The increasing importance of the oral microbiome in periodontal health and disease

It Takes a Village: Juvenile Idiopathic Arthritis and the Microbiome

Multiple risk factors for juvenile idiopathic arthritis (JIA) influence the microbiome, and various differences in the oral and fecal microbiome have been described to date in JIA. This review summarizes what is known and discusses potential implications for future research on the microbiome in JIA.

The Global Burden of Periodontal Disease: A Narrative Review on Unveiling Socioeconomic and Health Challenges

Periodontal disease is a prevalent chronic inflammatory condition that impacts over a billion people worldwide, leading to substantial tooth loss, reduced quality of life, and heightened systemic health risks. This narrative review synthesizes current evidence regarding the global burden of periodontal disease, its established associations with systemic conditions including cardiovascular disease, diabetes, adverse pregnancy outcomes, respiratory infections, and neurodegenerative disorders, and its significant socioeconomic implications. The review focused on the following research question: What is the global burden of periodontal disease, and how do its systemic and socioeconomic implications necessitate integrated public health strategies? A structured search of the PubMed, Scopus, and WHO databases from 2000 to 2024 was conducted to identify relevant literature using key terms, including "periodontal disease", "global burden", "systemic inflammation", and "public health strategies". Out of 312 initially identified articles, 175 satisfied the inclusion criteria for the final synthesis. The findings underscore the significance of periodontal disease as a modifiable risk factor for various noncommunicable diseases, the influence of healthcare disparities on disease progression, and the critical necessity for integrated public health strategies to mitigate the global burden of periodontal disease and its consequences. The review concludes that coordinated policy reform, health system integration, and enhanced research efforts are crucial for mitigating the global burden of periodontal disease and advancing health equity.

Antibiofilm, regenerative and bone homeostasis potential of the synergistic association of synoeca-MP peptide with chlorhexidine in oral cavity opportunistic infections

OBJECTIVE

Synoeca-MP is an antimicrobial peptide that belongs to the class of defense peptides, known for their antimicrobial and immunomodulatory properties. To evaluate in vitro the association between synoeca-MP peptide and chlorhexidine, regarding their antimicrobial and antibiofilm activities, saliva stability, effect on tissue repair, bone resorption processes, and mineralized matrix formation.

DESIGN

Initially, the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiofilm concentration were determined. The synergism and degradation of synoeca-MP and chlorhexidine in human saliva were assessed. Furthermore, biocompatibility was evaluated using MTT assays, hemolytic assays, and proliferation and migration assays of periodontal ligament cells. Finally, bone homeostasis was evaluated through osteoclastogenesis assays, alkaline phosphatase determination, and mineralized matrix formation assay with SaOs-2 and ligament cells.

RESULTS

The antimicrobial and antibiofilm activity against the tested microorganisms was confirmed. Low synergistic concentrations of the synoeca-MP and chlorhexidine combination inhibited tested microorganisms. The association of these molecules remained stable in healthy saliva. Nevertheless, it degraded as the severity of periodontal disease increased. Additionally, lower synergistic concentrations of the combination were not cytotoxic to human cells, promoted the proliferation and migration of ligament cells, inhibited osteoclastogenesis, and increased mineral matrix formation of ligament cells and SaOs-2.

CONCLUSIONS

Synoeca-MP and chlorhexidine combination shows potential for oral diseases treatment, as evidenced by its antimicrobial activity, regenerative potential, saliva stability, and bone homeostasis. It may be particularly effective for opportunistic oral infections and in conjunction with mechanical therapy.

Clinical and Microbiological Evaluation of 0.2% Tea Tree Oil Mouthwash in Prevention of Dental Biofilm-Induced Gingivitis

