Association of oral pathology, oral microbiology, and oral oncology

Periodontitis can disrupt oral and gut microbiota, leading to dysbiosis that affects overall systemic health. Besides the spread of periodontal pathogens by the hematogenous route, they can also be translocated into the gastrointestinal tract, possibly intervening in the neoplastic process in the gastrointestinal tract. This manuscript reviews the relationship between oral and gut microbiota due to periodontitis, discussing systemic health implications and potential links to gastrointestinal cancer. This article highlights the significance and effect of dysbiosis in the gut, emphasizing the importance of maintaining oral health to prevent systemic diseases. Lastly, it will go through therapeutic innovations such as probiotics and oral microbiota analysis tools for systemic disease detection. These findings will mark the integration of oral health management in clinical practice to lower systemic disease risk and improve overall patient outcomes. Aim of work: This manuscript aims to unravel the pathological interaction between oral and gut microbiota and their bidirectional effect on systemic diseases. Materials and methods: The review was performed using the MEDLINE and ScienceDirect databases. Reviewed articles were published in English between the year 2015 and 2024. The search used keywords such as (“oral microbiota” AND “periodontal disease”) OR (“oral microbiota” AND “gastrointestinal cancer”) OR (“Porphyromonas gingivalis” AND “periodontal disease”) OR (“Helicobacter pylori” AND “gastric cancer”) OR (“gut microbiome” AND “inflammatory bowel disease”) OR (“oral microbiome” AND “systemic diseases”). Conclusions: The dysbiotic change in the oral cavity due to periodontitis is linked directly and indirectly to systemic diseases such as IBS, neurodegenerative diseases, muscle joint diseases, respiratory infections, and gastrointestinal cancer; this underscores the importance of maintaining oral hygiene for prophylaxis of oral diseases and the prevention of systemic diseases. A better understanding of the interconnections between oral health and systemic diseases will integrate oral health management to offer new prevention, diagnostic, and treatment opportunities to improve overall patient outcomes.

