Multikingdom oral microbiome interactions in early-onset cryptogenic ischemic stroke.

Although knowledge of the role of the oral microbiome in ischemic stroke is steadily increasing, little is known about the multikingdom microbiota interactions and their consequences. We enrolled participants from a prospective multicentre case-control study and investigated multikingdom microbiome differences using saliva metagenomic datasets (n = 308) from young patients diagnosed with cryptogenic ischemic stroke (CIS) and age- and sex-matched stroke-free controls. Differentially abundant taxa were identified using Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC2). Functional potential was inferred using HUMANn3. Our findings revealed significant differences in the composition and functional capacity of the oral microbiota associated with CIS. We identified 51 microbial species, including 47 bacterial, 3 viral, and one fungal species associated with CIS in the adjusted model. Co-abundance network analysis highlighted a more intricate microbial network in CIS patients, indicating potential interactions and co-occurrence patterns among microbial species across kingdoms. The results of our metagenomic analysis reflect the complexity of the oral microbiome, with high diversity and multikingdom interactions, which may play a role in health and disease.

Shotgun metagenomic analysis of the oral microbiome in gingivitis: a nested case-control study.

Background: Gingivitis, i.e. inflammation of the gums, is often induced by dentalplaque. However, its exact link to the oral microbiota remains unclear. Methods: In a case-control study involving 120 participants, comprising 60 cases and 60 controls (mean age (SD) 36.6 (7.6) years; 50% males), nested within a prospective multicentre cohort study, we examined theoral microbiome composition of gingivitis patients and their controlsusing shotgun metagenomic sequencing of saliva samples. Participants underwent clinical and radiographic oral health examinations, including bleeding on probing (BOP), at six tooth sites. BOP ≥33%was considered 'generalized gingivitis/initial periodontitis'(GG/IP), and BOP <33% as 'healthy and localized gingivitis'(H/LG). Functional potential was inferred using HUMANn3. Results: GG/IP exhibited an increase in the abundance of Actinomyces, Porphyromonas, Aggregatibacter, Corynebacterium, Olsenella, and Treponema, whereas H/LG exhibited an increased abundance of Candidatus Nanosynbacter. Nineteen bacterial species and fourmicrobial functional profiles, including L-methionine, glycogen, andinosine-5'-phosphate biosynthesis, were associated with GG/IP. Constructing models with multiple markers resulted in a strong predictive value for GG/IP, with an area under the curve (ROC) of 0.907 (95% CI: 0.848-0.966). Conclusion: We observed distinct differences in the oral microbiome between the GG/IP and H/LG groups, indicating similar yet unique microbial profiles and emphasizing their potential role in progression of periodontal diseases.

Subgingival microbiome at different levels of cognition.

Oral health and declining cognition may have a bi-directional association. We characterized the subgingival microbiota composition of subjects from normal cognition to severe cognitive decline in two cohorts. Memory and Periodontitis (MINOPAR) include 202 home-living participants (50-80 years) in Sweden. Finnish Oral Health Studies in Older Adults (FINORAL) include 174 participants (≥65 years) living in long-term care in Finland. We performed oral examination and assessed the cognitive level with Mini Mental State Examination (MMSE). We sequenced the 16S-rRNA gene (V3-V4 regions) to analyse the subgingival bacterial compositions. The microbial diversities only tended to differ between the MMSE categories, and the strongest determinants were increased probing pocket depth (PPD) and presence of caries. However, abundances of 101 taxa were associated with the MMSE score. After adjusting for age, sex, medications, PPD, and caries, only eight taxa retained the significance in the meta-analyses of the two cohorts. Especially Lachnospiraceae [XIV] at the family, genus, and species level increased with decreasing MMSE. Cognitive decline is associated with obvious changes in the composition of the oral microbiota. Impaired cognition is accompanied with poor oral health status and the appearance of major taxa of the gut microbiota in the oral cavity. Good oral health-care practices require special deliberations among older adults.

Periodontitis and cardiometabolic disorders: The role of lipopolysaccharide and endotoxemia.

