The oralome and its dysbiosis: New insights into oral microbiome-host interactions

Microbiota associated with caries and apical periodontitis: A next-generation sequencing study

AIM

This study investigated the correlation between microbiota of caries-free enamel and caries-affected dentine biofilms and that of root canals with primary apical periodontitis, by using an Illumina MiSeq platform.

METHODOLOGY

Biofilm from caries-free enamel surface (Biofilm-C) or caries-affected dentine (Biofilm-E) and root canal paper point samples (Canal) were collected from 31 teeth with primary apical periodontitis. Microbial composition was analysed by amplicon sequencing that targeted the V3-V4 region of 16S rRNA gene. Alpha and beta diversities of bacterial communities between sampling sites were compared using the Kruskal-Wallis test and pairwise permutational multivariate analysis of variance, respectively. Differentially abundant taxa identified using MaAsLin2 were adjusted for multiple comparisons using the Benjamini-Hochberg method.

RESULTS

Totals of 16 phyla, 130 genera and 314 species were identified. Distinct and shared bacterial communities were observed between biofilm and canal samples. No significant differences in alpha diversity were observed across all sampling sites. A total of 32 genera including Acinetobacter, [Eubacterium], Dialister, Erysipelotrichaceae UCG-006, Lawsonella, W5053, Phocaeicola, Mogibacterium, Pyramidobacter and Parvimonas were more abundant in Canal samples compared to both Biofilm-C and Biofilm-E. The genera Hallella, Lactobacillus, Shuttleworthella, Olsenella, Cryptobacterium, Alloprevotella, Phocaeicola, Limosilactobacillus, Selenomonadaceae and Anaeroglobus were increased significantly in Biofilm-E compared to Biofilm-C. Hallela multisaccharivorax, Olsenella uli, Lactobacilllus gasseri, Selenomonadaceae species and Scardovia inopinata exhibited higher abundance in both Biofilm-E and Canal, than Biofilm-C. These differences in bacterial composition among sampling sites, including the increased presence of specific taxa in caries-affected dentine and root canals, suggest that these microorganisms may contribute to the development of primary apical periodontitis.

CONCLUSION

Bacterial community structure differed significantly between biofilm and root canal samples, but showed no significant differences among biofilm samples based on dental caries status. However, some taxa were shared among caries-affected lesions, including dentine and root canals. H. multisaccharivorax, O. uli, L. gasseri, Selenomonadaceae species and S. inopinata exhibited higher abundance in caries-affected dentine and root canals with primary apical periodontitis, suggesting that specific bacteria in caries-affected dentine play a crucial role in the development of root canal infections and the pathogenesis of primary apical periodontitis.

The Probiotic Effects of Lactobacillus brevis CD2 on Caries Related Variables of Dental Plaque Biofilm

OBJECTIVES

This study was based on the research question: "Does L. brevis CD2 have an effect on the acidogenicity of sugar-exposed bacteria? To solve this question, a multistep study was planned: first, an in vitro investigation aimed to assess the acid production of monoculture bacterial solutions; and second, an ex vivo experiment to evaluate the production or inhibition of acids from plaque samples.

METHODS

L. brevis CD2 and several control strains (Lactobacillus brevis CD2, Lactobacillus reuteri DSM 17938, Lactobacillus rhamnosus LB21, Lactobacillus plantarum 931, Streptococcus mutans Ingbritt) were tested with various sugars; pH changes were recorded at specific time points using a micro-pH electrode. Additionally, for the ex vivo phase, the same sugars were added to equal amounts of pooled plaque from 9 healthy subjects with bacterial suspensions, as well as a control solution, and pH was monitored for up to 90 minutes. For the ex vivo phase, 9 adults were randomised in a crossover design for 28 days. For the in vivo phase, 26 healthy subjects used 1/2 lozenges 3 times daily containing either L. brevis CD2 (active) or no probiotic bacteria (placebo). Plaque acidogenicity was assessed using the microtouch method after a 10 ml mouth rinse containing 10% sucrose for 1 minute (on day 0 and day 28).

RESULTS

L. brevis CD2 exhibited the highest ability to inhibit the fermentation of fructose, lactose, and sucrose compared to the control strains (P < .05). A significant reduction in plaque acidogenicity was observed in vivo from day 0 to day 28 in the test group (P < .05).

