The interaction between gut microbiome and bone health.

PURPOSE OF REVIEW: This review critically examines interconnected health domains like gut microbiome, bone health, interleukins, chronic periodontitis, and coronavirus disease 2019 (COVID-19), offering insights into fundamental mechanisms and clinical implications, contributing significantly to healthcare and biomedical research. RECENT FINDINGS: This review explores the relationship between gut microbiome and bone health, a growing area of study. It provides insights into skeletal integrity and potential therapeutic avenues. The review also examines interleukins, chronic periodontitis, and COVID-19, highlighting the complexity of viral susceptibility and immune responses. It highlights the importance of understanding genetic predispositions and immune dynamics in the context of disease outcomes. The review emphasizes experimental evidence and therapeutic strategies, aligning with evidence-based medicine and personalized interventions. This approach offers actionable insights for healthcare practitioners and researchers, paving the way for targeted therapeutic approaches and improved patient outcomes. SUMMARY: The implications of these findings for clinical practice and research underscore the importance of a multidisciplinary approach to healthcare that considers the complex interactions between genetics, immune responses, oral health, and systemic diseases. By leveraging advances in biomedical research, clinicians can optimize patient care and improve health outcomes across diverse patient populations.

Evaluation of NLRP3 and IL-18 Levels after Periodontal Therapy.

The progression of periodontitis depends on interactions between the periodontal pathogens and the host immune cytokines, including interleukin (IL)-1ß and IL-18. Production of IL-1ß is regulated by NOD-like receptors family pyrin domain containing 3 (NLRP3). This study aimed to evaluate the effect of periodontal treatment on the concentrations of IL-18 and NLRP3 in patients with chronic periodontitis. In this experimental study, 18 patients with chronic periodontitis and a mean age of 46.2±8.95 years, were included. The gingival crevicular fluid (GCF) was collected at the beginning of the study, 4 weeks after non-surgical (phase I), and 4 weeks after surgical periodontal treatment. The levels of NLRP3 and IL-18 were measured; using an enzyme-linked immunosorbent assay. Pearson correlation test was used to analyze the concentration of NLRP3 and IL-18 before and after the treatments with CAL and PD. There was a significant association between the level of NLRP3 and the mean values of PD and CAL before treatment. After each treatment phase, a significant decrease was observed in the NLRP3 level. There was no significant relationship between IL-18 and clinical parameters before and after periodontal treatments. Given the possible association between the level of NLRP3 and clinical parameters, we suggest it as a possible indicator of inflammation in chronic periodontitis and an index for evaluating the treatment outcome.

NLRP3 Inflammasome Expression in Gingival Crevicular Fluid of Patients with Periodontitis and Chronic Hepatitis C.

The study is aimed at assessing the impact that periodontal disease and chronic hepatitis C could have on gingival crevicular fluid levels of the NLRP3 inflammasome, caspase-1 (CASP-1), and interleukin-18 (IL-18) and at evaluating whether the increased local inflammatory reaction with clinical periodontal consequences is correlated to their upregulation. Patients were divided into four groups, according to their periodontal status and previously diagnosed hepatitis C, as follows: (i) CHC group, chronic hepatitis C patients; (ii) P group, periodontal disease patients, systemically healthy; (iii) CHC + P group, patients suffering from both conditions; and (iv) H group, systemically and periodontally healthy controls. Gingival crevicular samples were collected for quantitative analysis of the NLRP3 inflammasome, CASP-1, and IL-18. CHC + P patients expressed the worse periodontal status and the highest NLRP3, CASP-1, and IL-18 levels, the difference being statistically significant (p < 0.05). The P group patients also expressed significantly more elevated NLRP3, CASP-1, and IL-18 levels, as compared to nonperiodontal patients (CHC and H groups). Chronic hepatitis C and periodontal disease could have a significant influence on the upregulation of NLRP3 inflammasome and its components, possibly contributing to an increased local inflammatory reaction and clinical periodontal consequences.

Elevated salivary activity of mast cell chymase of periodontitis patients, and a new bradykinin generation cascade, mediating the cross-talks between mast cell and gingival fibroblast.

