The Impact of Periodontitis on Inflammatory Bowel Disease Activity

Causal Association Analysis of Periodontitis and Inflammatory Bowel Disease: A Bidirectional Mendelian Randomization Study

BACKGROUND

Periodontitis has been reported to be associated with inflammatory bowel disease (IBD), including ulcerative colitis (UC), and Crohn's disease (CD). However, the causality of these 2 diseases remains unclear. We conducted bidirectional Mendelian randomization (MR) to investigate the causal relationship between periodontitis and IBD.

METHODS

We obtained the genome-wide association study (GWAS) summary data of European populations from FinnGen database (for IBD) and a published article (for periodontitis), from which independent single nucleotide polymorphisms were selected as instrumental variables. Inverse variance-weighted (IVW), MR-Egger, and weighted median (WM) methods were utilized for MR analysis. Heterogeneity or pleiotropy was detected through Cochran's Q test and MR-Egger intercept, respectively. Outlier was identified with MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) and leave-one-out analysis. All statistical analyses were performed with R 4.2.1 and the packages of TwoSampleMR version 0.5.6.

RESULTS

Genetic prediction showed that periodontitis was the risk factor of UC (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.01-1.26; P = .027), rather than of CD (OR, 0.92; 95% CI, 0.74-1.15; P = .456) and IBD (OR, 0.96; 95% CI, 0.81-1.13; P = .619). To the contrary, CD, not UC or IBD, resulted in exacerbating periodontitis in terms of the results of the IVW (OR, 1.09; 95% CI, 1.01-1.17; P = .021) and WM (OR, 1.10; 95% CI, 1.01-1.20; P = .030) methods. Heterogeneity or pleiotropy was acceptable.

CONCLUSIONS

Our results indicated that CD was the risk factor for periodontitis; conversely, periodontitis was responsible for the exacerbation of UC, enhancing the existence of mouth-gut axis. Patients with UC should pay more attention to periodontal health, while patients with periodontitis should actively pay close heed to intestinal health.

The oral-gut microbiome axis in inflammatory bowel disease: from inside to insight

Inflammatory bowel disease (IBD) is an idiopathic and persistent inflammatory illness of the bowels, leading to a substantial burden on both society and patients due to its high incidence and recurrence. The pathogenesis of IBD is multifaceted, partly attributed to the imbalance of immune responses toward the gut microbiota. There is a correlation between the severity of the disease and the imbalance in the oral microbiota, which has been discovered in recent research highlighting the role of oral microbes in the development of IBD. In addition, various oral conditions, such as angular cheilitis and periodontitis, are common extraintestinal manifestations (EIMs) of IBD and are associated with the severity of colonic inflammation. However, it is still unclear exactly how the oral microbiota contributes to the pathogenesis of IBD. This review sheds light on the probable causal involvement of oral microbiota in intestinal inflammation by providing an overview of the evidence, developments, and future directions regarding the relationship between oral microbiota and IBD. Changes in the oral microbiota can serve as markers for IBD, aiding in early diagnosis and predicting disease progression. Promising advances in probiotic-mediated oral microbiome modification and antibiotic-targeted eradication of specific oral pathogens hold potential to prevent IBD recurrence.

The oral-gut microbiome axis in health and disease

The human body hosts trillions of microorganisms throughout many diverse habitats with different physico-chemical characteristics. Among them, the oral cavity and the gut harbour some of the most dense and diverse microbial communities. Although these two sites are physiologically distinct, they are directly connected and can influence each other in several ways. For example, oral microorganisms can reach and colonize the gastrointestinal tract, particularly in the context of gut dysbiosis. However, the mechanisms of colonization and the role that the oral microbiome plays in causing or exacerbating diseases in other organs have not yet been fully elucidated. Here, we describe recent advances in our understanding of how the oral and intestinal microbiota interplay in relation to their impact on human health and disease.

Gut microbial dysbiosis and inflammation: Impact on periodontal health

Periodontitis is widely acknowledged as the most prevalent type of oral inflammation, arising from the dynamic interplay between oral pathogens and the host's immune responses. It is also recognized as a contributing factor to various systemic diseases. Dysbiosis of the oral microbiota can significantly alter the composition and diversity of the gut microbiota. Researchers have delved into the links between periodontitis and systemic diseases through the "oral-gut" axis. However, whether the associations between periodontitis and the gut microbiota are simply correlative or driven by causative mechanistic interactions remains uncertain. This review investigates how dysbiosis of the gut microbiota impacts periodontitis, drawing on existing preclinical and clinical data. This study highlights potential mechanisms of this interaction, including alterations in subgingival microbiota, oral mucosal barrier function, neutrophil activity, and abnormal T-cell recycling, and offers new perspectives for managing periodontitis, especially in cases linked to systemic diseases.

