Activity of inflammatory bowel disease influences the expression of cytokines in gingival tissue

Lactobacillus paracasei Jlus66 relieves DSS-induced ulcerative colitis in a murine model by maintaining intestinal barrier integrity, inhibiting inflammation, and improving intestinal microbiota structure

PURPOSE

Ulcerative colitis (UC) is a serious health problem with increasing morbidity and prevalence worldwide. The pathogenesis of UC is complex, currently believed to be influenced by genetic factors, dysregulation of the host immune system, imbalance in the intestinal microbiota, and environmental factors. Currently, UC is typically managed using aminosalicylates, immunosuppressants, and biologics as adjunctive therapies, with the risk of relapse and development of drug resistance upon discontinuation. Therefore, further research into the pathogenesis of UC and exploration of potential treatment strategies are necessary to improve the quality of life for affected patients. According to previous studies, Lactobacillus paracasei Jlus66 (Jlus66) reduced inflammation and may help prevent or treat UC.

METHODS

We used dextran sulfate sodium (DSS) to induce a mouse model of UC to assess the effect of Jlus66 on the progression of colitis. During the experiment, we monitored mouse body weight, food and water consumption, as well as rectal bleeding. Hematoxylin-eosin staining was performed to assess intestinal pathological damage. Protein imprinting and immunohistochemical methods were used to evaluate the protein levels of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and tight junction (TJ) proteins in intestinal tissues. Fecal microbiota was analyzed based on partial 16S rRNA gene sequencing.

RESULTS

Jlus66 supplementation reduced the degree of colon tissue damage, such as colon shortening, fecal occult blood, colon epithelial damage, and weight loss. Supplementation with Jlus66 reduced DSS-induced upregulation of cytokine levels such as TNF-α, IL-1β, and IL-6 (p < 0.05). The NF-κB pathway and MAPK pathway were inhibited, and the expression of TJ proteins (ZO-1, Occludin, and Claudin-3) was upregulated. 16S rRNA sequencing of mouse cecal contents showed that Jlus66 effectively regulated the structure of the intestinal biota.

CONCLUSION

In conclusion, these data indicate that Jlus66 can alter the intestinal biota and slow the progression of UC, providing new insights into potential therapeutic strategies for UC.

Unravelling the Oral-Gut Axis: Interconnection Between Periodontitis and Inflammatory Bowel Disease, Current Challenges, and Future Perspective

As the opposite ends of the orodigestive tract, the oral cavity and the intestine share anatomical, microbial, and immunological ties that have bidirectional health implications. A growing body of evidence suggests an interconnection between oral pathologies and inflammatory bowel disease [IBD], implying a shift from the traditional concept of independent diseases to a complex, reciprocal cycle. This review outlines the evidence supporting an 'oral-gut' axis, marked by a higher prevalence of periodontitis and other oral conditions in IBD patients and vice versa. We present an in-depth examination of the interconnection between oral pathologies and IBD, highlighting the shared microbiological and immunological pathways, and proposing a 'multi-hit' hypothesis in the pathogenesis of periodontitis-mediated intestinal inflammation. Furthermore, the review underscores the critical need for a collaborative approach between dentists and gastroenterologists to provide holistic oral-systemic healthcare.

Salivary Th17 cytokine, human β-defensin 1-3, and salivary scavenger and agglutinin levels in Crohn's disease

OBJECTIVES

Crohn's disease patients, who are prone to develop periodontal diseases, may carry genetic defects in their Th17 cytokine, human beta-defensin (hBD) 1-3, and salivary and scavenger agglutinin (SALSA) expressions. Biochemical composition of saliva reflects the oral consequences of systemic immune response modifications. Our aim was to evaluate the salivary Th17 cytokine, epithelial hBD 1-3, and SALSA levels in relation to Crohn's disease.

MATERIALS AND METHODS

This cross-sectional study included 42 Crohn's disease patients and 34 systemically healthy controls. Periodontal and dental indexes were measured, and stimulated saliva samples were collected. Salivary Th17 cytokine levels were analyzed by multiplex technique, and hBD 1-3 and SALSA levels by enzyme-linked immunosorbent assay.

RESULTS

There were 19 gingivitis and 11 initial periodontitis patients in the Crohn's disease group, and 15 gingivitis and 4 initial periodontitis in the control group. In comparison to controls, higher salivary Th17 cytokine levels were observed in Crohn's disease patients. No statistical difference was observed between Crohn's disease and control groups in terms of their salivary hBD 1-3 and SALSA levels. Based on the regression analysis, there is no independent association between Crohn's disease and salivary Th17 cytokine levels.

