What can we learn about biofilm/host interactions from the study of inflammatory bowel disease

The effect of the "Oral-Gut" axis on periodontitis in inflammatory bowel disease: A review of microbe and immune mechanism associations

Periodontitis and inflammatory bowel diseases (IBD) are inflammatory diseases of the gastrointestinal tract that share common features of microbial-induced ecological dysregulation and host immune inflammatory response. The close relationship between periodontitis and IBD is characterized by a higher prevalence of IBD in patients with periodontitis and a higher prevalence and severity of periodontitis in patients with IBD, indicating that periodontitis and IBD are different from the traditional independent diseases and form an "Oral-Gut" axis between the two, which affect each other and thus form a vicious circle. However, the specific mechanisms leading to the association between the two are not fully understood. In this article, we describe the interconnection between periodontitis and IBD in terms of microbial pathogenesis and immune dysregulation, including the ectopic colonization of the gut by pathogenic bacteria associated with periodontitis that promotes inflammation in the gut by activating the host immune response, and the alteration of the oral microbiota due to IBD that affects the periodontal inflammatory response. Among the microbial factors, pathogenic bacteria such as Klebsiella, Porphyromonas gingivalis and Fusobacterium nucleatum may act as the microbial bridge between periodontitis and IBD, while among the immune mechanisms, Th17 cell responses and the secreted pro-inflammatory factors IL-1β, IL-6 and TNF-α play a key role in the development of both diseases. This suggests that in future studies, we can look for targets in the "Oral-Gut" axis to control and intervene in periodontal inflammation by regulating periodontal or intestinal flora through immunological methods.

Periodontitis prevalence in patients with ulcerative colitis and Crohn's disease - PPCC: A case-control study

AIM

The aim of this questionnaire-based case-control study was to assess whether self-reported oral health and periodontitis in patients with ulcerative colitis (UC) and Crohn's disease (CD) differ from those in matched controls without inflammatory bowel disease (IBD).

MATERIALS AND METHODS

A survey including questions on general anamnestic information, IBD diagnosis, and oral health was distributed online. Self-perceived overall health of teeth and gums, severe periodontitis, and tooth loss were defined as outcome parameters.

RESULTS

Analyses were based on answers from 1108 patients with IBD and 3429 controls. Patients with IBD reported significantly worse oral health and more periodontal problems compared to controls. Regression analyses corrected for relevant confounders showed significantly increased odds for fair or poor self-perceived overall health of teeth and gums (odds ratio [OR] 2.147 and 2.736, respectively) and for severe periodontitis (OR 1.739 and 2.574, respectively) for patients with UC and CD compared to controls; patients with CD presented additionally 91% higher odds for having <20 remaining teeth.

CONCLUSION

Patients with UC and CD have significantly increased odds for worse self-perceived oral health and severe periodontitis compared to controls, with the former being more severely affected and losing more teeth. It is strongly recommended that patients with IBD are kept under close surveillance to prevent periodontitis development and/or mitigate its progression.

Association between Porphyromonas Gingivalis and systemic diseases: Focus on T cells-mediated adaptive immunity

The association between periodontal disease and systemic disease has become a research hotspot. Porphyromonas gingivalis (P. gingivalis), a crucial periodontal pathogen, affects the development of systemic diseases. The pathogenicity of P. gingivalis is largely linked to interference with the host's immunity. This review aims to discover the role of P. gingivalis in the modulation of the host's adaptive immune system through a large number of virulence factors and the manipulation of cellular immunological responses (mainly mediated by T cells). These factors may affect the cause of large numbers of systemic diseases, such as atherosclerosis, hypertension, adverse pregnancy outcomes, inflammatory bowel disease, diabetes mellitus, non-alcoholic fatty liver disease, rheumatoid arthritis, and Alzheimer's disease. The point of view of adaptive immunity may provide a new idea for treating periodontitis and related systemic diseases.