Background: Dental biofilm-induced gingivitis is a prevalent condition caused by dental plaque accumulation. Chlorhexidine mouthwash is a gold standard for plaque control but is associated with adverse effects such as tooth staining and altered taste. This study aimed to evaluate the clinical and antimicrobial effectiveness of 0.2% tea tree oil mouthwash as a natural alternative to 0.2% chlorhexidine mouthwash. Methods: A comparative study was conducted on 60 participants aged 18-60 years, divided into two groups: Group T (tea tree oil) and Group C (chlorhexidine), each comprising 30 participants. Clinical outcomes assessed included Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BOP), and microbiological Colony Forming Units (CFUs). Parameters were recorded at baseline, 7 days, and 28 days. Results: Group T exhibited significantly lower PI and BOP scores at 7 and 28 days compared to Group C (p < 0.05). Both groups showed comparable reductions in CFU counts, indicating similar antimicrobial efficacy. Importantly, tea tree oil had fewer adverse effects, with no reports of tooth staining or altered taste, unlike chlorhexidine. Conclusion: Tea tree oil mouthwash demonstrated equivalent or superior clinical outcomes compared to chlorhexidine, with fewer side effects. It is a viable and well-tolerated alternative for managing plaque-induced gingivitis, supporting further research into its long-term use and efficacy.

Oral microbiome profiles of gingivitis and periodontitis by next-generation sequencing among a group of hospital patients in Korea: A cross-sectional study

OBJECTIVES

The oral microbiome plays an important role in the development and progression of periodontal disease. The purpose of this study was to compare microbial profiles of oral cavities in good health, with gingivitis, and in a state of periodontitis, and to identify novel pathogens involved in periodontal diseases.

METHODS

One hundred and two participants, including 33 healthy controls, 41 patients with gingivitis, and 28 patients with periodontitis, were included in this cross-sectional study. Salivary oral microbiomes were investigated using 16S rRNA metagenomic sequencing, and the microbial profiles of each group were compared using age- and sex-adjusted general linear models.

RESULTS

The abundance of amplicon sequence variants and Chao1 diversity were significantly elevated in the gingivitis and periodontitis groups relative to healthy controls (p = 0.046). Based on linear discriminant analysis (LDA) scores (>2), Tenericutes, Mollicutes, Mycoplasmatales, Mycoplasmataceae, Mycoplasma, Bacteroidaceae, and Phocaeicola were significantly enriched in the gingivitis group, and Synergistetes, Synergistia, Synergistales, Synergistaceae, Fretibacterium, Sinanaerobacter, and Filifactor were enriched in the periodontitis group. The relative abundances of Fretibacterium fastidiosum, Sinanaerobacter chloroacetimidivorans, and Filifactor alocis (q = 0.008, all bacteria) were highest in the periodontitis group and lowest in the control group. The relative abundance of Treponema denticola was significantly elevated in the periodontitis group compared to the other two groups (q = 0.024).

CONCLUSIONS

Oral microbiomes differed between groups. T. denticola, F. fastidiosum, S. chloroacetimidivorans and F. alocis were significantly more abundant in the periodontitis group than in the control group. Additionally, the abundance of T. denticola and F. fastidiosum in the periodontitis group was significantly different from that in the gingivitis group.

A Narrative Review of Periodontal Vaccines: Hope or Hype?

Globally, periodontal diseases, mainly driven by polymicrobial biofilms, are a widespread concern of social medicine due to their considerable incidence and tie-up to systemic disorders like diabetes, cardiovascular diseases, and complications during pregnancy. Traditional treatments focus on mechanical debridement and antimicrobial therapies, but these approaches have limitations, including recurrence and antibiotic resistance. Periodontal vaccines offer a promising alternative by targeting the immunological mechanisms underlying periodontal disease. This review explores the current state of periodontal vaccine development, highlighting key antigens, vaccine delivery systems, and preclinical and clinical advancements. Special emphasis is placed on antigen selection, host variability, immune tolerance, and future directions to overcome these barriers. This article highlights the advancements and challenges in periodontal vaccine research, offering insights into the capability of immunoprophylaxis as a groundbreaking way to manage periodontal diseases.

Case Report: Shift from Aggressive Periodontitis to Feline Chronic Gingivostomatitis Is Linked to Increased Microbial Diversity