CONCLUSIONS

This study indicates that L. brevis CD2 mitgates the acidogenic attributes of plaque biofilm organisma in vitro, in vivo and ex vivo, suggesting its potential benefit as a caries preventive probiotic agent.

Infectious and Immunological Links Between Periodontitis and COVID-19: A Review

Emerging evidence suggests a potential association between periodontitis and adverse outcomes in COVID-19. Both conditions share risk factors and exhibit similar immune dysregulation, including elevated pro-inflammatory cytokines, altered myeloid compartments, and T-cell dysfunction. SARS-CoV-2 uses angiotensin-converting enzyme type 2 and transmembrane protease serine 2 membrane proteins, highly expressed in the oral cavity, for cellular entry. Periodontitis may exacerbate COVID-19 through mechanisms such as oral microbe aspiration, increased viral receptor expression, and systemic inflammation. The shared immunopathogenesis, characterized by cytokine storms and perturbed immune profiles, suggests periodontitis can predispose patients to more severe COVID-19 outcomes. This article aims to review the associations between periodontitis and the severity of COVID-19 and the possible immune mechanisms involved.

Meta-Analysis of 16S rRNA Sequencing Reveals Altered Fecal but Not Vaginal Microbial Composition and Function in Women with Endometriosis

Background and Objectives: Dysbiosis of the oral-gut axis is related to several extraintestinal inflammatory diseases, including endometriosis. This study aims to assess the microbial landscape and pathogenic potential of distinct biological niches during endometriosis. Materials and Methods: A microbiome meta-analysis was conducted on 182 metagenomic sequences (79 of fecal and 103 of vaginal origin) from women with and without endometriosis. Fecal and vaginal microbial diversity, differential abundance, and functional analysis based on disease status were assessed. Random forest, gradient boosting, and generalized linear modeling were used to predict endometriosis based on differentially enriched bacteria. Results: Only intestinal microbes displayed distinctive taxonomic and functional characteristics in women with endometriosis compared to control women. Taxonomic differences were quantified using the microbial endometriosis index (MEI), which effectively distinguished between individuals with and without the disease. The observed functional enrichment pointed to proinflammatory pathways previously related to endometriosis development. Conclusions: Dysbiosis in the oral-gut microbial community appears to play a prevalent role in endometriosis. Our findings pave the ground for future studies exploring the potential mechanistic involvement of the oral-gut axis in disease pathogenesis.

Microbiological and molecular aspects of periodontitis pathogenesis: an infection-induced inflammatory condition

Periodontitis (PD) is the most common oral infectious disease. The primary etiologic cause of the onset and development of PD is dental plaque, which consists of bacterial biofilm domiciled within a complex extracellular mass. In PD patients, there is a progressive breakdown of the periodontal ligament and the alveolar bone. In more advanced stages, tooth loss occurs. The progression of this chronic inflammatory disease involves interactions among numerous microbial pathogens particularly, bacteria, the host's immune factors, and various environmental factors. Due to persistent infection by periodonto-pathogenic bacteria, there is an impairment of both innate and acquired immunity, leading to tissue destruction. Chronic inflammation in PD may be associated with several systemic diseases, including cardiovascular conditions, respiratory issues, diabetes, neurological diseases, cancer, and adverse pregnancy outcomes. Antibiotic treatment is one of the effective strategies for treating PD cases, although the emergence of some resistant strains may limit the effectiveness some antibiotics. In this review study, we discussed the main bacteria in PD, the interaction with the immune response, the pathogenesis of bacteria in PD and antibiotic treatment. We also outlined the emergence of resistance to antibiotics among these pathogens.

Devices to overcome the buccal mucosal barrier to administer therapeutic peptides