Bidirectional associations between periodontitis and inflammatory bowel disease: A systematic review of longitudinal studies with meta-analysis and trial sequential analysis

The bidirectional associations between periodontitis and inflammatory bowel disease (IBD) with temporal directionality remain inconclusive. This study aims to evaluate the bidirectional associations between periodontitis and IBD through a systematic review and meta-analysis. Five databases (PubMed, Embase, Web of Science, Scopus and Cochrane Library) were systematically searched from inception to 27 February 2024. Two independent reviewers performed a review of the retrieved studies. Longitudinal studies, including cohort and nested case-control studies, were considered eligible for the study design. The pooled risk ratio (RR) and hazard ratio (HR) derived from the meta-analysis were used to assess whether periodontitis (or IBD) was a risk factor for IBD (or periodontitis). Trial sequential analysis (TSA) was performed to evaluate the reliability of the results. Four studies (n = 10 270 912) on the risk of IBD in patients with periodontitis and two (n = 33 420) on the risk of periodontitis in patients with IBD were included. The result suggested that periodontitis did not increase the risk of IBD (pooled RR = 1.04, 95% confidence interval [CI]: 0.99-1.09; p = .164; I-squared statistic [I2] = 27%). For subtypes of IBD, periodontitis was associated with the occurrence of ulcerative colitis (UC) (pooled RR = 1.12, 95% CI: 1.04-1.21; p = .003; I2 = 38%), but not with Crohn's disease (CD) (pooled RR = 0.98, 95% CI: 0.92-1.04; p = .475; I2 = 0%). Specifically, the risk of UC was higher among men (pooled HR = 1.11, 95% CI: 1.01-1.22; p = .025; I2 = 0%) and smokers (pooled HR = 1.23, 95% CI: 1.07-1.42; p = .004; I2 = 0%) with periodontitis than their counterparts without periodontitis. Patients with IBD may have a higher risk of developing periodontitis (pooled HR = 1.37, 95% CI: 1.26-1.49; p < .001; I2 = 18%); however, whether IBD subtypes increased the occurrence of periodontitis remained uncertain. The TSA results confirmed the reliability of the primary findings. Based on limited longitudinal evidence, patients with periodontitis do not exhibit an increased risk of developing IBD overall, but they are at increased risk of UC (not CD). On the contrary, patients with IBD have a higher risk of developing periodontitis over time. More high-quality longitudinal studies are needed to determine the effect of specific subtypes of IBD on periodontitis.

Periodontitis and Inflammatory Bowel Disease: A Review

The complex relationship between periodontitis (PD) and inflammatory bowel disease (IBD) has received significant attention in recent studies. Emerging evidence suggests that the oral-gut axis plays a pivotal role in their interaction. This review provides a comprehensive, up-to-date analysis of original research from 2003 to 2023 on the PD-IBD relationship and aims to be a reference for future research. Relevant literature was sourced from the PubMed database using the keywords "periodontitis" and "inflammatory bowel disease". Additionally, a manual library search and a review of bibliographies were conducted. Of the 297 articles retrieved, 27 studies were chosen for final review. Out of these, 21 studies (78%), including both in vitro and in vivo research, indicated an association between PD and IBD. While many studies confirm a bi-directional relationship, others refute it or deem it clinically irrelevant. There is a need for more accessible studies, such as randomized trials, which also investigate the factors that could influence the outcomes to clarify the exact molecular mechanisms and clinical implications of this complex relationship.

Patients with inflammatory bowel disease have more oral health problems and higher costs of professional dental care than healthy controls: The Periodontitis Prevalence in ulcerative Colitis and Crohn disease (PPCC) case-control study

BACKGROUND

To describe the frequency and impact of oral lesions and professional dental care costs in patients with inflammatory bowel disease (IBD) (i.e., Crohn disease [CD] or ulcerative colitis [UC]) compared to matched controls).