Activated-mast cells (MCs) within gingival-tissue of chronic-periodontitis (CP) patients, release various inflammatory-factors. Bradykinin is a nine-amino-acid peptide and pro-inflammatory mediator, produced through factor-XII-cascade or tryptase-cascade. The ability of MC-chymase in bradykinin generation has not been discussed yet. This study investigated the salivary levels of MC-chymase, high molecular weight kininogen (HMWK) and bradykinin of CP patients; examined the potential of MC-proteases in bradykinin production using biochemistry-models; and explored the effects of bradykinin on gingival fibroblasts (GFs). Saliva-samples were collected; MC-protease activities were detected; HMWK cleavage was assessed by western-blot and SDS-PAGE; bradykinin levels were measured using immunoassay. Primary GFs were extracted and cultured with or without bradykinin; cell-viability, gelatine-zymography and flow-cytometry were applied. Immunocytochemistry and western-blot were used to detect intracellular protein expressions of bradykinin-stimulated GFs. The data showed that the salivary-levels of MC-proteases, bradykinin, HMWK, and lactoferrin of CP-patients were increased. HMWK was cleaved by MC-chymase in-vitro, resulting in bradykinin generation. Bradykinin promoted cell proliferation, cell cycle and matrix-metalloproteinase-2(MMP-2) activity, and increased intracellular expressions of nuclear-factor-kappa-B(NF-κB), focal-adhesion-kinase(FAK), transforming-growth-factor-ß(TGF-ß), P38, P53 of GFs. MC-chymase promotes bradykinin production to stimulate GFs and to continue inflammation during CP development. A new BK-generation cascade found in this study provides a new basis for the pathogenesis of CP and the mechanism of continuous inflammation. The activation of MC-chymase/bradykinin-generation cascade depends on HMWK level and MC-chymase activity under inflammatory condition. MC-chymase contributes to bradykinin production, mediating the cross-talks between MCs and GFs. MC-chymase can be used as a therapeutic target and a salivary biomarker in this case.

Single-Cell RNA Sequencing Identifies New Inflammation-Promoting Cell Subsets in Asian Patients With Chronic Periodontitis.

Periodontitis is a highly prevalent chronic inflammatory disease leading to periodontal tissue breakdown and subsequent tooth loss, in which excessive host immune response accounts for most of the tissue damage and disease progression. Despite of the imperative need to develop host modulation therapy, the inflammatory responses and cell population dynamics which are finely tuned by the pathological microenvironment in periodontitis remained unclear. To investigate the local microenvironment of the inflammatory response in periodontitis, 10 periodontitis patients and 10 healthy volunteers were involved in this study. Single-cell transcriptomic profilings of gingival tissues from two patients and two healthy donors were performed. Histology, immunohistochemistry, and flow cytometry analysis were performed to further validate the identified cell subtypes and their involvement in periodontitis. Based on our single-cell resolution analysis, we identified HLA-DR-expressing endothelial cells and CXCL13+ fibroblasts which are highly associated with immune regulation. We also revealed the involvement of the proinflammatory NLRP3+ macrophages in periodontitis. We further showed the increased cell-cell communication between macrophage and T/B cells in the inflammatory periodontal tissues. Our data generated an intriguing catalog of cell types and interaction networks in the human gingiva and identified new inflammation-promoting cell subtypes involved in chronic periodontitis, which will be helpful in advancing host modulation therapy.

Halofuginone functions as a therapeutic drug for chronic periodontitis in a mouse model.

Periodontitis is an inflammatory disease caused by host immune response, resulting in a loss of periodontium and alveolar bone. Immune cells, such as T cells and macrophages, play a critical role in the periodontitis onset. Halofuginone, a natural quinazolinone alkaloid, has been shown to possess anti-fibrosis, anti-cancer, and immunomodulatory properties. However, the effect of halofuginone on periodontitis has never been reported. In this study, a ligature-induced mice model of periodontitis was applied to investigate the potential beneficial effect of halofuginone on periodontitis. We demonstrated that the administration of halofuginone significantly reduced the expression levels of pro-inflammatory cytokines (IL-1ß, IL-6, and TNF-α) in vivo, and markedly suppressed immune cell infiltration into the infected sites. Furthermore, we also observed that halofuginone treatment blocked the T-helper 17 (Th17) cell differentiation in vivo and in vitro. We demonstrated for the first time that halofuginone alleviated the onset of periodontitis through reducing immune responses.