Lipopolysaccharide is a virulence factor of gram-negative bacteria with a crucial importance to the bacterial surface integrity. From the host's perspective, lipopolysaccharide plays a role in both local and systemic inflammation, activates both innate and adaptive immunity, and can trigger inflammation either directly (as a microbe-associated molecular pattern) or indirectly (by inducing the generation of nonmicrobial, danger-associated molecular patterns). Translocation of lipopolysaccharide into the circulation causes endotoxemia, which is typically measured as the biological activity of lipopolysaccharide to induce coagulation of an aqueous extract of blood cells of the assay. Apparently healthy subjects have a low circulating lipopolysaccharide activity, since it is neutralized and cleared rapidly. However, chronic endotoxemia is involved in the pathogenesis of many inflammation-driven conditions, especially cardiometabolic disorders. These include atherosclerotic cardiovascular diseases, obesity, liver diseases, diabetes, and metabolic syndrome, where endotoxemia has been recognized as a risk factor. The main source of endotoxemia is thought to be the gut microbiota. However, the oral dysbiosis in periodontitis, which is typically enriched with gram-negative bacterial species, may also contribute to endotoxemia. As endotoxemia is associated with an increased risk of cardiometabolic disorders, lipopolysaccharide could be considered as a molecular link between periodontal microbiota and cardiometabolic diseases.

Common complement factor H polymorphisms are linked with periodontitis in elderly patients.

BACKGROUND: In our recent genome-wide association study, we found that genetic polymorphisms in the complement factor H (CFH) gene and S100A gene region are strongly associated with serum matrix metalloproteinase 8 (MMP-8) concentration and the release of MMP-8 from neutrophils. As MMP-8 is centrally involved in the pathogenesis of periodontitis, we aimed to evaluate the presence of genetic polymorphisms of S100A8/A9/A12, MMP8, and CFH in periodontitis. In addition, we studied whether polymorphisms of these genes affect the concentrations of S100A8, S100A12, MMP-8, or complement activation marker in saliva. METHODS: We genotyped four single-nucleotide polymorphisms (SNPs, rs1560833 in S100A8/A9/A12, rs11225395 in MMP8, rs800292 in CFH, and rs1061170 in CFH) and measured salivary concentrations of S100A8, S100A12, MMP-8, and terminal complement complex (TCC) in the Parogene cohort (n = 508). The cohort was composed of patients with an indication to coronary angiography and all underwent a clinical and radiographic oral examination. RESULTS: CFH polymorphisms rs800292 and rs1061170 were associated with periodontal parameters. None of the polymorphisms showed association with salivary proteins. However, salivary concentrations of S100A8, S100A12, MMP-8, and TCC were strongly associated with the number of periodontal pockets and alveolar bone loss. CONCLUSION: Interestingly, genetic variants of CFH, MMP8, and S100A8/A9/A12 gene regions did not affect salivary levels of measured proteins. However, saliva levels of S100A8, S100A12, MMP-8, and TCC, and CFH polymorphisms were associated with clinical and radiographic signs of periodontitis. Our study further supports the observations that any dysregulation of complement may increase the risk of inflammatory disorders, such as periodontitis.

Periodontal conditions and incident dementia: A nationwide Swedish cohort study.

BACKGROUND: Periodontal disease has been proposed as a putative etiological factor for dementia. The aim of this investigation was to compare the incidence of dementia in individuals with or without deep probing pocket depths (DPPD), serving as a proxy for periodontitis. METHODS: In this cohort study, conducted in Sweden, we identified 7992 individuals with DPPD and 29,182 matched individuals without DPPD (non-DPPD), using the Swedish Quality Registry for Caries and Periodontal Diseases (SKaPa). The two groups were followed for incident dementia (mean follow-up time was 7.6 years) based on data from the Swedish Dementia Registry (SveDem). The exposure-outcome relationship was explored by applying the Royston-Parmar (RP) flexible parametric survival model. RESULTS: The incidence of dementia in the two groups was similar. In the DPPD group 137 (1.7%) developed dementia and 470 (1.6%) in the non-DPPD group. The incidence rate of dementia was estimated to be 2.3 per 1000 person-years (95% confidence interval [CI] 1.9 to 2.7) in the DPPD group and 2.1 per 1000 person-years (95% CI 1.9 to 2.3) in the non-DPPD group. The RP model disclosed no association between DPPD and dementia incidence after controlling for potential confounders (the exponentiated coefficient was estimated to 1.13 [95% CI = 0.39 to 3.24]). CONCLUSION: In this sample, no association was revealed between deep probing pocket depths and the incidence of dementia.