METHODS

IBD patients and matched controls were surveyed on general anamnestic information, eating and drinking habits, and oral health- and dental care-related questions; IBD patients were additionally surveyed on oral lesions. Problems related to oral lesions and the amount of money spent for professional dental care in the past 12 months were defined as primary outcome parameters.

RESULTS

Answers from 1108 IBD patients and 3429 controls were analyzed. About 30% of the patients indicated having had problems with oral lesions, with CD patients having 46% higher odds and having them more often in a generalized form compared to UC patients. Further, self-reported severe periodontitis increased the odds of having oral lesions by almost 2.3-times. However, only about 12.5% of IBD patients were informed by their physician about oral lesions and about 10% indicated receiving treatment for them. Compared to controls, IBD patients required more often dental treatment and spent more money; specifically, UC and CD patients had 27 and 89% higher odds, respectively, for having spent ≥3000 DKK (ca. 440 USD) at the dentist compared to controls.

CONCLUSIONS

IBD patients have more often oral health problems and higher expenses for professional dental care compared to matched controls. This included problems with IBD-related oral lesions, but these are rarely addressed by the medical or dental team.

Editorial: Unravelling the relationship between periodontal disease and inflammatory bowel disease

This article is linked to Williams et al paper. To view this article, visit https://doi.org/10.1111/apt.17732

Identification of disease-associate variants of aggressive periodontitis using genome-wide association studies

Aggressive periodontitis (AgP), Stage III or IV and Grade C according to the new periodontitis classification, is characterized by the rapid destruction of periodontal tissues in the systemically healthy population and often causes premature tooth loss. The presence of familial aggregation suggests the involvement of genetic factors in the pathogenesis. However, the genes associated with the onset and progression of the disease and details of its pathogenesis have not yet been fully identified. In recent years, the genome-wide approach (GWAS), a comprehensive genome analysis method using bioinformatics, has been used to search for disease-related genes, and the results have been applied in genomic medicine for various diseases, such as cancer. In this review, we discuss GWAS in the context of AgP. First, we introduce the relationship between single-nucleotide polymorphisms (SNPs) and susceptibility to diseases and how GWAS is useful for searching disease-related SNPs. Furthermore, we summarize the recent findings of disease-related genes using GWAS on AgP inside and outside Japan and a possible mechanism of the pathogenesis of AgP based on available literature and our research findings. These findings will lead to advancements in the prevention, prognosis, and treatment of AgP.

Current insights on the roles of gut microbiota in inflammatory bowel disease-associated extra-intestinal manifestations: pathophysiology and therapeutic targets

Inflammatory bowel disease (IBD) is a chronic, recurrent inflammatory disease of the gastrointestinal tract. In addition to digestive symptoms, patients with IBD may also develop extra-intestinal manifestations (EIMs), the etiology of which remains undefined. The gut microbiota has been reported to exert a critical role in the pathogenesis of IBD, with a similar pattern of gut dysbiosis observed between patients with IBD and those with EIMs. Therefore, it is hypothesized that the gut microbiota is also involved in the pathogenesis of EIMs. The potential mechanisms are presented in this review, including: 1) impaired gut barrier: dysbiosis induces pore formation in the intestinal epithelium, and activates pattern recognition receptors to promote local inflammation; 2) microbial translocation: intestinal pathogens, antigens, and toxins translocate via the impaired gut barrier into extra-intestinal sites; 3) molecular mimicry: certain microbial antigens share similar epitopes with self-antigens, inducing inflammatory responses targeting extra-intestinal tissues; 4) microbiota-related metabolites: dysbiosis results in the dysregulation of microbiota-related metabolites, which could modulate the differentiation of lymphocytes and cytokine production; 5) immunocytes and cytokines: immunocytes are over-activated and pro-inflammatory cytokines are excessively released. Additionally, we summarize microbiota-related therapies, including probiotics, prebiotics, postbiotics, antibiotics, and fecal microbiota transplantation, to promote better clinical management of IBD-associated EIMs.

Health-related quality of life aspects of the 'Periodontitis prevalence in ulcerative colitis and Crohn's disease' (PPCC) cohort

AIM

To assess whether oral health problems affect disease-specific quality of life (QoL) of inflammatory bowel disease (IBD) patients, and vice versa, whether IBD affects oral-health-related QoL.

