A review of the relationship between tooth loss, periodontal disease, and cancer

Current status and prospect of gut and oral microbiome in pancreatic cancer: Clinical and translational perspectives

Pancreatic cancer is a highly lethal malignancy, and its diagnosis and treatment continue to pose significant challenges. Despite advancements in surgical and comprehensive treatment methods, the five-year survival rate remains below 12 %. With the rapid development of microbiome science, the gut and oral microbiota, which are readily accessible and can be sampled non-invasively, have emerged as a novel area of interest in pancreatic cancer research. Dysbiosis in these microbial communities can induce persistent inflammatory responses and affect the host's immune system, promoting cancer development and impacting the efficacy of treatments like chemotherapy and immunotherapy. This review provides an up-to-date overview of the roles of both gut and oral microbiota in the onset, progression, diagnosis, and treatment of pancreatic cancer. It analyzes the potential of utilizing these microbiomes as biomarkers and therapeutic targets from a clinical application perspective. Furthermore, it discusses future research directions aimed at harnessing these insights to advance the diagnosis and treatment strategies for pancreatic cancer. By focusing on the microbiome's role in clinical and translational medicine, this review offers insights into improving pancreatic cancer diagnosis and treatment outcomes.

Oral Health and "Modern" Digestive Diseases: Pathophysiologic and Etiologic Factors

In the contemporary era of medicine, exploring the complexity of the human body and its intricate interactions has become a central concern for health researchers. The main purpose of this article is to summarize the current understanding of relevant pathophysiological factors such as chronic inflammation, dysbiosis (microbial imbalance), and metabolic disorders, as well as etiological factors including dietary habits, lifestyle choices, obesity, metabolic syndrome, and genetic predispositions, as well as to emphasize potential avenues for upcoming studies and their medical significance. Additionally, this article aims to assess the potential impact of integrated treatment approaches on patient outcomes, emphasizing the need for interdisciplinary collaboration between gastroenterologists, dentists, and other healthcare professionals to develop comprehensive care plans that address both oral and digestive health issues simultaneously. Among the branches with a significant impact on general well-being are oral cavity health and digestive diseases, which have been the subject of intensive research in recent decades. In this context, analysis of the current state of knowledge on oral cavity disorders in relation to "modern" digestive diseases such as non-alcoholic fatty liver disease (NAFLD), small intestinal bacterial overgrowth (SIBO), inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS) becomes essential for a deeper understanding of the interconnections between oral and digestive health. The temporal overlap or succession, whether preceding or following, of oral manifestations and digestive disorders should be taken seriously by both gastroenterologists and dentists to facilitate early diagnosis and explain to patients the correlation between these two body systems. In summary, this article underscores the importance of understanding the intricate relationship between oral and digestive health, advocating for interdisciplinary approaches to improve patient outcomes and guide future research.

The relationship between periodontal disease and cancer: Insights from a Systematic Literature Network Analysis

This paper investigates the relationship between periodontal disease and various cancer types. It provides a comprehensive overview of the existing knowledge about the interaction between periodontal disease and carcinogenesis, explores the underlying biological mechanisms of this connection, and consider the impact of these findings on healthcare practices and future research directions. Utilizing Systematic Literature Network Analysis, which combines bibliometric analysis with Systematic Literature Review, this study analyzes 164 documents from 2000 to 2023. Focus is placed on the 38 most globally cited papers, enabling a targeted and comprehensive analysis of the predominant research within this scope. This review highlights that colorectal, oral, pancreatic, lung, and gastrointestinal cancers have consistent associations with periodontal disease. On the other hand, hematological, breast and prostate cancers show associations with periodontal disease, but these links are less pronounced and more variable, indicating the need for targeted research in these domains. These insights emphasize the necessity for a multidisciplinary healthcare approach, recognizing the systemic implications of periodontal disease.

Assessment of Racial Misclassification Among American Indian and Alaska Native Identity in Cancer Surveillance Data in the United States and Considerations for Oral Health: A Systematic Review

Introduction

Misclassification of American Indian and Alaska Native (AI/AN) peoples exists across various databases in research and clinical practice. Oral health is associated with cancer incidence and survival; however, misclassification adds another layer of complexity to understanding the impact of poor oral health. The objective of this literature review was to systematically evaluate and analyze publications focused on racial misclassification of AI/AN racial identities among cancer surveillance data.

Methods

The PRISMA Statement and the CONSIDER Statement were used for this systematic literature review. Studies involving the racial misclassification of AI/AN identity among cancer surveillance data were screened for eligibility. Data were analyzed in terms of the discussion of racial misclassification, methods to reduce this error, and the reporting of research involving Indigenous peoples.

Results

A total of 66 articles were included with publication years ranging from 1972 to 2022. A total of 55 (83%) of the 66 articles discussed racial misclassification. The most common method of addressing racial misclassification among these articles was linkage with the Indian Health Service or tribal clinic records (45 articles or 82%). The average number of CONSIDER checklist domains was three, with a range of zero to eight domains included. The domain most often identified was Prioritization (60), followed by Governance (47), Methodologies (31), Dissemination (27), Relationships (22), Participation (9), Capacity (9), and Analysis and Findings (8).

Conclusion

To ensure equitable representation of AI/AN communities, and thwart further oppression of minorities, specifically AI/AN peoples, is through accurate data collection and reporting processes.

The microbial composition of pancreatic ductal adenocarcinoma: A systematic review of 16S rRNA gene sequencing

BACKGROUND

Pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC), continues to pose a significant clinical and scientific challenge. The most significant finding of recent years is that PDAC tumours harbour their specific microbiome, which differs amongst tumour entities and is distinct from healthy tissue. This review aims to evaluate and summarise all PDAC studies that have used the next-generation technique, 16S rRNA gene amplicon sequencing within each bodily compartment. As well as establishing a causal relationship between PDAC and the microbiome.

MATERIALS AND METHODS

This systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. A comprehensive search strategy was designed, and 1727 studies were analysed.

RESULTS

In total, 38 studies were selected for qualitative analysis and summarised significant PDAC bacterial signatures. Despite the growing amount of data provided, we are not able to state a universal 16S rRNA gene microbial signature that can be used for PDAC screening. This is most certainly due to the heterogeneity of the presentation of results, lack of available datasets and the intrinsic selection bias between studies.

CONCLUSION

Several key studies have begun to shed light on causality and the influence the microbiome constituents and their produced metabolites could play in tumorigenesis and influencing outcomes. The challenge in this field is to shape the available microbial data into targetable signatures. Making sequenced data readily available is critical, coupled with the coordinated standardisation of data and the need for consensus guidelines in studies investigating the microbiome in PDAC.

Periodontitis and the risk of oral cancer: a meta-analysis of case-control studies

OBJECTIVE

The current studies have yielded inconclusive findings regarding the connection between periodontitis  and oral cancer (OC). Therefore, our goal is to elucidate this relationship.

MATERIALS AND METHODS

We conducted a thorough search of electronic databases (EMBASE, PubMed, Web of Science, and Cochrane Library) up to September 2023. The Newcastle-Ottawa Scale (NOS) was applied to assess study quality. To evaluate potential publication bias, both a funnel plot and Egger's test were employed. Additionally, a sensitivity analysis was conducted to explore the source of heterogeneity when the I2 statistic exceeded 50%.

RESULTS

This systematic review encompassed 16 studies, involving a total of 6,032 OC patients and 7,432 healthy controls. Our meta-analysis, incorporating data from nine studies, revealed a significant correlation between periodontitis and the risk of OC (OR [odds ratio] = 2.94, 95% CI [confidence interval] (2.13, 4.07); five studies, 6,927 participants; low certainty of evidence). Findings also suggested that individuals with more than 15 missing teeth may have a heightened risk of OC (OR = 1.91, 95% CI (1.01, 3.62)). Furthermore, clinical attachment loss (CAL) and decayed, missing, and filled teeth (DMFT) in OC patients were more pronounced compared to the control group (CAL, SMD = 1.94, 95% CI (0.22, 3.66); DMFT, SMD = 0.65, 95% CI (0.12, 1.18)).

CONCLUSION

Periodontitis may serve as a potential risk factor for OC. However, caution is warranted in interpreting these findings due to the substantial level of heterogeneity.

An IoT-based aptasensor biochip for the diagnosis of periodontal disease

Severe periodontitis affects nearly 1 billion individuals worldwide, highlighting the need for early diagnosis. Here, an integrated system consisting of a microfluidic chip and a portable point-of-care (POC) diagnostic device is developed using a polymethyl methacrylate (PMMA) chip fabrication and a three-dimensional printing technique, which is automatically controlled by a custom-designed smartphone application to routinely assess the presence of a specific periodontitis biomarker, odontogenic ameloblast-associated protein (ODAM). A sandwich-type fluorescence aptasensor is developed on a microfluidic chip, utilizing aptamer pair (MB@OD64 and OD35@FAM) selectively binding to target ODAM. Then this microfluidic chip is integrated into an automated Internet of Things (IoT)-based POC device, where fluorescence intensity, as a signal, from the secondary aptamer binding to ODAM in a sandwich-type binding reaction on the microfluidic chip is measured by a complementary metal oxide semiconductor (CMOS) camera with a 488 nm light-emitting diode (LED) excitation source. Obtained signals are processed by a microprocessor and visualized on a wirelessly connected smartphone application. This integrated biosensor system allows the rapid and accurate detection of ODAM within 30 min with a remarkable limit of detection (LOD) of 0.011 nM under buffer conditions. Clinical application is demonstrated by successfully distinguishing between low-risk and high-risk individuals with 100 % specificity. A strong potential in the translation of this fluorescence-based microfluidic aptasensor integrated with an IoT-based POC system is expected to be employed for non-invasive, on-site, rapid, and accurate ODAM detection, facilitating periodontitis diagnosis.