Salivary IgA antibody to malondialdehyde-acetaldehyde associates with mild periodontal pocket depth.

OBJECTIVE: Oxidized epitopes such as malondialdehyde-acetaldehyde (MAA) play a crucial role in the progression of atherosclerosis through activation of the humoral immune response. The exact mechanism of the association between atherosclerosis and periodontal diseases is not fully understood. The aim of the current study is to evaluate the association of oral humoral immune response to oxidized epitopes with parameters of periodontal disease. MATERIALS AND METHODS: The Parogene cohort consist of patients who have undergone coronary angiography due to cardiac symptoms. In this study, 423 patients were randomly selected for an extensive oral examination. Salivary Immunoglobulin A to oxidized epitopes and bacterial antigens was determined by chemiluminescence immunoassay. RESULTS: In a binary logistic regression model adjusted with periodontal disease confounders, periodontal pocket depth (PPD) 4-5 mm associated with salivary IgA antibodies to MAA-LDL (p = 0.034), heat shock protein 60 of Aggregatibacter actinomycetemcomitans (p = 0.045), Porphyromonas gingivalis (p = 0.045), A. actinomycetemcomitans (p = 0.005), P. intermedia (p = 0.020), and total IgA (p = 0.003). CONCLUSIONS: The current study shows the association of salivary IgA to MAA-LDL with PPD 4-5 mm in a cohort of patients with chronic coronary artery disease. Humoral immune cross-reactivation to oxidized epitopes such MAA-LDL could partly explain the link of periodontitis with systemic diseases.

Genetic Profile of Endotoxemia Reveals an Association With Thromboembolism and Stroke.

Background Translocation of lipopolysaccharide from gram-negative bacteria into the systemic circulation results in endotoxemia. In addition to acute infections, endotoxemia is detected in cardiometabolic disorders, such as cardiovascular diseases and obesity. Methods and Results We performed a genome-wide association study of serum lipopolysaccharide activity in 11 296 individuals from 6 different Finnish study cohorts. Endotoxemia was measured by limulus amebocyte lysate assay in the whole population and by 2 other techniques (Endolisa and high-performance liquid chromatography/tandem mass spectrometry) in subpopulations. The associations of the composed genetic risk score of endotoxemia and thrombosis-related clinical end points for 195 170 participants were analyzed in FinnGen. Lipopolysaccharide activity had a genome-wide significant association with 741 single-nucleotide polymorphisms in 5 independent loci, which were mainly located at genes affecting the contact activation of the coagulation cascade and lipoprotein metabolism and explained 1.5% to 9.2% of the variability in lipopolysaccharide activity levels. The closest genes included KNG1, KLKB1, F12, SLC34A1, YPEL4, CLP1, ZDHHC5, SERPING1, CBX5, and LIPC. The genetic risk score of endotoxemia was associated with deep vein thrombosis, pulmonary embolism, pulmonary heart disease, and venous thromboembolism. Conclusions The biological activity of lipopolysaccharide in the circulation (ie, endotoxemia) has a small but highly significant genetic component. Endotoxemia is associated with genetic variation in the contact activation pathway, vasoactivity, and lipoprotein metabolism, which play important roles in host defense, lipopolysaccharide neutralization, and thrombosis, and thereby thromboembolism and stroke.

Subgingival microbiota in a population with and without cognitive dysfunction.

Aim: The aim of this study was to compare the subgingival microbiota of people with Alzheimer´s disease (AD), mild cognitive impairment (MCI), subjective cognitive decline (SCD) and cognitively healthy individuals. Materials and methods: The study population was recruited from 2013 to 2017 and comprised 132 cases recently diagnosed with AD (n = 46), MCI (n = 40) or SCD (n = 46), and 63 cognitively healthy controls. Subgingival samples were collected, and the microbiotas were characterized by 16S rRNA gene sequencing. Results: The relative abundance of the ten most common genera did not differ between the cases and control groups. However, the microbial richness and evenness were higher in cases than in controls and differed across the four groups. The variables with the greatest influence on the microbial community composition were related to periodontal disease followed by body mass index, study group affiliation and smoking. Ten taxa exhibited significant differences between case participants and controls. Two Operational Taxonomic Units were particularly abundant in AD compared to controls: Slackia exigua, which was also associated with deep periodontal pockets, and a Lachnospiraceae [G-7] bacterium. Conclusion: It is concluded that in individuals with cognitive impairment or AD, the subgingival microbiota exhibits shifts typical of periodontal disease.

