Subgingival Plaque Research Articles

Association between Porphyromonas gingivalis in subgingival plaque and coronary artery disease: A case-control study.

Periodontitis is a chronic inflammatory disease of the supporting tissue surrounding the teeth. The disease is caused by specific bacteria, such as Porphyromonas gingivalis, which lead to the destruction of periodontal ligaments and alveolar bone. The study aimed to evaluate the relationship between the prevalence of P. gingivalis in subgingival plaque and coronary artery disease (CAD). Fifty patients with CAD and 50 healthy controls (non-CAD) participated in this case-control study. The periodontal health in the groups was evaluated through the assessment of the pocket depth (PD), clinical attachment loss (CAL) and bleeding on probing (BoP). The presence of P. gingivalis in subgingival plaque samples was determined through real-time polymerase chain reaction (RT-PCR). The data was analyzed using the χ2 test and the Mann-Whitney U test. The mean PD was 3.30 ±1.55 mm and 3.56 ±0.97 mm in CAD patients and non-CAD subjects, respectively (p = 0.028). No significant differences were observed in the CAL (p = 0.858) and BoP (p = 1.000) between the groups. The RT-PCR results revealed the presence of P. gingivalis 16S rDNA in 32% and 22% of the subgingival plaque of patients with CAD and non-CAD, respectively, with a mean concentration of 7.7 × 106. No statistically significant association was observed between the prevalence of P. gingivalis and CAD (p = 0.260). The results of the multiple logistic regression analysis showed an association between CAD and male sex (p = 0.004, odds ratio (OR): 4.163), as well as age (p = 0.011, OR: 1.067). The findings of this study indicated that there is no statistically significant correlation between the prevalence of P. gingivalis in subgingival plaque and CAD.

The Effectiveness of Salivary Sampling for the Detection and Quantification of Aggregatibacter actinomycetemcomitans in Periodontitis Patients

The objective was to evaluate using unstimulated saliva in detecting Aggregatibacter actinomycetemcomitans and to compare the saliva and subgingival and mucosa membrane occurrence of this periodontal pathogen in patients diagnosed with advanced periodontitis. Patients with advanced forms of periodontitis (n = 220; mean age: 54.03 ± 03 years) at stage III/IV were sampled. Unstimulated saliva, buccal cheek mucosa, and pooled subgingival plaque samples were collected. The identification of A. actinomycetemcomitans was performed using qPCR. A descriptive analysis and Wilcoxon test and analysis of variance were performed. A. actinomycetemcomitans was isolated from 28.18% of the subjects. A total of 660 samples were obtained, 220 from unstimulated saliva, 220 from buccal cheek mucosa surfaces, and 220 from pooled subgingival plaque samples. A. actinomycetemcomitans was isolated from 21.80% of unstimulated saliva, 19.50% of buccal cheek swabs, and 17.70% of subgingival samples. There was a statistically significant difference between the presence of A. actinomycetemcomitans in the unstimulated saliva samples and in the buccal cheek mucosa swab samples and pooled subgingival plaque samples (p < 0.001). These results suggest that in advanced periodontitis, unstimulated saliva is representative of pooled subgingival plaque/buccal cheek mucosa samples and its use is adequate in the oral detection of A. actinomycetemcomitans in a cohort of patients with stage III and IV periodontitis.

Occurrence of Aggregatibacter actinomycetemcomitans and Its JP2 Genotype in a Cohort of 220 Western Australians with Unstable Periodontitis.