Peptide therapeutics are important in healthcare owing to their high target specificity, therapeutic efficacy, and relatively low side effect profile. Injections of these agents have improved thetreatment of chronic diseases including autoimmune, metabolic disorders, and cancer. However, their administration via injections can prove a barrier to patient acceptability of treatments. While oral delivery of these molecules is preferable, oral peptide formulations are associated with limited bioavailability due to degradation in the intestine and low epithelial permeability. Buccal administration of peptides is a potential alternative to injections and oral formulations. Similar to the oral route, the buccal route can promote better patient adherence to dosing regimens, along with the added advantages of not requiring restriction on food or drink consumption before and after administration, as well as avoidance of the liver first-pass metabolism. However, like oral, effective buccal absorption of peptides is still challenging due to the high epithelial permeability barrier. We present a multidisciplinary approach to understanding the buccal physiological barrier to macromolecule permeation and discuss how engineered devices may overcome it. Selected examples of buccal devices can facilitate fast and efficient macromolecule absorption through multiple mechanisms including physical disruption of epithelia, convection-based mass transfer, and a combination of physicochemical strategies. Importantly, minimally invasive devices can be self-applied and are associated with the maintenance of the barrier after exposure. We analysed the critical attributes that are required forthe clinical translation of buccal peptide administration devices. These include performance-driven device development, manufacturing features, patient acceptability, and commercial viability.

Porphyromonas gingivalis and Human Cytomegalovirus Co-Infection: A Potential Link Between Periodontal Disease and Oral Cancer Development

Periodontal disease (PD) is an inflammatory condition that can contribute to the development of oral cancer. Chronic inflammation from PD can lead to the release of inflammatory mediators and growth factors that promote tumorigenesis. Porphyromonas gingivalis (P. gingivalis) is one of several pathogens implicated in PD and its potential link to oral cancer. However, other viral infections, such as human cytomegalovirus (HCMV), can also contribute to chronic inflammation, creating a favorable environment for oral cancer development.

OBJECTIVES

The present literature review tries to investigate the possible influence of P. gingivalis and HCMV co-infection in fostering the development of oral cancer and chronic periodontitis.

METHODS

A comprehensive search was conducted in PubMed and Google Scholar, focusing on the relevance and significance of articles that examine the role of P. gingivalis and HCMV in periodontal disease and oral cancer.

RESULTS

The evidence suggests that P. gingivalis and HCMV may act synergistically to modulate host immunity, disrupt epithelial integrity, and interfere with key cellular pathways. These interactions may enhance tissue destruction and foster a microenvironment conducive to malignant transformation. However, most of these findings stem from in vitro models and small-scale clinical studies, limiting the generalizability and clinical relevance of current conclusions.

CONCLUSIONS

Although the proposed interaction between P. gingivalis and HCMV provides a compelling framework for understanding how microbial co-infections may influence oral cancer, the evidence remains preliminary and largely associative. To support these mechanistic hypotheses, future studies should give top priority to in vivo models, bigger patient cohorts, and longitudinal clinical studies.

Natural and induced immune responses in oral cavity and saliva

This review comprehensively explores the intricate immune responses within the oral cavity, emphasizing the pivotal role of saliva in maintaining both oral and systemic health. Saliva, a complex biofluid, functions as a dynamic barrier against pathogens, housing diverse cellular components including epithelial cells, neutrophils, monocytes, dendritic cells, and lymphocytes, which collectively contribute to robust innate and adaptive immune responses. It acts as a physical and immunological barrier, providing the first line of defense against pathogens. The multifaceted protective mechanisms of salivary proteins, cytokines, and immunoglobulins, particularly secretory IgA (SIgA), are elucidated. We explore the natural and induced immune responses in saliva, focusing on its cellular and molecular composition. In addition to saliva, we highlight the significance of a serum-like fluid, the gingival crevicular fluid (GCF), in periodontal health and disease, and its potential as a diagnostic tool. Additionally, the review delves into the impact of diseases such as periodontitis, oral cancer, type 2 diabetes, and lupus on salivary immune responses, highlighting the potential of saliva as a non-invasive diagnostic tool for both oral and systemic conditions. We describe how oral tissue and the biofluid responds to diseases, including considerations to periodontal tissue health and in disease periodontitis. By examining the interplay between oral and systemic health through the oral-systemic axis, this review underscores the significance of salivary immune mechanisms in overall well-being and disease pathogenesis, emphasizing the importance of salivary mechanisms across the body.