<p dir="ltr">Oral microbiome is regarded as a complex ecological community consisting of different bacteria, archaea, and viruses, dedicated to not only the health of the oral cavity but also to the whole system. Altered oral microbiome is associated with many systemic inflammation and diseases, especially in the gastrointestinal system, including oral infection, pancreas diseases, and liver dysfunction. This thesis focused primarily on the role of the oral microbiome in different diseases in the gastrointestinal system to investigate the cross-talk between the host immune system and the oral microbial community.</p><p dir="ltr">In paper I, a cohort study was performed to investigate the interaction between humoral immunity to pancreas-associated oral microbes and Intraductal papillary mucinous neoplasms (IPMNs), a cystic precursor to pancreatic cancer (PC). Our findings indicated that humoral reactivity against pancreas-associated oral microbes, Fusobacterium Nucleatum (F. Nucleatum) could reflect IPMN severity, and validate the possible binding sites of this oral pathogen, which are beneficial for biomarker development to identify the phase of IPMN and spot the potential risk in the progression to PC.</p><p dir="ltr">In paper II, we studied the Mucosal-associated invariant T (MAIT) cells, one of the subsets of innate-like T cells, in a classic oral infectious disease - apical periodontitis (AP) and the involvement of MAIT cells in the local defense at the oral tissue barrier. The novel and optimized methods described the presence of MAIT cells at the site of AP lesion in the oral cavity where the translocation of oral microbiota could take place, and bacteria relative abundance was observed to be negatively correlated with MAIT cell T cell receptor (TCR) transcript expressions in AP, which deepen the understanding the immune sensing of polymicrobial-related oral diseases.</p><p dir="ltr">In paper III, we described the oral dysbiosis observed in alcoholic liver disease (ALD) patients with liver injury and established an animal model of ALD to investigate the role and mechanism of Porphyromonas gingivalis (P. gingivalis), a keystone pathogen for periodontitis, in the advancement of this diseases. P. gingivalis was observed to aggravate the hepatic steatosis and inflammation cell infiltration in vivo and demonstrated to induce the ferroptosis in human fetal hepatocyte line in vitro. Our findings showed that P. gingivalis was a promoter that could aggravate the pathogenesis of ALD via ferroptosis, suggesting that periodontal disease treatment and oral microbial control in ALD patients accompanied by ferroptosis inhibition may be a potential treatment in the future.</p><p dir="ltr">In paper IV, we investigated the oral bacterial community in patients diagnosed with chronic hepatitis B (CHB), focusing on those with well-controlled liver function who were not receiving antiviral treatment. We characterized their oral microbiota composition and assessed their oral health status. Our findings underscore the importance of the oral microbiome in the context of viral hepatitis, suggesting that maintaining oral health could serve as a beneficial adjunctive strategy in managing liver diseases.</p><h3>List of scientific papers</h3><p dir="ltr">I. Hassan Alkharaan, Liyan Lu, Giorgio Gabarrini, Asif Halimi, Zeeshan Ateeb, Michał J. Sobkowiak, Haleh Davanian, Carlos Fernández Moro, Leif Jansson, Marco Del Chiaro, Volkan Özenci, Margaret Sällberg Chen. Circulating and Salivary Antibodies to Fusobacterium nucleatum Are Associated with Cystic Pancreatic Neoplasm Malignancy. Front Immunol. 2020;11:2003.<br><a href="https://doi.org/10.3389/fimmu.2020.02003" rel="noreferrer" target="_blank">https://doi.org/10.3389/fimmu.2020.02003</a></p><p dir="ltr"><br></p><p dir="ltr">II. Haleh Davanian, Rogier Aäron Gaiser, Mikael Silfverberg, Luisa W. Hugerth, Michał J. Sobkowiak, Liyan Lu, Katie Healy, Johan K. Sandberg, Peggy Näsman, Jörgen Karlsson, Leif Jansson, Lars Engstrand, Margaret Sällberg Chen. Mucosal-associated invariant T cells and oral microbiome in persistent apical periodontitis. Int J Oral Sci. 2019;11(2):16.<br><a href="https://doi.org/10.1038/s41368-019-0049-y" rel="noreferrer" target="_blank">https://doi.org/10.1038/s41368-019-0049-y</a></p><p dir="ltr"><br></p><p dir="ltr">III. Chao Yao, Liyan Lu, Dongmei Lan, Xueqin Zhu, Xue Li, Yaohui Gao, Yingqun Zhou, Yan Wang, Yuanzhi Xu, Shengcai Qi. Porphyromonas gingivalis as a promotor in the development of the alcoholic liver disease via ferroptosis. Microbes Infect. 2024;26(3):105250.<br><a href="https://doi.org/10.1016/j.micinf.2023.105250" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.micinf.2023.105250</a></p><p dir="ltr"><br></p><p dir="ltr">IV. Liyan Lu, Lingjun Yan, Amir Sohrab, Karin Lindahl, Susanne Cederberg, Raorao Wang, Weimin Ye, Soo Aleman, Margaret Sällberg Chen. The salivary microbiome and oral health status in HBeAg-negative chronic hepatitis B. [Accepted]</p>