CONCLUSIONS

Crohn's disease does not relate to salivary antimicrobial hBD 1-3 or SALSA levels. While Crohn's disease patients have higher salivary Th17 cytokine levels in comparison to systemically healthy controls, an independent association between Crohn's disease and Th17 cytokine profile is still missing.

CLINICAL RELEVANCE

Diminished Th17 cytokine response in Crohn's disease, which might be related to genetic susceptibility, can be also visualized in saliva.

Association of Periodontitis and Atopic Dermatitis with the Levels of IL-13, IL-31, and TSLP in the Gingival Crevicular Fluid

Emerging epidemiological evidence links atopic dermatitis (AD) and periodontitis, although the mechanisms remain unclear. Th2-derived cytokines are key in the development of both diseases, and different gingival crevicular fluid (GCF) profiles among healthy and diseased subjects have been previously reported. This case-control study examined the GCF levels of interleukins (IL)-13, IL-31, and thymic stromal lymphopoietin (TSLP) in 29 subjects with moderate-to-severe AD and 33 controls. All subjects underwent comprehensive clinical and oral evaluations, followed by GCF collection. GCF levels of IL-13, IL-31, and TSLP were assessed using a multiplex-bead immunoassay. Demographic and periodontal parameters were similar among groups (p > 0.05). The GCF levels of IL-31 and TSLP were higher in AD subjects compared to controls (p < 0.05), whereas no significant differences in the GCF levels of IL-13 were noticed (p = 0.377). Moderate-to-severe AD was positively associated with the GCF levels of IL-31 and TSLP, whereas severe periodontitis was negatively associated with IL-31 (p < 0.05). The GCF levels of IL-13 showed no significant associations with either condition (p = 0.689). There was no significant interaction between AD and periodontitis for IL-31 (p < 0.869). These results suggest that AD and periodontitis independently influence the GCF levels of IL-31 in opposing ways, whereas AD alone influences the levels of TSLP.

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.

Exploration of the shared gene signatures and molecular mechanisms between periodontitis and inflammatory bowel disease: evidence from transcriptome data

Background

Periodontitis disease (PD) is associated with a systemic disorder of inflammatory bowel disease (IBD). The immune response is the common feature of the two conditions, but the more precise mechanisms remain unclear.

Methods

Differential expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA) were performed on PD and Crohn's disease (CD) data sets to identify crosstalk genes linking the two diseases. The proportions of infiltrating immune cells were calculated by using Single-sample Gene Set Enrichment Analysis. In addition, a data set of isolated neutrophils from the circulation was performed via WGCNA to obtain PD-related key modules. Then, single-cell gene set enrichment scores were computed for the key module and grouped neutrophils according to score order in the IBD scRNA-seq data set. Single-cell gene enrichment analysis was used to further explore the biological process of the neutrophils.

Results

A total of 13 crosstalk genes (IL1B, CSF3, CXCL1, CXCL6, FPR1, FCGR3B, SELE, MMP7, PROK2, SRGN, FCN1, TDO2 and CYP24A1) were identified via DEGs analysis and WGCNA by combining PD and CD data sets. The enrichment analysis showed that these genes were involved in interleukin-10 signaling and inflammatory response. The immune infiltration analysis showed a significant difference in the proportion of neutrophils in PD and CD compared with healthy patients. Neutrophils were scored based on the expression of a periodontitis-related gene set in the scRNA-seq data set of IBD. The enrichment analysis demonstrated that inflammatory response, TNFα signaling via NF-κB and interferon-gamma response were upregulated in the high-score group, which expressed more pro-inflammatory cytokines and chemokines compared with the low-score group.

Conclusions

This study reveals a previously unrecognized mechanism linking periodontitis and IBD through crosstalk genes and neutrophils, which provides a theoretical framework for future research.

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.

Colitis induced by dextran sulphate sodium causes histopathological and immunological changes in the periodontal tissues of Wistar rats

OBJECTIVE

This study investigated the impact of colitis induced by dextran sulphate sodium (DSS)-induced colitis (DIC) on histopathological and immunological outcomes in the periodontal tissues of Wistar rats.

BACKGROUND

Inflammatory bowel diseases (IBD) and periodontitis have been reported to present a bidirectional relationship. However, the inflammatory pathway that connects both diseases needs further investigation.