Environmental particulate matter-one of the culprits in the development of caries

With the development of society, ecological and environmental problems have gradually become the focus of attention of countries around the world, among which environmental particulate matter poses a major harm to health. This article elucidates the association between environmental particulate matter and dental caries and provides new insights into the underlying mechanisms. In addition, this study emphasizes the role of oxidative stress in the occurrence and development of dental caries, and a new research pathway based on the interaction between oxidative stress and dental caries based on the Nrf2 pathway has become the focus of future research on the pathogenesis of dental caries. The relevant content of this review can provide a certain theoretical basis for the follow-up multidisciplinary joint research of researchers, and provide a certain reference for public health personnel and policymakers to formulate prevention strategies and public health interventions, carry out more accurate individualized treatment for high-risk groups, implement key prevention and treatment, and promote the overall improvement of effective prevention and treatment of caries. Ultimately, more attention must be paid to addressing the relationship between environmental particulate pollution and dental caries, with a focus on pollution control and reducing preventable environmental risks in order to protect oral health more broadly.

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.

Development of the breastfed infant oral microbiome over the first two years of life in the BLOSOM Cohort

Background

Acquisition and development of the oral microbiome are dynamic processes that occur over early life. This study aimed to characterize the temporal development of the oral microbiome of predominantly breastfed infants during the first two years of life.

Methods

Infant oral samples (n=667) were collected at ten time points from the first week to year two of life from 84 infants. Bacterial DNA profiles were analyzed using full-length 16S rRNA gene sequencing.

Results

The oral microbiome was dominated by Streptococcus mitis, Gemella haemolysans, and Rothia mucilaginosa. Bacterial richness decreased from 1 to 2 months (P = 0.043) and increased from 12 to 24 months (P = 0.038). Shannon diversity increased from 1 week to 1 month and again from 6 to 9 months and 9 to 12 months (all P ≤ 0.04). The composition of the infant oral microbiome was associated with multiple factors, including early pacifier use, intrapartum antibiotic prophylaxis, maternal allergy, pre-pregnancy body mass index, siblings, delivery mode, maternal age, pets at home, and birth season (all P < 0.01). Introduction of solid foods was a significant milestone in oral microbiome development, triggering an increase in bacterial diversity (richness P = 0.0004; Shannon diversity P = 0.0007), a shift in the abundance of seven species, and a change in beta diversity (P = 0.001).

Conclusion

These findings underscore the importance of multiple factors, particularly the introduction of solid foods, in shaping the oral microbiome of breastfed infants during early life.

An Overview of the Etiopathogenic Mechanisms Involved in the Expression of the Oral Microbiota

Background/Objectives: The diversity of the oral microbiota exerts its effects in maintaining dental and overall health. The unique genetic profile of each individual influences the composition of the oral microbiota, determining susceptibility to certain diseases. The aim is to observe its role by highlighting the pathogenic mechanisms involved in oral dysbiosis and identify genetic determinism's influence in maintaining balance. Methods: This study was designed as a narrative review of the oral microbiota, utilizing some of the principles and guidelines of systematic review to increase methodological rigor. We examined 121 articles such as reviews, meta-analyses, editorials, and observational studies, which met the inclusion and exclusion criteria. The inclusion criteria for studies were as follows: (1) studies that evaluated the impact of the microbiota in oral or/and systemic diseases; (2) studies that observed pathogenic mechanisms in the oral microbiota; (3) studies that evaluated the interaction of the microbiota with the immune system (4); studies that evaluated genetic implications in the microbiota. Results: Host genes regulate inflammatory and immunological reactions that play a role in microbiological balance. This explains the increased resistance of some to diseases, including gingivitis or periodontitis. Also, the implications of oral dysbiosis are reflected not only locally, but also generally, being associated with various systemic conditions. Conclusions: Understanding the pathogenic mechanisms and genetic determinants involved in oral dysbiosis may help create individualized therapies for preventing and managing oral and systemic disorders. A healthy lifestyle and adequate oral hygiene can facilitate a diverse and balanced microbiome, crucial for overall health.

Alcohol exposure alters the diversity and composition of oral microbiome

Introduction

Alcohol exposure has been shown to have complex, and sometimes paradoxical, associations with various serious diseases. Currently, there is no knowledge about the effects of alcohol exposure on the dynamics of oral microbial communities.

Objective

The study aims to investigate the effects of chronic alcohol consumption on the diversity and composition dynamics of the rat oral microbiota using 16S rRNA gene amplicon sequencing.

Methods

In our study, there were 2 groups, including a control group (C group) and an alcohol group (A group), with 10 rats in every group. For ten weeks, rats in the A group were treated with alcohol intragastrically every day, whereas rats in the C group got water. After 10 weeks, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. Oral swabs were taken from both groups, and total DNA was extracted for high-throughput sequencing of the 16S rRNA gene.