<p dir="ltr">Oral microbiome is regarded as a complex ecological community consisting of different bacteria, archaea, and viruses, dedicated to not only the health of the oral cavity but also to the whole system. Altered oral microbiome is associated with many systemic inflammation and diseases, especially in the gastrointestinal system, including oral infection, pancreas diseases, and liver dysfunction. This thesis focused primarily on the role of the oral microbiome in different diseases in the gastrointestinal system to investigate the cross-talk between the host immune system and the oral microbial community.</p><p dir="ltr">In paper I, a cohort study was performed to investigate the interaction between humoral immunity to pancreas-associated oral microbes and Intraductal papillary mucinous neoplasms (IPMNs), a cystic precursor to pancreatic cancer (PC). Our findings indicated that humoral reactivity against pancreas-associated oral microbes, Fusobacterium Nucleatum (F. Nucleatum) could reflect IPMN severity, and validate the possible binding sites of this oral pathogen, which are beneficial for biomarker development to identify the phase of IPMN and spot the potential risk in the progression to PC.</p><p dir="ltr">In paper II, we studied the Mucosal-associated invariant T (MAIT) cells, one of the subsets of innate-like T cells, in a classic oral infectious disease - apical periodontitis (AP) and the involvement of MAIT cells in the local defense at the oral tissue barrier. The novel and optimized methods described the presence of MAIT cells at the site of AP lesion in the oral cavity where the translocation of oral microbiota could take place, and bacteria relative abundance was observed to be negatively correlated with MAIT cell T cell receptor (TCR) transcript expressions in AP, which deepen the understanding the immune sensing of polymicrobial-related oral diseases.</p><p dir="ltr">In paper III, we described the oral dysbiosis observed in alcoholic liver disease (ALD) patients with liver injury and established an animal model of ALD to investigate the role and mechanism of Porphyromonas gingivalis (P. gingivalis), a keystone pathogen for periodontitis, in the advancement of this diseases. P. gingivalis was observed to aggravate the hepatic steatosis and inflammation cell infiltration in vivo and demonstrated to induce the ferroptosis in human fetal hepatocyte line in vitro. Our findings showed that P. gingivalis was a promoter that could aggravate the pathogenesis of ALD via ferroptosis, suggesting that periodontal disease treatment and oral microbial control in ALD patients accompanied by ferroptosis inhibition may be a potential treatment in the future.</p><p dir="ltr">In paper IV, we investigated the oral bacterial community in patients diagnosed with chronic hepatitis B (CHB), focusing on those with well-controlled liver function who were not receiving antiviral treatment. We characterized their oral microbiota composition and assessed their oral health status. Our findings underscore the importance of the oral microbiome in the context of viral hepatitis, suggesting that maintaining oral health could serve as a beneficial adjunctive strategy in managing liver diseases.</p><h3>List of scientific papers</h3><p dir="ltr">I. Hassan Alkharaan, Liyan Lu, Giorgio Gabarrini, Asif Halimi, Zeeshan Ateeb, Michał J. Sobkowiak, Haleh Davanian, Carlos Fernández Moro, Leif Jansson, Marco Del Chiaro, Volkan Özenci, Margaret Sällberg Chen. Circulating and Salivary Antibodies to Fusobacterium nucleatum Are Associated with Cystic Pancreatic Neoplasm Malignancy. Front Immunol. 2020;11:2003.<br><a href="https://doi.org/10.3389/fimmu.2020.02003" rel="noreferrer" target="_blank">https://doi.org/10.3389/fimmu.2020.02003</a></p><p dir="ltr"><br></p><p dir="ltr">II. Haleh Davanian, Rogier Aäron Gaiser, Mikael Silfverberg, Luisa W. Hugerth, Michał J. Sobkowiak, Liyan Lu, Katie Healy, Johan K. Sandberg, Peggy Näsman, Jörgen Karlsson, Leif Jansson, Lars Engstrand, Margaret Sällberg Chen. Mucosal-associated invariant T cells and oral microbiome in persistent apical periodontitis. Int J Oral Sci. 2019;11(2):16.<br><a href="https://doi.org/10.1038/s41368-019-0049-y" rel="noreferrer" target="_blank">https://doi.org/10.1038/s41368-019-0049-y</a></p><p dir="ltr"><br></p><p dir="ltr">III. Chao Yao, Liyan Lu, Dongmei Lan, Xueqin Zhu, Xue Li, Yaohui Gao, Yingqun Zhou, Yan Wang, Yuanzhi Xu, Shengcai Qi. Porphyromonas gingivalis as a promotor in the development of the alcoholic liver disease via ferroptosis. Microbes Infect. 2024;26(3):105250.<br><a href="https://doi.org/10.1016/j.micinf.2023.105250" rel="noreferrer" target="_blank">https://doi.org/10.1016/j.micinf.2023.105250</a></p><p dir="ltr"><br></p><p dir="ltr">IV. Liyan Lu, Lingjun Yan, Amir Sohrab, Karin Lindahl, Susanne Cederberg, Raorao Wang, Weimin Ye, Soo Aleman, Margaret Sällberg Chen. The salivary microbiome and oral health status in HBeAg-negative chronic hepatitis B. [Accepted]</p>

