Oro-hepatic link, endotoxemia, and systemic inflammation: The role of chronic periodontitis

Role of viruses in periodontitis: An extensive review of herpesviruses, human immunodeficiency virus, coronavirus-19, papillomavirus and hepatitis viruses

Periodontitis is the inflammation of the supporting structures around the dentition. Several microbial agents, mostly bacteria, have been identified as causative factors for periodontal disease. On the other hand, oral cavity is a rich reservoir for viruses since it contains a wide variety of cell types that can be targeted by viruses. Traditionally, the focus of research about the oral flora has been on bacteria because the most widespread oral diseases, like periodontitis and dental caries, are outcomes of bacterial infection. However, recently and especially after the emergence of coronavirus disease 2019, there is a growing tendency toward including viruses also into the scope of oral microbiome investigations. The global high prevalence of periodontitis and viral infections may point out to a concomitant or synergistic effect between the two. Although the exact nature of the mechanism still is not clearly understood, this could be speculated through the manipulation of the immune system by viruses; hence facilitating the furthermore colonization of the oral tissues by bacteria. This review provides an extensive and detailed update on the role of the most common viruses including herpes family (herpes simplex, varicella-zoster, Epstein-Barr, cytomegalovirus), Human papillomaviruses, Human immunodeficiency virus and severe acute respiratory syndrome coronavirus 2 in the initiation, progression and prognosis of periodontitis.

Association between periodontitis with the all-cause and cause specific mortality among the population with hyperlipidemia

BACKGROUND

To explore the association between periodontitis and all-cause as well as cause-specific mortality rates in U.S. adults with hyperlipidemia.

METHODS

Participants were extracted from NHANES during 1988-1994, 1999-2004 and 2009-2014 periods. To assess the association between moderate-to-severe periodontitis and mortality rates for both all-cause and cause-specific mortality, hazard ratios (HRs), time ratios (TRs), and their respective 95% confidence intervals (CIs) were calculated using Cox proportional hazards and Weibull accelerated failure time (AFT) models.

RESULTS

Over a median follow-up duration of 11.83 years, 4,623 deaths of 16,848 participants were recorded. Multivariate Cox regression and AFT analyses showed moderate-to-severe periodontitis were associated with an increased risk of all-cause (HR: 1.31, 95% CI: 1.20-1.44, P < 0.001; TR: 0.85, 95% CI: 0.80-0.90, P < 0.001), cardiovascular disease (CVD)-related (HR: 1.36, 95% CI: 1.14-1.63, P = 0.001; TR: 0.83, 95% CI: 0.75-0.92, P < 0.001) and cancer-related mortality ( HR: 1.35, 95% CI: 1.12-1.63, P = 0.002; TR: 0.82, 95% CI: 0.72-0.93, P = 0.002). Meanwhile, there was a significant upward trend in the risk of mortality with increasing severity of periodontitis (P for trend < 0.001).

CONCLUSIONS

Our study highlights the moderate-to-severe periodontitis is associated with an increased risk of all-cause, CVD-related and cancer-related mortality among U.S. adults with hyperlipidemia. And the mortality risk increasing alongside the severity of periodontitis.

Periodontitis and the risk of all-cause and cause-specific mortality among US adults with diabetes: A population-based cohort study

AIM

To evaluate the association between periodontitis, all-cause and cause-specific mortality, and its prognostic utility among adults with diabetes.

MATERIALS AND METHODS

Periodontal health records were retrieved from the NHANES database for 4297 participants with diabetes aged >30 years at baseline during 1988-1994, 1999-2004 and 2009-2014. Multivariable Cox proportional hazards regression model was applied to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for moderate/severe periodontitis with all-cause and cause-specific mortality in participants with diabetes. Area under the curve (AUC) was used to assess predictive value.

RESULTS

During a median follow-up of 15.41 years, 1701 deaths occurred. After multivariate adjustments, moderate/severe periodontitis was significantly associated with increased risk of all-cause (HR: 1.27; 95% CI: 1.07-1.50; p = .005) and cardiovascular disease (CVD)-related (HR: 1.35, 95% CI: 1.03-1.76, p = .031) mortality in participants with diabetes. The absolute risk difference based on the cumulative incidence information was 0.022 (5-year, 95% CI: 0.021-0.023) and 0.044 (10-year, 95% CI: 0.041-0.048). Periodontitis improved the prediction of all-cause (AUC: 0.652; 95% CI: 0.627-0.676) and CVD-related (AUC: 0.649; 95% CI: 0.624-0.676) mortality over standard risk factors (all-cause: AUC: 0.631; 95% CI: 0.606-0.656; CVD-related: AUC: 0.629; 95% CI: 0.604-0.655).

CONCLUSIONS

Moderate/severe periodontitis is associated with an increased risk of all-cause and CVD-related mortality in adults with diabetes. Periodontitis might represent a marker for residual risk.