Bifidobacterium animalis subsp lactis HN019 presents antimicrobial potential against periodontopathogens and modulates the immunological response of oral mucosa in periodontitis patients.

OBJECTIVE: To evaluate the effects of Bifidobacterium animalis subsp. lactis HN019 (HN019) on clinical periodontal parameters (plaque accumulation and gingival bleeding), on immunocompetence of gingival tissues [expression of beta-defensin (BD)-3, toll-like receptor 4 (TLR4), cluster of differentiation(CD)-57 and CD-4], and on immunological properties of saliva (IgA levels) in non-surgical periodontal therapy in generalized chronic periodontitis (GCP) patients. Adhesion to buccal epithelial cells (BEC) and the antimicrobial properties of HN019 were also investigated. MATERIALS AND METHODS: Thirty patients were recruited and monitored clinically at baseline (before scaling and root planing-SRP) and after 30 and 90 days. Patients were randomly assigned to Test (SRP+Probiotic, n = 15) or Control (SRP+Placebo, n = 15) group. Probiotic lozenges were used for 30 days. Gingival tissues and saliva were immunologically analyzed. The adhesion of HN019 with or without Porphyromonas gingivalis in BEC and its antimicrobial properties were investigated in in vitro assays. Data were statistically analyzed (p<0.05). RESULTS: Test group presented lower plaque index (30 days) and lower marginal gingival bleeding (90 days) when compared with Control group. Higher BD-3, TLR4 and CD-4 expressions were observed in gingival tissues in Test group than in Control group. HN019 reduced the adhesion of P. gingivalis to BEC and showed antimicrobial potential against periodontopathogens. CONCLUSION: Immunological and antimicrobial properties of B. lactis HN019 make it a potential probiotic to be used in non-surgical periodontal therapy of patients with GCP. CLINICAL RELEVANCE: B. lactis HN019 may be a potential probiotic to improve the effects of non-surgical periodontal therapy. Name of the registry and registration number (ClinicalTrials.gov): "Effects of probiotic therapy in the treatment of periodontitis"-NCT03408548.

The Role of the Immune Response in Chronic Marginal and Apical Periodontitis.

The immune response is a complex, dynamic and strongly individual biologic network that plays an essential role in the pathogenesis of chronic apical and marginal periodontitis. Recent research in the field of periodontology has indicated that the major determinant of susceptibility to disease is the nature of the immunoinflammatory response as marginal periodontal tissue damage is thought to be primarily mediated by the host reaction. Whether the same rules apply for the development of apical periodontitis, however, remains largely unexplored. This review aims to draw parallels between the pathogenesis of chronic periodontitis of endodontic and marginal origin, outline the evidence for the destructive role of immune response in chronic marginal periodontitis and raise questions about its role in chronic apical periodontitis. It would be worthy to further explore the impact of the immune system on the characteristics and progress of these diseases and transfer some of the scientific models from the field of periodontology to the field of endodontics. Research in this area could lead to a more comprehensive understanding of the dynamics of apical and marginal periodontitis and lay the foundation of new personalized treatment strategies.

Evaluation of Endocan and Tumor Necrosis Factor-α as Inflammatory Biomarkers in Type 2 Diabetes and Periodontal Disease.