Rationale: Mechanisms of HIV-associated chronic obstructive pulmonary disease (COPD) are poorly understood. The oral microbiome shapes the lung microbiome, and gut dysbiosis can affect lung diseases; however, relationships of the oral and gut microbiome to COPD in HIV have not been explored.Objectives: To examine alterations in the oral and gut microbiome associated with pulmonary disease in persons with HIV (PWH).Methods: Seventy-five PWH and 93 HIV-uninfected men from the MACS (Multicenter AIDS Cohort Study) performed pulmonary function testing. Sequencing of bacterial 16S ribosomal RNA in saliva and stool was performed. We used nonmetric multidimensional scaling, permutational multivariate ANOVA, and linear discriminant analysis to analyze communities by HIV and lung function.Measurements and Main Results: Oral microbiome composition differed by HIV and smoking status. Alterations of oral microbial communities were observed in PWH with abnormal lung function with increases in relative abundance of Veillonella, Streptococcus, and Lactobacillus. There were no significant associations between the oral microbiome and lung function in HIV-uninfected individuals. No associations with HIV status or lung function were seen with the gut microbiome.Conclusions: Alterations of oral microbiota in PWH were related to impaired pulmonary function and to systemic inflammation. These results suggest that the oral microbiome may serve as a biomarker of lung function in HIV and that its disruption may contribute to COPD pathogenesis.

The oral microbiota plays a critical role in both local and systemic inflammation. Metabolic syndrome (MetS) is characterized by low-grade inflammation, and many studies have been conducted on the gut microbiota from stool specimens. However, the etiological role of the oral microbiota in the development of MetS is unclear. In this study, we analyzed the oral and gut microbiome from 228 subgingival plaque and fecal samples from a Korean twin-family cohort with and without MetS. Significant differences in microbial diversity and composition were observed in both anatomical niches. However, a host genetic effect on the oral microbiota was not observed. A co-occurrence network analysis showed distinct microbiota clusters that were dependent on the MetS status. A comprehensive analysis of the oral microbiome identified Granulicatella and Neisseria as bacteria enriched in subjects with MetS and Peptococcus as bacteria abundant in healthy controls. Validation of the identified oral bacteria by quantitative PCR (qPCR) showed that healthy controls possessed significantly lower levels of G. adiacens (p = 0.023) and a higher ratio of Peptococcus to Granulicatella (p < 0.05) than MetS subjects. Our results support that local oral microbiota can be associated with systemic disorders. The microbial biomarkers identified in this study would aid in determination of which individuals develop chronic diseases from their MetS and contribute to strategic disease management.

Background: The oral cavity is associated with local and systemic diseases, although oral samples are not as commonly studied as fecal samples in microbiome research. There is a gap in understanding between the similarities and differences in oral and gut microbiomes and how they may influence each other. Methods: A scoping literature review was conducted comparing oral and gut microbiome communities in healthy humans. Results: Ten manuscripts met inclusion criteria and were examined. The oral microbiome sites demonstrated great variance in differential bacterial abundance and the oral microbiome had higher alpha diversity as compared to the gut microbiome. Studies using 16S rRNA sequencing analysis resulted in overall community differences between the oral and gut microbiomes when beta diversity was analyzed. Shotgun metagenomics sequencing increased taxonomic resolution to strain level (intraspecies) and demonstrated a greater percentage of shared taxonomy and oral bacterial translocation to the gut microbiome community. Discussion: The oral and gut microbiome bacterial communities may be more similar than earlier research has suggested, when species strain is analyzed through shotgun metagenomics sequencing. The association between oral health and systemic diseases has been widely reported but many mechanisms underlying this relationship are unknown. Although future research is needed, the oral microbiome may be a novel interventional target through its downstream effects on the gut microbiome. As nurse scientists are experts in symptom characterization and phenotyping of patients, they are also well posed to lead research on the connection of the oral microbiome to the gut microbiome in health and disease.

The human microbiome project (HMP) promoted further understanding of human oral microbes. However, research on the human oral microbiota has not made as much progress as research on the gut microbiota. Currently, the causal relationship between the oral microbiota and oral diseases remains unclear, and little is known about the link between the oral microbiota and human systemic diseases. To further understand the contribution of the oral microbiota in oral diseases and systemic diseases, a Human Oral Microbiome Database (HOMD) was established in the US. The HOMD includes 619 taxa in 13 phyla, and most of the microorganisms are from American populations. Due to individual differences in the microbiome, the HOMD does not reflect the Chinese oral microbial status. Herein, we established a new oral microbiome database—the Oral Microbiome Bank of China (OMBC, http://www.sklod.org/ombc). Currently, the OMBC includes information on 289 bacterial strains and 720 clinical samples from the Chinese population, along with lab and clinical information. The OMBC is the first curated description of a Chinese-associated microbiome; it provides tools for use in investigating the role of the oral microbiome in health and diseases, and will give the community abundant data and strain information for future oral microbial studies.