Patients with inflammatory bowel disease have a higher chance of developing periodontitis: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Periodontitis affects up to one billion people worldwide, and has been proven to be associated with several systemic inflammatory conditions. This study investigates the specific relationship between two multifactorial diseases: Inflammatory bowel disease (IBD) and periodontitis. To thoroughly explore this issue, we investigated separately whether IBD patients have a higher chance of developing periodontitis, and equally, whether patients with periodontitis have a higher chance of developing IBD.

METHODS

The systematic search was performed in three databases: MEDLINE, Cochrane Trials, and Embase, up to 26 October 2021. The protocol was registered in PROSPERO. All eligible studies investigating the association between IBD and periodontitis from either direction were included. The Newcastle-Ottawa Scale was used to assess the risk of bias. As a primary outcome, we investigated the prevalence of IBD and periodontitis, and calculated the odds ratio (OR). Our secondary outcomes involved comparing the clinical periodontal outcomes of IBD patients to those of IBD-free patients.

RESULTS

The systematic search resulted in 1,715 records, 14 of which were eligible for qualitative synthesis and 8 for quantitative synthesis. On the basis of the results of the primary outcome, IBD diagnosis was associated with significantly higher odds of periodontitis: OR = 2.65 (CI: 2.09-3.36, I 2 = 0 (CI: 0-0.75)). For subgroup analysis, we investigated separately the odds in Crohn's disease (CD) patients: OR = 2.22 (CI: 1.49-3.31, I 2 = 0.05 (CI: 0-0.76)) and in ulcerative colitis (UC) patients: OR = 3.52 (CI: 2.56 to 4.83, I 2 = 0 (CI: 0-0.75)); the odds were significantly higher in all cases. Two studies investigated whether patients with periodontitis were more susceptible to IBD, and both found that periodontitis was significantly associated with the risk of subsequent UC, but not with subsequent CD. However, more studies are needed to prove an association.

CONCLUSION

Our analysis confirmed that IBD patients have a higher chance of developing periodontitis, and are a higher risk population in dentistry. Both dentists and gastroenterologists should be aware of this relationship and should emphasize the importance of prevention even more than in the healthy population.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021286161].

Inflammatory bowel disease and periodontitis: A retrospective chart analysis

Objectives

This study examined the variation in prevalence of periodontitis among different sexes, age groups, smoking status, and oral hygiene adherence in patients affected by either Crohn's disease (CD) or ulcerative colitis (UC).

Materials & Methods

This study was a retrospective chart analysis that collected data from the School of Dentistry's Oral Health Clinic at the University of Alberta, Edmonton, Canada. Patients' electronic health records between the years of 2013 and 2019 were analyzed. Multiple keywords such as IBD, CD, UC, and periodontal disease with various spelling combinations were used for searching and gathering pertinent data, which was then further assessed. After applying the inclusion and exclusion criteria, a total of 80 patient charts were included. These patient charts were thoroughly screened to gather information such as age, sex, smoking status, and a variety of periodontal parameters. Collected data were analyzed using SPSS software by using Pearson's χ², Pearson's correlation, and Mann–Whitney U‐test.

Results

IBD had an impact on the severity of periodontitis in patients between the ages of 50 and 64 years with higher odds ratio (OR). Biological sex or history of smoking in IBD patients did not have higher odds of developing periodontitis. Plaque score derived from this retrospective study was used to estimate the patient's oral hygiene status and showed no impact. Also, prevalence of periodontitis did not differ between UC and CD. We anticipated some of these findings because of the retrospective nature of the study.

Conclusions

Within the limitation of the retrospective study, IBD patients in the 50–64 age group years showed a higher odds ratio for a greater prevalence of periodontitis. Thus, a closer periodontal recall and evaluation in these patients is recommended for early diagnosis and preventive care. It is advised that periodontists work closely with gastroenterologists to maintain periodontal health in IBD‐affected individuals.