Purpose: Type 2 diabetes mellitus (type 2 DM) and periodontitis encompass vascular endothelial changes. Endocan, a marker of endothelial dysfunction, has not been previously evaluated in diabetic patients with periodontal disease. This study was designed to evaluate the levels of endocan and tumor necrosis factor-alpha (TNF-α) in chronic periodontitis (CP) subjects with type 2 DM before and after nonsurgical periodontal therapy (NSPT). Materials and Methods: This study included 75 subjects with varying degrees of CP. Group I-included 25 systemically healthy individuals with CP, and Groups II and III-included 25 CP patients each with type 2 DM under good control (hemoglobin A1c [HbA1c] <7%) and poor control (HbA1c >8%), respectively. Periodontal parameters were assessed, and gingival crevicular fluid collections were performed for all patients at baseline and again following three months of NSPT. Levels of endocan and TNF-α were assessed using enzyme-linked immunosorbent assay. Results: Endocan levels were elevated in CP subjects with type 2 DM at baseline. There was a significant reduction in the Endocan and HbA1c levels (p < 0.01) among all the groups after NSPT. Conclusion: Endocan may be used as a novel diagnostic marker for pateints with type 2 DM and CP and as a potential prognostic marker for monitoring improvement in periodontal and glycemic status during NSPT.

Clinical and Immunological Effects of Er,Cr:YSGG Laser in Nonsurgical Periodontal Treatment: A Randomized Clinical Trial.

Objective: The aim of this study was to compare the clinical and immunological results of nonsurgical periodontal treatment with or without the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser. Background data: As lasers have begun to be used in dentistry, the Er,Cr:YSGG laser has started to attract attention in the field of periodontology. Materials and methods: Fifty-nine nonsmoking patients with advanced chronic periodontitis were randomly allocated to a test group (full-mouth ultrasonic supra- and subgingival debridement+Er,Cr:YSGG laser application) and a control group (full-mouth ultrasonic supra- and subgingival debridement+root planing with Gracey curettes). The laser parameters were set as follows: 1.5 W output power, pulse mode H (pulse duration of 140 µs), pulse frequency of 20 Hz, and an air-water spray ratio of 10% air and 15% water. The instrumentation was performed until the operator felt that the root surfaces were adequately debrided. Probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), plaque index, interleukin-1 beta (IL-1ß), matrix metalloproteinase-8 (MMP-8), tissue inhibitor metalloproteinase-1 (TIMP-1), and MMP-8/TIMP-1 levels in gingival crevicular fluid were evaluated at baseline, 6 weeks, and 3 months postoperatively. Results: There were statistically significant differences in PD, which was our primary outcome, and BOP between the groups at both examinations [p < 0.001 and p < 0.001 (for PD) and p = 0.048 and p < 0.001 (for BOP), respectively], in favor of the laser group. However, there were no significant differences among groups at any time for CAL gain (p = 563 and p = 369, respectively). No significant differences in MMP-8, TIMP-1, and MMP-8/TIMP-1 levels were detected among groups. There was a statistically significant difference for IL-1ß levels among groups at 3-month evaluations in favor of the laser group. Conclusions: Using the Er,Cr:YSGG laser instead of hand instruments in nonsurgical periodontal treatment has shown additional improvements in terms of pocket reduction and gingival bleeding compared with traditional nonsurgical therapy.

CD40 up-regulation on dendritic cells correlates with Th17/Treg imbalance in chronic periodontitis in young population.

We aimed to discover the influence of age on the development of chronic periodontitis and illustrate the molecular mechanism in this process. Blood samples were collected from 63 chronic periodontitis patients and 30 healthy controls. Th17 cell/Foxp3+ regulatory T cell (Treg) ratio and expression of costimulatory molecules in dendritic cells (DCs) were analyzed by flow cytometry. The serum levels of soluble CD40 ligand (CD40L) and IL-17 were examined by ELISA. In young chronic periodontitis patients, the Th17/Treg ratio was significantly higher than that in old patients. CD40 on DCs and serum levels of CD40L and IL-17 were all higher in young chronic periodontitis patients. Mature DCs with high CD40 expression level elevated the Th17/Treg ratio in vitro. During the pathogenesis of chronic periodontitis, young patients had higher Th17/Treg ratio than old patients and this phenomenon was in line with the differential expression levels of CD40 in DCs.

Systemic Th17 response in the presence of periodontal inflammation.