Systemic Antibiotics Influence Periodontal Parameters and Oral Microbiota, But Not Serological Markers.

The use of systemic antibiotics may influence the oral microbiota composition. Our aim was to investigate in this retrospective study whether the use of prescribed antibiotics associate with periodontal status, oral microbiota, and antibodies against the periodontal pathogens. The Social Insurance Institution of Finland Data provided the data on the use of systemic antibiotics by record linkage to purchased medications and entitled reimbursements up to 1 year before the oral examination and sampling. Six different classes of antibiotics were considered. The Parogene cohort included 505 subjects undergoing coronary angiography with the mean (SD) age of 63.4 (9.2) years and 65% of males. Subgingival plaque samples were analysed using the checkerboard DNA-DNA hybridisation. Serum and saliva antibody levels to periodontal pathogens were analysed with immunoassays and lipopolysaccharide (LPS) activity with the LAL assay. Systemic antibiotics were prescribed for 261 (51.7%) patients during the preceding year. The mean number of prescriptions among them was 2.13 (range 1-12), and 29.4% of the prescriptions were cephalosporins, 25.7% penicillins, 14.3% quinolones, 12.7% macrolides or lincomycin, 12.0% tetracycline, and 5.8% trimethoprim or sulphonamides. In linear regression models adjusted for age, sex, current smoking, and diabetes, number of antibiotic courses associated significantly with low periodontal inflammation burden index (PIBI, p < 0.001), bleeding on probing (BOP, p = 0.006), and alveolar bone loss (ABL, p = 0.042). Cephalosporins associated with all the parameters. The phyla mainly affected by the antibiotics were Bacteroidetes and Spirochaetes. Their levels were inversely associated with the number of prescriptions (p = 0.010 and p < 0.001) and directly associated with the time since the last prescription (p = 0.019 and p < 0.001). Significant inverse associations were observed between the number of prescriptions and saliva concentrations of Prevotella intermedia, Tannerella forsythia, and Treponema denticola and subgingival bacterial amounts of Porphyromonas gingivalis, P. intermedia, T. forsythia, and T. denticola. Saliva or serum antibody levels did not present an association with the use of antibiotics. Both serum (p = 0.031) and saliva (p = 0.032) LPS activity was lower in patients having any antibiotic course less than 1 month before sampling. Systemic antibiotics have effects on periodontal inflammation and oral microbiota composition, whereas the effects on host immune responses against the periodontal biomarker species seem unchanged.

Endotoxemia is associated with an adverse metabolic profile.

Our aim was to analyze whether endotoxemia, i.e. translocation of LPS to circulation, is reflected in the serum metabolic profile in a general population and in participants with cardiometabolic disorders. We investigated three Finnish cohorts separately and in a meta-analysis (n = 7178), namely population-based FINRISK97, FinnTwin16 consisting of young adult twins, and Parogene, a random cohort of cardiac patients. Endotoxemia was determined as serum LPS activity and metabolome by an NMR platform. Potential effects of body mass index (BMI), smoking, metabolic syndrome (MetS), and coronary heart disease (CHD) status were considered. Endotoxemia was directly associated with concentrations of VLDL, IDL, LDL, and small HDL lipoproteins, VLDL particle diameter, total fatty acids (FA), glycoprotein acetyls (GlycA), aromatic and branched-chain amino acids, and Glc, and inversely associated with concentration of large HDL, diameters of LDL and HDL, as well as unsaturation degree of FAs. Some of these disadvantageous associations were significantly stronger in smokers and subjects with high BMI, but did not differ between participants with different CHD status. In participants with MetS, however, the associations of endotoxemia with FA parameters and GlycA were particularly strong. The metabolic profile in endotoxemia appears highly adverse, involving several inflammatory characters and risk factors for cardiometabolic disorders.

Immunological and Microbiological Profiling of Cumulative Risk Score for Periodontitis.