The main purpose of the present study was to investigate the carrier rate of Aggregatibacter actinomycetemcomitans and its JP2 genotype in a cohort of 200 Western Australians diagnosed with periodontitis. In this descriptive cross-sectional study, 220 consecutive patients with periodontitis, aged 18 years and older, were recruited to a specialist periodontal practice in Perth City. Every patient included in this study contributed three different intra-oral samples. Periodontal, radiographical, and microbiological assessments were performed. The samples were analysed using a polymerase chain reaction for the detection of Aggregatibacter actinomycetemcomitans and its JP2 genotype using the primers and conditions described previously. A Chi-square test and logistic regression analysis were performed to evaluate the results. The prevalence of Aggregatibacter actinomycetemcomitans was 28.18%. The carrier rates of A. actinomycetemcomitans in the unstimulated saliva, cheek swabs, and pooled subgingival plaque samples were 21.80%, 19.50%, and 17.70%, respectively. There was a significant correlation between the severe form of periodontitis (stage IV, grade C) and younger age (p = 0.004), positive family history of periodontitis (p < 0.001), oral hygiene method (p < 0.001), and irregular dental visit attendance (p < 0.001). The binary logistic regression analysis revealed that having severe periodontitis risk increased almost three times in those who were young (OR: 2.812) and came from a family with a history of periodontal disease (OR: 3.194). However, the risk of severe periodontitis was five times higher in those patients with tooth loss due to periodontal disease (OR: 5.071). The highly leukotoxic JP2 genotype of Aggregatibacter actinomycetemcomitans was not detected. This study of a Western Australian cohort confirmed the low presence of Aggregatibacter actinomycetemcomitans and the complete absence of its JP2 genotype. Young age, family history of periodontal disease, lack of flossing, irregular dental visits, and tooth loss due to periodontitis were identified as potential risk factors for periodontitis stage IV, grade C in this cohort.

Clinical and Microbiological Periodontal Biofilm Evaluation of Patients with Type I Diabetes.

Background/Objectives: The purpose of this study was to assess the microbial composition and density of subgingival plaque samples for periodontal pathogens while correlating the values with glycemic control levels via glycated hemoglobin (HbA1c), a type of hemoglobin that has chemically linked glucose, in type I diabetes individuals who will undergo complex oral rehabilitation through orthodontic treatment and implant surgery. Methods: A cohort of 42 adults with type I diabetes were included in this study. The subjects sustained a comprehensive periodontal clinical examination as well as microbiological assessments of their subgingival plaque samples through quantitative real-time PCR. The samples were collected from the two deepest pockets of each subject. Results: The highest number of periodontopathogenic bacteria was observed in the pockets of 5-7 mm. T. forsythia showed the highest prevalence (20.48%), with decreasing numbers as follows: T. denticola (13.31%), P. gingivalis (11.26%), A. actinomycetemcomitans (7%), and P. intermedia (4.9%). T. denticola and T. forsythia were significantly more commonly observed in individuals with elevated HbA1c serum levels. No correlation was observed between P. gingivalis, A. actinomycetemcomitans, P. intermedia presence, and the HbA1c value. Conclusions: Periodontopathogenic agents' presence in subgingival biofilm samples varied in accordance with the pocket probing depth and metabolic control of the diabetic individuals. In our study, the appearance of these periodontopathogenic agents was linked to lowered metabolic control in patients with type I diabetes mellitus.

Salivary microbiota reflecting changes in subgingival microbiota.

The salivary microbiota has attracted increasing attention as a promising method for monitoring periodontal disease. With regard to the pathogenesis of periodontal disease, however, subgingival plaque microbiota is the dominant etiological factor. Although it has been established that periodontopathogenic bacteria exist in saliva and their distribution differs, depending on the severity of the disease, it is necessary to analyze the extent to which the salivary microbiota reflects the subgingival microbiota. This study explored whether subgingival microbial changes according to the severity of periodontal disease and following the non-surgical periodontal treatment of periodontitis are reflected in the saliva microbiota and concluded that the salivary microbiota can reflect changes in the subgingival microbiota. Saliva can be used as a diagnostic tool to monitor the periodontal health status of individuals.

Applications Of Photodynamic Therapy In Periodontal Diseases

Background: According to A. Marcacci et al (1888), when many reports emerged on light absorbing properties and of fluorescence of various dyes, it became clear that dye excitation by light exerts destructive action in biological systems. This so-called photodynamic action was described as a process in which light, after being absorbed by dyes sensitizes organisms for visible light inducing cell damage. The supra- and subgingival plaque biofilm on tooth surfaces should easily be accessible for flushing with the dye and for activating them by light. Thus, periodontal diseases are promising applications of Photodynamic Therapy. Introduction: Chronic periodontitis is the most common periodontal disease which is related to the chronic accumulation of bacterial plaque. Since mechanical methods are not sufficient in the treatment of this disease, administration of local/systemic antibiotic is recommended following mechanical debridement. However, side effects of antibiotics such as microbial resistance and patient allergy led to development of alternative methods. One of these suggested methods is the antimicrobial photodynamic therapy (aPDT). PDT is a local noninvasive treatment modality without the side effects caused by antibiotics. Objectives: In this review, the mechanism of action of PDT and its application in the treatment of various periodontal conditions along with its future trends are discussed. Conclusion: Even though PDT is still in experimental stages of development and testing, the method may be an adjunct to conventional antibacterial measures in periodontology and Implant related perspectives.