BACKGROUND: The relationship between periodontitis and the pathogenesis of other inflammatory diseases, such as diabetes, rheumatoid arthritis and obesity has been an important topic of study in recent decades. The Th17 pathway plays a significant role in how local inflammation can influence systemic inflammation in the absence of systemic pathology. OBJECTIVE: To determine Th17 biased-cells in systemically healthy patients in the presence of generalized chronic periodontitis. METHODOLOGY: A total of 28 patients were recruited without systemic inflammatory pathology, which was determined by clinical history, the Health Assessment Questionnaire (HAQ) and rheumatoid factor detection. Of these patients, 13 were diagnosed as healthy/gingivitis (H/G) and 15 as generalized chronic periodontitis (GCP). Th17 (CD4+CD161+) cells and Th17IL23R+ (CD4+CD161+IL-23R+) cells were quantified by flow cytometry, based on the total cells and on the lymphocyte region, termed the "enriched population" (50,000 events for each). RESULTS: The percentages of Th17 cells of the H/G and periodontitis groups were similar on total cells and enriched population (19 vs 21.8; p=4.134 and 19.6 vs 21.8; p=0.55). However, Th17IL23R+ cells differ significantly between periodontally healthy patients and generalized chronic periodontitis patients in both total cell (0.22% vs 0.65%; p=0.0004) and enriched populations (0.2% vs 0.75%; p=0.0266). CONCLUSIONS: GCP patients (otherwise systemically healthy) were characterized by increased Th17-proinflammatory cell phenotype positive for the IL-23 receptor in peripheral blood. The proportion of Th17 cells that are negative for the IL-23 receptor in the peripheral blood of systemically healthy patients seemed to be unaffected by the presence or absence of chronic periodontitis.

Refractory neutrophil activation in type 2 diabetics with chronic periodontitis.

BACKGROUND: Inflammation increases diabetes mellitus type 2 (T2DM) progression and severity. T2DM patients are at high risk of the rapid development of chronic periodontitis (CP). Topical presence, high numbers, and bactericidal effects of immune cells are challenged by augmented antigen-induced inflammation, which promotes both diseases. OBJECTIVES: To investigate gingival cellular inflammatory responses in individuals with previously undiagnosed T2DM with CP or CP alone and in systemically and periodontally healthy controls (H) in vivo and to establish an ex vivo technique permitting quantitative and qualitative assessments of gingival crevicular immune cells. MATERIALS AND METHODS: T2DM + CP, CP, and H individuals (n = 10, each) received a 2-week oral hygiene regimen (OHR). Afterwards, a noninvasive sampling technique was performed to evaluate gingival inflammation induced under standardized conditions in vivo, that is, in the absence of severe periodontal destruction and inflammation at clinically healthy sites. Stimuli (casein/test or phosphate-buffered saline w/o. Ca2+ or Mg2+ , PBS(-/-) /control) were randomly applied contralaterally in the gingival sulci of participants' upper dentes canini. One day after completion of the OHR, gingival crevicular fluid (GCF) was kinetically assayed between the time of the baseline (BL) measurement and 55 minutes. Polymorphonuclear leukocyte (PMN) content (PMNGCF ) was quantitated at an optimum time of 35 minutes. PMNGCF counts reflect local inflammation. Ex vivo samples were fluorimetrically labeled, gated according to the donor's peripheral blood polymorphonuclear neutrophils (PMNPB ), and then counted, employing flow cytometry. RESULTS: PMNGCF counts in unstimulated gingival crevices (at BL) in the T2DM + CP group were higher than those in the CP and H groups. PMNGCF counts were elevated in casein vs PBS(-/-) -stimulated gingival crevices in all groups. Patients with T2DM + CP showed increased PMNGCF counts compared to those with CP (P = .035) according to scatter plots. CD45+ counts in the stimulated sites in T2DM + CP patients were higher than those in CP and H patients (P = .041). Under stimulation conditions, the CD45+ counts differed from those under placebo conditions (P = .019), indicating augmented, inducible inflammatory leukocyte infiltrate in T2DM + CP patients. CONCLUSIONS: This noninvasive technique permits quantitative assessment of (experimental) gingival inflammation in vivo, revealing an influence of T2DM + CP on the number of primary immune cells in the gingival crevice. Patients who are challenged with (local) leukocytosis are likely at risk of collateral damage to the gingival crevice neighboring tissues, favoring the severity and progression of CP and consequently T2DM (www.clinicaltrials.gov NCT01848379).