Aggressive Periodontitis (AP) and Feline Chronic Gingivostomatitis (FCGS) are two oral inflammatory diseases in cats with unknown etiology. Both conditions present with severe inflammation of the oral cavity and in FCGS it is found with additional deterioration of the non-keratinized mucosa. The oral microbiome is increasingly implicated in disease progression, but little is known about shifts in the microbial community during the AP and FCGS progression. To that end, we used deep metagenomic sequencing with total RNA on three longitudinal samples of the oral microbiome in a cat first diagnosed with AP that progressed to FCGS. This deep sequencing approach revealed that increased diversity at both the genus and species levels marked the shift from AP to FCGS, including increases in Porphyromonas and Treponema species, and decreased Streptobacillus species. The metatranscriptomes were then probed for expression of antimicrobial resistance genes and virulence factors. Disease-related genes that include cheY, and ompP5 were expressed in early AP and FCGS, while others like galU were only expressed in one or the other disease state. Both genus and species-level shifts were observed along the longitudinal microbiome samples with a noted increase in species diversity in the FCGS-associated microbiome. Corroborating that functional shifts accompany taxonomic changes, the AMR and virulence factor expression similarly changed between the sampling points. Together, these taxonomic and functional shifts indicate that AP and FCGS are potentially linked and may be marked by changes in the oral microbiome, which supports the development of microbial-based clinical diagnostics and therapeutics.

Exploring the role of oral bacteria in oral cancer: a narrative review

A growing body of research indicates that a wide range of cancer types may correlate with human microbiome components. On the other hand, little is known about the potential contribution of the oral microbiota to oral cancer. However, some oral microbiome components can stimulate different tumorigenic processes associated with the development of cancer. In this line, two prevalent oral infections, Porphyromonas gingivalis, and Fusobacterium nucleatum can increase tumor growth. The microbiome can impact the course of the illness through direct interactions with the human body and major modifications to the toxicity and responsiveness to different kinds of cancer therapy. Recent research has demonstrated a relationship between specific phylogenetic groupings and the results of immunotherapy treatment for particular tumor types. Conversely, there has been a recent upsurge in interest in the possibility of using microbes to treat cancer. At the moment, some species, such as Salmonella typhimurium and Clostridium spp., are being explored as possible cancer treatment vectors. Thus, understanding these microbial interactions highlights the importance of maintaining a healthy oral microbiome in preventing oral cancers. From this perspective, this review will discuss the role of the microbiome on oral cancers and their possible application in oral cancer treatment/improvement.

The Potential Role of Microbiota in Age-Related Cognitive Decline: A Narrative Review of the Underlying Molecular Mechanisms

As the world's population continues to age, social patterns are changing, making aging a notable public health challenge. With aging as the major risk factor for cognitive decline, the global prevalence of dementia is projected to triple in the next 25 years. In light of the growing body of evidence of the involvement of microbiota in health and pathology, its role in age-related cognitive decline should be explored. Therefore, the aim of this narrative review is to thoroughly analyze the ways in which microbiota might affect the aging process and age-related cognitive decline. Overall, aging is a complex phenomenon manifested at systemic, cellular and molecular levels. According to recent studies, gut microbiota composition may influence age-related changes through the gut-brain axis. One mechanism involves dysbiosis-related chronic systemic inflammation, leading to the blood-brain barrier disruption and subsequent neuroinflammatory processes. In addition to inflammaging, gut microbiota may induce oxidative stress, which is another key factor in brain aging. Finally, not only gut microbiota, but also microbiota colonizing the oral cavity may be associated with age-related neurodegenerative diseases.

Association of endogenous sex hormone levels with tooth loss due to periodontitis in men and post-menopausal women: The multi-ethnic study of atherosclerosis

AIM

To investigate the association between endogenous sex hormone levels and history of tooth loss related to periodontitis in healthy middle-aged to older men and post-menopausal women.

METHODS

This cross-sectional study included 5649 participants aged 45-84 (mean age, 63 ± 10 years) from the Multi-Ethnic Study of Atherosclerosis cohort who had sex hormone levels measured and answered a questionnaire regarding perceived periodontal status at exam 1. Multivariable logistic regression was used to examine the association of sex hormones (exposure) with history of tooth loss (outcome), stratified by sex.

RESULTS

Among post-menopausal women, higher free testosterone (per 1SD) was associated with a greater prevalence of tooth loss [OR 1.49 (95% CI, 1.08-2.05)], whereas higher sex hormone binding globulin (SHBG) was associated with a lower prevalence of tooth loss [OR 0.74 (0.58-0.94)], after adjustment for cardiometabolic risk factors and reproductive factors. In men, higher free testosterone and lower SHBG were associated with a lower prevalent probability of tooth loss in unadjusted analysis, but these associations lost significance after covariate adjustment.

CONCLUSION

A higher androgenic sex hormone profile in post-menopausal women (i.e., increased free testosterone, lower SHBG) was associated with an increased prevalence of tooth loss, after adjusting cardiometabolic risk factors. No such association was found in men. These findings suggest that sex hormones may influence or serve as a marker for periodontal health.