MATERIAL AND METHODS

Twenty-five male Wistar rats were allocated in four groups: unilateral ligature-induced periodontitis for 14 days: LIP (n = 7); dextran sulphate sodium-induced colitis only: DIC (n = 6); DIC + LIP (n = 6) and controls (n = 6). Digital images were obtained from the histological sections. In order to assess the attachment loss (AL), the linear distance between the cementoenamel junction (CEJ) and the alveolar bone crest was measured on the mesial root using histological photomicrography's ImageJ software. Immunological analyses of gingival tissues and plasma were performed by Bio-Plex Th1/Th2 Assay.

RESULTS

The DIC group showed inflammatory cells extending to the periodontal connective tissues, which contained significantly elevated expressions of IL-1α, IL-1β, IL-2, IL-6, IL-12, IL-13, GM-CSF, IFN-γ and TNF-α compared to controls. There was no significant difference in bone loss between controls and DIC. There were no significant histopathological differences between DIC + LIP and LIP. However, DIC + LIP presented a significantly lower IL-2 and IL-5 than the LIP group. There was no bone loss difference between LIP+DIC and LIP groups. DIC + LIP group presented significantly higher levels of GM-CSF in plasma.

CONCLUSION

DSS-induced colitis was associated with an overexpression of Th1/Th2- related cytokines in the gingival tissue.

Untangling the oral-gut axis in the pathogenesis of intestinal inflammation

An increasing body of literature reveals that host-microbe networks are well-coordinated and impact human health and disease. Recently, it has become evident that an abnormal alteration in bacterial configuration in the oral cavity, namely oral dysbiosis, caused by periodontal inflammation, is associated with various distant inflammatory diseases, including inflammatory bowel disease. However, the extent to which the relationships between oral and distant disorders are merely an association or are causally triggered by oral microorganisms remains debated. In this mini-review, we highlight mechanisms in inter-related organ system diseases , particularly the one between oral and gut inflammation. Further, we discuss clinical perspectives and propose a novel concept of a multi-hit hypothesis in the pathogenesis of gut inflammation, based on our updated knowledge of shared microbiological and immunological pathways between the oral and gut mucosae.

An Evaluation of Periodontal Status and Cytokine Levels in Saliva and Gingival Crevicular Fluid of Patients with Inflammatory Bowel Diseases

AIMS

Periodontal diseases and inflammatory bowel diseases (IBD, ulcerative colitis [UC] and Crohn's disease [CD]) have been reported to present with increased salivary and gingival crevicular fluid (GCF) concentrations of cytokines. The aim of this study was to evaluate the salivary and GCF levels of TNF-α, IL-1β, IL-10, and IL-17A and their associations with the periodontal statuses of UC, CD and non-IBD patients, and to analyze the interrelationships among these cytokines, IBD conditions, and periodontal diseases.

MATERIALS AND METHODS

This cross-sectional study was performed with a total of 131 patients (62 women and 69 men, mean age 42.96±13.02 years). Patients were divided into three groups: UC, CD, and non-IBD. Periodontal status was defined according to the 2017 World Workshop Disease Classification. Salivary and GCF cytokine levels were analyzed using ELISA.

RESULTS

UC and CD patients diagnosed as having periodontitis and gingivitis presented with significantly higher levels of TNF-α and lower levels of IL-10 as compared with non-IBD patients (p<0.05). UC patients diagnosed with periodontitis exhibited significantly higher scores of bleeding on probing (p = 0.011) and increased salivary and GCF IL-1β levels as compared with CD patients (p = 0.005, and 0.012 respectively). Considering the active and remission status of IBD, salivary IL-1β was found to be correlated with the parameters representing the severity of periodontal diseases in active UC and CD patients.

CONCLUSION(S)

In the presence of periodontal diseases, UC and CD patients showed different expression levels of TNF-α, IL-1β, and IL-10 in oral secretions as compared with non-IBD patients. This article is protected by copyright. All rights reserved.

