriers and predictors for seeking oral healthcare among patients with cardiovascular disease.

METHODS

With the use of a cross-sectional descriptive study design, 307 patients with cardiovascular disease attending cardiac rehabilitation/outpatient cardiac clinics were surveyed between 2016 and 2017 in Sydney, Australia. Survey items included the prevalence of accessing dental services and a new "barriers to seeking frequent dental care" scale.

RESULTS

Most respondents (81%) reported at least 1 oral health problem, yet only 10% received any oral health information and more than half (58%) saw a dentist in the preceding 12 months. The barriers to seeking frequent dental care scale was internally consistent (Cronbach's α = 0.82) with 2 subscales, identified as personal-related and system-related barriers to accessing oral healthcare. Respondents were more likely to have seen a dentist in the previous 12 months if they received oral health information (adjusted odds ratio [AOR], 5.08; 95% confidence interval [CI], 1.62-15.93), had private health insurance (AOR, 3.33; 95% CI, 1.91-5.83), reported low barriers (AOR, 2.68; 95% CI, 1.61-4.47), or were born overseas (AOR, 2.13; 95% CI, 1.25-3.63).

CONCLUSIONS

The accessibility and affordability of dental care, as well as lack of oral health awareness, are key barriers and predictors for patients with cardiovascular disease accessing dental care. Greater emphasis on oral health is needed in the cardiac setting, along with appropriate dental referral pathways.

In Vitro Evaluation of the Antimicrobial and Immunomodulatory Activity of Culinary Herb Essential Oils as Potential Perioceutics

Due to their antimicrobial, immunomodulatory, antioxidant, and regenerative activities, culinary herbs have multiple medicinal uses, among which to prevent and treat oral diseases. The whole essential oils (EOs) have multiple advantages over purified components, such as a low probability to select for antimicrobial resistance, synergic effects of different components, and multi-pharmacological activities. In this study, we aimed to evaluate essential oils from Salvia officinalis (sage), Satureja hortensis (summer savory), and Anethum graveolens (dill) using an in vitro analysis of their antimicrobial activity against Gram-positive and Gram-negative bacterial strains isolated from the oral cavity of patients with periodontitis; the assays addressed both the planktonic and biofilm growth states and used culture-based approaches. Some of the tested EOs exhibited excellent bactericidal and antibiofilm activity, being active at concentrations as low as 0.08-1.36 mg/mL. Flow cytometry was used to investigate the potential mechanisms of their antibacterial activity and confirmed that the tested EOs act by permeabilizing the bacterial membrane and by inhibiting the activity of the efflux pumps. The immunomodulatory effect of the three EOs was determined by analyzing the gene expression profiles for pro- and anti-inflammatory cytokines of the THP-1 cells. The summer savory EO induced a clear proinflammatory effect, while the others did not significantly influence the cytokines profile of the tested cells. Taken together, our results indicate that summer savory EO and, to a lesser extent, sage and dill EOs could be used to inhibit bacteria involved in oral plaque formation and to reduce the expression of genes known to contribute to the inflammatory response using cell culture assessment.

Gallstone Disease and Microbiome

Gallstone disease (GSD) has, for many years, remained a high-cost, socially significant public health problem. Over the past decade, a number of studies have been carried out—both in humans and in animal models—confirming the role of the microbiota in various sections of the gastrointestinal tract as a new link in the etiopathogenesis of GSD. The microbiome of bile correlates with the bacterial composition of saliva, and the microbiome of the biliary tract has a high similarity with the microbiota of the duodenum. Pathogenic microflora of the oral cavity, through mechanisms of immunomodulation, can affect the motility of the gallbladder and the expression of mucin genes (MUC1,Muc3, MUC4), and represent one of the promoters of stone formation in the gallbladder. The presence of H. pylori infection contributes to the formation of gallstones and affects the occurrence of complications of GSD, including acute and chronic cholecystitis, cholangitis, pancreatitis. Intestinal bacteria (Clostridium, Bifidobacterium, Peptostreptococcus, Bacteroides, Eubacterium, and Escherichia coli) participating in the oxidation and epimerization of bile acids can disrupt enterohepatic circulation and lead to the formation of gallstones. At the same time, cholecystectomy due to GSD leads to the further transformation of the composition of the microbiota in various parts of the gastrointestinal tract, increasing the risk of developing stomach cancer and colorectal cancer. Further research is required to determine the possibility of using the evaluation of the composition of the microbiota of the gastrointestinal and biliary tracts as an early diagnostic marker of various gastroenterological diseases.