Association of Entamoeba gingivalis with Periodontal Disease-Systematic Review and Meta-Analysis

The oral cavity is a habitat to a diverse range of organisms that make up an essential element of the human microbiota. There are up to 1000 species of micro-organisms capable of colonizing the mouth. Thirty percent of them are uncultivable. The genus Entamoeba includes several species, out of which at least seven of them are able to inhabit the human body (Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba coli, Entamoeba polecki, Entamoeba hartmann, Entamoeba gingivalis). It was shown that only E. gingivalis is able to colonize the oral cavity. The aim of this study was to evaluate the association and prevalence of E. gingivalis in periodontal disease using two electronic database search engines. In order to have a broader view of the subject, a comprehensive manual search was conducted between 15th February 2023 and 1 April 2023 on these content aggregators and the initial search resulted in 277 articles using the keywords "E. gingivalis", "periodontitis", "E. gingivalis", "periodontal disease", "prevalence", and "incidence", in different combinations. The results showed that 755 patients were infected with E. gingivalis out of a total number of 1729 patients diagnosed with periodontal disease, indicating a global prevalence of 43% in the set of patients analyzed. E. gingivalis was prevalent in 58% of the patients that had gingivitis and in 44% of the patients with periodontitis. Prevalence of E. gingivalis based on gender was 43% in female patients and 47% in male patients. The results indicate that the higher incidence of E. gingivalis in people with periodontal disease compared to healthy people is more than just a sign of the disease; it could also be linked to the severity of the condition and the disease propensity to progress.

Association of DOK3 and infiltrated tumor-associated macrophages with risk for the prognosis of Porphyromonas gingivalis-infected oral cancer: a 12-year data analysis of 200 patients from a tertiary teaching hospital, Urumqi, China

BACKGROUND

While there is an understanding of the association between the expression of Porphyromonas gingivalis (P. gingivalis) and prognosis of oral squamous cell carcinoma (OSCC), significance specially to address the relevance between different immunohistochemical intensities of P. gingivalis and tumor-associated macrophages (TAMs) in OSCC tissue and related clinicopathologic characteristics has not been well investigated. The present study aimed to investigate the pathological features related to M2-TAM in P. gingivalis-infected OSCC and ascertain its clinical relevance with patients' prognosis.

METHODS

A prospective cohort study was designed to comparatively analyze 200 patients from June 2008 to June 2020. Bioinformatics analyses were implemented to identify DOK3 as a key molecule and to appraise immunocyte infiltration using Gene Expression Omnibus and The Cancer Genome Atlas databases. Immunohistochemical evaluation was performed to analyze the association between the expression levels of P. gingivalis, DOK3, and M2-TAM and clinicopathological variables using Fisher's exact test or Pearson's chi-square test. Cox analysis was used to calculate hazard ratios (HR) with corresponding 95% confidence interval (CI) for various clinicopathological features. The Kaplan-Meier approach and log-rank test were used to plot the survival curves.

RESULTS

The expression level of P. gingivalis was positively associated with DOK3 and M2-TAMs expression level (P < 0.001). Parameters, including body mass index, clinical stage, recurrence, tumor differentiation, and P. gingivalis, DOK3, and M2-TAM immunoexpression levels, affected the prognosis of patients with OSCC (all P < 0.05). In addition, P. gingivalis (HR = 1.674, 95%CI 1.216-4.142, P = 0.012), DOK3 (HR = 1.881, 95%CI 1.433-3.457, P = 0.042), and M2-TAM (HR = 1.649, 95%CI 0.824-3.082, P = 0.034) were significantly associated with the 10-year cumulative survival rate.

CONCLUSIONS

Elevated expression of P. gingivalis and DOK3 indicates M2-TAM infiltration and unfavorable prognosis of OSCC, and could be considered as three novel independent risk factors for predicting the prognosis of OSCC.

Poor Dental Health as a Risk Factor for Alveolar Ridge Malignancies

OBJECTIVE

To determine the association between poor dental health and risk of oral cavity squamous cell cancer (OCSCC) at individual tumor subsites.

STUDY DESIGN

Case-control and cross-sectional METHODS: A case-control study was performed using a population-based cohort in North Carolina (Carolina Head and Neck Cancer Epidemiology Study [CHANCE]). A secondary cross-sectional analysis was performed with an institutional cohort (WashU/Siteman). Cases were adults with primary OCSCC and an identifiable tumor subsite. In the CHANCE cohort, controls were adults without head and neck cancer. In the Washington University/Siteman cohort, patients with tongue cancer served as the comparator group. We used number of missing teeth (categorized 0-6, 7-24, 25-28) as a surrogate for poor dental health, which was self-reported in CHANCE and measured on a pretreatment computed tomography scan in the WashU/Siteman study. Adjusted odds ratios (aORs) for missing teeth were estimated for each tumor subsite using binomial logistic regression models.

RESULTS

Near complete tooth loss (25-28 teeth) was associated with a 3.5-fold increased risk of alveolar ridge malignancy (aOR: 3.51; 95% confidence interval [CI]: 1.14-11.01, P = .03) in the CHANCE study. This association was confirmed in our cross-sectional analysis (WashU/Siteman study) where missing 25-28 teeth was associated with an increased risk of alveolar ridge compared to tongue cancer (aOR: 4.60; 95% CI: 1.97-11.10, P = .001).

CONCLUSIONS

This study suggests an association between poor dental health and risk of alveolar ridge cancer independent of smoking, alcohol use, age, race, and sex. Future prospective and translational studies are needed to confirm this association and elucidate the mechanism of dental disease in alveolar ridge malignancies.

Structure-function analysis of PorXFj, the PorX homolog from Flavobacterium johnsioniae, suggests a role of the CheY-like domain in type IX secretion motor activity

The type IX secretion system (T9SS) is a large multi-protein transenvelope complex distributed into the Bacteroidetes phylum and responsible for the secretion of proteins involved in pathogenesis, carbohydrate utilization or gliding motility. In Porphyromonas gingivalis, the two-component system PorY sensor and response regulator PorX participate to T9SS gene regulation. Here, we present the crystal structure of PorXFj, the Flavobacterium johnsoniae PorX homolog. As for PorX, the PorXFj structure is comprised of a CheY-like N-terminal domain and an alkaline phosphatase-like C-terminal domain separated by a three-helix bundle central domain. While not activated and monomeric in solution, PorXFj crystallized as a dimer identical to active PorX. The CheY-like domain of PorXFj is in an active-like conformation, and PorXFj possesses phosphodiesterase activity, in agreement with the observation that the active site of its phosphatase-like domain is highly conserved with PorX.

Role of innate host defense proteins in oral cancerogenesis

It is nowadays well accepted that chronic inflammation plays a pivotal role in tumor initiation and progression. Under this aspect, the oral cavity is predestined to examine this connection because periodontitis is a highly prevalent chronic inflammatory disease and oral squamous cell carcinomas are the most common oral malignant lesions. In this review, we describe how particular molecules of the human innate host defense system may participate as molecular links between these two important chronic noncommunicable diseases (NCDs). Specific focus is directed toward antimicrobial polypeptides, such as the cathelicidin LL-37 and human defensins, as well as S100 proteins and alarmins. We report in which way these peptides and proteins are able to initiate and support oral tumorigenesis, showing direct mechanisms by binding to growth-stimulating cell surface receptors and/or indirect effects, for example, inducing tumor-promoting genes. Finally, bacterial challenges with impact on oral cancerogenesis are briefly addressed.

Interactions Between Oral Microbiota and Cancers in the Aging Community: A Narrative Review

The oral microbiome potentially wields significant influence in the development of cancer. Within the human oral cavity, an impressive diversity of more than 700 bacterial species resides, making it the second most varied microbiome in the body. This finely balanced oral microbiome ecosystem is vital for sustaining oral health. However, disruptions in this equilibrium, often brought about by dietary habits and inadequate oral hygiene, can result in various oral ailments like periodontitis, cavities, gingivitis, and even oral cancer. There is compelling evidence that the oral microbiome is linked to several types of cancer, including oral, pancreatic, colorectal, lung, gastric, and head and neck cancers. This review discussed the critical connections between cancer and members of the human oral microbiota. Extensive searches were conducted across the Web of Science, Scopus, and PubMed databases to provide an up-to-date overview of our understanding of the oral microbiota's role in various human cancers. By understanding the possible microbial origins of carcinogenesis, healthcare professionals can diagnose neoplastic diseases earlier and design treatments accordingly.