The cumulative risk score (CRS) is a mathematical salivary diagnostic model to define an individual's risk of having periodontitis. In order to further validate this salivary biomarker, we investigated how periodontal bacteria, lipopolysaccharide (LPS), and systemic and local host immune responses relate to CRS. Subgingival plaque, saliva, and serum samples collected from 445 individuals were used in the analyses. Plaque levels of 28 microbial species, especially those of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, and Tannerella forsythia, and serum and salivary levels of IgA and IgG against these five species were determined. Additionally, LPS activity was measured. High CRS associated strongly with all IgA/IgG antibody and LPS levels in saliva, whereas in serum the associations were not that obvious. In the final logistic regression model, the best predictors of high CRS were saliva IgA burden against the five species (OR 7.04, 95% CI 2.25-22.0), IgG burden (3.79, 1.78-8.08), LPS (2.19, 1.38-3.47), and the sum of 17 subgingival Gram-negative species (6.19, 2.10-18.3). CRS is strongly associated with microbial biomarker species of periodontitis and salivary humoral immune responses against them.

Serum lipopolysaccharide neutralizing capacity in ischemic stroke.

INTRODUCTION: Periodontitis is associated with increased serum lipopolysaccharide (LPS) activity, which may be one mechanism linking periodontitis with the risk of cardiovascular diseases. As LPS-carrying proteins including lipoproteins modify LPS-activity, we investigated the determinants of serum LPS-neutralizing capacity (LPS-NC) in ischemic stroke. The association of LPS-NC and Aggregatibacter actinomycetemcomitans, a major microbial biomarker in periodontitis, was also investigated. MATERIALS AND METHODS: The assay to measure LPS-NC was set up by spiking serum samples with E. coli LPS. The LPS-NC, LPS-binding protein (LBP), soluble CD14 (sCD14), lipoprotein profiles, apo(lipoprotein) A-I, apoB, and phospholipid transfer protein (PLTP) activity, were determined in 98 ischemic stroke patients and 100 age- and sex-matched controls. Serum and saliva immune response to A. actinomycetemcomitans, its concentration in saliva, and serotype-distribution were examined. RESULTS: LPS-NC values ranged between 51-83% in the whole population. Although several of the LPS-NC determinants differed significantly between cases and controls (PLTP, sCD14, apoA-I, HDL-cholesterol), the levels did not (p = 0.056). The main determinants of LPS-NC were i) triglycerides (ß = -0.68, p<0.001), and ii) HDL cholesterol (0.260, <0.001), LDL cholesterol (-0.265, <0.001), PLTP (-0.196, 0.011), and IgG against A. actinomycetemcomitans (0.174, 0.011). Saliva A. actinomycetemcomitans concentration was higher [log mean (95% CI), 4.39 (2.35-8.19) vs. 10.7 (5.45-21) genomes/ml, p = 0.023) and serotype D more frequent (4 vs. 0%, p = 0.043) in cases than controls. Serotypeablity or serotypes did not, however, relate to the LPS-NC. CONCLUSION: Serum LPS-NC comprised low PLTP-activity, triglyceride and LDL cholesterol concentrations, as well as high HDL cholesterol and IgG against A. actinomycetemcomitans. The present findings let us to conclude that LPS-NC did not associate with stroke.

Saliva and Serum Immune Responses in Apical Periodontitis.

Apical periodontitis is an inflammatory reaction at the apex of an infected tooth. Its microbiota resembles that of marginal periodontitis and may induce local and systemic antibodies binding to bacteria- and host-derived epitopes. Our aim was to investigate the features of the adaptive immune response in apical periodontitis. The present Parogene cohort (n = 453) comprises patients with cardiac symptoms. Clinical and radiographic oral examination was performed to diagnose apical and marginal periodontitis. A three-category endodontic lesion score was designed. Antibodies binding to the bacteria- and host-derived epitopes were determined from saliva and serum, and bacterial compositions were examined from saliva and subgingival samples. The significant ORs (95% CI) for the highest endodontic scores were observed for saliva IgA and IgG to bacterial antigens (2.90 (1.01-8.33) and 4.91 (2.48-9.71)/log10 unit), saliva cross-reacting IgG (2.10 (1.48-2.97)), serum IgG to bacterial antigens (4.66 (1.22-10.1)), and Gram-negative subgingival species (1.98 (1.16-3.37)). In a subgroup without marginal periodontitis, only saliva IgG against bacterial antigens associated with untreated apical periodontitis (4.77 (1.05-21.7)). Apical periodontitis associates with versatile adaptive immune responses against both bacterial- and host-derived epitopes independently of marginal periodontitis. Saliva immunoglobulins could be useful biomarkers of oral infections including apical periodontitis-a putative risk factor for systemic diseases.