Oral Health Status in Patients with Inflammatory Bowel Diseases: A Systematic Review

Inflammatory bowel diseases (IBD) are chronic disorders that affect the gastrointestinal tract, including the oral cavity. This systematic review was designed to answer the question “Is there a relationship between oral health status and inflammatory bowel diseases?”. Following the inclusion and exclusion criteria, fifteen studies were included (according to PRISMA statement guidelines). Due to their heterogeneity, only six articles about the prevalence of periodontal disease in IBD patients were included in the meta-analysis. Both Crohn’s disease (CD) and ulcerative colitis (UC) patients had an increased odds of periodontitis coincidence compared to the controls, more than 2- and 3-fold, respectively. Moreover, in most studies, patients with IBD were characterized by higher values of caries indices. In conclusion, despite the conducted systematic review, the risk of oral diseases in IBD patients cannot be clearly established due to the possible association of other factors, e.g., sociodemographic or environmental factors.

Porphyromonas gingivalis exacerbates ulcerative colitis via Porphyromonas gingivalis peptidylarginine deiminase

Ulcerative Colitis (UC) has been reported to be related to Porphyromonas gingivalis (P. gingivalis). Porphyromonas gingivalis peptidylarginine deiminase (PPAD), a virulence factor released by P. gingivalis, is known to induce inflammatory responses. To explore the pathological relationships between PPAD and UC, we used homologous recombination technology to construct a P. gingivalis strain in which the PPAD gene was deleted (Δppad) and a Δppad strain in which the PPAD gene was restored (comΔppad). C57BL/6 mice were orally gavaged with saline, P. gingivalis, Δppad, or comΔppad twice a week for the entire 40 days (days 0-40), and then, UC was induced by dextran sodium sulfate (DSS) solution for 10 days (days 31-40). P. gingivalis and comΔppad exacerbated DDS-induced colitis, which was determined by assessing the parameters of colon length, disease activity index, and histological activity index, but Δppad failed to exacerbate DDS-induced colitis. Flow cytometry and ELISA revealed that compared with Δppad, P. gingivalis, and comΔppad increased T helper 17 (Th17) cell numbers and interleukin (IL)-17 production but decreased regulatory T cells (Tregs) numbers and IL-10 production in the spleens of mice with UC. We also cocultured P. gingivalis, Δppad, or comΔppad with T lymphocytes in vitro and found that P. gingivalis and comΔppad significantly increased Th17 cell numbers and decreased Treg cell numbers. Immunofluorescence staining of colon tissue paraffin sections also confirmed these results. The results suggested that P. gingivalis exacerbated the severity of UC in part via PPAD.

The Association between Periodontitis and Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Background

It has been reported that patients with inflammatory bowel disease (IBD) are more susceptible to periodontitis. However, data regarding the risk of periodontitis in IBD patients are scarce, and results from individual studies remain controversial. The aim of this study is to investigate the risk of periodontitis in IBD patients.

Methods

Web of Science, PubMed, and Embase were searched for studies investigating the risk of periodontitis in the IBD patient population from Jan. 2000 to Nov. 2020. Articles were included if they contained the number of people with IBD diagnosed with periodontitis (or periodontal disease parameters) compared with a control group. Case reports, reviews, animal studies, and articles without available abstracts were excluded. A pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the association between periodontitis and IBD.

Results

Six studies were included in the meta-analysis. The overall risk of periodontitis was significantly higher in IBD patients than controls (OR: 2.10, 95% CI: 1.60-2.74; I² = 27%). In particular, Crohn's disease (CD) and ulcerative colitis (UC) were both linked to an increased risk of periodontitis (OR: 1.72, 95% CI: 1.36-2.19; I² = 0% for CD vs. OR:2.39, 95% CI: 1.19-4.80; I² = 85% for UC).

Conclusions

IBD patients are at higher risk of periodontitis than controls. After subgroup analysis, the elevated risk remained significant when analyzing CD or UC alone. UC patients were at higher risk of developing periodontitis than CD patients.