Comparative Evaluation of Mogibacterium timidum in Diabetic Patients With Chronic Periodontitis, Nondiabetic Patients with Chronic Periodontitis, and Healthy Patients During Pretreatment and Posttreatment: A Real-Time PCR Study.

Introduction Mogibacterium is a rod-shaped, anaerobic, gram-positive new bacteria. Mogibacterium genus included new species such as Mogibacterium timidum, Mogibacterium vescum, and Mogibacterium pumilum by taxonomic nomenclature in the year 2000. Its presence in oral bacterial flora is believed to increase severity of gingivitis and periodontitis, indicating some link between this bacterium and periodontal disease. Its frequency of detection in subjects with chronic periodontitis and those with diabetes along with chronic periodontitis has yet to be investigated. Therefore, the aim of this study was to determine the frequency of detection of Mogibacterium timidum in subgingival samples of such subjects. Aims We aimed to comparatively evaluate Mogibacterium timidum levels from subgingival plaque in non-diabetic subjects with chronic periodontitis, diabetic subjects with chronic periodontitis, and healthy subjects at baseline and six weeks post-scaling and root planing. Materials and methods The study was conducted in Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Pune, India. A total sample size of 45 patients was chosen by first screening the patients on the basis of plaque index, probing pocket depth, and relative clinical attachment level. Subjects were divided into the following groups: group A comprised healthy subjects, group B comprised those with chronic periodontitis without diabetes, and group C comprised those with chronic periodontitis with diabetes. Subjects with probing pocket depth and clinical attachment level of 2-3mm were grouped into healthy subjects (group A). Subjects with pocket depth and clinical attachment level of more than or equal to 5mm were grouped into the chronic periodontitis group with and without diabetes in group B and group C, respectively. Real-time polymerase chain reactionwas performed for plaque samples taken from gingival pockets for quantification and detection of the count of M. timidum. Results A statistical insignificant difference was found in the pre- and posttreatment counts of the bacteria in healthy subjects. A statistically significant difference was found in the pre- and posttreatment counts of DNA copies of Mogibacterium timidum in group B (chronic periodontitis subjects without diabetes) and group C (chronic periodontitis subjects with type 2 diabetes mellitus). The results indicate a significant association of this bacteria with periodontal destruction especially in diabetic subjects. The counts of the bacteria were highest in diabetic group, followed by the non-diabetic group (both having chronic periodontitis), with least counts in the healthy group both during pre- and posttreatment. Conclusion Significant association between chronic periodontitis, diabetes, and Mogibacterium is seen with the highest numbers of bacteria and destruction in the diabetic group, followed by the only chronic periodontitis group, and least association in the healthy group.

Study on the Mechanism of Nd:YAG Laser-Assisted Therapy on the Changes of Subgingival Flora in Periodontitis.

This study evaluated the therapeutic efficacy of combining Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser with subgingival curettage and root planing (SRP) in generalised stage III/grade C periodontitis patients and its effects on cytokine dynamics and microbial community. Fifteen patients diagnosed with stage III/grade C periodontitis were included in the cohort. The right and left sides of the mouth were randomly assigned either the conventional SRP (control) group or the SRP supplemented with Nd:YAG laser group (experimental group, 160 mJ, 4 W) in a split-mouth design. Clinical periodontal indices were recorded at baseline and at the 6-week follow-up post-treatment. ELISA was utilised to measure IL-1β and TNF-α levels in gingival crevicular fluid. The subgingival microbiota's composition and variations were characterised using 16S rDNA amplicon sequencing, while quantitative real-time polymerase chain reaction (qRT-PCR) was employed to analyse the changes in the red-complex bacteria in subgingival plaque. The SRP&#43;Nd group exhibited a statistically significant reduction in record probing depth (PD) and bleeding on probing (BOP) compared to the SRP group after treatment (p0.05). The SRP&#43;Nd group showed a markedly lower IL-1β level than the SRP group (p0.05). Furthermore, there was no statistically significant difference in the dominant subgingival microbiota composition and level of the red-complex bacteria between the two groups (p>0.05). The adjunctive use of Nd:YAG laser with SRP demonstrates promising short-term therapeutic benefits for patients with extensive stage III/grade C periodontitis. Both SRP as a standalone treatment and its combination with Nd:YAG laser effectively facilitate a transition in the dominant bacterial community from periodontitis-associated to periodontal health-associated microbiota.