Melatonin ameliorates periodontitis-related inflammatory stress at cardiac left ventricular tissues in rats

BACKGROUND

The aim of this experimental rat study was to investigate the potential inflammatory effects of periodontitis on cardiac left ventricular tissue and the therapeutic activity of melatonin on these effects.

METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into three groups: control, experimental periodontitis (Ep), and Ep-melatonin (Ep-Mel). Experimental periodontitis was induced by placing and maintaining 3.0 silk ligatures at a peri marginal position on the left and right mandibular first molars for 5 weeks. Afterward, following the removal of ligatures, melatonin (10 mg/body weight) to Ep-Mel group, and vehicle (saline) to Ep and control groups were administered intraperitoneally for 14 days. On the first day of the eighth week, mandibular and cardiac left ventricular tissue samples were obtained following the euthanasia of the rats in all groups. Alveolar bone loss measurements were made on histological and microcomputed tomographic slices. Cardiac tissue levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), matrix metalloproteinase-9 (MMP-9), and cardiac Troponin-T (cTnT) were evaluated by appropriate biochemical methods.

RESULTS

Measurements made on the histological and microcomputed tomographic slices showed that melatonin significantly limits the ligature-induced periodontal tissue destruction (P <0.01). In addition, melatonin was detected to cause a significant decrease of MDA, MMP-9, and cTnT levels which were found to be significantly higher on rats with Ep (P <0.05) while having no significant effect on antioxidant levels (GSH, SOD, and CAT) (P >0.05).

CONCLUSION

Melatonin might be regarded as an important supportive therapeutic agent to reduce the early degenerative changes and possible hypertrophic remodeling at cardiac left ventricular tissues provoked by periodontitis-related bacteria and/or periodontal inflammation.

Breastfeeding may have a long-term effect on oral microbiota: results from the Fin-HIT cohort

BACKGROUND

Breastfeeding contributes to gastrointestinal microbiota colonization in early life, but its long-term impact is inconclusive. We aimed to evaluate whether the type of feeding during the first six months of life was associated with oral microbiota in adolescence.

METHODS

This is a cross-sectional sub-study using baseline information of 423 adolescents from the Finnish Health in Teens (Fin-HIT) cohort. Type of feeding was recalled by parents and dichotomized as (i) No infant formula; (ii) Infant formula (breastmilk + formula or only formula). Saliva microbiota was analysed using 16S rRNA (V3-V4) sequencing. Alpha diversity and beta diversity were compared between feeding type groups using ANCOVA and PERMANOVA, respectively. Differential bacteria abundance was tested using appropriate general linear models.

RESULTS

Mean age and body mass index were 11.7 years and 18.0 kg/m2, respectively. The No formula group contained 41% of the participants. Firmicutes (51.0%), Bacteroidetes (19.1%), and Proteobacteria (16.3%) were the most abundant phyla among all participants. Alpha and beta diversity indices did not differ between the two feeding groups. Three Operational Taxonomic Units (OTUs) belonging to Eubacteria and Veillonella genera (phylum Firmicutes) were more abundant in the No formula than in the Infant formula group (log2fold changes/ p - values - 0.920/ < 0.001, - 0.328/ 0.001, - 0.577/ 0.004).

CONCLUSION

Differences exist in abundances of some OTUs in adolescence according to feeding type during the first six months of life, but our findings do not support diversity and overall oral microbiota composition in adolescents being affected by early feeding type.

Severe and moderate periodontitis are associated with acute myocardial infarction

BACKGROUND

An association between periodontitis and cardiovascular disease is now well documented; however, the effect of periodontitis severity levels on this outcome, specifically on acute myocardial infarction (AMI), remains unexplored. This study investigated the association between levels of periodontitis severity (exposure) and AMI (outcome).