ASSOCIATION BETWEEN PERIODONTITIS AND LIVER DISEASE

Recent clinical and scientific evidence confirms the negative impact of long-term periodontitis on the clinical course and progression of various liver diseases. Periodontitis is a chronic, slow-progressing infectious disease of the tooth supporting tissues caused mainly by the gram-negative bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Tannerella forsythia. These specific pathogens can be easily translocated from oral cavity to the intestine. Disruption of the intestine microbiota composition by orally derived periodontal pathogenic bacteria has recently been suggested to be a causal mechanism between periodontitis and liver disease. Furthermore, both diseases have the ability to induce an inflammatory response and lead to the creation of inflammatory mediators through which they may influence each other. Recent epidemiologic studies have demonstrated that individuals with liver cirrhosis have considerably poorer periodontal clinical parameters than those without cirrhosis. Periodontal therapy in cirrhosis patients favorably modulates oral and gut microbiome, the course of systemic inflammation, cirrhosis prognostic factors, and cognitive function. Therefore, future clinical researches should be focused on detailed examination of the biological mechanisms, strength and direction of the association between advanced liver disease and periodontitis.

Oral Health and Liver Disease: Bidirectional Associations—A Narrative Review

Several links between chronic liver disease and oral health have been described and are discussed in this narrative review. Oral manifestations such as lichen planus, ulcers, xerostomia, erosion and tongue abnormalities seem to be particularly prevalent among patients with chronic liver disease. These may be causal, coincidental, secondary to therapeutic interventions, or attributable to other factors commonly observed in liver disease patients. In addition, findings from both experimental and epidemiological studies suggest that periodontitis can induce liver injury and contribute to the progression of chronic liver disease through periodontitis-induced systemic inflammation, endotoxemia, and gut dysbiosis with increased intestinal translocation. This has brought forward the hypothesis of an oral-gut-liver axis. Preliminary clinical intervention studies indicate that local periodontal treatments may lead to beneficial liver effects, but more human studies are needed to clarify if treatment of periodontitis truly can halt or reverse progression of liver disease and improve liver-related outcomes.

Visfatin regulates Pg LPS-induced proinflammatory/prodegradative effects in healthy and inflammatory periodontal cells partially via NF-κB pathway

Periodontitis is a widespread chronic infectious-inflammatory disease associated with multiple systemic diseases. Visfatin is an adipokine-enzyme that can be locally produced by human periodontal ligament cells (hPDLCs) and human gingival fibroblasts (hGFs). It can upregulate proinflammatory cytokines and matrix metalloproteinases (MMPs) in various types of cells. However, the effects of visfatin on healthy and inflammatory human periodontal cells as well as the underlying molecular mechanisms remain unclear. This study firstly demonstrated visfatin expression was highly elevated in inflamed human gingiva and Pg LPS-treated hPDLCs. Moreover, recombinant visfatin significantly upregulated the expression of proinflammatory cytokines (TNF-α, IL-1β and IL-6) and prodegradative factors (EMPPRIN, MMP1, MMP3 and MMP13) in hPDLCs. Next, we found the levels of proinflammatory and prodegradative cytokines were significantly increased in visfatin-overexpressing hPDLCs, and decreased in visfatin-silencing inflammatory hGFs (iGFs) when treated with Pg LPS. In the absence of Pg LPS, visfatin silencing failed to affect the expression of these factors in iGFs, and overexpression of visfatin upregulated MMPs but no other factors in hPDLCs. Furthermore, marked NF-κB pathway activation with increased phosphorylation of p65 was observed in visfatin-overexpressing hPDLCs. BAY11-7082, a specific inhibitor of NF-κB, partially reversed the upregulation proinflammatory and prodegradative factors induced by visfatin overexpression. Taken together, this study showed that visfatin critically regulates Pg LPS-induced proinflammatory/prodegradative effects in healthy and inflammatory periodontal cells partially via NF-κB pathway. The findings suggest that visfatin is closely involved in the development of periodontitis, and may serve as a promising novel biomarker and therapeutic target for periodontitis management.

Unique subgingival microbiota associated with periodontitis in cirrhosis patients

Liver cirrhosis is a severe disease with major impact on the overall health of the patient including poor oral health. Lately, there has been increasing focus on oral diseases as cirrhosis-related complications due to the potential impact on systemic health and ultimately mortality. Periodontitis is one of the most common oral diseases in cirrhosis patients. However, no studies have investigated the composition of the subgingival microbiome in patients suffering from periodontitis and liver cirrhosis. We analysed the subgingival microbiome in 21 patients with periodontitis and cirrhosis using long-reads Illumina sequencing. The subgingival microbiota was dominated by bacteria belonging to the Firmicutes phylum and to a lesser extend the Actinobacteria and Bacteroidetes phyla. Bacteria usually considered periodontal pathogens, like Porhyromonas ginigivalis, Tannerella forsythia, Treponema denticola, generally showed low abundancy. Comparing the microbiota in our patients with that of periodontitis patients and healthy controls of three other studies revealed that the periodontitis-associated subgingival microbiota in cirrhosis patients is composed of a unique microbiota of bacteria not normally associated with periodontitis. We hypothesise that periodontitis in cirrhosis patients is a consequence of dysbiosis due to a compromised immune system that renders commensal bacteria pathogenic.