Results

According to the results obtained from our study, significant differences were observed in the relative abundances of microbial communities. Alpha diversity measures were statistically significantly higher (P < 0.05) in the A group compared to the C group. At the genus level, alcohol exposure altered the relative abundance of several microbes, including increased relative abundance of unidentified_Chloroplast, Acinetobacter, Vibrio, Romboutsia, Pseudoalteromonas, Aeromonas, Ralstonia, Turicibacter, Shewanella, and Bacteroides. Conversely, Haemophilus and Streptococcus were significantly less abundant in the A group.

Conclusion

Alcohol exposure was associated with the diversity and composition of the oral microbiome. These findings contribute to our understanding of the potential role of oral bacteria in alcohol-related oral and systemic diseases, providing foundational work for future prevention and intervention studies.

The Oral-Gut Microbiome-Brain Axis in Cognition

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline and neuronal loss, affecting millions worldwide. Emerging evidence highlights the oral microbiome-a complex ecosystem of bacteria, fungi, viruses, and protozoa as a significant factor in cognitive health. Dysbiosis of the oral microbiome contributes to systemic inflammation, disrupts the blood-brain barrier, and promotes neuroinflammation, processes increasingly implicated in the pathogenesis of AD. This review examines the mechanisms linking oral microbiome dysbiosis to cognitive decline through the oral-brain and oral-gut-brain axis. These interconnected pathways enable bidirectional communication between the oral cavity, gut, and brain via neural, immune, and endocrine signaling. Oral pathogens, such as Porphyromonas gingivalis, along with virulence factors, including lipopolysaccharides (LPS) and gingipains, contribute to neuroinflammation, while metabolic byproducts, such as short-chain fatty acids (SCFAs) and peptidoglycans, further exacerbate systemic immune activation. Additionally, this review explores the influence of external factors, including diet, pH balance, medication use, smoking, alcohol consumption, and oral hygiene, on oral microbial diversity and stability, highlighting their role in shaping cognitive outcomes. The dynamic interplay between the oral and gut microbiomes reinforces the importance of microbial homeostasis in preserving systemic and neurological health. The interventions, including probiotics, prebiotics, and dietary modifications, offer promising strategies to support cognitive function and reduce the risk of neurodegenerative diseases, such as AD, by maintaining a diverse microbiome. Future longitudinal research is needed to identify the long-term impact of oral microbiome dysbiosis on cognition.

Quantitative analysis of Streptococcus mutans, Bifidobacterium, and Scardovia Wiggsiae in occlusal biofilm and their association with Visible Occlusal Plaque Index (VOPI) and International Caries Detection and Assessment System (ICDAS)

AIMS

To quantitatively detect S. mutans, Bifidobacterium, and S. wiggsiae in occlusal biofilm from permanent first molars based on the Visible Occlusal Plaque Index (VOPI), and to analyse the association between their levels and the occlusal enamel caries occurrence following the diagnosis of the International Caries Detection and Assessment System (ICDAS).

STUDY DESIGN

One hundred twenty plaque samples were collected from children aged 6-8 years and divided into four groups (n = 30 each group) according to VOPI scores (0 = no visible plaque, 1 = thin plaque, 2 = thick plaque, and 3 = heavy plaque). Scores 0 and 1 were identified by running dental probe on the groove. Scores 2 and 3 were visually identified. ICDAS scores were recorded by scoring 0-3 (0 = sound tooth surface, 1 = opacity or discoloration of enamel after air drying, 2 = visual change in enamel when wet, and 3 = localised enamel breakdown).

METHODS

DNA was extracted from plaque samples and performed quantitative real-time PCR using SYBR green and specific primers for total bacteria including the 16S rRNA gene sequences conserved in all bacteria (BAC16S), S. mutans, Bifidobacterium, and S. wiggsiae.

RESULTS

Ages of the children were different amongst VOPI groups (p < 0.001). Levels of total bacteria (p < 0.001) and S. mutans (p = 0.026) increased when VOPI increased. The ratio of S. mutans to total bacteria (p = 0.015) and the ratio of Bifidobacterium to total bacteria (p < 0.001) decreased from VOPI 0 to VOPI 3. Significant differences in total bacteria (p < 0.001) and S. mutans (p = 0.018) were detected from VOPI 0 to VOPI 2. A difference in Bifidobacterium (p < 0.001) was detected from VOPI 0 to VOPI 1.