Efficacy of toothpaste containing OPTIMEALTH® OR in inhibiting dental plaque and gingivitis: A randomized controlled trial

BACKGROUND

This randomized double-blind, placebo-controlled clinical trial evaluated the effects of 2% OPTIMEALTH® OR toothpaste in regulating dental plaque microbiota and alleviating gingivitis.

METHODS

Subjects were randomly assigned to the placebo group and test group. They were instructed to brush their teeth with placebo toothpaste (placebo group) or OPTIMEALTH® OR toothpaste (test group) for a continuous 4 weeks. Clinical indices of plaque index, gingival index, and bleeding on probe (%) were examined, and images of dental plaque staining were captured at baseline and after 2 and 4 weeks. The plaque microbiome was analyzed by 16s rDNA amplicon sequencing at baseline and after 4 weeks.

RESULTS

Thirty-two participants with similar characteristics were recruited. After using OPTIMEALTH® OR toothpaste for 4 weeks, a decrease of 27.05% (P < .01), 8.29% (P > .05), and 47.44% (P < .05) in plaque index, gingival index, and bleeding on probe (%) scores was observed compared to the baseline, respectively. The extent of decline in these indices is greater than that in the placebo group. A decrease in dental plaque could be observed after 2 and 4 weeks in the test group. The 16s rDNA sequencing results showed that the observed species index and Chao index, but not the Shannon index and beta diversity, were reduced significantly after using OPTIMEALTH® OR toothpaste for 4 weeks. In addition, compared with the placebo group, using OPTIMEALTH® OR toothpaste reduced the abundance of bacterial species such as Veillonella parvula and Prevotella denticola.

CONCLUSION

Brushing teeth with 2% OPTIMEALTH® OR-fortified toothpaste could effectively reduce dental plaque and regulate plaque microbiota.

Relationship Between the Salivary Microbiome and Oral Malodor Metabolites in Older Thai Individuals with Periodontitis and the Cytotoxic Effects of Malodor Compounds on Human Oral Squamous Carcinoma (HSC-4) Cells

Background/Objectives: Halitosis is primarily caused by the activity of oral microorganisms. In this study, we employed metagenomic sequencing and metabolomic approaches to investigate the differences in salivary microbiota and metabolite profiles between individuals with halitosis and periodontitis and healthy controls. Additionally, we expanded the study to examine how oral malodorous compounds interact with human oral squamous carcinoma (HSC-4) cells. Methods: Saliva samples were collected and analyzed using Ultra-High Performance Liquid Chromatography-Mass Spectrometry (UHPLC-MS) to identify metabolites. We then assessed the correlations between the microbiota and metabolites. Furthermore, the impact of oral malodorous substances on HSC-4 cells was investigated by evaluating apoptosis, antioxidant activity, and inflammatory properties. Results: The microbiota and metabolite profiles showed significant differences between the halitosis with periodontitis group and the periodontally healthy group. The halitosis with periodontitis group exhibited significantly higher relative abundances of eight genera: Tannerella, Selenomonas, Bacteroides, Filifactor, Phocaeicola, Fretibacterium, Eubacterium saphenum, and Desulfobulbus. In contrast, the periodontally healthy group showed significantly higher relative abundances of Family XIII UCG-001, Haemophilus, and Streptobacillus. Two metabolites, 2,3-dihydro-1H-indole and 10,11-dihydro-12R-hydroxy-leukotriene E4, were significantly higher in individuals with halitosis and periodontitis. In the treatment of HSC-4 cells with metabolites, dimethyl sulfide (DMS) did not show significant effects while indole appeared to induce cell death in HSC-4 cells by triggering apoptotic pathways. Additionally, both indole and DMS affected the inflammatory and antioxidant properties of HSC-4 cells. Conclusions: This study provides insights into the mechanisms of halitosis by exploring the correlations between microbiota and metabolite profiles. Furthermore, oral metabolites were shown to impact the cellular response of HSC-4 cells.