METHODS

This case-control study, matched by sex and age, was conducted with 621 participants, with 207 individuals treated in the emergency department of Santa Izabel and Ana Nery Hospitals in Salvador, Bahia, Brazil, diagnosed with a first AMI event, and compared to 414 individuals without a diagnosis of AMI. Levels of periodontitis severity followed two criteria: (1) Center for Disease Prevention and Control and American Academy of Periodontology; (2) Gomes-Filho et al. (2018) using criteria that also evaluated bleeding upon probing. Conditional logistic regression analysis was performed and odds ratios (ORs) and their 95% confidence intervals (CIs) were obtained.

RESULTS

The adjusted association measurements showed a positive association between both severe (OR_adjusted ranged from 2.21 to 3.92; 95% CI ranged from 1.03 to 10.05) and moderate periodontitis (OR_adjusted ranged from 1.96 to 2.51; 95% CI ranged from 1.02 to 6.19), and AMI, for both periodontitis diagnostic criteria. It demonstrated that among those with moderate and severe periodontitis, the chance of having AMI was approximately two to four times greater than among those without periodontitis.

CONCLUSION

The findings demonstrate that there is an association between the severity of the periodontal condition and AMI, suggesting a possible relationship among the levels of periodontitis severity and the cardiovascular condition.

Impact of Treating Oral Disease on Preventing Vascular Diseases: A Model-Based Cost-effectiveness Analysis of Periodontal Treatment Among Patients With Type 2 Diabetes

OBJECTIVE

Previous randomized trials found that treating periodontitis improved glycemic control in patients with type 2 diabetes (T2D), thus lowering the risks of developing T2D-related microvascular diseases and cardiovascular disease (CVD). Some payers in the U.S. have started covering nonsurgical periodontal treatment for those with chronic conditions, such as diabetes. We sought to identify the cost-effectiveness of expanding periodontal treatment coverage among patients with T2D.

RESEARCH DESIGN AND METHODS

A cost-effectiveness analysis was conducted to estimate lifetime costs and health gains using a stochastic microsimulation model of oral health conditions, T2D, T2D-related microvascular diseases, and CVD of the U.S.

POPULATION

Model parameters were obtained from the nationally representative National Health and Nutrition Examination Survey (NHANES) (2009-2014) and randomized trials of periodontal treatment among patients with T2D.

RESULTS

Expanding periodontal treatment coverage among patients with T2D and periodontitis would be expected to avert tooth loss by 34.1% (95% CI -39.9, -26.5) and microvascular diseases by 20.5% (95% CI -31.2, -9.1), 17.7% (95% CI -32.7, -4.7), and 18.4% (95% CI -34.5, -3.5) for nephropathy, neuropathy, and retinopathy, respectively. Providing periodontal treatment to the target population would be cost saving from a health care perspective at a total net savings of $5,904 (95% CI -6,039, -5,769) with an estimated gain of 0.6 quality-adjusted life years per capita (95% CI 0.5, 0.6).

CONCLUSIONS

Providing nonsurgical periodontal treatment to patients with T2D and periodontitis would be expected to significantly reduce tooth loss and T2D-related microvascular diseases via improved glycemic control. Encouraging patients with T2D and poor oral health conditions to receive periodontal treatment would improve health outcomes and still be cost saving or cost-effective.

The Human Oral Microbiome in Health and Disease: From Sequences to Ecosystems

Abstract: The human oral cavity is home to an abundant and diverse microbial community (i.e., the oral microbiome), whose composition and roles in health and disease have been the focus of intense research in recent years. Thanks to developments in sequencing-based approaches, such as 16S ribosomal RNA metabarcoding, whole metagenome shotgun sequencing, or meta-transcriptomics, we now can efficiently explore the diversity and roles of oral microbes, even if unculturable. Recent sequencing-based studies have charted oral ecosystems and how they change due to lifestyle or disease conditions. As studies progress, there is increasing evidence of an important role of the oral microbiome in diverse health conditions, which are not limited to diseases of the oral cavity. This, in turn, opens new avenues for microbiome-based diagnostics and therapeutics that benefit from the easy accessibility of the oral cavity for microbiome monitoring and manipulation. Yet, many challenges remain ahead. In this review, we survey the main sequencing-based methodologies that are currently used to explore the oral microbiome and highlight major findings enabled by these approaches. Finally, we discuss future prospects in the field.