Background: The oral microbiota may be involved in head and neck squamous cell cancer (HNSCC) etiology, yet current evidence is largely limited to bacterial 16S amplicon sequencing or small retrospective case-control studies. We tested whether any oral bacteria and/or fungi influence the subsequent risk of HNSCC development. Methods: We conducted a prospective case-control study nested within three epidemiological cohorts: the ACS-Cancer Prevention Study-II Nutrition Cohort (ACS-CPS-II), the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), and the Southern Community Cohort Study (SCCS). Among 159,840 cohort participants, 236 individuals developed HNSCC during an average of 5.1 years of follow-up, and 485 controls who remained HNSCC-free were selected by 2:1 frequency matching, by cohort, age, sex, race/ethnicity, and time since mouthwash collection. All participants provided mouthwash samples and were cancer-free at baseline. We characterized the oral bacterial microbiome, using whole-genome shotgun sequencing, and the oral fungal microbiome, using ITS sequencing. We assessed relative abundance of microbiome-wide bacterial and fungal taxa for association with HNSCC by ANCOM-BC analysis. We also evaluated selected oral pathogen complexes for association with HNSCC by logistic regression. A microbial risk score (MRS) for HNSCC risk was calculated from all risk-associated microbes. Results: Overall microbiome diversity at baseline was not related to the subsequent risk of HNSCC; however, we found that 13 oral bacterial species were differentially associated with development of this disease (P&amp;lt;0.05), including newly identified Prevotella salivae, Streptococcus sanguinis, Leptotrichia sp, and several species belonging to Beta- and Gamma-proteobacteria. Furthermore, a priori periodontal pathogen complexes were associated with a higher risk of HNSCC (“red/orange” complex, OR=1.06, 95% CI=1.00-1.12). We did not identify any fungal taxa associated with HNSCC risk. Together, an MRS constructed for risk-associated bacteria and bacterial periodontal complexes conferred a 50% increase in HNSCC risk, per standard deviation increase in the MRS (multivariate OR=1.50, 95% CI=1.21-1.85). Conclusions: Our research yields compelling evidence that oral bacteria are a risk factor for the development of HNSCC. The identified bacteria and bacterial complexes hold promise for identifying high-risk individuals and may further lead to personalized prevention approaches for HNSCC. Citation Format: Soyoung Kwak, Mykhaylo Usyk, Feng Wu, Neal D. Freedman, Wen-Yi Huang, Marji L. Mccullough, Caroline Y. Um, Martha J. Shrubsole, Qiuyin Cai, Chan Wang, Huilin Li, Jiyoung Ahn, Richard B. Hayes. Oral microbiome and subsequent risk for head and neck squamous cell cancer development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6617.

BackgroundPeriodontal disease and lung function impairment were found to be associated with low-grade systemic or local inflammation, and it might be that gingival/periodontal inflammation triggers lung function due to systemic inflammation or the transfer of oral bacteria or its components to the lung. A recent observational study in non-smoking subjects showed that lung volumes and flow rates were significantly reduced by 71–185 ml for severe gingivitis regardless of the adjustment for potential confounders. The result did not show any confounding by smoking, and the association between gingivitis and lower lung function was not modified by systemic inflammation. The designed interventional trial primarily aims to test the hypothesis that gingivitis reduction by optimized daily oral hygiene, professional tooth cleaning and antibacterial chlorhexidine (CHX)-containing mouth rinse improves lung function in terms of forced vital capacity (FVC) by at least 2%. The secondary objective will test the hypothesis that gingivitis reduction improves forced expiratory volume in 1 s (FEV1) and forced expiratory flow at 25–75% of the pulmonary volume (FEF25-75) by at least 2%. Furthermore, the influence of the oral microbiome will be taken into account.MethodsThe study has to include 120 non-smoking subjects aged between 18 and 30 years with biofilm-induced gingivitis. The chosen “waiting control group design” will compare the immediate intervention group with the delayed intervention group, which serves as a control group. Dental and gingival status, lung function and oral microbiome will be recorded. The intensified preventive intervention—professional tooth cleaning, one-stage full-mouth disinfection with CHX and safeguarding an optimal daily oral hygiene by each subject—cannot be blinded, but the outcome measurement in terms of lung function tests is blind.DiscussionThis proposed multidisciplinary study has several strengths. Only one previous intervention study with patients with severe periodontitis (mostly smokers) has been performed. It is novel to include non-smoking subjects with mild and potentially reversible oral inflammation. Furthermore, this research is innovative, because it includes evidence-based interventions for gingivitis reduction, standardized measures of the outcome on lung function and oral microbiome and combines expertise from dentistry, lung physiology, oral microbiology and epidemiology/statistical modelling.Trial registrationGerman Clinical Trial Register DRKS00028176. Registered on February 2022.