CONCLUSION

Quantities of total bacteria (p < 0.001), S. mutans (p = 0.02) and ICDAS scores (p < 0.001) and VOPI scores were positively correlated. Quantities of ratio of S. mutans to total bacteria (p = 0.003) and ratio of Bifidobacterium to total bacteria (p < 0.001) and VOPI scores and ICDAS scores (p < 0.001) were negatively correlated.

Periodontal Status and Herpesiviridae, Bacteria, and Fungi in Gingivitis and Periodontitis of Systemically Compromised Pediatric Subjects: A Systematic Review

BACKGROUND

Gingivitis and periodontitis are microbially associated diseases, with some features characteristic of pediatric age and others linked to systemic diseases. While the role of periodontal pathogenic bacteria is well recognized, the contribution of fungi and viruses, particularly Herpesviridae, remains controversial. Studies in adults have highlighted the presence of Herpesviridae, but evidence in pediatric subjects, especially systemically compromised, is limited. This systematic review aimed to assess periodontal status (e.g., health, gingivitis, periodontitis, necrotizing gingivitis, and/or periodontitis) and the subgingival and/or salivary microbial (bacterial, viral, and fungal) profile in systemically compromised pediatric (≤18 years) subjects with gingivitis and/or periodontitis compared to clinical periodontal health.

METHODS

The review protocol was registered on PROSPERO (CRD42024597695) and followed the PRISMA statement. Data from eight studies were descriptively analyzed and qualitatively assessed through ROBINS-I and JBI tools.

RESULTS

CMV was frequently detected, particularly in necrotizing gingivitis (19.40%). EBV was found in necrotizing gingivitis (20.69%) and periodontitis (10.34%); HSV was mainly associated with gingivitis and necrotizing gingivitis. Bacteria species in periodontitis included Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium, and Campylobacter species. Candida albicans was detected in periodontitis, suggesting a fungal involvement in the disease's pathogenesis. Although the bacterial and fungal profile was not investigated, limited viral presence was noted in subjects with healthy periodontium, indicating a stable microbiome.

CONCLUSIONS

These findings underscore the dynamics of microbial interactions in the progression of periodontal disease in systemically compromised pediatric subjects.

Anti-inflammatory and antimicrobial efficacy of coconut oil for periodontal pathogens: a triple-blind randomized clinical trial

OBJECTIVES

To evaluate the effect of coconut oil on the oral bacteriome and inflammatory response in patients with periodontitis by integrating next-generation sequencing analyses of pathogenic bacterial shifts and quantification of inflammatory markers, thereby assessing its potential as a natural adjunct to standard nonsurgical periodontal therapy.

MATERIALS AND METHODS

A triple-blind clinical trial was conducted with 30 participants diagnosed with periodontitis, randomized into 3 groups: (1) coconut oil, (2) chlorhexidine and (3) placebo. Saliva and gingival crevicular fluid (GCF) samples were collected before treatment, one month after treatment, and one month post-non-surgical periodontal therapy. Bacterial DNA was extracted, and the V3-V4 region of the 16 S rRNA gene was PCR-amplified and sequenced using Illumina MiSeq technologies. Inflammatory biomarkers, including Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were quantified from GCF samples.

RESULTS

Coconut oil treatment significantly reduced pathogenic bacterial families such as Spirochaetaceae and Tannerellaceae while promoting beneficial bacteria such as Streptococcaceae. At the genus and species levels, coconut oil reduced pathogens such as Tannerella forsythia and Treponema denticola along with increase in beneficial bacteria such as Streptococcus. The subgingival microbial dysbiosis index improved significantly in both coconut oil and chlorhexidine groups. Furthermore, the coconut oil demonstrated a reduction in IL-6 and TNF-α levels, indicating decreased local inflammation.

CONCLUSIONS

Coconut oil treatment significantly modulated the oral microbiome and reduced inflammatory markers in patients with periodontitis, suggesting its potential as a natural and effective adjunct in periodontal therapy.