The "Gum-Gut" Axis in Inflammatory Bowel Diseases: A Hypothesis-Driven Review of Associations and Advances

In modern medicine, the oral cavity has often been viewed as a passive conduit to the upper airways and gastrointestinal tract; however, its connection to the rest of the body has been increasingly explored over the last 40 years. For several diseases, the periodontium and gingiva are at the center of this oral-systemic link. Over 50 systemic conditions have been specifically associated with gingival and periodontal inflammation, including inflammatory bowel diseases (IBD), which have recently been elevated from simple "associations" to elegant, mechanistic investigations. IBD and periodontitis have been reported to impact each other's progression via a bidirectional relationship whereby chronic oral or intestinal inflammation can impact the other; however, the precise mechanisms for how this occurs remain unclear. Classically, the etiology of gingival inflammation (gingivitis) is oral microbial dysbiosis in the subgingival crevice that can lead to destructive periodontal disease (periodontitis); however, the current understanding of gingival involvement in IBD is that it may represent a separate disease entity from classical gingivitis, arising from mechanisms related to systemic inflammatory activation of niche-resident immune cells. Synthesizing available evidence, we hypothesize that once established, IBD can be driven by microbiomial and inflammatory changes originating specifically from the gingival niche through saliva, thereby worsening IBD outcomes and thus perpetuating a vicious cycle. In this review, we introduce the concept of the "gum-gut axis" as a framework for examining this reciprocal relationship between the periodontium and the gastrointestinal tract. To support and explore this gum-gut axis, we 1) provide a narrative review of historical studies reporting gingival and periodontal manifestations in IBD, 2) describe the current understanding and advances for the gum-gut axis, and 3) underscore the importance of collaborative treatment and research plans between oral and GI practitioners to benefit this patient population.

Periodontitis and inflammatory bowel disease: a meta-analysis

Background

Periodontitis was reported to be associated with inflammatory bowel disease (IBD). However, the association between them has not been firmly established in the existing literature. Therefore, this meta-analysis was conducted to evaluate the relationship between periodontitis and IBD.

Methods

Electronic databases were searched for publications up to August 1, 2019 to include all eligible studies. The pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated to determine the association between periodontal disease and IBD using a random or fixed effects model according to heterogeneity.

Results

Six eligible studies involving 599 IBD patients and 448 controls were included. The pooled OR between periodontitis and IBD was 3.17 (95% CI: 2.09–4.8) with no heterogeneity observed (I² = 0.00%). The pooled ORs were 3.64 (95% CI: 2.33–5.67) and 5.37 (95% CI: 3.30–8.74) for the associations between periodontitis and the two sub-categories of IBD, Crohn’ s disease and ulcerative colitis, respectively.

Conclusions

The results demonstrated that periodontitis was significantly associated with IBD. However, the mechanisms underlying periodontitis and IBD development are undetermined. Further studies are needed to elucidate this relationship.

An Oral Rinse Active Matrix Metalloproteinase-8 Point-of-Care Immunotest May Be Less Accurate in Patients with Crohn's Disease

The diagnostic accuracy of point-of-care (PoC) applications may be compromised in individuals with additional inflammatory conditions. This cross-sectional study examined the performance of a commercial oral rinse active matrix metalloproteinase-8 (aMMP-8) PoC immunotest in individuals with (n = 47) and without Crohn's disease (CD) (n = 41). Oral rinse collected from the participants was analyzed by the PoC immunotest. Molecular forms and fragments of salivary MMP-8 were detected by western immunoblotting. The sensitivity of the immunotest for periodontitis was 60.0% in the CD group and 90.0% in the control group. The respective specificity was 75.0% and 80.0%. In both groups, clinical diagnosis of periodontitis exhibited a significant association with the immunotest results, however, the odds ratio (OR) was more than ten-fold in controls (OR 54.3, 95% CI: 3.1-953, p = 0.006) in comparison to CD patients (OR 5.2, 95% CI: 1.3-21.6, p = 0.022). According to Western immunoblot results, the immunotest MMP-8 positivity was not related to elevated levels of molecular forms and fragments of MMP-8 in the CD group, as in the control group. The diagnostic accuracy of the aMMP-8 PoC oral rinse immunotest is reduced in CD patients, which may be related to lower levels or undetectable complexes.

Increased risks of dental caries and periodontal disease in Chinese patients with inflammatory bowel disease

OBJECTIVES

Inflammatory bowel disease (IBD) may be associated with oral diseases, but few relevant studies have been reported in China. This study aimed to compare the prevalence, severity and extent of dental caries and periodontal disease in Chinese IBD patients and healthy controls.