Antibacterial efficacy of Doxycycline as a Photosensitizer in Photodynamic Therapy against Subgingival Plaque Bacteria

Background: Periodontitis is an inflammation that occurs in the periodontium and is caused by the host immune responses and subgingival plaque bacteria. Subgingival plaque bacteria can initiate periodontal disease because they have the potential to induce the release of proinflammatory cytokines. Mechanical debridement alone not always possible to completely remove pathogenic bacteria that cause periodontal infections due to accessibility and location. New treatments, such as photodynamic therapy, which uses lasers, can offer an alternative option. Photodynamic therapy is a non-invasive therapy that uses photons of light energy for medical purposes. The mechanism of photodynamic therapy is based on a triad consisting of a photosensitizer, a light source, and molecular oxygen. Microorganisms first absorb the photosensitizer, then are activated by light of a specific wavelength. Photosensitizer can transfer the received energy to molecular oxygen and convert oxygen into ROS, then cause the death of microorganisms by affecting their membranes, proteins, and nucleic acids. Doxycycline is widely used in periodontal therapy and is known to act as an exogenous photosensitizer. Objective: The aim of the research was to evaluate the potential of doxycycline as a photosensitizer in photodynamic therapy against subgingival plaque bacteria. Method: The research used the diffusion method to test the bacterial inhibition with 4 replications. This research was divided into 6 groups: (1) control, (2) photodynamic therapy, (3) 0,0125% doxycycline with photodynamic therapy, (4) 0,025% doxycycline with photodynamic therapy, (5) 0,05% doxycycline with photodynamic therapy, and (6) 0,1% doxycycline with photodynamic therapy. Subgingival plaque bacteria were collected from stock and put into a reaction tube that contained liquid BHIB. After that, the subgingival plaque bacteria culture was incubated for 48hours at 37ºC, and then the subgingival plaque bacteria culture was planted on Mueller Hinton agar with the spreading technique. Filter paper was inserted into each of the doxycycline concentrations and placed on the petridish that has been planted with subgingival plaque bacteria. Photodynamic therapy with a wavelength of 405nm for 30 seconds was exposed to the paper. Then, the agar plates were incubated for 48 hours at 37ºC. Result: The avarage inhibition zone of subgingival plaque bacteria was obtained in the following groups: (1) 0mm, (2) 13.375mm, (3) 14.6125mm, (4) 15.450mm, (5) 17.325mm, and (6) 19.2875mm. Conclusion: The doxycycline 0.1% concentration group that is combined with photodynamic therapy for 30 seconds has the biggest inhibition zone in the subgingival plaque bacteria.

Intraperitoneal Injection of the Porphyromonas gingivalis Outer Membrane Vesicle (OMV) Stimulated Expressions of Neuroinflammatory Markers and Histopathological Changes in the Brains of Adult Zebrafish.

Porphyromonas gingivalis is the major pathogenic bacteria found in the subgingival plaque of patients with periodontitis, which leads to neuroinflammation. The bacteria destroy periodontal tissue through virulence factors, which are retained in the bacteria's outer membrane vesicles (OMV). This study aimed to determine the real-time effect of an intraperitoneal injection of P. gingivalis OMV on the production and expression of inflammatory markers and histopathological changes in adult zebrafishes' central nervous systems (CNS). Following the LD50 (21 µg of OMV), the zebrafish were injected intraperitoneally with 18 µg of OMVs, and the control group were injected with normal saline at seven different time points. Brains of experimental zebrafish were dissected at desired time points for colorimetric assays, ELISA, and histology. This study discovered that nitric oxide and PGE2 were significantly increased at 45 min, while IL-1β and IL-6 were expressed at subsequent 12 h and 24 h time points, respectively. Histopathological changes such as blood coagulation, astrocytosis, edema, spongiosis, and necrosis were observed between the 6hour and 24 h time points. The two apoptotic enzymes, caspases 3 and 9, were not expressed at any point. In summary, the OMV-induced neuroinflammatory responses and histopathological changes in adult zebrafish were time-point dependent. This study will enrich our understanding of the mechanism of P. gingivalis OMVs in neuroinflammation in a zebrafish model, most especially the timing of the expression of inflammatory mediators in relation to observable changes in brain tissues.