Upper gastrointestinal tract microbiota with oral origin in relation to oesophageal squamous cell carcinoma

Introduction: Poor oral hygiene is linked to high risks of many systemic diseases, including cancers. Oral dysbiosis is closely associated with poor oral hygiene, causing tooth loss, gingivitis, and periodontitis. We provide a summary of studies and discuss the risk factors for oesophageal squamous cell carcinoma (ESCC) from a microbial perspective in this review.Methods: A literature search of studies published before December 31, 2022 from PubMed, Web of Science, and The Cochrane Library was performed. The search strategies included the following keywords: (1) oral care, oral health, oral hygiene, dental health, dental hygiene, tooth loss, teeth loss, tooth absence, missing teeth, edentulism, tooth brushing, mouthwash, and tooth cleaning; (2) esophageal, esophagus, oesophagus, and oesophageal; (3) cancer, carcinoma, tumor, and neoplasm.Discussion: Poor oral health, indicated by infrequent tooth brushing, chronic periodontitis, and tooth loss, has been associated with an increased risk of squamous dysplasia and ESCC. Oral microbial diversity and composition are profoundly dysregulated during oesophageal tumorigenesis. Similar to the oral microbiota, the oesophageal microbiota varies distinctly in multiple bacterial taxa in ESCC and gastric cardia adenocarcinoma, both of which have high co-occurrence rates in the "Oesophageal Cancer Belt". In addition, the potential roles of oncogenic viruses in ESCC have also been discussed. We also briefly explore the potential mechanisms underlying the tumor-promoting role of dysregulated microbiota for the development of therapeutic targeting strategies.Conclusion: Poor oral health is an established risk indicator of ESCC. The dysbiosis of microbiota in upper gastrointestinal tract that highly resembles the oral microbial ecosystem but with distinct features at individual sites contributes to the development and progression of ESCC.

Interplay between oral health and lifestyle factors for cancer risk in rural and urban China: a population-based cohort study

Background

Although poor oral health and several lifestyle factors have been found to be associated with cancer risk, their joint relationship has rarely been studied.

Methods

We prospectively examined the associations of oral health and healthy lifestyle factors with cancer risk among 0.5 million rural and urban residents from the China Kadoorie Biobank (2004-2015). Oral health status was assessed from self-reported baseline questionnaires. A healthy lifestyle index comprising non-smoking, non-drinking, ideal body shape, physical activity and healthy diet was calculated for each participant, and categorized into favorable, intermediate and unfavorable lifestyle behavior. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) relating oral health and healthy lifestyle index to cancer risk using Cox proportional hazards models. We estimated the population attributable risk percent (PAR%) and 95% CIs using multivariate models.

Results

During a median follow-up of 9 years, 23,805 new cancer cases were documented, with 52% from rural areas and 48% from urban areas. Compared with those with good oral health and favorable lifestyle, participants with poor oral health and unfavorable lifestyle had a higher risk of developing cancer in both rural (adjusted HR, 1.55 [95% CI, 1.39-1.74]; P for trend < 0.001) and urban areas (adjusted HR, 1.44 [95% CI, 1.24-1.67]; P for trend < 0.001). A significant multiplicative interaction between oral health and healthy lifestyle index on cancer risk was found in rural residents (P for interaction = 0.004) rather than in urban residents (P for interaction = 0.973). Assuming poor oral health as an additional risk factor, the PAR% of total cancer increased by 3.0% and 1.1% for participants with intermediate lifestyle and unfavorable lifestyle, respectively.

Conclusions

These findings suggest a joint effect of oral health and common lifestyle factors on cancer risk. Promotion of healthy lifestyle by integration of good oral health would be beneficial to consider in cancer prevention strategies.

Head and neck cancer patients show poor oral health as compared to those with other types of cancer

PURPOSE

Several studies have found associations between periodontitis and various types of cancer. Since the site of head and neck cancer (HNC) has contiguity or proximity to the oral cavity, it may be particularly influenced by oral inflammation. This study aimed to determine whether HNC patients have poor oral health as compared to those with other types of cancer.

METHODS

This study retrospectively examined oral environmental factors including periodontal inflamed surface area (PISA), a new periodontal inflammatory parameter. A total of 1030 cancer patients were divided into the HNC (n = 142) and other cancer (n = 888) groups. Furthermore, the HNC group was divided into high (n = 71) and low (n = 71) PISA subgroups, and independent risk factors affecting a high PISA value were investigated.

RESULTS

Multivariate logistic regression analysis showed that number of missing teeth (odds ratio 1.72, 95% CI 1.15-2.56, P < 0.01), PISA (odds ratio 1.06, 95% CI 1.03-1.06, P < 0.05), and oral bacterial count (odds ratio 1.02, 95% CI 1.01-1.03, P < 0.01) were independent factors related to HNC. In addition, multivariate logistic regression analysis indicated that current smoker (odds ratio 7.51, 95% CI 1.63-34.71, P < 0.01) and presence of untreated dental caries (odds ratio 3.33, 95% CI 1.23-9.00, P < 0.05) were independent risk factors affecting high PISA values in HNC patients.

CONCLUSION

HNC patients have higher levels of gingival inflammation and poor oral health as compared to patients with other types of cancer, indicating that prompt oral assessment and an effective oral hygiene management plan are needed at the time of HNC diagnosis.

Human oral mucosa and oral microbiome interactions following supragingival plaque reconstitution in healthy volunteers: a diet-controlled balanced design proof-of-concept model to investigate oral pathologies

Changes in the oral microbiome may contribute to oral pathologies, especially in patients undergoing cancer therapy. Interactions between oral microbiome and oral mucosa may exacerbate inflammation. We determined whether probiotic-controlled plaque formation could impact proximal oral mucosa gene expression profiles in healthy volunteers. A 3-weeks balanced sample collection design from healthy volunteers (HVs) was implemented. At Week-1 plaques samples and labial mucosa brush biopsies were obtained from HVs in the morning (N = 4) and/or in the afternoon (N = 4), and groups were flipped at Week-3. A fruit yogurt and tea diet were given 2-4hrs before sample collection. mRNA gene expression analysis was completed using RNA-Seq and DESeq2. Bacterial taxa relative abundance was determined by 16S HOMINGS. Bacterial diversity changes and metabolic pathway enrichment were determined using PRIMERv7 and LEfSe programs. Alpha- and beta-diversities did not differ morning (AM) vs. afternoon (PM). The most affected KEGG pathway was Toll-like receptor signaling in oral mucosa. Eighteen human genes and nine bacterial genes were differentially expressed in plaque samples. Increased activity for 'caries-free' health-associated calcifying Corynebacterium matruchotii and reduced activity for Aggregatibacter aphrophilus, an opportunistic pathogen, were observed. Microbial diversity was not altered after 8 hours plaque formation in healthy individuals as opposed to gene expression.

Associations between missing teeth and the risk of cancer in Korea: a nationwide cohort study

BACKGROUND

Poor dental health is correlated with an increased risk of cancer. Using a nationwide population cohort database, we investigated which cancer is highly associated with poor dental health and which dental indicator mostly influences cancer risk.

METHODS

This study was conducted using the National Health Checkups (NHC) and National Health Insurance System (NHIS) database in Korea. NHC in Korea includes dental examinations. We retrieved subjects who underwent NHC between 2002 and 2003 and their medical information in NHIS database was followed until December 31,2015.

RESULTS

Data for 200,170 who participated in the NHC between 2002 and 2003 were analysed. During the maximum follow-up period of 13 years, 15,506 (7.75%) subjects were diagnosed with cancer. The median time to cancer diagnosis after the dental examination was 87 months (range, 51-119 months). The proportion of people with missing teeth was higher in the cancer-diagnosed group than in the non-diagnosed group (26.27% vs. 22.59%, p < 0.001). Among several dental health factors, missing teeth were significantly associated with higher cancer risk. Subjects with missing teeth showed a 12% increased cancer risk compared to those without missing teeth (odds ratio [OR] 1.12, 95% confidence interval [CI], 1.08-1.16). The risk was significantly higher, especially in lung, head and neck, pancreatic, liver, biliary, and esophageal cancers (OR 1.27 [95% CI, 1.14-1.41], 1.32 [95% CI, 1.13-1.55], 1.27 [95% CI, 1.02-1.58], 1.24 [95% CI, 1.1-1.4], 1.28 [95% CI, 1.03-1.6], 1.4 [95% CI, 1.04-1.88], respectively).

CONCLUSIONS

Missing teeth were the most important dental indicator associated with cancer risk. Korean adults with missing teeth should be cautious about the risk of several cancers, particularly head and neck, lung, gastrointestinal, hepatobiliary, and pancreatic cancer.

Microbiota Regulates Pancreatic Cancer Carcinogenesis through Altered Immune Response

The microbiota is present in many parts of the human body and plays essential roles. The most typical case is the occurrence and development of cancer. Pancreatic cancer (PC), one of the most aggressive and lethal types of cancer, has recently attracted the attention of researchers. Recent research has revealed that the microbiota regulates PC carcinogenesis via an altered immune response. Specifically, the microbiota, in several sites, including the oral cavity, gastrointestinal tract, and pancreatic tissue, along with the numerous small molecules and metabolites it produces, influences cancer progression and treatment by activating oncogenic signaling, enhancing oncogenic metabolic pathways, altering cancer cell proliferation, and triggering chronic inflammation that suppresses tumor immunity. Diagnostics and treatments based on or in combination with the microbiota offer novel insights to improve efficiency compared with existing therapies.