MATERIALS AND METHODS

Individuals reporting IBD and matched controls were surveyed on general anamnestic information, oral-health-related questions and the Oral Health Impact Profile (OHIP)-5. IBD patients were additionally surveyed on years since diagnosis, disease activity and severity as well as health-related QoL (Short Inflammatory Bowel Disease Questionnaire, sIBDQ). OHIP-5 and sIBDQ were defined as primary outcome parameters, and several predictors and confounders were used in adjusted univariable and multivariable regression analyses.

RESULTS

Answers from 1108 IBD patients and 3429 controls were analysed. Compared with controls, IBD patients reported significantly more frequently an oral impact on daily life and worse oral-health-related QoL, with Crohn's disease (CD) patients being more severely affected than ulcerative colitis (UC) patients. The diagnosis of UC and CD, having <20 teeth, severe periodontitis and stressful daily-life experience were associated with a higher prevalence of poor oral-health-related QoL. Among IBD patients, an impaired IBD-specific, health-related QoL was significantly associated with the diagnosis of CD and depression, IBD activity and severity, having <20 teeth, presence of oral lesions and stressful daily-life experience, while a longer time since diagnosis was significantly associated with an improved IBD-specific, health-related QoL.

CONCLUSIONS

The results of the present study indicate, for the first time, that oral health problems are associated with an impairment of IBD-specific health-related QoL, and vice versa, IBD is associated with an impaired oral health-related QoL. This emphasizes the potential advantages of including dental professionals in the multi-disciplinary treatment teams of IBD patients.

Sol-Gel Technologies to Obtain Advanced Bioceramics for Dental Therapeutics

The aim of this work is to review the application of bioceramic materials in the context of current regenerative dentistry therapies, focusing on the latest advances in the synthesis of advanced materials using the sol-gel methodology. Chemical synthesis, processing and therapeutic possibilities are discussed in a structured way, according to the three main types of ceramic materials used in regenerative dentistry: bioactive glasses and glass ceramics, calcium phosphates and calcium silicates. The morphology and chemical composition of these bioceramics play a crucial role in their biological properties and effectiveness in dental therapeutics. The goal is to understand their chemical, surface, mechanical and biological properties better and develop strategies to control their pore structure, shape, size and compositions. Over the past decades, bioceramic materials have provided excellent results in a wide variety of clinical applications related to hard tissue repair and regeneration. Characteristics, such as their similarity to the chemical composition of the mineral phase of bones and teeth, as well as the possibilities offered by the advances in nanotechnology, are driving the development of new biomimetic materials that are required in regenerative dentistry. The sol-gel technique is a method for producing synthetic bioceramics with high purity and homogeneity at the molecular scale and to control the surfaces, interfaces and porosity at the nanometric scale. The intrinsic nanoporosity of materials produced by the sol-gel technique correlates with the high specific surface area, reactivity and bioactivity of advanced bioceramics.

Identification and Validation of Signature Genes and Potential Therapy Targets of Inflammatory Bowel Disease and Periodontitis

Background

Inflammatory bowel disease (IBD) and periodontitis (PD) are correlated, although the pathogenic mechanism behind their correlation has not been clarified. This study aims to explore the common signature genes and potential therapeutic targets of IBD and PD using transcriptomic analysis.

Methods

The GEO database was used to download datasets of IBD and PD, and differential expression analysis was used to identify DEGs. We then conducted GO and KEGG enrichment analyses of the shared genes. Next, we applied 4 machine learning (ML) algorithms (GLM, RF, GBM, and SVM) to select the best prediction model for diagnosing the disease and obtained the hub genes of IBD and PD. The diagnostic value of the signature genes was verified by a validation set and qRT‒PCR experiments. Subsequently, immune cell infiltration in IBD samples and PD samples was analyzed by ssGSEA. Finally, we investigated and validated the response of hub genes to infliximab therapy.

Results

We identified 43 upregulated genes as shared genes by intersecting the DEGs of IBD and PD. Functional enrichment analysis suggested that the shared genes were closely associated with immunity and inflammation. The ML algorithm and qRT‒PCR results indicated that IGKC and COL4A1 were the hub genes with the most diagnostic value for IBD and PD. Subsequently, through immune infiltration analysis, CD4 T cells, NK cells and neutrophils were identified to play crucial roles in the pathogenesis of IBD and PD. Finally, through in vivo and in vitro experiments, we found that IGKC and COL4A1 were significantly downregulated during the treatment of patients with IBD using infliximab.