Association Between Dietary Patterns and Subgingival Microbiota: Results From the Oral Infections, Glucose Intolerance, and Insulin Resistance Study (ORIGINS).

To study the association between dietary patterns and subgingival microbiota. Participants (n = 651) who were enrolled in the Oral Infections, Glucose Intolerance, and Insulin Resistance Study (ORIGINS) with subgingival plaque sampling (n = 890 plaques) and a dietary assessment were included. 16S rRNA gene amplicon sequences of subgingival plaque from sites with either probing depth <4 or ≥4 mm were processed separately and used to obtain α-diversity metrics (Faith, Shannon, Simpson, Observed) and taxa ratios (Red Complex to Corynebacterium [RCLR], Treponema to Corynebacterium [TCLR], and Treponema to Neisseria [TNLR]). Food frequency questionnaires (FFQs) were processed to calculate Alternate Healthy Eating Index (AHEI) and A Priori Diet Quality Score (APDQS) scores. Mixed regression models examined the mean levels of microbial metrics across quartiles of diet quality. Means ± standard errors are reported along with p-values. In multivariable models assessing the association between diet scores and α-diversity metrics, higher AHEI values were significantly associated with lower Faith (p-value = 0.01) and Observed (p-value = 0.04) diversity values; similar findings were observed for APDQS (p-value = 0.01, p-value = 0.04). In multivariable models assessing the association between diet scores (AHEI and APDQS) and taxa ratios (RCLR, TCLR and TNLR), as the AHEI quartile increased, all taxa ratios decreased significantly as follows: -1.06 ± 0.093 in Q1 to -1.34 ± 0.099 in Q4 (RCLR), -0.43 ± 0.077 in Q1 to -0.64 ± 0.083 in Q4 (TCLR) and -0.09 ± 0.083 in Q1 to -0.38 ± 0.089 in Q4 (TNLR), respectively. In contrast, as the APDQS quartiles increased, only TNLR decreased significantly from -0.08 ± 0.085 in Q1 to -0.34 ± 0.091 in Q4. Diets rich in fruits, vegetables, whole grains and other nutritionally rich plant foods are associated with lower oral microbial diversity and favourable ratios of pathogenic to commensal microbiota.

Multi-site analysis of biosynthetic gene clusters from the periodontitis oral microbiome.

Background. Bacteria significantly influence human health and disease, with bacterial biosynthetic gene clusters (BGCs) being crucial in the microbiome-host and microbe-microbe interactions.Gap statement. Despite extensive research into BGCs within the human gut microbiome, their roles in the oral microbiome are less understood.Aim. This pilot study utilizes high-throughput shotgun metagenomic sequencing to examine the oral microbiota in different niches, particularly focusing on the association of BGCs with periodontitis.Methodology. We analysed saliva, subgingival plaque and supragingival plaque samples from periodontitis patients (n=23) and controls (n=16). DNA was extracted from these samples using standardized protocols. The high-throughput shotgun metagenomic sequencing was then performed to obtain comprehensive genetic information from the microbial communities present in the samples.Results. Our study identified 10 742 BGCs, with certain clusters being niche-specific. Notably, aryl polyenes and bacteriocins were the most prevalent BGCs identified. We discovered several 'novel' BGCs that are widely represented across various bacterial phyla and identified BGCs that had different distributions between periodontitis and control subjects. Our systematic approach unveiled the previously unexplored biosynthetic pathways that may be key players in periodontitis.Conclusions. Our research expands the current metagenomic knowledge of the oral microbiota in both healthy and periodontally diseased states. These findings highlight the presence of novel biosynthetic pathways in the oral cavity and suggest a complex network of host-microbe and microbe-microbe interactions, potentially influencing periodontal disease. The BGCs identified in this study pave the way for future investigations into the role of small-molecule-mediated interactions within the human oral microbiota and their impact on periodontitis.