Association of Childhood Oral Infections With Cardiovascular Risk Factors and Subclinical Atherosclerosis in Adulthood.

Importance: Severe forms of common chronic oral infections or inflammations are associated with increased cardiovascular risk in adults. To date, the role of childhood oral infections in cardiovascular risk is not known because no long-term studies have been conducted. Objective: To investigate whether signs of oral infections in childhood are associated with cardiovascular risk factors and subclinical atherosclerosis in adulthood. Design, Setting, and Participants: The cohort study (n = 755) was derived from the Cardiovascular Risk in Young Finns Study, an ongoing prospective cohort study in Finland initiated in 1980. Participants underwent clinical oral examinations during childhood, when they were aged 6, 9, or 12 years and a clinical cardiovascular follow-up in adulthood in 2001 at age 27, 30, or 33 years and/or in 2007 at age 33, 36, or 39 years. Cardiovascular risk factors were measured at baseline and during the follow-up until the end of 2007. Final statistical analyses were completed on February 19, 2019. Main Outcomes and Measures: Four signs of oral infections (bleeding on probing, periodontal probing pocket depth, caries, and dental fillings) were documented. Cumulative lifetime exposure to 6 cardiovascular risk factors was calculated from dichotomized variables obtained by using the area-under-the-curve method. Subclinical atherosclerosis (ie, carotid artery intima-media thickness [IMT]) was quantified in 2001 (n = 468) and 2007 (n = 489). Results: This study included 755 participants, of whom 371 (49.1%) were male; the mean (SD) age at baseline examination was 8.07 (2.00) years. In this cohort, 33 children (4.5%) had no sign of oral infections, whereas 41 (5.6%) had 1 sign, 127 (17.4%) had 2 signs, 278 (38.3%) had 3 signs, and 248 (34.1%) had 4 signs. The cumulative exposure to risk factors increased with the increasing number of oral infections both in childhood and adulthood. In multiple linear regression models, childhood oral infections, including signs of either periodontal disease (R2 = 0.018; P = .01), caries (R2 = 0.022; P = .008), or both (R2 = 0.024; P = .004), were associated with adulthood IMT. The presence of any sign of oral infection in childhood was associated with increased IMT (third tertile vs tertiles 1 and 2) with a relative risk of 1.87 (95% CI, 1.25-2.79), whereas the presence of all 4 signs produced a relative risk of 1.95 (95% CI, 1.28-3.00). The associations were more obvious in boys: if periodontal disease were present, the corresponding estimate was 1.69 (95% CI, 1.21-2.36); if caries, 1.46 (95% CI, 1.04-2.05); and if all 4 signs of oral infections, 2.25 (95% CI, 1.30-3.89). The associations were independent of cardiovascular risk factors. Conclusions and Relevance: Oral infections in childhood appear to be associated with the subclinical carotid atherosclerosis seen in adulthood.

Smoking confounds the periodontal diagnostics using saliva biomarkers.

BACKGROUND: Smoking is a risk factor for periodontal disease because of its complex impact on the inflammatory response in the periodontium. We investigated the effect of smoking on salivary periodontal biomarkers, matrix metalloproteinase (MMP)-8, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and myeloperoxidase (MPO). METHODS: Saliva biomarkers were analyzed in the Parogene population (n = 480) comprising a random cohort of patients that have undergone coronary angiography and oral examination. The effect of time since cessation and pack years of smoking on biomarkers were investigated. RESULTS: Saliva MMP-8, MMP-9, TIMP-1, and MPO concentrations distinguished periodontitis patients significantly from patients without periodontitis. When the time since cessation was considered, the area-under-the-curve values (p-value) for periodontitis were 0.76 (<0.001), 0.74 (<0.001), 0.70 (<0.001), and 0.76 (<0.001), respectively. Adding information about smoking habits in the models improved slightly the sensitivities of all biomarkers. In logistic regression model saliva, MMP-8 was mainly affected by pack years of smoking, whereas saliva MMP-9, TIMP-1, and MPO were mostly affected by time since cessation, especially if smoking currently or quit recently (<1 year ago). CONCLUSION: Smoking confounds the salivary diagnostics of periodontitis and should be considered when interpreting the results obtained by potential diagnostic tests.