Chronic atrophic gastritis aggravate chronic periodontitis with Helicobacter pylori infection and CD4+Th cytokines infiltration.

OBJECTIVE: To investigate the potential effect of chronic atrophic gastritis on chronic periodontitis and further explore the possible mechanism. METHODS: Local periodontal lesions were collected from periodontitis tissues of 30 CAG patients and 35 control adults without CAG (non-CAG). Clinical periodontal parameters were recorded, and the expression levels of distinct CD4+ Th specific cytokines at local periodontitis lesions were evaluated by real time PCR (RT-PCR). Helicobacter pylori (H. pylori) detection was carried out in both gastric and periodontitis lesions of CAG and non CAG patients. RESULTS: Clinical parameters analysis showed that the level of clinical attachment loss in periodontitis lesions of CAG group was significantly higher than non-CAG group. It was observed that the infection rate of H. pylori in the CAG group was higher than non-CAG group. Further cytokine analysis showed that Th17 associated cytokines IL-17, IL-21 and IL-23 were increased in periodontal lesions of CAG patients when compared with non-CAG patients. However, Th1, Th2, Th9 and Treg cells specific cytokines were not significantly increased in CAG group when compared with non-CAG group. CONCLUSIONS: Patients with CAG demonstrated that significant elevated attachment loss in periodontitis lesions, while elevated Th17 cytokines IL-17, IL-21 and IL-23 participate in immunopathogenesis of both diseases.

Systemic Th17 response in the presence of periodontal inflammation

Abstract The relationship between periodontitis and the pathogenesis of other inflammatory diseases, such as diabetes, rheumatoid arthritis and obesity has been an important topic of study in recent decades. The Th17 pathway plays a significant role in how local inflammation can influence systemic inflammation in the absence of systemic pathology. Objective: To determine Th17 biased-cells in systemically healthy patients in the presence of generalized chronic periodontitis. Methodology: A total of 28 patients were recruited without systemic inflammatory pathology, which was determined by clinical history, the Health Assessment Questionnaire (HAQ) and rheumatoid factor detection. Of these patients, 13 were diagnosed as healthy/gingivitis (H/G) and 15 as generalized chronic periodontitis (GCP). Th17 (CD4+CD161+) cells and Th17IL23R+ (CD4+CD161+IL-23R+) cells were quantified by flow cytometry, based on the total cells and on the lymphocyte region, termed the "enriched population" (50,000 events for each). Results: The percentages of Th17 cells of the H/G and periodontitis groups were similar on total cells and enriched population (19 vs 21.8; p=4.134 and 19.6 vs 21.8; p=0.55). However, Th17IL23R+ cells differ significantly between periodontally healthy patients and generalized chronic periodontitis patients in both total cell (0.22% vs 0.65%; p=0.0004) and enriched populations (0.2% vs 0.75%; p=0.0266). Conclusions: GCP patients (otherwise systemically healthy) were characterized by increased Th17-proinflammatory cell phenotype positive for the IL-23 receptor in peripheral blood. The proportion of Th17 cells that are negative for the IL-23 receptor in the peripheral blood of systemically healthy patients seemed to be unaffected by the presence or absence of chronic periodontitis.

Systemic inflammation linking chronic periodontitis to cognitive decline.

Persistent inflammation in the systemic immune system can impose detrimental effects on the central nervous system (CNS). Neuroinflammation might be a result of this to accelerate the progressive deterioration of neuronal functions during aging. In this regard, controlling inflammation through delaying and/or preventing chronic inflammatory diseases may be a potential strategy to prevent or modify the progression of Alzheimer's Disease (AD). Periodontitis is a chronic inflammatory disease of the oral cavity that is common among the elderly, especially for those who have decline in cognitive functions. While epidemiological findings support the association of chronic periodontitis and cognitive decline, whether they have causal relationship remains unclear. Nonetheless, the possibility that periodontopathogens, systemic immune cells and inflammatory cytokines could reach the CNS should not be overlooked. The impacts of periodontitis on CNS homeostasis and inflammation as a pathophysiological factor concerning the association between periodontitis and AD will be discussed in this review. Future work should elucidate the pathological pathways involved in periodontitis-induced cerebral infections and inflammation, and define the role of the latter in AD progression.