Exploring heme and iron acquisition strategies of Porphyromonas gingivalis-current facts and hypotheses

Iron and heme are crucial for pathogenic bacteria living in the human host but are not available in free form due to their binding by iron- and heme-sequestering proteins. Porphyromonas gingivalis causes dysbiosis in the oral microbiome and is considered a keystone pathogen in the onset and progression of periodontal diseases. Its ability to infect and multiply in host cells and its presence in distant tissues and fluids highlights its pathogenic versatility and explains the relationship between periodontal diseases and systemic or neurodegenerative diseases. Porphyromonas gingivalis has evolved specialized mechanisms that allow it to thrive in the host under adverse nutrient-limited conditions. This review presents the updated summary of the mechanisms of iron and heme acquisition by P. gingivalis, with a central role played by gingipains and the unique Hmu system. The potential role of other iron and heme acquisition systems, such as Hus and Iht, indicates the importance of the partially conserved heme biosynthesis pathway, involving homologs of the HemN, HemG, and HemH proteins. In light of increasing antibiotic resistance, difficulties with diagnosis, and drug administration, targeting the mechanisms of heme and iron acquisition of P. gingivalis represents a promising target for developing diagnostic tests, preventive or therapeutic strategies.

Oral Microbiome Research in Biopsy Samples of Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma and Its Challenges

This study aims to evaluate the potential benefits and challenges of integrating oral microbiome research into the clinical management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC). The oral microbiome has gained significant attention for its role in the pathogenesis and progression of these conditions, with emerging evidence suggesting its value as a diagnostic and prognostic tool. By critically analyzing current evidence and methodological considerations, this manuscript examines whether microbiome analysis in biopsy samples can aid in the early detection, prognosis, and management of OPMD and OSCC. The complexity and dynamic nature of the oral microbiome require a multifaceted approach to fully understand its clinical utility. Based on this review, we conclude that studying the oral microbiome in this context holds significant promise but also faces notable challenges, including methodological variability and the need for standardization. Ultimately, this manuscript addresses the question, “Should such research be undertaken, given the intricate interactions of various factors and the inherent obstacles involved?”, and also emphasizes the importance of further research to optimize clinical applications and improve patient outcomes.

Microbial functional pathways based on metatranscriptomic profiling enable effective saliva-based health assessments for precision wellness

It is increasingly recognized that an important step towards improving overall health is to accurately measure biomarkers of health from the molecular activities prevalent in the oral cavity. We present a general methodology for computationally quantifying the activity of microbial functional pathways using metatranscriptomic data. We describe their implementation as a collection of eight oral pathway scores using a large salivary sample dataset (n = 9350), and we evaluate score associations with oropharyngeal disease phenotypes within an unseen independent cohort (n = 14,129). Through this validation, we show that the relevant oral pathway scores are significantly worse in individuals with periodontal disease, acid reflux, and nicotine addiction, compared with controls. Given these associations, we make the case to use these oral pathway scores to provide molecular health insights from simple, non-invasive saliva samples, and as molecular endpoints for actionable interventions to address the associated conditions.

Relationship between oral microbiota and colorectal cancer: A systematic review

This systematic review aims to investigate the microbial basis underlying the association between oral microbiota and colorectal cancer. A comprehensive search was conducted across four databases, encompassing potentially relevant studies published up to April 2024 related to the PECO question: "Is there a differentiation in oral microbial composition between adult patients diagnosed with colorectal cancer compared to healthy patients?". The Newcastle-Ottawa Scale was used to evaluate the quality of the studies included. The level of evidence was assessed through the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) tool. Sixteen studies fulfilled the eligibility criteria. Based on low to moderate evidence profile, high levels of certain subspecies within Firmicutes (such as Streptococcus anginosus, Peptostreptococcus stomatis, S. koreensis, and S. gallolyticus), Prevotella intermedia, Fusobacterium nucleatum, and Neisseria oralis were found to be associated with colorectal cancer. Conversely, certain bacteria (e.g., Lachnospiraceae, F. periodonticum, and P. melaninogenica) could exert a symbiotic protective effect against colorectal cancer. Based on existing evidence, it appears that variations in oral microbiota composition exist among individuals with and without colorectal cancer. However, further research is necessary to determine the mechanisms of oral dysbiosis in colorectal carcinogenesis.

Oral Microbiome and Subsequent Risk of Head and Neck Squamous Cell Cancer

Importance

The oral microbiota may be involved in development of head and neck squamous cell cancer (HNSCC), yet current evidence is largely limited to bacterial 16S amplicon sequencing or small retrospective case-control studies.