Background The oral microbiome in ulcerative colitis (UC) patients and its role in the pathogenesis of the disease are still poorly understood. Although there are studies investigating the composition of oral microbiome in UC, there are no studies on concomitant analyses of oral and colonic mucosal samples in treatment-naïve patients. In this study, the oral and mucosal gut microbiome of UC patients and oral microbiota of healthy individuals (HC) were compared. Methods Sixty patients with newly-diagnosed active (mild-moderate severity) UC patients (n=30) and HC (n=30) were included in the study. Dietary habits were stable in the last three months of participants (checked by dietary recall questionnaires) and co-morbidities affecting microbiota profiles were excluded. Multiple colonic mucosa biopsies were obtained from inflamed areas before treatment in UC group. Simultaneously, subgingival plaque samples were analyzed. All samples were identified through next-generation DNA sequencing analysis, evaluated using bioinformatic tests. Results The potential signature bacterial species associated with UC were determined by examining of both gut and oral microbiomes. According to the Microbiome Lefse analysis, Prevotella copri emerged as the prominent common species in the colonic mucosal and subgingival plaque biopsies of UC group. Oral microbiome comparison between UC and HC patients revealed increased Haemophilus parainfluenza and Corynebacterium durum species and decreased F. prastnutzii and Akkermansia muciniphilia in the UC group (p&amp;lt;0.022). Comparative Boxplot analysis of bacterial abundance and alpha-diversity, as indicated by the Shannon index data, revealed that the HC group exhibited higher bacterial abundance and diversity in subgingival plaque samples than the UC group. We found significant association of Bacteroides vulgatus, Prevotella copri, Bacteroides fragilis, Parabacteroides merdae in both colonic mucosal and subgingival plaque samples (oral microbiome) of UC patients (p&amp;lt;0.044). Conclusion Our study is the first to show the oral and colonic mucosal microbiome relationship in UC. The presence of oral dysbiosis associated with UC in our study supports the hypothesis that UC could be associated not only with gut dysbiosis, as previously observed, but also with an imbalance in the oral microbial communities. Interestingly, we could not detect previously reported species of Streptococcus, Oribacterium, Rothia, Neisseria and Porphyromonas in the oral microbiome samples of the UC group. However, oral and gut microbiome profiles share some common microorganisms such as Prevotella copri and Bacteroides fragilis. Further studies are required for determining the potential role of oral dysbiosis is disease severity.

BackgroundSignificant gaps exist in understanding the gastrointestinal microbiota in patients with pancreatic cancer (PCA) versus benign or low-grade malignant pancreatic tumors (NPCA). This study aimed to analyze these microbiota characteristics and explore their potential use in distinguishing malignant pancreatic lesions.MethodsBetween September 2020 and May 2024, fecal and oral samples were collected from 121 patients undergoing surgical resection or diagnostic biopsy of pancreatic lesions, including 75 patients with PCA and 46 patients with NPCA, and 16s rRNA sequencing was performed. Random forest models based using fecal and oral microbiota data were developed to diagnose PCA and NPCA, with performance assessed using the leave-one-out cross validation method.ResultsThe Shannon index and PCoA analysis revealed significant differences in oral microbiota composition between PCA and NPCA (p < 0.001 and p = 0.001, respectively). Fecal microbiome richness differed significantly (p = 0.02), though composition similarity was noted (p = 0.238). LEfSe identified 16 and 23 genera with significant differences in fecal and oral microbiomes, respectively. Random forest classifiers based on fecal and oral microbiota achieved areas under the curves (AUCs) of 89.4% and 96.3%, respectively, for distinguishing PCA and NPCA. In the mucinous tumor cohort, oral and fecal microbiome classifiers outperformed CA19-9, yielding AUCs of 83.0% and 85.2%, respectively.ConclusionFecal and oral microbiota compositions were significantly different between PCA and NPCA patients. Random forest classifiers utilizing fecal and oral microbiota data effectively distinguish between benign or low-grade malignant and malignant pancreatic lesions.