Candida spp. Determination and Th1/Th2 Mixed Cytokine Profile in Oral Samples From HIV+ Patients With Chronic Periodontitis.

Background: Chronic periodontitis (CP), caused by bacteria and fungi, appears in up to 66% of HIV-patients. The impact and association of HIV-treatment (HAART) and Candida itself has not been properly evaluated in the development and progression of CP. The immunopathogenesis is characterized by CD4+ T-cells activation and the balance between the T-helper 1 (Th1) and T-helper 2 (Th2) or a mixed cytokine profile. Currently, the associated causes of an immune response in HIV-patients with CP is controversial. Our aims were the determination of Candida spp. and cytokine profile in oral samples from HIV-positive patients with CP, considering the CD4+ T cells levels and HAART use. Methods: From 500 HIV-positive patients evaluated, 228 patients were enrolled. Patients were separated in groups: (A) n = 53 (≤200 CD4+ T-cells on HAART); (B) n = 57 (≤200 CD4+ T-cells without HAART); (C) n = 50 (>200 CD4+ T-cells without HAART); (D) n = 68 (>200 CD4+ T-cells on HAART). Candida spp. were isolated from the oral biofilm and crevicular fluid in CHROMagar and confirmed by endpoint PCR. Cytokine levels were measured by beads-based immunoassay in saliva by flow cytometry. Results: 147 patients (64.5%) were positive to Candida spp. and 204 strains were isolated; 138 (67.6%) were C. albicans and the remaining C. non-albicans species (C. glabrata>C. tropicalis>C. krusei>C. dubliniensis). In this study, CHROMagar showed good sensitivity (95%) but poor specificity (68%); since of the 152 samples identified as C. albicans, only 131 were confirmed by PCR; from the 10 samples identified as C. glabrata, only six were confirmed. Finally, of the 42 samples detected as C. tropicalis, only five were confirmed. When evaluating Candida spp. presence, group A and D had higher isolation, while group B had the highest species diversity. Whereas, group C had a significant reduction of Candida spp. Despite the presence of Candida and HAART, we found a Th1/Th2 hybrid profile in the saliva of patients with low CD4+ T-cell count (group A). Conclusion: Abundance and diversity of the Candida spp. detected in HIV-patients with CP could be related to HAART and low CD4+ T-cells levels. Also, the immunosuppression might promote a local Th1/Th2 hybrid cytokine profile.

Identification of Salivary Microbiota and Its Association With Host Inflammatory Mediators in Periodontitis.

Periodontitis is a microbial-induced chronic inflammatory disease, which may not only result in tooth loss, but can also contribute to the development of various systemic diseases. The transition from healthy to diseased periodontium depends on microbial dysbiosis and impaired host immune response. Although periodontitis is a common disease as well as associated with various systemic inflammatory conditions, the taxonomic profiling of the salivary microbiota in periodontitis and its association with host immune and inflammatory mediators has not been reported. Therefore, the aim of this study was to identify key pathogens and their potential interaction with the host's inflammatory mediators in saliva samples for periodontitis risk assessment. The microbial 16S rRNA gene sequencing and the levels of inflammatory mediators were performed in saliva samples from patients with chronic periodontitis and periodontally healthy control subjects. The salivary microbial community composition differed significantly between patients with chronic periodontitis and healthy controls. Our analyses identified a number of microbes, including bacteria assigned to Eubacterium saphenum, Tannerella forsythia, Filifactor alocis, Streptococcus mitis/parasanguinis, Parvimonas micra, Prevotella sp., Phocaeicola sp., and Fretibacterium sp. as more abundant in periodontitis, compared to healthy controls. In samples from healthy individuals, we identified Campylobacter concisus, and Veillonella sp. as more abundant. Integrative analysis of the microbiota and inflammatory mediators/cytokines revealed associations that included positive correlations between the pathogens Treponema sp. and Selenomas sp. and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6Rß. In addition, a negative correlation was identified between IL-10 and Filifactor alocis. Our results reveal distinct and disease-specific patterns of salivary microbial composition between patients with periodontitis and healthy controls, as well as significant correlations between microbiota and host-mediated inflammatory cytokines. The positive correlations between the pathogens Treponema sp. and Selenomas sp. and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6Rß might have the future potential to serve as a combined bacteria-host salivary biomarker panel for diagnosis of the chronic infectious disease periodontitis. However, further studies are required to determine the capacity of these microbes and inflammatory mediators as a salivary biomarker panel for periodontitis.