Ophiopogonin D Inhibiting Epithelial NF-κB Signaling Pathway Protects Against Experimental Colitis in Mice

The sustained activation of the nuclear factor κB (NF-κB) signaling pathway has been observed in human inflammatory bowel disease (IBD). Ophiopogonin D (OP-D) is a small molecular compound isolated from Ophiopogon japonicus, a widely used herbal remedy. In this study, dextran sodium sulfate was used to make a mouse model of experimental colitis and verify the effect of OP-D on the mouse model of experimental colitis. Small molecule-protein molecular docking approaches were also used to discover the mechanisms underlying the OP-D-induced regulation of colitis. In colitis, the OP-D can inhibit the apoptosis of intestinal mucosa cells, restore the intestinal barrier, and alleviate inflammation. The molecular docking simulations showed that OP-D had a high affinity with the REL-homology domain of NF-κB-p65 that affected its translocation to the nucleus. In a cell study, the effects of OP-D on inflammation and barrier dysfunction were significantly decreased by a small interfering RNA targeting NF-κB-p65. Further, the LPS-induced increase in NF-κB-p65 in the nucleus was also significantly inhibited by OP-D. OP-D alleviated experimental colitis by inhibiting NF-κB. New insights into the pathogenesis and treatment options of colitis are provided through this study.

A prospective interventional trial on the effect of periodontal treatment on Fusobacterium nucleatum abundance in patients with colorectal tumours

Fusobacterium nucleatum is associated with the progression of colorectal cancer. Thus, the possibility of preventing colorectal cancer or its progression by targeting F. nucleatum has been explored. As F. nucleatum is associated with periodontitis, we analysed whether treating periodontitis could influence F. nucleatum abundance in the colon. Patients with colorectal tumours who underwent colonoscopy were recruited. Patients diagnosed with periodontitis by a dentist were treated for approximately 3 months. Endoscopic resection of colorectal tumours was performed after periodontitis treatment, and resected tumours were pathologically classified as high-(HGD) or low-grade dysplasia (LGD). Saliva and stool samples were collected before and after the treatment. Of the 58 patients with colorectal tumours, 31 were included in the study, 16 showed improvement in periodontitis, and 11 showed no improvement. Stool F. nucleatum levels before treatment were significantly lower in the LGD group than in the HGD group. A significant decrease in faecal F. nucleatum levels was observed in patients who underwent successful treatment but not in those whose treatment failed. Salivary F. nucleatum levels were not altered in patients despite periodontal treatment. Thus, successful periodontitis treatment reduces stool F. nucleatum levels and may aid research on periodontitis and suppression of colorectal cancer development.

Cytokine profile in serum and gingival crevicular fluid of children with inflammatory bowel disease: A case-control study

BACKGROUND

To evaluate the cytokine profile in gingival crevicular fluid (GCF) and serum of pediatric inflammatory bowel disease (IBD) patients and determine the cluster patterns of cytokines.

METHODS

Fifty IBD patients and 21 systemically healthy children were enrolled in the study. The GCF samples were collected from the participants during periodontal examination and periodontal indices were recorded. Based on activity indexes and response to conventional treatment, patients with IBD were further categorized into subgroups as: remission, active disease, and treatment-resistant. Serum samples were obtained from IBD patients to determine serum levels of cytokines. The levels of pro- (interleukin (IL)-1β, IL-12, IL-21, IL-22, IL-23, IL-17A, IL-17F) and anti-inflammatory (IL-4, IL-10) cytokines in serum and GCF were measured using Enzyme-linked Immunosorbent Assay (ELISA) kits.

RESULTS

Among 50 IBD patients, 58% were in remission, 20% had active disease, and 22% were defined as treatment-resistant. The severity of gingival inflammation measured by the criteria of Löe had increasing trends in IBD patients with active disease and treatment resistance. GCF IL-1β level was lower and GCF IL-4 and GCF IL-23 levels were higher in IBD patients compared to healthy controls. In the active disease group, more cytokine clusters occurred compared to the control group and other IBD subgroups, as explained by increased cytokine-cytokine interactions.

CONCLUSIONS

Considering the increased complexity of cytokine interactions and the increased severity of gingival inflammation in patients with active disease, it can be concluded that disease activity might have an impact on gingival inflammation in pediatric patients with IBD.

Co-pathogens in Periodontitis and Inflammatory Bowel Disease

Localized inflammatory lesions in one area of the body may affect other distant organs through various modes of transmission thus initiating secondary inflammatory infections. Periodontal disease (PD) and inflammatory bowel disease (IBD) have been shown to coexist. Periodontitis is a multifactorial inflammatory disease, and dental plaque is considered to be the initial risk factor. Individuals with genetic susceptibility are more likely to develop periodontitis when exposed to external stimuli. IBD is affected by host genetics, immunoregulation, daily diet, and the gut microbiota, and its risk factors appear to be shared with those of PD. However, the key etiologies of both diseases remain unclear, thus hindering the exploration of possible links between IBD and PD. Recent studies and systematic reviews have focused on evidence-based statistics of the prevalence and clinical manifestations of both diseases, but discussions of the microbial etiological correlation between periodontitis and intestinal inflammation are scarce. Here, we summarize the potential common pathogenic microorganisms that may serve as bridges between the two diseases. Studies have shown that invasive microorganisms such as Porphyromonas gingivalis, Fusobacterium nucleatum, Klebsiella spp. and Campylobacter spp. play key roles in the comorbidity of PD and IBD.