The role of Fusobacteria in oral cancer and immune evasion

PURPOSE OF REVIEW

There is growing evidence that suggests a possible role for bacteria in the progression of cancer. Fusobacteria have been detected in different types of cancers, including colorectal and oral cancers. Fusobacteria are common opportunistic oral bacteria known to cause various infections. In this review, we focus on the association between Fusobacteria and cancer, specifically oral cancer, and provide insight into the role of Fusobacteria in carcinogenesis and immune evasion.

RECENT FINDINGS

Recently, it has been suggested that Fusobacteria are among the bacteria that contribute to the progression of cancer and might affect disease prognosis and treatment outcome. Moreover, Fusobacteria might alter tumor microenvironment and have an impact on tumor immune response. Thus, understanding the effect of Fusobacteria on cancer cells and tumor microenvironment is crucial to improve treatment outcome.

SUMMERY

Recent evidences suggest that Fusobacteria not only have an impact on tumor progression, but might also affect tumor immune response. Moreover, Fusobacteria presence in the tumor microenvironment might have an impact on treatment outcome and might be used as a prognostic factor.

Could there be an interplay between periodontal changes and pancreatic malignancies?

The term "periodontal disease" refers to a group of chronic inflammatory illnesses caused by specific microorganisms from subgingival biofilm, that affect the tooth-supporting tissues. Recent research has also shown that periodontal infection plays a role in aggravating systemic disease states at distal sites, reinforcing the significance of the oral cavity for general health. Additionally, it has been suggested that gastroenterological malignancies may be promoted by hematogenous, enteral or lymphatic translocation of periopathogens. In the past 25 years, the global burden of pancreatic cancer (PC) has more than doubled, making it one of the major causes of cancer-related mortality. Periodontitis has been linked to at least 50% increased risk of PC and it could be considered a risk factor for this malignancy. A recent study performed on 59000 African American women with a follow up of 21 years showed that participants who had poor dental health had higher chances of PC. The findings, according to researchers, might be related to the inflammation that some oral bacteria trigger. Regarding the mortality of PC, periodontitis considerably raises the chance of dying from PC. Microbiome alterations in the gut, oral cavity and pancreatic tissues of PC patients occur when compared to healthy flora, demonstrating a link between PC and microecology. Inflammation may also contribute to PC development, although the underlying pathway is not yet known. The function of the microbiome in PC risk has drawn more focus over the last decade. Future risk of PC has been linked to the oral microbiome, specifically increased levels of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and decreased relative abundance of Leptotrichia and Fusobacteria, suggesting that it may have an impact on the inflammatory condition by expanding, altering, and regulating the commensal microbiome. Patients who received periodontal treatment had significantly decreased incidence rate ratios for PC. By analyzing patterns in the microbiome composition throughout PC development and establishing strategies to enhance the cancer-associated microbial system, we can increase the efficacy of therapy and eventually find an application for the microbial system. The development of immunogenomics and gut micro-genomics in the life sciences will result in a significant advancement in our understanding of how microbial systems and immunotherapy interact, and it may also have intriguing therapeutic implications for extending the lifetime of PC patients.

A Novel Chitosan Composite Biomaterial with Drug Eluting Capacity for Maxillary Bone Regeneration

Bone grafting is one of the most commonly performed treatments for bone healing or repair. Autografts, grafts from the same patient, are the most frequently used bone grafts because they can provide osteogenic cells and growth factors at the site of the implant with reduced risk of rejection or transfer of diseases. Nevertheless, this type of graft presents some drawbacks, such as pain, risk of infection, and limited availability. For this reason, synthetic bone grafts are among the main proposals in regenerative medicine. This branch of medicine is based on the development of new biomaterials with the goal of increasing bone healing capacity and, more specifically in dentistry, they aim at simultaneously preventing or eliminating bacterial infections. The use of fibers made of chitosan (CS) and hydroxyapatite (HA) loaded with an antibiotic (doxycycline, DX) and fabricated with the help of an injection pump is presented as a new strategy for improving maxillary bone regeneration. In vitro characterization of the DX controlled released from the fibers was quantified after mixing different amounts of HA (10-75%). The 1% CS concentration was stable, easy to manipulate and exhibited adequate cuttability and pH parameters. The hydroxyapatite concentration dictated the combined fast and controlled release profile of CSHA50DX. Our findings demonstrate that the CS-HA-DX complex may be a promising candidate graft material for enhancing bone tissue regeneration in dental clinical practice.

The association between the number of teeth and frailty among older nursing home residents: a cross-sectional study of the CLHLS survey

BACKGROUND

Given that few studies have explored the association between oral health and frailty among older nursing home residents, the purpose of this study was to assess the association between oral health (i.e., the number of teeth and oral behaviors) and frailty in this population using the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

METHODS

This was a national cross-sectional study derived from the seventh wave of CLHLS in 2018, consisting of 365 older nursing home residents aged 65 years or older. The frailty index was constructed based on 32 variables consisting of self-rated health status, anxiety, depression, ADL and IADL. Oral health was measured through the number of natural teeth and tooth brushing behavior. Multiple logistic regression was used to identify this association between the number of teeth, oral health behaviors, and frailty.

RESULTS

The mean age of this sample was 87.6 (SD = 9.5), with 154 (42.2%) males. The prevalence of frailty and edentulism was 71.2% and 33.4%, respectively. Multiple logistic regression analysis found that the likelihood of frailty decreased with an increased number of teeth, with an OR of 0.94 (95% CI: 0.91-0.98). Compared with participants with edentulism, older adults with 1 to 20 teeth had a lower likelihood of frailty (OR = 0.39, 95% CI: 0.17-0.88); these results were also found in older adults with more than 20 teeth (OR = 0.20, 0.07-0.57). Additionally, older adults who brush their teeth regularly have a lower likelihood of frailty than those who never brush their teeth (OR = 0.37, 95% CI: 0.13-0.99).

CONCLUSION

Older nursing home residents who maintain their natural teeth can help lower the risk of frailty, and regular toothbrushing also contributes to decreasing the risk of frailty. Our study emphasizes the importance of oral health, and cohort studies with large-scale samples to address this important issue are warranted in the future.

Novel Copper Oxide Bio-Nanocrystals to Target Outer Membrane Lectin of Vancomycin-Resistant Enterococcus faecium (VREfm): In Silico, Bioavailability, Antimicrobial, and Anticancer Potential

In present study, we used Olea europaea leaf extract to biosynthesize in situ Copper Oxide nanocrystals (CuO @OVLe NCs) with powerful antibacterial and anti-cancer capabilities. Physio-chemical analyses, such as UV/Vis, FTIR, XRD, EDX, SEM, and TEM, were applied to characterize CuO @OVLe NCs. The UV/Vis spectrum demonstrated a strong peak at 345 nm. Furthermore, FTIR, XRD, and EDX validated the coating operation's contact with colloidal CuO @OVLe NCs. According to TEM and SEM analyses, CuO @OVLe NCs exhibited a spherical shape and uniform distribution of size with aggregation, for an average size of ~75 nm. The nanoparticles demonstrated a considerable antibacterial effect against E. faecium bacterial growth, as well as an increased inhibition rate in a dose-dependent manner on the MCF-7, PC3, and HpeG2 cancer cell lines and a decreased inhibition rate on WRL-68. Molecular docking and MD simulation were used to demonstrate the high binding affinity of a ligand (Oleuropein) toward the lectin receptor complex of the outer membrane to vancomycin-resistant E. faecium (VREfm) via amino acids (Leu 195, Thr 288, His 165, and Ser 196). Hence, our results expand the accessibility of OVLe's bioactive components as a promising natural source for the manufacture of physiologically active components and the creation of green biosynthesis of metal nanocrystals.

Genetic contribution to cancer risk in patients with tooth loss: a genetic association study

Early-stage cancer diagnosis is critical for higher survival rates. Because early cancers can be difficult to detect, our focus is on the identification of cancer risk markers such as pleiotropic genes involved in the etiology of both craniofacial conditions and cancers. In this study we aimed to test if our previously detected association between ERN1 rs196929 marker and oral health outcomes would be detected in individuals diagnosed with cancer as well as in a subpopulation of individuals who also had one or more teeth missing due to dental caries, periodontal disease, or periapical lesions. We genotyped a total of 1,671 subjects and selected a subset of 1,421 subjects for stratified analysis of cancer types; three hundred and twelve self-reported a diagnosis of various cancer types and 1,109 reported never receiving a diagnosis of cancer. Our results showed a statistically significant association between the rs196929 in ERN1, and cancer overall in both the additive and dominant models (OR = 1.37, 95% C.I. 1.06-1.79, p = 0.014). When we stratified the analysis for each cancer type, our results show that the rs196929 ERN1 variant is associated with skin cancer (OR = 2.07, 95% C.I. 1.27-3.37, p = 0.003) and breast cancer (OR = 1.83, 95% C.I. 1.13-2.99, p = 0.013) in the subset of patients that had tooth loss. An additional nominal association between the rs196929 in ERN1 and male's reproductive system cancers (OR = 1.96, 95% C.I. 1.07-3.59, p = 0.028) was identified. We hope that our study helps guide future genetic studies on these cancers and this specific genetic variant as well as drive attention to the potential for oral health outcomes to serve as indicators for cancer risk. The early identification of genetic markers and/or oral conditions that indicate increased cancer risk could positively impact cancer outcomes and survival rates with timely implementation of preventive and diagnostic measures. In conclusion, our results suggest that the genetic variant in ERN1 (rs196929) is associated with increased risk of skin and breast cancers.