MATERIALS AND METHODS

In this cross-sectional study, questionnaires and oral examinations were completed for 389 IBD patients [265 with Crohn's disease (CD) and 124 with ulcerative colitis (UC)] and 265 healthy controls based on the established criteria of the World Health Organization. Tobit regression, multiple linear regression and logistic regression were performed to analyse the data.

RESULTS

After adjusting for confounders, the decayed, missing and filled surfaces indices were significantly increased in the CD and UC patients compared with those in the controls (P < 0.001). Patients with CD [odds ratio (OR) = 4.27, 95% confidence interval (95% CI): 2.63-6.95, P < 0.001] and UC (OR = 2.21, 95% CI: 1.24-3.94, P = 0.007) had significantly higher risks of dental caries than controls. Significantly higher percentages of sites with probing pocket depth ≥ 5 mm and clinical attachment loss ≥ 4 mm were observed in CD and UC patients compared with controls (P < 0.001). A fully adjusted model revealed that CD and UC were risk indicators for periodontitis (OR = 4.46, 95% CI: 2.50-7.95, P < 0.001; OR = 4.66, 95% CI: 2.49-8.71, P < 0.001, respectively). No significant differences in dental caries and periodontal disease were observed between the CD and UC patients.

CONCLUSIONS

Chinese IBD patients have a higher prevalence, severity and extent of dental caries and/or periodontal disease than controls, and require oral health education and multidisciplinary treatment.

Active matrix metalloproteinase-8 and periodontal bacteria-interlink between periodontitis and inflammatory bowel disease?

BACKGROUND

The aim of this study was the investigation of concentration and prevalence of selected periodontal pathogenic bacteria and concentration of active matrix metalloproteinase-8 (aMMP-8) within a group of patients with inflammatory bowel diseases (IBD) and to compare the results with a group of healthy control subjects (HC).

METHODS

Fifty-nine IBD patients with Crohn`s disease (CD, n = 30) or ulcerative colitis (UC, n = 29) and 59 HC were included in this cross-sectional study. Based on periodontal probing depth (PD) and clinical attachment level (CAL), periodontitis was classified as healthy/mild, moderate, or severe. aMMP-8 was analyzed from gingival crevicular fluid using enzyme linked immunosorbent assay. Eleven selected periodontal pathogenic bacteria were analyzed in subgingival plaque samples using polymerase chain reaction.

RESULTS

IBD patients showed higher CAL (P < 0.01), more severe periodontitis (P = 0.04), gingival bleeding (P < 0.01) and aMMP-8 concentration (P < 0.01) than HC. Only in CD, increasing severity of periodontitis was associated with an increase in aMMP-8 concentration (P = 0.02). The prevalences of Eubacterium nodatum and Eikenella corrodens were significantly lower in IBD compared to HC (P = 0.01). Additionally, the prevalence of Eikenella corrodens was significantly higher in CD compared to the UC group (P = 0.04). Further statistically significant differences in selected bacteria between IBD and HC or CD and UC groups could not be found (P > 0.05).

CONCLUSIONS

The results reveal changes in host immune response of IBD patients in terms of aMMP-8. Only in CD increasing aMMP-8 was associated with severity of periodontal disease. The role of periodontal pathogenic bacteria in the interrelationship between IBD and periodontitis remains unclear.

Increased risk of periodontitis among patients with Crohn's disease: a population-based matched-cohort study

BACKGROUND

Periodontitis is a frequently cited extraintestinal manifestation of Crohn's disease (CD). Despite a plethora of investigations and a recent meta-analysis linking CD and periodontitis, no study has estimated the risk of periodontitis among CD patients with respect to a comparison group nor has any investigation analyzed the effect of CD-specific medications on the risk of periodontitis. The present cohort study compared CD patients and matched subjects without a history of inflammatory bowel disease (IBD) to estimate the effect of CD and CD-specific pharmaceutical prescriptions on the risk of developing periodontitis by leveraging a population-based dataset in Taiwan.