Association between Periodontal Disease and Oral Benign, Potentially Malignant, Malignant, and Chronic Immune-Mediated Disorders: A Clinical Study.

Background: Periodontal disease is an inflammatory, chronic, and multifactorial disease. The objective of this study is to analyze the association between periodontal disease and some disorders such as papillomas (benign lesions), lichen planus (a chronic immune-mediated disorder), leukoplakia (potentially malignant lesions), and oral cancer (malignant lesions). Methods: For this study, 42 patients were recruited whose supragingival and subgingival plaque was qualitatively analyzed using a phase-contrast microscope, which allowed for the detection of compatible bacterial flora (immobile and composed mainly of cocci) indicative of periodontal health and incompatible bacterial flora (mobile and composed mainly of spirochetes) indicative of periodontal pathology. Patients with incompatible bacterial flora were then subjected to a laser-assisted periodontal treatment with irrigation with hydrogen peroxide within the periodontal pockets (a non-surgical laser-assisted periodontal protocol which is referred to as dye-free photodynamic therapy). Results: Based on the 42 patients recruited, there was no association between oral cavity lesions and periodontal pathogenic bacteria. Four of them were found to have incompatible bacterial flora. Indeed, it was found that almost all the patients had been previously instructed in the proper techniques of home oral hygiene, and more than half of them reported that they carried out periodic check-ups by a dental hygienist. Of the four patients with signs and symptoms of periodontitis, two stated a willingness to undergo the non-surgical laser-assisted periodontal protocol and showed improvements in periodontal indices such as CAL, PPD, and BoP. Conclusions: hygienists and dentists are determining factors in the prevention of periodontal disease and for the maintenance of good oral health.

Assessment of the Efficacy of Indigenously Prepared Azadirachta Indica Mouthwash on P. Gingivalis in Chronic Periodontitis Patients: A Microbiological Study

Aim: The present study aimed to compare and evaluate the antimicrobial effect of Azadirachta Indica (Neem mouthwash) to chlorhexidine mouthwash on P. gingivalis. Materials ans Methods: The subjects were divided into 2 groups. Group I included 5 subjects who used self-prepared neem mouthwash, and Group II included 5 subjects who used 0.2% chlorhexidine mouthwash. Subgingival plaque samples were taken at baseline and the 15th day after using the mouthwash and subjected to microbiological evaluation. Results: The colony forming unit (CFU) of P. gingivalis was calculated at baseline and on the 15th day after using mouthwash using the digit colony counter. A comparison of the total CFU of both mouthwashes revealed that the neem mouth was effective in reducing the microbial colonies of P. gingivalis from baseline to the 15th day. Conclusion: It was concluded that the self-prepared neem mouthwash was effective in reducing the colony-forming unit of P. gingivalis in the sub-gingival plaque samples and showed better results than the commercially available chemical-based chlorhexidine mouthwash.

Roles of oral and gut microbiota in acute myocardial infarction

IntroductionThe significance of oral/gut microbiota in acute myocardial infarction (AMI) has been increasingly appreciated. However, correlations between oral/gut microbiota and AMI parameter, as well as the key microbiota that may have a crucial function in this process, remain unclear. ObjectivesTo investigate the composition and structure of oral and gut microbiota associated with AMI and explore the roles of specific bacterial species in the progression of AMI. MethodsWe conducted a case-control study with 37 AMI patients and 36 controls. Oral and gut sample were collected and sequenced. Using correlation analysis, we combined bioinformatics data with AMI clinical parameters and obtained heatmaps of correlation coefficients. Additionally, we used antibiotics to eliminate the gut microbiota of C57BL/6J mice, followed by the transplantation of selected bacteria to verify the gut colonization of oral bacteria and their impact on AMI. ResultsThe component of oral and gut microbiota of AMI group showed significant alterations when compared to the control group. 17 salivary genera, 21 subgingival genera, and 8 gut genera in AMI group substantially differed from those in control group. Additionally, 19 genera from saliva, 19 genera from subgingival plaque, and 11 genera from feces substantially correlated with AMI clinical parameters. Orally administrated S.o (Streptococcus oralis subsp. dentisani), S.p (Streptococcus parasanguinis), and S.s (Streptococcus salivarius) were able to colonize in the gut and exacerbate myocardial infarction. ConclusionThere is a strong correlation between oral/gut microbiota and AMI. Streptococcus spp. is capable to transmit from oral to gut and exacerbate myocardial infarction in mice. Monitoring and control of specific oral microbiota may be an effective new strategy for improving the therapy of AMI.