Associations Between Poor Oral Hygiene and Risk of Pancreatic Cancer: A Meta-analysis of Observational Studies

OBJECTIVES

Epidemiological studies have reported the association of poor oral hygiene, especially periodontal disease, and tooth loss with the risk of pancreatic cancer (PC). However, these studies have yielded inconsistent results. Therefore, this systematic review and meta-analysis aimed to investigate the relationship between oral disease and PC.

METHODS

We systematically searched the PubMed, Embase, and Cochrane Library databases for English literature since inception through May 2021. We used relative risks, hazard ratios, or odds ratios to measure the association between oral disease and PC. A fixed- or random-effects model was applied to evaluate pooled risk estimates, and sensitivity and subgroup analyses were performed to identify sources of heterogeneity and pooled estimation.

RESULTS

We identified 17 relevant observational studies involving 1,352,256 participants. Notably, oral disease correlated significantly with PC (hazard ratio [HR], 1.32; 95% confidence interval [CI], 1.13-1.54). In subgroup analyses, subjects with periodontal disease (HR, 1.38; 95% CI, 1.12-1.71) had a higher risk of developing PC than those with tooth loss (HR, 1.19; 95% CI, 0.97-1.46).

CONCLUSIONS

The results suggest that subjects with oral disease may face a significant and independent risk of PC. However, the mechanisms linking oral disease and PC are uncertain, and additional investigations of this correlation are warranted.

A retrospective study comparing oral health in cancer patients and healthy people

The purpose of this study was to investigate the relationship between oral and dental health in cancer patients and control group, which was conducted in Tabriz Shahid Gazi hospital. A researchers-made and validated questionnaire including oral and dental health criteria, was filled by the cancer patients (201 cases) and healthy controls (199 cases). Then, the results of the study were analyzed by SPSS software, and reported as Odds ratios (95 % confidence intervals) in tow groups. The results indicate that comparison of filled tooth, tooth extraction, dental caries, and gingival problems including bleeding, gum surgery and inflammation in cancer and controls were significantly meaningful. However, the comparison between the two groups was not significant in terms of the type of the tooth (natural or denture) and the number of daily toothbrushes, but they were considered as risk factors due to statistical results. Environmental factors, and especially oral hygiene, can play an important role in the incidence of different cancers. Among these, the type of oral microorganisms, and their overgrowth and released antigens should be studied further in the emergence of different kinds of cancer in humans.

Poor Oral Health and Esophageal Cancer Risk: A Nationwide Cohort Study

BACKGROUND

Previous research indicates that poor dental health increases risks for certain types of cancers, including esophageal cancer. This study aimed to investigate the association with esophageal cancer using Swedish Dental Health Register.

METHODS

This is a prospective cohort study. The exposures were dental diagnoses classified into healthy, caries, root canal infection, mild inflammation, and periodontitis, as well as number of remaining teeth, at baseline and during multiple visits. The outcome was the incidence of esophageal cancer, which was further divided into esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC). Cox proportional hazards models were used to estimate hazard ratios (HR) and its corresponding confidence intervals (CI).

RESULTS

A total of 5,042,303 individuals were included in the study and 1,259 EAC and 758 ESCC cases were identified. Root canal infection at baseline was associated with 41% higher risk for EAC (HR, 1.41; 95% CI, 1.10-1.82), whereas periodontitis at baseline was linked to 32% and 45% higher risks for respective histopathological subtypes (HR for EAC, 1.32; 95% CI, 1.13-1.53; HR for ESCC, 1.45; 95% CI, 1.20-1.75). Fewer remaining teeth at baseline also increased the risks for both histopathological types of esophageal cancer, with a dose-response effect (Ptrend < 0.01). Cox regression analyses with time-varying exposures corroborated the above-mentioned results.

CONCLUSIONS

Impaired dental health before cancer diagnosis is associated with excess risks for both histopathological subtypes of esophageal cancer.

IMPACT

Our study provided corroborating evidence for the association between poor oral health and esophageal cancer risk.

SGK1 negatively regulates inflammatory immune responses and protects against alveolar bone loss through modulation of TRAF3 activity

Serum- and glucocorticoid-regulated kinase 1 (SGK1) is a serine/threonine kinase that plays important roles in the cellular stress response. While SGK1 has been reported to restrain inflammatory immune responses, the molecular mechanisms involved remain elusive, especially in oral bacteria-induced inflammatory milieu. Here, we found that SGK1 curtails Porphyromonas gingivalis-induced inflammatory responses through maintaining levels of tumor necrosis factor receptor-associated factor (TRAF) 3, thereby suppressing NF-κB signaling. Specifically, SGK1 inhibition significantly enhances production of proinflammatory cytokines, including tumor necrosis factor α, interleukin (IL)-6, IL-1β, and IL-8 in P. gingivalis-stimulated innate immune cells. The results were confirmed with siRNA and LysM-Cre-mediated SGK1 KO mice. Moreover, SGK1 deletion robustly increased NF-κB activity and c-Jun expression but failed to alter the activation of mitogen-activated protein kinase signaling pathways. Further mechanistic data revealed that SGK1 deletion elevates TRAF2 phosphorylation, leading to TRAF3 degradation in a proteasome-dependent manner. Importantly, siRNA-mediated traf3 silencing or c-Jun overexpression mimics the effect of SGK1 inhibition on P. gingivalis-induced inflammatory cytokines and NF-κB activation. In addition, using a P. gingivalis infection-induced periodontal bone loss model, we found that SGK1 inhibition modulates TRAF3 and c-Jun expression, aggravates inflammatory responses in gingival tissues, and exacerbates alveolar bone loss. Altogether, we demonstrated for the first time that SGK1 acts as a rheostat to limit P. gingivalis-induced inflammatory immune responses and mapped out a novel SGK1-TRAF2/3-c-Jun-NF-κB signaling axis. These findings provide novel insights into the anti-inflammatory molecular mechanisms of SGK1 and suggest novel interventional targets to inflammatory diseases relevant beyond the oral cavity.

Periodontal disease affects oral cancer progression in a surrogate animal model for tobacco exposure

For decades, the link between poor oral hygiene and the increased prevalence of oral cancer has been suggested. Most recently, emerging evidence has suggested that chronic inflammatory diseases from the oral cavity (e.g., periodontal disease), to some extent, play a role in the development of oral squamous cell carcinoma (OSCC). The present study aimed to explore the direct impact of biofilm‑induced periodontitis in the carcinogenesis process using a tobacco surrogate animal model for oral cancer. A total of 42 Wistar rats were distributed into four experimental groups: Control group, periodontitis (Perio) group, 4‑nitroquinoline 1‑oxide (4‑NQO) group and 4NQO/Perio group. Periodontitis was stimulated by placing a ligature subgingivally, while oral carcinogenesis was induced by systemic administration of 4NQO in the drinking water for 20 weeks. It was observed that the Perio, 4NQO and 4NQO/Perio groups presented with significantly higher alveolar bone loss compared with that in the control group. Furthermore, all groups receiving 4NQO developed lesions on the dorsal surface of the tongue; however, the 4NQO/Perio group presented larger lesions compared with the 4NQO group. There was also a modest overall increase in the number of epithelial dysplasia and OSCC lesions in the 4NQO/Perio group. Notably, abnormal focal activation of cellular differentiation (cytokeratin 10‑positive cells) that extended near the basal cell layer of the mucosa was observed in rats receiving 4NQO alone, but was absent in rats receiving 4NQO and presenting with periodontal disease. Altogether, the presence of periodontitis combined with 4NQO administration augmented tumor size in the current rat model and tampered with the protective mechanisms of the cellular differentiation of epithelial cells.

Tooth Loss and Risk of Lung Cancer among Urban Chinese Adults: A Cohort Study with Meta-Analysis

Epidemiological evidence on tooth loss and lung cancer risk remains limited, especially for smoking-specific associations. To investigate the association between tooth loss and lung cancer risk by smoking status, we first analyzed data from the Shanghai Men’s Health Study (n = 49,868) and the Shanghai Women’s Health Study (n = 44,309). Cox regression models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for lung cancer risk in relation to tooth loss. We also conducted a meta-analysis to summarize epidemiologic findings to date, incorporating results from the current study and six previously published studies. For 7.3 median follow-up years, 973 incident lung cancer cases (613 men and 360 women) were ascertained. After adjustment for major covariates, tooth loss was associated with an increased risk of lung cancer among men (HR [95% CI] for >10 teeth vs. none = 1.59 [1.21−2.11]) but not among women (0.86 [0.50−1.46]). The positive association was stronger among male current smokers (1.75 [1.26−2.45], p-interaction by smoking status = 0.04). In a meta-analysis incorporating 4052 lung cancer cases and 248,126 non-cases, tooth loss was associated with a 1.64-fold increased risk of developing lung cancer (relative risk [RR, 95% CI] for the uppermost with the lowest category = 1.64 [1.44−1.86]). The positive association was more evident among current smokers (1.86 [1.41−2.46]), but no significant associations were found among never or former smokers. Our findings suggest that tooth loss may be associated with an increased risk of lung cancer, and the association could be modified by smoking status.