Association between periodontitis and risk of Alzheimer's disease, mild cognitive impairment and subjective cognitive decline: A case-control study.

AIMS: To test the hypothesis that periodontal disease contributes to increased risk of mild cognitive impairment (MCI), subjective cognitive decline (SCD) and Alzheimer's disease (AD). MATERIALS AND METHODS: This case-control study was conducted over a 3-year period in the municipality of Huddinge, Sweden. In total, 154 cases were consecutively enrolled from the Karolinska Memory Clinic at the Karolinska University Hospital and allotted to three diagnostic groups: AD, MCI and SCD, collectively referred to as "cases." Seventy-six cognitively healthy age- and gender-matched controls were randomly sampled through the Swedish population register. All cases and controls underwent clinical and radiographic oral examinations. Statistical analysis was based on logistic regression models adjusted for potential confounders. RESULTS: Poor oral health and marginal alveolar bone loss were more prevalent among cases than among controls. The cases group was associated with generalized marginal alveolar bone loss (odds ratio [OR] = 5.81; 95% confidence interval [CI] = 1.14-29.68), increased number of deep periodontal pockets (OR = 8.43; CI 4.00-17.76) and dental caries (OR = 3.36; CI 1.20-9.43). CONCLUSION: The results suggest that marginal periodontitis is associated with early cognitive impairment and AD. However, the study design does not preclude noncausal explanations.

Mediators between oral dysbiosis and cardiovascular diseases.

Clinical periodontitis is associated with an increased risk for cardiovascular diseases (CVDs) through systemic inflammation as the etiopathogenic link. Whether the oral microbiota, especially its quality, quantity, serology, and virulence factors, plays a role in atherogenesis is not clarified. Patients with periodontitis are exposed to bacteria and their products, which have access to the circulation directly through inflamed oral tissues and indirectly (via saliva) through the gastrointestinal tract, resulting in systemic inflammatory and immunologic responses. Periodontitis is associated with persistent endotoxemia, which has been identified as a notable cardiometabolic risk factor. The serology of bacterial biomarkers for oral dysbiosis is associated with an increased risk for subclinical atherosclerosis, prevalent and future coronary artery disease, and incident and recurrent stroke. In addition to species-specific antibodies, the immunologic response includes persistent, cross-reactive, proatherogenic antibodies against host-derived antigens. Periodontitis may affect lipoprotein metabolism at all levels, and all lipoprotein classes are affected. Periodontitis or its bacterial signatures may be involved not only in increased storage of proatherogenic lipids but also in attenuation of the anti-atherogenic processes, thereby putatively increasing the net risk of atherosclerosis. In this review we summarize possible molecular mediators between the dysbiotic oral microbiota and atherosclerotic processes.

Salivary biomarkers in association with periodontal parameters and the periodontitis risk haplotype.

Genetic factors play a role in periodontitis. Here we examined whether the risk haplotype of MHC class III region BAT1-NFKBIL1-LTA and lymphotoxin-α polymorphisms associate with salivary biomarkers of periodontal disease. A total of 455 individuals with detailed clinical and radiographic periodontal health data were included in the study. A 610 K genotyping chip and a Sequenom platform were used in genotyping analyses. Phospholipid transfer protein activity, concentrations of lymphotoxin-α, IL-8 and myeloperoxidase, and a cumulative risk score (combining Porphyromonas gingivalis, IL-1ß and matrix metalloproteinase-8) were examined in saliva samples. Elevated IL-8 and myeloperoxidase concentrations and cumulative risk scores associated with advanced tooth loss, deepened periodontal pockets and signs of periodontal inflammation. In multiple logistic regression models adjusted for periodontal parameters and risk factors, myeloperoxidase concentration (odds ratio (OR); 1.37, P = 0.007) associated with increased odds for having the risk haplotype and lymphotoxin-α concentration with its genetic variants rs2857708, rs2009658 and rs2844482. In conclusion, salivary levels of IL-8, myeloperoxidase and cumulative risk scores associate with periodontal inflammation and tissue destruction, while those of myeloperoxidase and lymphotoxin-α associate with genetic factors as well.