Differences Between Vietnamese Living in Germany and German Periodontitis Patients in Periodontal Conditions and Subgingival Microbiota

Introduction and aimsA number of studies have reported ethnic differences in the prevalence and severity of periodontitis. Such discrepancies could be attributed to disparities in periodontal risk factors, as well as variations in the composition of the subgingival microbiota. Given the substantial Vietnamese population residing in the former German Democratic Republic, the present study aimed to compare the clinical and microbial characteristics of periodontitis patients of Vietnamese Asian origin living in Germany with those of German Caucasian periodontitis patients. MethodsA total of 60 patients with a minimum stage II periodontitis diagnosis were included in the study. Of these, 30 were of Vietnamese origin, with an average age of 55 years and a male prevalence of 33.3%. The remaining 30 patients were of German origin, with an average age of 54.5 years and a male prevalence of 40%. The periodontal diagnosis was made in accordance with the recently revised classification of periodontal disease. The pooled subgingival plaque samples were subjected to next-generation sequencing on the MiSeq platform (Illumina). ResultsThe German patients were significantly more likely to be smokers (56.7% vs 13.3%), had significantly higher body mass index (26 vs 22.6 kg/m²), probing depth (4.1 vs 3.6 mm), and clinical attachment loss (5 vs 4.1 mm). In terms of microbiota, the Vietnamese patients exhibited significantly lower beta diversity compared to the German patients, and smokers demonstrated a significantly higher beta diversity compared to nonsmokers. The microbiota of both groups differed most significantly in the relative abundance of Porphyromonas gingivalis (Vietnamese) and Fusobacteriia (German). ConclusionsGerman patients with periodontitis showed more severe periodontal symptoms and more pronounced periodontal risk factors compared to Vietnamese patients. Both patient groups also showed significant differences in the subgingival microbiota. Clinical relevanceCompared to Vietnamese living in Germany, German patients have a higher need for periodontal treatment and at the same time the risk factors of smoking and obesity should be reduced. More research is needed before the differences in oral microbiota between the two groups can lead to individualised therapeutic approaches.

SIRT6 alleviates senescence induced by Porphyromonas gingivalis in human gingival fibroblasts.

Bidirectional influences between senescence and inflammation are newly discovered. This study aimed to clarify the roles and mechanism of Porphyromonas gingivalis (P. gingivalis) in exacerbating senescence in human gingival fibroblasts (HGFs). Subgingival plaque and gingivae were collected from twenty-four periodontitis patients and eighteen periodontally healthy subjects. Quantities of P. gingivalis in subgingival plaque were explored using real-time PCR and the expressions of p53, p21 and SIRT6 in gingivae were detected by IHC. Moreover, senescence in HGFs was induced by P. gingivalis lipopolysaccharide (LPS) and the expressions of senescence-related β-galactosidase (SA-β-gal), p53, p21 and senescence-associated secretory phenotype (IL-6 and IL-8) with or without treatment by SIRT6 activator UBCS039 were explored by IHC, western blot and ELISA, respectively. In addition, the levels of SIRT6, Nrf2, HO-1 and reactive oxygen species (ROS) were examined by western blot and flow cytometry. Quantities of P. gingivalis in subgingival plaque and semi-quantitative scores of p53 and p21 in gingivae of periodontitis patients were increased compared with healthy controls (p < 0.05), while SIRT6 score in periodontitis patients was decreased (p < 0.001). Quantities of P. gingivalis were positively correlated with p53 and p21 scores (0.6 < r < 0.9, p < 0.01), and negatively correlated with SIRT6 score (-0.9 < r<-0.6, p < 0.01). Moreover, P. gingivalis LPS increased the levels of SA-β-gal, p53, p21, IL-6, IL-8 and ROS and decreased the levels of SIRT6, Nrf2 and HO-1 in HGFs, which was rescued by UBCS039 (p < 0.05). P. gingivalis LPS could induce senescence of HGFs, which could be reversed by SIRT6 via Nrf2-HO-1 signaling pathway.