METHODS

We sourced 6657 CD patients and 26,628 comparison subjects without a history of IBD from the Taiwan National Health Insurance Database. Cox proportional hazards regressions were used to estimate the risk of subsequent periodontitis by CD status and pharmaceutical prescription during the follow-up period.

RESULTS

After adjusting for socioeconomic status (SES), urbanicity, selected medical co-morbidities, and CD-specific pharmaceutical prescriptions, the hazard ratio (HR) for subsequent periodontitis among patients with CD was 1.36 (95% CI = 1.25-1.48) that of comparison subjects. There was not a significant difference in risk between genders or across ages. Steroids (95% CI = 0.66-0.77) appeared to confer a protective effect and Aspirin, Plavix, and Licodin were marginally protective (95% CI = 0.76-0.95).

CONCLUSION

This is the first study to report an increased HR for subsequent periodontitis among CD patients when compared to matched comparison subjects without IBD. The protective effect of some pharmaceuticals may suggest that treatment of CD protects against periodontitis.

The relationship between the immune system and oral manifestations of inflammatory bowel disease: a review

Inflammatory bowel diseases (IBDs) are chronic, relapsing inflammatory diseases characterized by exacerbations and remissions of the gastrointestinal tract, clinically manifested as Crohn's disease and ulcerative colitis. The etiology of IBDs is considered to be multi factorial, comprising environmental, immune, microbial and genetic factors. Clinical signs may include abdominal pain, frequent bloody diarrheas, mucorrhea, vomiting, fever, fatigue or weight loss. Changes in the oral cavity often precede intestinal symptoms. Inflammatory bowel disease leads to a significant deterioration of oral health, which indicates that cooperation between the dentist and the gastroenterologist is necessary when considering patients' welfare. Patients with IBD have an altered immune response, but microorganisms of the oral cavity may also be responsible for its modification. This review paper discusses the correlation between the immune system and inflammatory bowel disease manifestations in the oral cavity.

Periodontal and inflammatory bowel diseases: Is there evidence of complex pathogenic interactions?

Periodontal disease and inflammatory bowel disease (IBD) are both chronic inflammatory diseases. Their pathogenesis is mediated by a complex interplay between a dysbiotic microbiota and the host immune-inflammatory response, and both are influenced by genetic and environmental factors. This review aimed to provide an overview of the evidence dealing with a possible pathogenic interaction between periodontal disease and IBD. There seems to be an increased prevalence of periodontal disease in patients with IBD when compared to healthy controls, probably due to changes in the oral microbiota and a higher inflammatory response. Moreover, the induction of periodontitis seems to result in gut dysbiosis and altered gut epithelial cell barrier function, which might contribute to the pathogenesis of IBD. Considering the complexity of both periodontal disease and IBD, it is very challenging to understand the possible pathways involved in their coexistence. In conclusion, this review points to a complex pathogenic interaction between periodontal disease and IBD, in which one disease might alter the composition of the microbiota and increase the inflammatory response related to the other. However, we still need more data derived from human studies to confirm results from murine models. Thus, mechanistic studies are definitely warranted to clarify this possible bidirectional association.

Arthritis-induced alveolar bone loss is associated with changes in the composition of oral microbiota

Rheumatoid arthritis (RA) and periodontitis (PD) are chronic inflammatory disorders that cause bone loss. PD tends to be more prevalent and severe in RA patients. Previous experimental studies demonstrated that RA triggers alveolar bone loss similarly to PD. The aim of this study was to investigate if arthritis-induced alveolar bone loss is associated with modification in the oral microbiota. Checkerboard DNA-DNA hybridization was employed to analyze forty oral bacterial species in 3 groups of C57BL/6 mice: control (n = 12; without any challenge); Y4 (n = 8; received oral inoculation of Aggregatibacter Actinomycetemcomitans strain FDC Y4) and AIA group (n = 12; chronic antigen-induced arthritis). The results showed that AIA and Y4 group exhibited similar patterns of bone loss. The AIA group exhibited higher counts of most bacterial species analyzed with predominance of Gram-negative species similarly to infection-induced PD. Prevotella nigrescens and Treponema denticola were detected only in the Y4 group whereas Campylobacter showae, Streptococcus mitis and Streptococcus oralis were only found in the AIA group. Counts of Parvimonas micra, Selenomonas Noxia and Veillonella parvula were greater in the AIA group whereas Actinomyces viscosus and Neisseira mucosa were in large proportion in Y4 group. In conclusion, AIA is associated with changes in the composition of the oral microbiota, which might account for the alveolar bone loss observed in AIA mice.