Conclusion

We investigated the potential association between IBD and PD using transcriptomic analysis. The IGKC and COL4A1 genes were identified as characteristic genes and novel intervention targets for these two diseases. Infliximab may be used to treat or prevent IBD and PD.

Association between inflammatory bowel disease and periodontitis: A bidirectional two-sample Mendelian randomization study

AIM

This Mendelian randomization (MR) study was performed to explore the potential bidirectional causal association between inflammatory bowel disease (IBD) and periodontitis.

MATERIALS AND METHODS

We used genetic instruments from the genome-wide association study summary statistics of European descent for IBD (12,882 cases and 21,770 controls) to investigate the association with periodontitis (3046 cases and 195,395 controls) and vice versa. The radial inverse-variance weighted method was carried out to obtain the primary causal estimates, and the robustness of the results was assessed by a series of sensitivity analyses. Due to multiple testing, associations with p values <.008 were considered as statistically significant, and p values ≥.008 and <.05 were considered as suggestively significant.

RESULTS

In the primary causal estimates, IBD as a whole was associated with an increased risk of periodontitis (odds ratio [OR], 1.060; 95% confidence interval [CI], 1.017; 1.105; p = .006). Subtype analyses showed that ulcerative colitis (UC) was associated with periodontitis (OR, 1.074; 95% CI 1.029; 1.122; p = .001), while Crohn's disease (CD) was not. Regarding the reverse direction, periodontitis showed a suggestive association with IBD as a whole (OR, 1.065; 95% CI 1.013; 1.119; p = .014). Subtype analyses revealed that periodontitis was associated with CD (OR, 1.100; 95% CI 1.038; 1.167; p = .001) but not UC. The final models after outlier removal showed no obvious pleiotropy, indicating that our primary analysis results were reliable.

CONCLUSIONS

The present MR study provides moderate evidence on the bidirectional causal relationship between IBD and periodontitis. The bidirectional increased risk found in our study was marginal and, possibly, of limited clinical relevance. More studies are needed to support the findings of our current study.

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.

Influence of Genetics, Immunity and the Microbiome on the Prognosis of Inflammatory Bowel Disease (IBD Prognosis Study): the protocol for a Copenhagen IBD Inception Cohort Study

INTRODUCTION

Inflammatory bowel diseases (IBD), encompassing Crohn's disease and ulcerative colitis, are chronic, inflammatory diseases of the gastrointestinal tract. We have initiated a Danish population-based inception cohort study aiming to investigate the underlying mechanisms for the heterogeneous course of IBD, including need for, and response to, treatment.

METHODS AND ANALYSIS

IBD Prognosis Study is a prospective, population-based inception cohort study of unselected, newly diagnosed adult, adolescent and paediatric patients with IBD within the uptake area of Hvidovre University Hospital and Herlev University Hospital, Denmark, which covers approximately 1 050 000 inhabitants (~20% of the Danish population). The diagnosis of IBD will be according to the Porto diagnostic criteria in paediatric and adolescent patients or the Copenhagen diagnostic criteria in adult patients. All patients will be followed prospectively with regular clinical examinations including ileocolonoscopies, MRI of the small intestine, validated patient-reported measures and objective examinations with intestinal ultrasound. In addition, intestinal biopsies from ileocolonoscopies, stool, rectal swabs, saliva samples, swabs of the oral cavity and blood samples will be collected systematically for the analysis of biomarkers, microbiome and genetic profiles. Environmental factors and quality of life will be assessed using questionnaires and, when available, automatic registration of purchase data. The occurrence and course of extraintestinal manifestations will be evaluated by rheumatologists, dermatologists and dentists, and assessed by MR cholangiopancreatography, MR of the spine and sacroiliac joints, ultrasonography of peripheral joints and entheses, clinical oral examination, as well as panoramic radiograph of the jaws. Fibroscans and dual-energy X-ray absorptiometry scans will be performed to monitor occurrence and course of chronic liver diseases, osteopenia and osteoporosis.

ETHICS AND DISSEMINATION

This study has been approved by Ethics Committee of the Capital Region of Denmark (approval number: H-20065831). Study results will be disseminated through publication in international scientific journals and presentation at (inter)national conferences.