Systemic Immunologic Consequences of Chronic Periodontitis.

Chronic periodontitis (ChP) is a prevalent inflammatory disease affecting 46% of the US population. ChP produces a profound local inflammatory response to dysbiotic oral microbiota that leads to destruction of alveolar bone and tooth loss. ChP is also associated with systemic illnesses, including cardiovascular diseases, malignancies, and adverse pregnancy outcomes. However, the mechanisms underlying these adverse health outcomes are poorly understood. In this prospective cohort study, we used a highly multiplex mass cytometry immunoassay to perform an in-depth analysis of the systemic consequences of ChP in patients before (n = 28) and after (n = 16) periodontal treatment. A high-dimensional analysis of intracellular signaling networks revealed immune system-wide dysfunctions differentiating patients with ChP from healthy controls. Notably, we observed exaggerated proinflammatory responses to Porphyromonas gingivalis-derived lipopolysaccharide in circulating neutrophils and monocytes from patients with ChP. Simultaneously, natural killer cell responses to inflammatory cytokines were attenuated. Importantly, the immune alterations associated with ChP were no longer detectable 3 wk after periodontal treatment. Our findings demarcate systemic and cell-specific immune dysfunctions in patients with ChP, which can be temporarily reversed by the local treatment of ChP. Future studies in larger cohorts are needed to test the boundaries of generalizability of our results.

Chronic Inflammation as a Link between Periodontitis and Carcinogenesis.

Periodontitis is characterized by a chronic inflammation produced in response to a disease-associated multispecies bacterial community in the subgingival region. Although the inflammatory processes occur locally in the oral cavity, several studies have determined that inflammatory mediators produced during periodontitis, as well as subgingival species and bacterial components, can disseminate from the oral cavity, contributing therefore, to various extraoral diseases like cancer. Interestingly, carcinogenesis associated with periodontal species has been observed in both the oral cavity and in extra oral sites. In this review, several studies were summarized showing a strong association between orodigestive cancers and poor oral health, presence of periodontitis-associated bacteria, tooth loss, and clinical signs of periodontitis. Proinflammatory pathways were also summarized. Such pathways are activated either by mono- or polymicrobial infections, resulting in an increase in the expression of proinflammatory molecules such as IL-6, IL-8, IL-1ß, and TNF-α. In addition, it has been shown that several periodontitis-associated species induce the expression of genes related to cell proliferation, cell cycle, apoptosis, transport, and immune and inflammatory responses. Intriguingly, many of these pathways are linked to carcinogenesis. Among them, the activation of Toll-like receptors (TLRs) and antiapoptotic pathways (such as the PI3K/Akt, JAK/STAT, and MAPK pathways), the reduction of proapoptotic protein expression, the increase in cell migration and invasion, and the enhancement in metastasis are addressed. Considering that periodontitis is a polymicrobial disease, it is likely that mixed species promote carcinogenesis both in the oral cavity and in extra oral tissues and probably-as observed in periodontitis-synergistic and/or antagonistic interactions occur between microbes in the community. To date, a good amount of studies has allowed us to understand how monospecies infections activate pathways involved in tumorigenesis; however, more studies are needed to determine the combined effect of oral species in carcinogenesis.