Comparative analysis of blood and saliva expression profiles in chronic and refractory periodontitis patients

Background

This study aimed to identify characteristic representative genes through a comparative analysis of gene expression profiles in the blood and saliva of chronic periodontitis (CP) and refractory periodontitis (RP) patients to provide new treatment strategies that may be helpful in the treatment of different forms of periodontitis.

Methods

GSE43525 was downloaded from Gene Expression Omnibus. In the dataset, thirteen samples were from blood including 4 controls, 4 CP and 5 RP samples, and ten samples were from saliva including 3 controls, 4 CP and 3 RP samples. After comparing the CP and RP samples, differentially expressed genes (DEGs) between these two types of periodontitis in the blood and saliva samples were identified by an LIMMA package. Then, functional and pathway enrichment analyses were performed by DAVID and KOBAS, respectively. The significantly associated miRNAs in CP and RP were searched by WebGestalt.

Results

In total, 213 DEGs in CP and 45 DEGs in RP were identified. Functional enrichment showed that the DEGs of CP were mainly enriched in ribosome and regulation of apoptosis-related pathways in blood as well as saliva, while the DEGs of RP were significantly enriched in immune responses and response to organic substance-related pathways. Several miRNAs, such as miR-381 and miR-494, were identified as being closely associated with CP. In addition, CD24, EST1, MTSS1, ING3, CCND2 and SYNE2 might be potential targets for diagnosis and treatment of CP.

Conclusion

The identified DEGs and miRNAs might be potential targets for the treatment of chronic and refractory periodontitis.

Mitochondrial dysfunction in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) represents a group of idiopathic disorders characterized by chronic or recurring inflammation of the gastrointestinal tract. While the exact etiology of disease is unknown, IBD is recognized to be a complex, multifactorial disease that results from an intricate interplay of genetic predisposition, an altered immune response, changes in the intestinal microbiota, and environmental factors. Together, these contribute to a destruction of the intestinal epithelial barrier, increased gut permeability, and an influx of immune cells. Given that most cellular functions as well as maintenance of the epithelial barrier is energy-dependent, it is logical to assume that mitochondrial dysfunction may play a key role in both the onset and recurrence of disease. Indeed several studies have demonstrated evidence of mitochondrial stress and alterations in mitochondrial function within the intestinal epithelium of patients with IBD and mice undergoing experimental colitis. Although the hallmarks of mitochondrial dysfunction, including oxidative stress and impaired ATP production are known to be evident in the intestines of patients with IBD, it is as yet unclear whether these processes occur as a cause of consequence of disease. We provide a current review of mitochondrial function in the setting of intestinal inflammation during IBD.

Restoring host-microbe homeostasis via selective chemoattraction of Tregs

The disruption of host-microbe homeostasis at the site of periodontal disease is considered a key factor for disease initiation and progress. While the downstream mechanisms responsible for the tissue damage per se are relatively well-known (involving various patterns of immune response operating toward periodontal tissue destruction), we are only beginning to understand the complexity of host-microbe interactions in the periodontal environment. Unfortunately, most of the research has been focused on the disruption of host-microbe homeostasis instead of focusing on the factors responsible for maintaining homeostasis. In this context, regulatory T-cells (Tregs) comprise a CD4+FOXp3 +T-cell subset with a unique ability to regulate other leukocyte functions to avoid excessive immune activation and its pathological consequences. Tregs act as critical determinants of host-microbe homeostasis, as well as determinants of a balanced host response after the disruption of host-microbe homeostasis by pathogens. In periodontitis, Tregs play a protective role, with their natural recruitment being responsible for conversion of active into inactive lesions. With controlled-release technology, it is now possible to achieve a selective chemoattraction of Tregs to periodontal tissues, attenuating experimental periodontitis evolution due to the local control of inflammatory immune response and the generation of a pro-reparative environment.