Early microbial markers of periodontal and cardiometabolic diseases in ORIGINS

Periodontitis affects up to 50% of individuals worldwide, and 8.5% are diagnosed with diabetes. The high-comorbidity rate of these diseases may suggest, at least in part, a shared etiology and pathophysiology. Changes in oral microbial communities have been documented in the context of severe periodontitis and diabetes, both independently and together. However, much less is known about the early oral microbial markers of these diseases. We used a subset of the ORIGINS project dataset, which collected detailed periodontal and cardiometabolic information from 787 healthy individuals, to identify early microbial markers of periodontitis and its association with markers of cardiometabolic health. Using state-of-the-art compositional data analysis tools, we identified the log-ratio of Treponema to Corynebacterium bacteria to be a novel Microbial Indicator of Periodontitis (MIP), and found that this MIP correlates with poor periodontal health and cardiometabolic markers early in disease pathogenesis in both subgingival plaque and saliva.

Role of Porphyromonas gingivalis in oral and orodigestive squamous cell carcinoma

Oral and esophageal squamous cell carcinomas harbor a diverse microbiome that differs compositionally from precancerous and healthy tissues. Though causality is yet to be definitively established, emerging trends implicate periodontal pathogens such as Porphyromonas gingivalis as associated with the cancerous state. Moreover, infection with P. gingivalis correlates with a poor prognosis, and P. gingivalis is oncopathogenic in animal models. Mechanistically, properties of P. gingivalis that have been established in vitro and could promote tumor development include induction of a dysbiotic inflammatory microenvironment, inhibition of apoptosis, increased cell proliferation, enhanced angiogenesis, activation of epithelial-to-mesenchymal transition, and production of carcinogenic metabolites. The microbial community context is also relevant to oncopathogenicity, and consortia of P. gingivalis and Fusobacterium nucleatum are synergistically pathogenic in oral cancer models in vivo. In contrast, oral streptococci, such as Streptococcus gordonii, can antagonize protumorigenic epithelial cell phenotypes induced by P. gingivalis, indicating functionally specialized roles for bacteria in oncogenic communities. Consistent with the notion of the bacterial community constituting the etiologic unit, metatranscriptomic data indicate that functional, rather than compositional, properties of the tumor-associated communities have more relevance to cancer development. A consistent association of P. gingivalis with oral and orodigestive carcinoma could have diagnostic potential for early detection of these conditions that have a high incidence and low survival rates.

A Comprehensive Review of the Current and Future Role of the Microbiome in Pancreatic Ductal Adenocarcinoma

Simple Summary

This review summarizes the current literature related to the microbiome and pancreatic ductal adenocarcinoma (PDAC). The aim of this review is to explore the current role of the microbiome in the disease process, screening/diagnostics and to postulate the future role with regards to therapeutic strategies including chemotherapy, immunotherapy and surgery. We further explore the future of microbiome modulation (faecal microbiome transplants, bacterial consortiums, anti-microbials and probiotics), their applications and how we can improve the future of microbiome modulation in a bid to improve PDAC outcomes.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second most common cause of cancer death in the USA by 2030, yet progress continues to lag behind that of other cancers, with only 9% of patients surviving beyond 5 years. Long-term survivorship of PDAC and improving survival has, until recently, escaped our understanding. One recent frontier in the cancer field is the microbiome. The microbiome collectively refers to the extensive community of bacteria and fungi that colonise us. It is estimated that there is one to ten prokaryotic cells for each human somatic cell, yet, the significance of this community in health and disease has, until recently, been overlooked. This review examines the role of the microbiome in PDAC and how it may alter survival outcomes. We evaluate the possibility of employing microbiomic signatures as biomarkers of PDAC. Ultimately this review analyses whether the microbiome may be amenable to targeting and consequently altering the natural history of PDAC.

Structural and functional analyses of the Porphyromonas gingivalis type IX secretion system PorN protein

Porphyromonas gingivalis, the major human pathogen bacterium associated with periodontal diseases, secretes virulence factors through the Bacteroidetes-specific type IX secretion system (T9SS). Effector proteins of the T9SS are recognized by the complex via their conserved C-terminal domains (CTDs). Among the 18 proteins essential for T9SS function in P. gingivalis, PorN is a periplasmic protein that forms large ring-shaped structures in association with the PorK outer membrane lipoprotein. PorN also mediates contacts with the PorM subunit of the PorLM energetic module, and with the effector’s CTD. However, no information is available on the PorN structure and on the implication of PorN domains for T9SS assembly and effector recognition. Here we present the crystal structure of PorN at 2.0-Å resolution, which represents a novel fold with no significant similarity to any known structure. In agreement with in silico analyses, we also found that the N- and C-terminal regions of PorN are intrinsically disordered. Our functional studies showed that the N-terminal disordered region is involved in PorN dimerization while the C-terminal disordered region is involved in the interaction with PorK. Finally, we determined that the folded PorN central domain is involved in the interaction with PorM, as well as with the effector’s CTD. Altogether, these results lay the foundations for a more comprehensive model of T9SS architecture and effector transport.

How Phantom Networks, Provider Qualities, and Poverty Sway Medicaid Dental Care Access: A Geospatial Analysis of Manhattan

Access to general dental care is essential for preventing and treating oral diseases. To ensure adequate spatial accessibility for the most vulnerable populations, New York State mandates a ratio of one general dentist to 2000 Medicaid recipients within 30 min of public transportation. This study employed geospatial methods to determine whether the requirement is met in Manhattan by verifying the online directories of ten New York managed care organizations (MCOs), which collectively presented 868 available dentists from 259 facilities. Our survey of 118 dental facilities representing 509 dentists revealed that significantly fewer dentists are available to treat Medicaid recipients compared to MCO directories. The average dentist-to-patient ratio derived from the MCO listings by the Two-Step Floating Catchment Area (2SFCA) method was 1:315, while the average verified ratio was only 1:1927. “Phantom networks”, or inaccurate provider listings, substantially overstated Medicaid dental accessibility. Surprisingly, our study also discovered additional Medicaid providers unlisted in any MCO directory, which we coined “hidden networks”. However, their inclusion was inconsequential to the overall dental supply. We further scrutinized dental care access by uniquely applying six “patient-centered characteristics”, and these criteria vastly reduced accessibility to an average ratio of merely 1:4587. Our novel evaluation of the spatial association between poverty, dental care access, and phantom networks suggests that Medicaid dental providers wish to be located in wealthier census tracts that are in proximity to impoverished areas for maximum profitability. Additionally, we discovered that poverty and phantom networks were positively correlated, and phantom providers masked a lack of dental care access for Medicaid recipients.

The biological index of frailty: A new index for the assessment of frailty in human skeletal remains

OBJECTIVE

Frailty is the physiological stress that individuals suffer during their life. In past populations, frailty is conventionally assessed through the occurrence of different biomarkers of biological stress. Some efforts have been made to propose indexes that combine all biomarkers. However, these indices have some critical limitations: they cannot be used on incomplete skeletons, do not consider the severity and/or healing of lesions, and assign equal importance to different biomarkers. To address these limitations, we propose a new index to assess frailty in skeletal individuals.

MATERIAL AND METHODS

By statistically analyzing a large amount of osteological data available from the Museum of London, and using a Logit model, we were able to define a different weight for each reported biomarker of frailty, based on their importance in increasing the risk of premature death for the individuals.

RESULTS

The biological index of frailty (BIF) is the weighted mean of all biomarkers scored on the individuals, according to a different degree of importance assigned to each one. It also considers the severity and healing of the biomarkers when this is relevant to diagnose frailty. We applied BIF on a sample of Monastics and Non-Monastics from medieval England and compared it with the skeletal index of frailty (SFI).

DISCUSSION

BIF is the first frailty index that gives a different weight to each skeletal biomarker of stress, considers both severity and healing of the lesions, and can be applied on partial skeletal remains. The comparison with SFI showed that BIF is applicable to a larger number of skeletal individuals, revealing new differences between the Monastic and the Non-Monastic groups.

Microbiome and Cancers of the Esophagus: A Review

Esophageal cancer (EC) is an aggressive malignant disease ranking amongst the leading causes of cancer deaths in the world. The two main histologic subtypes, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC), have distinct geographic and temporal patterns and risk factor profiles. Despite decades of research, the factors underlying these geo-temporal patterns are still not fully understood. The human microbiome has recently been implicated in various health conditions and disease, and it is possible that the microbiome may play an important role in the etiology of EC. Although studies of the microbiome and EC are still in their early stages, we review our current understanding of the potential links between ESCC, EAC, and bacterial communities in the oral cavity and esophagus. We also provide a summary of the epidemiology of EC and highlight some key challenges and future directions.