Oral infection with a periodontal pathogen alters oral and gut microbiomes

Background:Chronic HIV-1 infection is associated with increased inflammation-related comorbidities, despite effective viral suppression with antiretroviral therapy. While the role of the gut microbiome in inflammation is well-studied, the contribution of the oral microbiome remains less clear. This study investigates the relationship between the oral and gut microbiomes in driving systemic inflammation in persons with HIV.Methods:This cross-sectional study utilized archived samples from 198 participants (99 with HIV and 99 without HIV). Oral microbiome composition was analyzed via 16S rRNA sequencing and systemic inflammatory biomarkers were measured using multiplex assays. Gut microbiome data from previous studies were integrated for comparative analyses. Bacterial inflammatory potential was assessed through in vitro co-culture and epithelial barrier permeability assays.Results:The oral microbiome in HIV was characterized by increased Veillonella, Capnocytophaga, and Megasphaera, and several decreased genera including Fusobacterium. Using PERMANOVA, we found that the oral microbiome was a significant driver of cytokine variation in HIV compared to the gut microbiome, and identified specific associations with oral Veillonella and Megasphaera. We found no differences in anti-Veillonella parvula serum IgG by HIV status, but IgG titers did correlate with microbial translocation markers sCD14 and LBP in HIV. In vitro studies demonstrated that Veillonella parvula increased oral epithelial barrier permeability and induced monocyte activation.Conclusions:The oral microbiome, particularly Veillonella parvula, may contributes to systemic inflammation in HIV through mechanisms involving epithelial barrier disruption, oral translocation, and monocyte activation.

The human microbiome functions as an intricate and coordinated microbial network, residing throughout the mucosal surfaces of the skin, oral cavity, gastrointestinal tract, respiratory tract, and reproductive system. The oral microbiome encompasses a highly diverse microbiota, consisting of over 700 microorganisms, including bacteria, fungi, and viruses. As our understanding of the relationship between the oral microbiome and human health has evolved, we have identified a diverse array of oral and systemic diseases associated with this microbial community, including but not limited to caries, periodontal diseases, oral cancer, colorectal cancer, pancreatic cancer, and inflammatory bowel syndrome. The potential predictive relationship between the oral microbiota and these human diseases suggests that the oral cavity is an ideal site for disease diagnosis and development of rapid point-of-care tests. The oral cavity is easily accessible with a non-invasive collection of biological samples. We can envision a future where early life salivary diagnostic tools will be used to predict and prevent future disease via analyzing and shaping the infant’s oral microbiome. In this review, we present evidence for the establishment of the oral microbiome during early childhood, the capability of using childhood oral microbiome to predict future oral and systemic diseases, and the limitations of the current evidence.

Purpose of review: This review investigates the oral microbiome’s composition, functions, influencing factors, connections to oral and systemic diseases, and personalized oral care strategies. Recent findings: The oral microbiome is a complex ecosystem consisting of bacteria, fungi, archaea, and viruses that contribute to oral health. Various factors, such as diet, smoking, alcohol consumption, lifestyle choices, and medical conditions, can affect the balance of the oral microbiome and lead to dysbiosis, which can result in oral health issues like dental caries, gingivitis, periodontitis, oral candidiasis, and halitosis. Importantly, our review explores novel associations between the oral microbiome and systemic diseases including gastrointestinal, cardiovascular, endocrinal, and neurological conditions, autoimmune diseases, and cancer. We comprehensively review the efficacy of interventions like dental probiotics, xylitol, oral rinses, fluoride, essential oils, oil pulling, and peptides in promoting oral health by modulating the oral microbiome. Summary: This review emphasizes the critical functions of the oral microbiota in dental and overall health, providing insights into the effects of microbial imbalances on various diseases. It underlines the significant connection between the oral microbiota and general health. Furthermore, it explores the advantages of probiotics and other dental care ingredients in promoting oral health and addressing common oral issues, offering a comprehensive strategy for personalized oral care.