Immunological Traits of Patients with Coexistent Inflammatory Bowel Disease and Periodontal Disease: A Systematic Review

This systematic review assessed studies that evaluated the immunological traits of patients with both inflammatory bowel disease (IBD) and periodontal disease. An electronic search for literature was conducted on PubMed, Embase, Scopus, Cochrane and Web of Science. Studies that evaluated the immunological response in patients with IBD and periodontal disease were considered eligible for inclusion. A total of 6 cross-sectional studies of 275 patients were included. Immunological analyses were performed in gingival crevicular fluid, saliva, serum, intestinal and gingival biopsies. Four studies identified that the presence of IBD and periodontal disease was associated with higher levels of prostaglandin E2, aMMP8, IL-18 and S100A12, respectively, when compared to patients without the coexistence of both diseases. Furthermore, another study identified higher aMMP-8 levels with increasing severity of periodontitis in Crohn’s disease patients. The quality of overall evidence ranged from high to low due to the observational nature of contributing studies. The coexistence of IBD and periodontal disease seems to be associated with a more responsive inflammatory reaction compared with individuals having one or the other. More randomized controlled studies evaluating the coexistence of IBD and periodontitis are required to better explore the immunological interplay between them.

Periodontal and dental health in inflammatory bowel diseases: a systematic review

Introduction: An increased risk of dental caries and periodontal diseases has been reported for inflammatory bowel disease (IBD) patients and are challenging conditions to manage.Areas covered: The authors searched international databases to find all studies assessing dental/periodontal outcomes in patients with IBD and other immune-mediated inflammatory disease (IMID), as well as the association between IMID medications and dental/periodontal status.Expert opinion: IBD are associated with a higher risk of both periodontitis and caries. Some evidence from rheumatoid arthritis suggests that periodontitis may be associated with a lower response to anti-TNF. There is no reliable evidence that IBD patients may be at greater risk of complications during routine dental care. On the basis of current data, guidelines can be proposed for the dental management focusing on the detection and eradication of infectious foci prior to the implementation of immunosuppressants/biologics and modified dental treatment protocol for invasive dental procedures that includes antibiotic prophylaxis.

Shared microbiological and immunological patterns in periodontitis and IBD: A scoping review

OBJECTIVES

To extract the microbiological and immunological evidence underpinning the association between periodontitis and inflammatory bowel disease (IBD).

METHODS

Relevant articles were sorted through a systematic search on PubMed, Embase, Scopus and Web of Science up to October 2020. Available evidence was grouped in three different clusters: (a) studies that examined oral microbial alterations in IBD patients; (b) studies that investigated intestinal dysbiosis in patients with periodontitis; and (c) evidence for a shared immunological pattern between the two conditions.

RESULTS

A total of 15 studies involving 1,171 patients were included. Oral microbiome, either subgingival or salivary, was consistently altered in patients with IBD compared to healthy subjects (a) Additionally, gut dysbiotic microbiota of IBD patients was colonized by pathobionts from oral origin, either via haematogenous or enteric route. Suffering from periodontitis is associated with lower alpha diversity in the gut microbiome (b) Lastly, both IBD and periodontitis are characterized by similar expression patterns of inflammatory cytokines at the gingival and gut levels that are exacerbated when both diseases are present (c).

CONCLUSIONS

Periodontitis and IBD share common dysbiotic and immunological traits. Well-designed preclinical models and longitudinal cohort studies are required to better explore the causal pathways between the two conditions (PROSPERO CRD42020194379).

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.