Composite likelihood inference for ordinal periodontal data with replicated spatial patterns

Spatial ordinal data observed separately for multiple subjects are common in biomedical research, yet statistical methodology for such ordinal data analysis is limited. The existing methodology often assumes a single realization of spatial ordinal data without replications, a commonplace in disease mapping studies, and thus are not directly applicable. Motivated by a dataset evaluating periodontal disease (PD) status, we propose a multisubject spatial ordinal model that assumes a geostatistical spatial structure within a regression framework through an elegant latent variable representation. For achieving computational scalability within a classical inferential framework, we develop a maximum composite likelihood method for parameter estimation, and establish the asymptotic properties of the parameter estimates. Another major contribution is the development of model diagnostic measures for our dependent data scenario using generalized surrogate residuals. A simulation study suggests sound finite sample properties of the proposed methods. We also illustrate our proposed methodology via application to the motivating PD dataset. A companion R package clordr is available for easy implementation.

The Microbiome as a Potential Target for Therapeutic Manipulation in Pancreatic Cancer

Simple Summary

Pancreatic cancer is one of the most lethal cancers. It is a difficult cancer to treat, and the complexity surrounding the pancreatic tumour is one of the contributing factors. The microbiome is the collection of microorganisms within an environment and its genetic material. They reside on body surfaces and most abundantly within the human gut in symbiotic balance with their human host. Disturbance in the balance can lead to many diseases, including cancers. Significant advances have been made in cancer treatment since the introduction of immunotherapy, and the microbiome may play a part in the outcome and survival of patients with cancer, especially those treated with immunotherapy. Immunotherapy use in pancreatic cancer remains challenging. This review will focus on the potential interaction of the microbiome with pancreas cancer and how this could be manipulated.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and is projected to be the second most common cause of cancer-related death by 2030, with an overall 5-year survival rate between 7% and 9%. Despite recent advances in surgical, chemotherapy, and radiotherapy techniques, the outcome for patients with PDAC remains poor. Poor prognosis is multifactorial, including the likelihood of sub-clinical metastatic disease at presentation, late-stage at presentation, absence of early and reliable diagnostic biomarkers, and complex biology surrounding the extensive desmoplastic PDAC tumour micro-environment. Microbiota refers to all the microorganisms found in an environment, whereas microbiome is the collection of microbiota and their genome within an environment. These organisms reside on body surfaces and within mucosal layers, but are most abundantly found within the gut. The commensal microbiome resides in symbiosis in healthy individuals and contributes to nutritive, metabolic and immune-modulation to maintain normal health. Dysbiosis is the perturbation of the microbiome that can lead to a diseased state, including inflammatory bowel conditions and aetiology of cancer, such as colorectal and PDAC. Microbes have been linked to approximately 10% to 20% of human cancers, and they can induce carcinogenesis by affecting a number of the cancer hallmarks, such as promoting inflammation, avoiding immune destruction, and microbial metabolites can deregulate host genome stability preceding cancer development. Significant advances have been made in cancer treatment since the advent of immunotherapy. The microbiome signature has been linked to response to immunotherapy and survival in many solid tumours. However, progress with immunotherapy in PDAC has been challenging. Therefore, this review will focus on the available published evidence of the microbiome association with PDAC and explore its potential as a target for therapeutic manipulation.

Periodontitis as a risk factor for head and neck cancer

Background

Periodontitis may be associated with the development of head and neck cancer (HNC). A literature review was conducted to understand the possible association between them.

Material and Methods

Articles published in the PubMed database from January 1999 and May 2020 were retrieved. Limitations of the studies and biological mechanisms were discussed.

Results

A total of 4,232 articles were found. Of these, 13 were analyzed according to inclusion criteria. Most papers found some association between periodontitis and HNC, although differences in periodontal evaluation, sample size, study design and tumor sites were observed. Porphyromonas gingivalis appears to increase the chance of both diseases, and it may be one of their main potential risk factors. Genetic predisposition is increased by exposure to environmental factors which can directly induce epigenetic changes that contribute to these diseases.

Conclusions

Understanding the mechanisms related to periodontitis and HNC has increased, however, well-designed clinical studies are needed for better conclusions. Furthermore, the advent of multiple "omic" technologies will help comprehend their possible association.

Key words:Periodontitis, head and neck cancer, oral cancer, risk factors, biological factors.

Oral Health and Risk of Upper Gastrointestinal Cancers in a Large Prospective Study from a High-risk Region: Golestan Cohort Study

Tooth loss and periodontal disease have been associated with several cancers, and poor oral health may be an important risk factor for upper gastrointestinal (UGI, i.e., esophageal and gastric) cancers. We assessed the relationship between oral health and UGI cancers using a large prospective study of over 50,000 adults living in Golestan Province, Iran, a high-incidence area for these cancers. Hazard ratios (HRs) and 95% confidence intervals (CI) were estimated for the association between three different measures of oral health [frequency of tooth brushing; number of missing teeth; and the sum of decayed, missing, and filled teeth (DMFT)] and UGI cancers. During a median follow-up duration of 13 years, there were 794 incident UGI cancers (396 esophageal and 398 gastric cancers). Daily tooth brushing was associated with a decreased risk of developing both esophageal (HR = 0.670; 95% CI: 0.486-0.924) and gastric (HR = 0.741; 95% CI: 0.544-1.01) cancers (combined UGI cancer HR = 0.697; 95% CI: 0.558-0.871) compared with never brushing. Tooth loss in excess of the loess smoothed, age- and sex-specific median number of teeth lost was significantly associated with esophageal (HR = 1.64; 95% CI: 1.08-2.47) and gastric cancers (HR = 1.58; 95% CI: 1.05-2.38). There were some adverse associations between DMFT and UGI cancers but most were not statistically significant. These results suggest increased risk of developing UGI cancers among individuals with poor oral health, and those who do not perform regular oral hygiene. PREVENTION RELEVANCE: Poor oral health is associated with the risk of upper gastrointestinal cancers, and oral hygiene practices may help prevent these cancers.

Decellularized matrix could affect the proliferation and differentiation of periodontal ligament stem cells in vitro

OBJECTIVE AND BACKGROUND

Recently, decellularized matrix (DCM) is considered as a new biomaterial for tissue regeneration. To explore the possible application of DCM in periodontal regeneration, the effect of DCM from three different cells on the proliferation and differentiation of human periodontal ligament stem cells (PDLSCs) was investigated.

METHODS

DCM derived from human periodontal ligament cells (PDLCs), dental pulp cells (DPCs), and gingival fibroblasts (GFs) were fabricated using Triton X-100/NH₄ OH combined with DNase I. Allogeneic PDLSCs were cultured on PDLC-DCM, DPC-DCM, and GF-DCM, respectively. The proliferative capacity of PDLSCs was evaluated by PicoGreen assay kit. The expression of alkaline phosphatase (ALP), runt-related transcription factor-2 (RUNX2), osteocalcin (OCN), collagen I (COL1), periostin (POSTN), and cementum protein 1 (CEMP1) were detected by qRT-PCR and western blotting.

RESULTS

PDLC-DCM, DPC-DCM, and GF-DCM had similar and integrated networks of extracellular matrix, as well as significantly decreased DNA content. Compared with control group in which PDLSCs were directly seeded in culture plates, PDLC-DCM, DPC-DCM, and GF-DCM promoted the proliferation of re-seeded PDLSCs. Additionally, PDLSCs on DCM exhibited higher mRNA and protein expression levels of ALP, RUNX2, OCN, and COL1. The expression of POSTN in PDLC-DCM group was significantly higher than control group at both mRNA and protein levels.

CONCLUSIONS

PDLC-DCM, DPC-DCM, and GF-DCM could enhance the proliferation of PDLSCs. PDLC-DCM facilitated osteogenic differentiation and periodontal ligament differentiation of PDLSCs, while DPC-DCM and GF-DCM promoted osteogenic differentiation.

Investigating efficacy of "microbiota modulation of the gut-lung Axis" combined with chemotherapy in patients with advanced NSCLC: study protocol for a multicenter, prospective, double blind, placebo controlled, randomized trial

Background

Most NSCLCs metastasised out of the lungs at the time of diagnosis and cannot be surgically removed . Cytotoxic chemotherapy drugs have become the main treatment in recent decades, especially in patients with NSCLC without EGFR, ALK, and ROS gene mutations. The prognosis of lung cancer is poor, and the overall 5-year survival rate is only 9–13%. Therefore the treatment of advanced NSCLC remains a significant medical need. Recent studies have shown a significant relationship between the gut-lung axis microecology and malignant tumors. Intestinal probiotics are likely to play a role in inhibiting tumorigenesis through “intestinal-pulmonary axis microecological regulation”. This study will seek to investigate the efficacy of “Microbiota modulation of the Gut-Lung Axis” combined with chemotherapy in patients with advanced NSCLC.