Genetic dysbiosis: the role of microbial insults in chronic inflammatory diseases

Thousands of bacterial phylotypes colonise the human body and the host response to this bacterial challenge greatly influences our state of health or disease. The concept of infectogenomics highlights the importance of host genetic factors in determining the composition of human microbial biofilms and the response to this microbial challenge. We hereby introduce the term ‘genetic dysbiosis’ to highlight the role of human genetic variants affecting microbial recognition and host response in creating an environment conducive to changes in the normal microbiota. Such changes can, in turn, predispose to, and influence, diseases such as: cancer, inflammatory bowel disease, rheumatoid arthritis, psoriasis, bacterial vaginosis and periodontitis. This review presents the state of the evidence on host genetic factors affecting dysbiosis and microbial misrecognition (i.e. an aberrant response to the normal microbiota) and highlights the need for further research in this area.

The association between inflammatory bowel disease and periodontitis among Jordanians: a case-control study

BACKGROUND AND OBJECTIVE

Inflammatory bowel disease (IBD) is hypothesized to involve immuno-inflammatory alterations, and the condition has been related to increased susceptibility to oral challenges. The objective of the study was to determine the association between the prevalence, severity and extent of periodontitis and both ulcerative colitis (UC) and Crohn's disease (CD).

MATERIAL AND METHODS

A case-control study was conducted among patients who attended outpatient clinics at King Hussein Medical City in Jordan during the study period. All participants completed the questionnaire and underwent thorough oral and periodontal examinations. Periodontitis was defined as presence of four or more teeth with one or more sites with probing pocket depth ≥ 4 mm and clinical attachment level ≥ 3 mm. The general linear model multivariate procedure and multivariate binary logistic regression were used to analyse the data.

RESULTS

This case-control study included 260 Jordanian adults (101 with UC, 59 with CD and 100 with no IBD) with a mean (SD) age of 39.4 (0.7) years. The prevalence of periodontitis was much higher among patients with CD and those with UC compared with subjects having no IBD in the age groups < 36 and 36-45 years old only. After adjusting for age and number of missing teeth, patients with CD (odds ratio 4.9, 95% confidence interval 1.8-13.2) and patients with UC (odds ratio 7.00, 95% confidence interval 2.8-17.5) had significantly higher odds of periodontitis than subjects with no IBD. In multivariate analysis, the severity of periodontitis was significantly higher among patients with CD and patients with UC when compared with subjects having no IBD. Ulcerative colitis patients but not CD patients had significantly higher prevalence of deep ulcers in oral soft tissues than the non-IBD group (p = 0.004).

CONCLUSION

Patients with IBD have higher prevalence, severity and extent of periodontitis compared with those having no IBD.

Periodontal infections: understanding the complexity--consensus of the Seventh European Workshop on Periodontology

INTRODUCTION

Periodontal diseases are the pathological manifestation of the host response against the bacterial challenge from the dental biofilm at the tooth/gingival interface. The remit of this working group was to update the existing knowledge on the infectious nature of periodontal diseases.

MATERIAL AND METHODS

The literature was systematically searched and critically reviewed. Four manuscripts were produced in specific topics identified as key areas to understand the importance of the microorganisms in the etio-pathogenesis of periodontal diseases.

RESULTS/CONCLUSIONS

The results and conclusions of the review process are presented in the following papers, together with the group consensus statements aiming to answer the following questions: (1) Has the use of molecular methods for the characterization of the human oral microbiome changed our understanding of the role of bacteria in the pathogenesis of periodontal disease process? (2) Are the periodontal microbial complexes associated with specific cell and tissue responses? (3) How is the development of dental biofilms influenced by the host? (4) What can we learn about biofilm/host interactions from the study of inflammatory bowel disease? This consensus report provides answers to these questions with the most updated information on periodontal microbiology.