Objective

To test whether oral bacterial and fungal microbiomes are associated with subsequent risk of HNSCC development.

Design, Setting, and Participants

Prospective nested case-control study among participants providing oral samples in 3 epidemiological cohorts, the American Cancer Society Cancer Prevention Study II Nutrition Cohort, the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, and the Southern Community Cohort Study. Two hundred thirty-six patients who prospectively developed HNSCC were identified during a mean (SD) of 5.1 (3.6) years of follow-up. Control participants who remained HNSCC free were selected by 2:1 frequency matching on cohort, age, sex, race and ethnicity, and time since oral sample collection. Data analysis was conducted in 2023.

Exposures

Characterization of the oral bacterial microbiome using whole-genome shotgun sequencing and the oral fungal microbiome using internal transcribed spacer sequencing. Association of bacterial and fungal taxa with HNSCC was assessed by analysis of compositions of microbiomes with bias correction. Association with red and orange oral pathogen complexes was tested by logistic regression. A microbial risk score for HNSCC risk was calculated from risk-associated microbiota.

Main Outcomes and Measures

The primary outcome was HNSCC incidence.

Results

The study included 236 HNSCC case participants with a mean (SD) age of 60.9 (9.5) years and 24.6% women during a mean of 5.1 (3.6) years of follow-up, and 485 matched control participants. Overall microbiome diversity at baseline was not related to subsequent HNSCC risk; however 13 oral bacterial species were found to be differentially associated with development of HNSCC. The species included the newly identified Prevotella salivae, Streptococcus sanguinis, and Leptotrichia species, as well as several species belonging to beta and gamma Proteobacteria. The red/orange periodontal pathogen complex was moderately associated with HNSCC risk (odds ratio, 1.06 per 1 SD; 95% CI, 1.00-1.12). A 1-SD increase in microbial risk score (created based on 22 bacteria) was associated with a 50% increase in HNSCC risk (multivariate odds ratio, 1.50; 95% CI, 1.21-1.85). No fungal taxa associated with HNSCC risk were identified.

Conclusions and Relevance

This case-control study yielded compelling evidence that oral bacteria are a risk factor for HNSCC development. The identified bacteria and bacterial complexes hold promise, along with other risk factors, to identify high-risk individuals for personalized prevention of HNSCC.

Revisiting Socransky's Complexes: A Review Suggesting Updated New Bacterial Clusters (GF-MoR Complexes) for Periodontal and Peri-Implant Diseases and Conditions

This review aimed to identify newly discovered bacteria from individuals with periodontal/peri-implant diseases and organize them into new clusters (GF-MoR complexes) to update Socransky's complexes (1998). For methodological development, the PCC (Population, Concept, Context) strategy was used for the focus question construction: "In patients with periodontal and/or peri-implant disease, what bacteria (microorganisms) were detected through laboratory assays?" The search strategy was applied to PubMed/MEDLINE, PubMed Central, and Embase. The search key terms, combined with Boolean markers, were (1) bacteria, (2) microbiome, (3) microorganisms, (4) biofilm, (5) niche, (6) native bacteria, (7) gingivitis), (8) periodontitis, (9) peri-implant mucositis, and (10) peri-implantitis. The search was restricted to the period 1998-2024 and the English language. The bacteria groups in the oral cavity obtained/found were retrieved and included in the GF-MoR complexes, which were based on the disease/condition, presenting six groups: (1) health, (2) gingivitis, (3) peri-implant mucositis, (4) periodontitis, (5) peri-implantitis, and (6) necrotizing and molar-incisor (M-O) pattern periodontitis. The percentual found per group refers to the number of times a specific bacterium was found to be associated with a particular disease. A total of 381 articles were found: 162 articles were eligible for full-text reading (k = 0.92). Of these articles, nine were excluded with justification, and 153 were included in this review (k = 0.98). Most of the studies reported results for the health condition, periodontitis, and peri-implantitis (3 out of 6 GF-MoR clusters), limiting the number of bacteria found in the other groups. Therefore, it became essential to understand that bacterial colonization is a dynamic process, and the bacteria present in one group could also be present in others, such as those observed with the bacteria found in all groups (Porphyromonas gingivalis, Tannarela forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans) (GF-MoR's red triangle). The second most observed bacteria were grouped in GF-MoR's blue triangle: Porphyromonas spp., Prevotela spp., and Treponema spp., which were present in five of the six groups. The third most detected bacteria were clustered in the grey polygon (GF-MoR's grey polygon): Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens. These three geometric shapes had the most relevant bacteria to periodontal and peri-implant diseases. Specifically, per group, GF-MoR's health group had 58 species; GF-MoR's gingivitis group presented 16 bacteria; GF-MoR's peri-implant mucositis included 17 bacteria; GF-MoR's periodontitis group had 101 different bacteria; GF-MoR's peri-implantitis presented 61 bacteria; and the last group was a combination of necrotizing diseases and molar-incisor (M-I) pattern periodontitis, with seven bacteria. After observing the top seven bacteria of all groups, all of them were found to be gram-negative. Groups 4 and 5 (periodontitis and peri-implantitis) presented the same top seven bacteria. For the first time in the literature, GF-MoR's complexes were presented, gathering bacteria data according to the condition found and including more bacteria than in Socransky's complexes. Based on this understanding, this study could drive future research into treatment options for periodontal and peri-implant diseases, guiding future studies and collaborations to prevent and worsen systemic conditions. Moreover, it permits the debate about the evolution of bacterial clusters.