Sishen Pill Treatment of DSS-Induced Colitis via Regulating Interaction With Inflammatory Dendritic Cells and Gut Microbiota

Sishen Pill (SSP) is a typical prescription in the pharmacopeia of traditional Chinese medicine (TCM), and is usually used to treat inflammatory bowel disease (IBD). It is known that inflammatory dendritic cells (DCs) and imbalance of gut microbiota play significant roles in the pathogenesis of IBD. However, it is not clear whether SSP can treat IBD by regulating interaction of DCs and gut microbiota. In the present study, the levels of inflammatory DCs and gut microbiota were analyzed by flow cytometry and 16S rDNA analysis. SSP relieved the pathological damage to the colon of mice with colitis induced by dextran sodium sulfate (DSS). As typical indicators of inflammatory DCs, the levels of CD11c⁺CD103⁺E-cadherin⁺ cells and pro-inflammatory cytokines [interleukin (IL)-1β, -4, -9, and -17A] were decreased in mice with colitis treated by SSP for 10 days. Simultaneously, the gut microbiota composition was regulated, and beneficial bacteria were increased and pathogenic bacteria were reduced. The results indicated that SSP regulated the interaction between inflammatory DCs and gut microbiota to treat DSS-induced colitis.

Cytocompatibility of 3D printed dental materials for temporary restorations on fibroblasts

Background

Three-dimensional (3D) printing is widely used in the fabrication of dental prostheses; however, the influence of dental materials used for 3D printing on temporary restoration of fibroblasts in tissues is unclear. Thus, the influence of different dental materials on fibroblasts were investigated.

Methods

Digital light processing (DLP) type 3D printing was used. Specimens in the control group were fabricated by mixing liquid and powder self-curing resin restoration materials. The temporary resin materials used were Model, Castable, Clear-SG, Tray, and Temporary, and the self-curing resin materials used were Lang dental, Alike, Milky blue, TOKVSO CUREFAST, and UniFast III. Fibroblast cells were cultured on each specimen and subsequently post-treated for analysis. Morphology of the adhered cells were observed using a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM).

Results

CLSM and SEM cell imaging revealed that the 3D printed material group presented better cell adhesion with well-distributed filopodia compared to that in the conventional resin material group. Cell proliferation was significantly higher in the 3D printing materials.

Conclusion

Superior cytocompatibility of the specimens fabricated through 3D printing and polishing process was demonstrated with the proof of better cell adhesion and higher cell proliferation.

Increased Risk of Ulcerative Colitis in Patients with Periodontal Disease: A Nationwide Population-Based Cohort Study

Both periodontal disease (PD) and inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are important diseases of the alimentary tract. Microbiome and immune-mediated inflammatory processes play important roles in these diseases. An association between PD and IBD may exist. This study investigated the risk of IBD in patients with PD. This study used data from the National Health Insurance Research Database of Taiwan from 1996 to 2013. A total of 27,041 patients with PD were enrolled as a study group, and 108,149 patients without PD were selected as the control group after matching by gender, age, insured region, urbanization, and income with a 1:4 ratio. Cox proportional hazards regression was used to calculate the risk of IBD. Of the 135,190 participants enrolled in this study, 5392 (4%) with newly diagnosed IBD were identified. The overall incidence of subsequent IBD was similar in both groups (3.8% vs. 4%, adjusted hazard ratio (aHR) = 1.01, 95% confidence interval (CI): 0.94⁻1.08). However, an increased risk of UC in the PD group was found after adjusting confounding factors (aHR: 1.56, 95% CI: 1.13⁻2.15; p < 0.05). This study demonstrated that patients with PD had approximately one-half higher risk of subsequent UC. Further studies are warranted to elucidate the relationship between PD and UC.

Mucus Detachment by Host Metalloprotease Meprin β Requires Shedding of Its Inactive Pro-form, which Is Abrogated by the Pathogenic Protease RgpB

The host metalloprotease meprin β is required for mucin 2 (MUC2) cleavage, which drives intestinal mucus detachment and prevents bacterial overgrowth. To gain access to the cleavage site in MUC2, meprin β must be proteolytically shed from epithelial cells. Hence, regulation of meprin β shedding and activation is important for physiological and pathophysiological conditions. Here, we demonstrate that meprin β activation and shedding are mutually exclusive events. Employing ex vivo small intestinal organoid and cell culture experiments, we found that ADAM-mediated shedding is restricted to the inactive pro-form of meprin β and is completely inhibited upon its conversion to the active form at the cell surface. This strict regulation of meprin β activity can be overridden by pathogens, as demonstrated for the bacterial protease Arg-gingipain (RgpB). This secreted cysteine protease potently converts membrane-bound meprin β into its active form, impairing meprin β shedding and its function as a mucus-detaching protease.