Methods

The research is a multicenter, prospective, double blind, placebo controlled, randomized trial. Based on the theoretical basis of “intestinal and lung axis microecological adjustment”, combined with traditional platinum-containing two-drug chemotherapy, the efficacy of the new therapy on patients with advanced NSCLC was observed. Collect the basic information of the patient, and study the effect of platinum-based combined chemotherapy on the diversity of intestinal flora in patients with lung cancer after receiving chemotherapy treatment, feces before and after chemotherapy, and the status and extent of adverse reactions during chemotherapy . A total of 180 subjects were included, divided into a control group (platinum-containing dual-drug chemotherapy) and an intervention group (platinum-containing dual-drug chemotherapy combined with Bifico), and were randomly assigned to the group 1:1.

Discussion

As a result, intestinal-pulmonary microecological balance could become a new target for the treatment of lung cancer. This study explores the combination of intestinal microecological regulation and chemotherapy to provide new treatment strategies and basis for lung cancer patients. It can help prolong the survival time of lung cancer patients and improve the quality of life, thereby generating huge economic and social benefits. The results can be promoted and applied to units engaged in the treatment of lung cancer.

Trial registration number

NCT03642548, date: August 22, 2018, the first version protocol. The URL of trial registry record: https://clinicaltrials.gov/ct2/show/NCT03642548?term=NCT03642548&draw=2&rank=1.

A Sandwich Structure of Human Dental Pulp Stem Cell Sheet, Treated Dentin Matrix, and Matrigel for Tooth Root Regeneration

Tooth loss can cause a lot of physiological and psychological suffering. And tooth root engineering is a promising way for tooth loss treatment. Two kinds of seed cells are usually adopted for tooth root regeneration. In this study, a practical sandwich structure for tooth root regeneration was developed, which was constituted by only one kind of seed cell: human dental pulp stem cells (hDPSCs) and three kinds of graft materials: Vitamin C (VC) induced hDPSC sheet, human treated dentin matrix (hTDM), and Matrigel. It was found that VC could induce hDPSCs to form a cell sheet with two or three cell layers and promote their collagen type I (COL1) mRNA expression obviously. hDPSCs could attach and grow on hTDM, and the mRNA expression of osteocalcin (OCN), dentin sialophosphoprotein (DSPP), vascular endothelial growth factor receptor 1 (VEGFR1), and Nestin in hDPSCs was obviously upregulated by hTDM leaching solution. hDPSCs could stretch and proliferate in Matrigel. And when cultured in Matrigel condition medium, they positively expressed CD31, β3-Tubulin, and Nestin proteins, as well as increased the mRNA expression of OCN, ALP, and Nestin. Furthermore, periodontium, dentin, and pulp-like tissues were successfully regenerated after the sandwich structure of hDPSC sheet/TDM/Matrigel was transplanted in nude mice subcutaneously for 3 months. Periodontium-like dense connective tissue was regenerated around the hTDM, and a great mass of predentin was formed on the cavity side of hTDM. Odontoblast-like cells and blood vessel-like structures, even nerve-like fibers, were observed in the pulp cavity. In summary, the above results showed that hDPSCs could be used as seed cells for the whole tooth root regeneration, and the sandwich structure constituted by hDPSC sheet, TDM/hDPSCs, and Matrigel/hDPSCs could be utilized for tooth root regeneration.

Relationship between the prevalence of oral human papillomavirus DNA and periodontal disease (Review)

Human papillomavirus (HPV) is a small DNA virus that infects the basal keratinocytes of squamous epithelium in the skin, and in the oral and genital mucosa. Smoking and sexual behavior have been recognized as significant risk factors for oral HPV infection. In the present review, the findings of recent studies of oral HPV infection in relation to periodontitis are discussed, as well as periodontopathic bacteria and periodontal herpes virus. Previous research suggests that HPV localizes to the inflammatory periodontal tissue. Inflammatory periodontal pockets may thus act as a reservoir for HPV. The interactions between HPV and periodontopathic bacteria remain unclear, but it is hypothesized that oral HPV infection may be related to a characteristic oral microbiome. Smoking is associated with HPV and periodontitis, as smoking induces destruction of periodontal tissue and suppresses the host defense, allowing HPV to infect periodontal tissue. Carcinogenic HPV and periodontitis may lead to the development of oral cavity cancer. However, oral HPV E6/E7 expression (transcriptionally active HPV) has not yet been fully investigated in patients with periodontitis. Collectively, the evidence suggests that oral HPV prevalence may be associated with periodontitis. The effect of clinical factors (age, sex, smoking, immunosuppressive condition and vaccination) on oral HPV DNA prevalence should be considered when clarifying the relationship between oral HPV and periodontitis. Additionally, the sampling method should be carefully chosen to directly detect HPV DNA in periodontal tissues.

Direct MALDI-TOF profiling of gingival crevicular fluid sediments for periodontitis diagnosis

Periodontitis is a widespread stomatological disease and represents one of the main causes of tooth loss in adults. Traditional diagnosis of periodontitis relies on the judgment by professional periodontists that cannot reveal its progression at the early stage. In this work, we characterized the gingival crevicular fluid (GCF) sediments of patients with periodontitis and healthy volunteers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Potential protein biomarkers were selected based on the multivariate statistical analysis of the MALDI-TOF mass spectra, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification. Twelve potential protein biomarkers were identified from 17 patients compared to 7 healthy volunteers, including 5 microbial proteins and 7 human proteins, indicating the microbial composition and host response components related to the etiology of periodontitis. The panel of biomarkers was then verified with the GCF samples of another 11 patients. The 12 biomarkers also showed potential value in the early diagnosis of periodontitis. This work developed a rapid assay to screen periodontitis among populations. It can be popularized to non-periodontal specialists such as community general practitioners, benefiting the early and accurate monitoring of periodontitis. The identification of the potential biomarkers can also help in the understanding of the pathogenesis of periodontitis.

Association of Edentulism with Various Chronic Diseases in Mexican Elders 60+ Years: Results of a Population-Based Survey

Objective: To determine the association of edentulism with different chronic diseases and mental disorders in Mexicans aged 60 years and over. Material and Methods: A cross-sectional study was carried out using data from the World Health Survey for Mexico, in a probabilistic, multi-stage cluster sampling framework. Data for self-report of chronic diseases (diabetes, arthritis, angina pectoris and asthma), mental disorders (depression and schizophrenia) and edentulism were analyzed. Edentulism data were available for 20 of the 32 States of Mexico. Statistical analysis was performed in Stata 14.0 using the svy module for complex sampling (Complex nature under which individuals are sampled). Results: In total 4213 subjects were included, representing a population of 7,576,057 individuals. Mean age was 70.13 ± 7.82 years (range 60 to 98); 56.2% were women. Chronic diseases’ prevalence and mental disorders prevalence were as follows: diabetes 15.0% (N = 1,132,693); arthritis 13.2% (N = 1,001,667); depression 5.5% (N = 414,912); angina pectoris 4.5% (344,315); asthma 3.6% (N = 269,287); and schizophrenia 2.2% (N = 16,988). The prevalence of edentulism was 26.3%, which pertained to 1,993,463 people aged 60 years and over. Angina in women aged 60 to 69 years (p < 0.05) and depression in men aged 70 years and over (p < 0.0001) were associated with higher prevalence of edentulism. Conclusions: There was generally sparse association between edentulism on chronic diseases and mental disorders included in the study, except for women aged 60 to 69 years for angina, and in men aged 70 and over, for depression. Although our findings are misaligned with previous reports, longitudinal studies are required to test causal and temporal relationships between edentulism with chronic diseases and mental disorders.

Tailored Doxycycline Hyclate Loaded In Situ Gel for the Treatment of Periodontitis: Optimization, In Vitro Characterization, and Antimicrobial Studies

Currently, periodontitis is treated by oral dosage forms (antibiotics) which shows systemic side effects and failed to reach the therapeutic concentration (above minimum inhibitory concentration, MIC) in the periodontal pocket. The present study aimed to overcome the above issues, by designing tailored doxycycline hyclate laden in situ gel by Poloxamer 407, chitosan, and polyethylene glycol 600. The in situ gel-forming system has attracted attention owing to its ability of sustained drug release above MIC, easy administration (syringeability), and high drug retention (localization) in the periodontal cavity. The Box-Behnken design (BBD) was used to tailor and optimize the concentration of Poloxamer 407 (X₁ = 14.3%), chitosan (X₂ = 0.58%), and polyethylene glycol 600 (X₃ = 1.14%) to achieve sufficient syringeability (149 N), t_90% (1105 min), and viscosity at non-physiological condition (512 cps) and physiological condition (5415 cps). The optimized in situ gel was clear and isotonic (RBCs test). The gelation temperature of the optimized in situ was 34 ± 1°C with sufficient mucoadhesive strength (26 ± 2 dyn/cm²), gel strength (29 ± 2 sec), and texture profile for periodontal application. The in vitro drug release studies showed sustain release from optimized in situ gel (24h) in comparison to marketed gel (7h). The antimicrobial activity (cup plate technique) of the in situ gel was equivalent to the marketed doxycycline gel, which suggests that the doxycycline hyclate retained its antimicrobial efficacy when formulated as in situ gelling system. In conclusion, BBD was effectively utilized to optimize in situ gel with minimum level of polymers to achieve the required characteristics of the in situ gel for sustaining drug delivery to treat periodontitis.