Microbial Dynamics in Periodontal Regeneration: Understanding Microbiome Shifts and the Role of Antifouling and Bactericidal Materials: A Narrative Review

Periodontal regeneration is a multifaceted therapeutic approach to restore the tooth-supporting structures lost due to periodontal diseases. This manuscript explores the intricate interactions between regenerative therapies and the oral microbiome, emphasizing the critical role of microbial balance in achieving long-term success. While guided tissue regeneration (GTR), bone grafting, and soft tissue grafting offer promising outcomes in terms of tissue regeneration, these procedures can inadvertently alter the oral microbial ecosystem, potentially leading to dysbiosis or pathogenic recolonization. Different grafting materials, including autografts, allografts, xenografts, and alloplasts, influence microbial shifts, with variations in the healing timeline and microbial stabilization. Biologics and antimicrobials, such as enamel matrix derivatives (EMD) and sub-antimicrobial dose doxycycline (SDD), play a key role in promoting microbial homeostasis by supporting tissue repair and reducing pathogenic bacteria. Emerging strategies, such as enzyme-based therapies and antifouling materials, aim to disrupt biofilm formation and enhance the effectiveness of periodontal treatments. Understanding these microbial dynamics is essential for optimizing regenerative therapies and improving patient outcomes. The future of periodontal therapy lies in the development of advanced materials and strategies that not only restore lost tissues but also stabilize the oral microbiome, ultimately leading to long-term periodontal health.

Akkermansia muciniphila as a Potential Guardian against Oral Health Diseases: A Narrative Review

The oral microbiome is a diverse ecosystem containing a community of symbiotic, commensal, and pathogenic microorganisms. One key microorganism linked to periodontal disease (PD) is Porphyromonas gingivalis (P. gingivalis), a Gram-negative anaerobic bacterium known to have several virulence factors that trigger inflammation and immune evasion. On the other hand, Akkermansia muciniphila (A. muciniphila), a symbiotic bacterium, has been recently shown to play an important role in mitigating inflammation and reducing periodontal damage. In vivo and in vitro studies have shown that A. muciniphila decreases inflammatory mediators and improves immune responses, suggesting its role in mitigating PD and related inflammatory systemic conditions such as diabetes, hypertension, and obesity. This review discusses the anti-inflammatory effects of A. muciniphila, its impact on periodontal health, and its potential role in managing systemic diseases. The overall aim is to elucidate how this bacterium might help reduce inflammation, improve oral health, and influence broader health outcomes.

Oral and Gut Microbiota Dysbiosis Due to Periodontitis: Systemic Implications and Links to Gastrointestinal Cancer: A Narrative Review

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.