Meta-analysis of oral microbiome reveals sex-based diversity in biofilms during periodontitis.

Sex is an often overlooked, yet compulsory, biological variable when performing biomedical research. Periodontitis is a common yet progressively debilitating chronic inflammatory disorder affecting the tissues supporting teeth that ultimately leads to tooth loss if left untreated. The incidence of periodontitis is sex biased, with increased prevalence in males compared with females but with unknown etiology. We performed a sex-specific meta-analysis using publicly available oral microbiome data from different sampling sites of patients with periodontitis and periodontally healthy controls; sex balance was established for each periodontal health condition. Our results show sex-based diversity in oral biofilms of individuals with periodontitis but not in their saliva, with increased abundance of several periodontal pathogens in subgingival plaques from females compared with males. We devised a quantitative measure, uniquely defined as the Microsexome Index (MSI), which indicates that sexual dimorphism in subgingival bacterial composition is a distinct feature of reduced microbial diversity during periodontitis but not under healthy conditions. In addition, we found that smoking exacerbates microsexome diversity in supragingival biofilms, particularly during periodontitis. Taken together, we provide insights regarding sex-based diversity in periodontitis, a disease with multiorgan associations, and provide the rationale for further mechanistic, diagnostic, and therapeutic studies.

Bacterial Membrane Vesicles: The Missing Link Between Bacterial Infection and Alzheimer Disease.

Periodontitis is a common chronic inflammatory disease, affecting approximately 19% of the global adult population. A relationship between periodontal disease and Alzheimer disease has long been recognized, and recent evidence has been uncovered to link these 2 diseases mechanistically. Periodontitis is caused by dysbiosis in the subgingival plaque microbiome, with a pronounced shift in the oral microbiota from one consisting primarily of Gram-positive aerobic bacteria to one predominated by Gram-negative anaerobes, such as Porphyromonas gingivalis. A common phenomenon shared by all bacteria is the release of membrane vesicles to facilitate biomolecule delivery across long distances. In particular, the vesicles released by P gingivalis and other oral pathogens have been found to transport bacterial components across the blood-brain barrier, initiating the physiologic changes involved in Alzheimer disease. In this review, we summarize recent data that support the relationship between vesicles secreted by periodontal pathogens to Alzheimer disease pathology.

Integrative microbiome and metabolome profiles reveal the impacts of periodontitis via oral-gut axis in first-trimester pregnant women

BackgroundPeriodontitis results from host-microbe dysbiosis and the resultant dysregulated immunoinflammatory response. Importantly, it closely links to numerous systemic comorbidities, and perplexingly contributes to adverse pregnancy outcomes (APOs). Currently, there are limited studies on the distal consequences of periodontitis via oral-gut axis in pregnant women. This study investigated the integrative microbiome-metabolome profiles through multi-omics approaches in first-trimester pregnant women and explored the translational potentials.MethodsWe collected samples of subgingival plaques, saliva, sera and stool from 54 Chinese pregnant women at the first trimester, including 31 maternal periodontitis (Perio) subjects and 23 Non-Perio controls. By integrating 16S rRNA sequencing, untargeted metabolomics and clinical traits, we explored the oral-gut microbial and metabolic connection resulting from periodontitis among early pregnant women.ResultsWe demonstrated a novel bacterial distinguisher Coprococcus from feces of periodontitis subjects in association with subgingival periodontopathogens, being different from other fecal genera in Lachnospiraceae family. The ratio of fecal Coprococcus to Lachnoclostridium could discriminate between Perio and Non-Perio groups as the ratio of subgingival Porphyromonas to Rothia did. Furthermore, there were differentially abundant fecal metabolic features pivotally enriched in periodontitis subjects like L-urobilin and kynurenic acid. We revealed a periodontitis-oriented integrative network cluster, which was centered with fecal Coprococcus and L-urobilin as well as serum triglyceride.ConclusionsThe current findings about the notable influence of periodontitis on fecal microbiota and metabolites in first-trimester pregnant women via oral-gut axis signify the importance and translational implications of preconceptional oral/periodontal healthcare for enhancing maternal wellbeing.