The Impact of Oral Microbiome Dysbiosis on the Aetiology, Pathogenesis, and Development of Oral Cancer

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. Although the oral cavity is an easily accessible area for visual examination, the OSCC is more often detected at an advanced stage. The global prevalence of OSCC is around 6%, with increasing trends posing a significant health problem due to the increase in morbidity and mortality. The oral cavity microbiome has been the target of numerous studies, with findings highlighting the significant role of dysbiosis in developing OSCC. Dysbiosis can significantly increase pathobionts (bacteria, viruses, fungi, and parasites) that trigger inflammation through their virulence and pathogenicity factors. In contrast, chronic bacterial inflammation contributes to the development of OSCC. Pathobionts also have other effects, such as the impact on the immune system, which can alter immune responses and contribute to a pro-inflammatory environment. Poor oral hygiene and carbohydrate-rich foods can also increase the risk of developing oral cancer. The risk factors and mechanisms of OSCC development are not yet fully understood and remain a frequent research topic. For this reason, this narrative review concentrates on the issue of dysbiosis as the potential cause of OSCC, as well as the underlying mechanisms involved.

The Bloody Crossroads: Interactions between Periodontitis and Hematologic Diseases

Periodontitis is a common oral condition that can have a significant impact on the overall health of the body. In recent years, attention has been paid to potential relationships between periodontitis and various hematological disorders. This publication aims to present information available in the literature on this relationship, focusing on examples of red blood cell disorders (such as aplastic anemia and sickle cell anemia) and white blood cell disorders (such as cyclic neutropenia, maladaptive trained immunity, clonal hematopoiesis, leukemia, and multiple myeloma). Understanding these associations can help physicians and dentists better diagnose, monitor, and treat patients associated with both groups of conditions, highlighting the need for interdisciplinary care for patients with oral disorders and hematologic diseases.

Microbiota Transplantation as an Adjunct to Standard Periodontal Treatment in Periodontal Disease: A Systematic Review

Periodontitis is a disease linked to severe dysbiosis of the subgingival microbiome. The treatment of periodontitis aims to change the dysbiosis environment to a symbiosis environment. We hypothesized that oral microbiota transplantation can lead to a significant improvement in periodontitis. Therefore, the aim of this study was to determine the effectiveness of microbiota transplantation after standard periodontal treatment in periodontitis patients. The search strategy was carried out by using the Boolean term "AND" to combine the keywords, which were "periodontitis AND microbiota transplantation". Due to the limited resources of the study, we included both in vitro and in vivo investigations in this systematic review. The QUIN risk of bias tool was employed to assess the risk of bias in in vitro studies, while SYRCLE's risk of bias assessment was used for in vivo studies. Oral microbiota transplants (OMTs) have shown potential in treating periodontitis. OMTs significantly reduced periodontitis-associated pathogenic microbial species (P. endodontalis, Prevotella intermedia, T. vincentii, Porphyromonas sp.) and increased beneficial bacteria (P. melaninogenica, Fusobacterium nucleatum, P. catoniae, Capnocytophaga ochracea, C. sputigena, C. gingivalis, Haemophilus parainfluenzae, and Neisseria elongata) upon in vitro testing. Furthermore, in the in vivo tests, single adjunctive OMT also had an effect on the oral microbiota composition compared to the full-mouth mechanical and antimicrobial debridement. OMTs may be cheaper and more effective at addressing high-risk individuals. At present, it is not possible to provide OMT clinical advice due to the lack of available information. This treatment needs to be subjected to more safety and efficacy testing before being included human clinical trials.

The Complicated Relationship of Short-Chain Fatty Acids and Oral Microbiome: A Narrative Review

The human oral microbiome has emerged as a focal point of research due to its profound implications for human health. The involvement of short-chain fatty acids in oral microbiome composition, oral health, and chronic inflammation is gaining increasing attention. In this narrative review, the results of early in vitro, in vivo, and pilot clinical studies and research projects are presented in order to define the boundaries of this new complicated issue. According to the results, the current research data are disputable and ambiguous. When investigating the role of SCFAs in human health and disease, it is crucial to distinguish between their local GI effects and the systemic influences. Locally, SCFAs are a part of normal oral microbiota metabolism, but the increased formation of SCFAs usually attribute to dysbiosis; excess SCFAs participate in the development of local oral diseases and in oral biota gut colonization and dysbiosis. On the other hand, a number of studies have established the positive impact of SCFAs on human health as a whole, including the reduction of chronic systemic inflammation, improvement of metabolic processes, and decrease of some types of cancer incidence. Thus, a complex and sophisticated approach with consideration of origin and localization for SCFA function assessment is demanded. Therefore, more research, especially clinical research, is needed to investigate the complicated relationship of SCFAs with health and disease and their potential role in prevention and treatment.