CLINICAL RELEVANCE

This study highlights coconut oil's potential as a natural adjunct in periodontal therapy, effectively reducing pathogenic bacteria and inflammatory markers (IL-6, TNF-α). It offers a safe alternative to chlorhexidine, promoting microbiome balance and improved periodontal health.

A Potential Link Between Oral Microbiota and Female Reproductive Health

Oral cavity dysbiosis is associated with numerous inflammatory diseases, including diabetes, inflammatory bowel diseases, and periodontal disease. Changes in the oral microenvironment lead to bidirectional interactions between pathogens and individual host systems, which may induce systemic inflammation. There is increasing evidence linking the condition of the oral cavity with the most common causes of female infertility, such as polycystic ovary syndrome and endometriosis, as well as gestational complications, e.g., low birth weight, preterm delivery, and miscarriages. This review highlights the composition of the female oral microbiome in relation to infertility-related disorders, such as endometriosis and polycystic ovary syndrome, and provides a comprehensive overview of the current state of knowledge on the relationship between a dysbiotic oral microbiome, pregnancy, and its impact on the female reproductive tract.

Candida albicans and NCAC species: acidogenic and fluoride-resistant oral inhabitants

Objective

Although Candida species are thought to contribute to dental caries, their acid production under anaerobic conditions and susceptibility to fluoride have not been thoroughly studied. We therefore investigated the growth, acid production, and effect of fluoride on Candida species.

Methods

Aerobic growth, acid production from glucose and its end-products under aerobic and anaerobic conditions, and enolase activity were measured in C. albicans and non-Candida-albicans-Candida (NCAC) species (C. tropicalis, C. parapsilosis, C. maltosa, and C. glabrata), and the effect of fluoride on these abilities was evaluated.

Results

All Candida species produced acids under aerobic and anaerobic conditions, and acetate and TCA cycle metabolites were detected. However, these organic acids only accounted for 1.9-57.6% of the acids produced. Up to 80 mM fluoride hardly inhibited growth and did not inhibit acid production except for C. glabrata, despite the low 50% inhibitory fluoride concentration of 0.19-0.34 mM for enolase.

Conclusion

Candida species produced acids under aerobic and anaerobic conditions, indicating their significant cariogenicity. Their growth and acid production were highly fluoride-resistant, whereas their enolase was fluoride-sensitive, suggesting mechanisms for maintaining low intracellular fluoride. The mechanisms underlying the fluoride resistance remain underexplored. Approaches other than fluoride may be needed to control Candida-associated caries.

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.

Oral SARS-CoV-2 Infection and Risk for Long Covid

SARS-CoV-2 is an oral pathogen that infects and replicates in mucosal and salivary epithelial cells, contributing to oral post-acute sequelae COVID-19 (PASC) and other oral and non-oral pathologies. While pre-existing inflammatory oral diseases provides a conducive environment for the virus, acute infection and persistence of SARS-CoV-2 can also results in oral microbiome dysbiosis that further worsens poor oral mucosal health. Indeed, oral PASC includes periodontal diseases, dysgeusia, xerostomia, pharyngitis, oral keratoses, and pulpitis suggesting significant bacterial contributions to SARS-CoV-2 and oral tissue tropism. Dysbiotic microbiome-induced inflammation can promote viral entry via angiotensin-converting enzyme receptor-2 (ACE2), serine transmembrane TMPRSS2 and possibly other non-canonical pathways. Additionally, metabolites derived from a dysbiotic microbiome can alter the physiological and biochemical pathways related to the metabolism of lipids, carbohydrates, and amino acids. This may promote a pro-inflammatory microenvironment, leading to immune exhaustion, loss of tolerance, and susceptibility to a variety of oral pathogens, causing acute and later chronic inflammation. Microbial release of mimics of host metallopeptidases related to furin, ADAM17 (A disintegrin and metalloproteinase 17), and glycoprotein metabolites can further aid viral attachment to T cell immunoglobulin-like (TIMs), enhancing viral entry while simultaneously depressing oral mucosal immune resistance and clearance. Membrane reorganization characterised by neuroproteins, such as neuropilins, also functionally assists with SARS-CoV-2 entry and extends the pathogenesis of PASC from the oral cavity to the brain, gut, or other non-oral tissues. Thus, poor oral health, characterised by disrupted oral microbiomes can promote viral tropism, weaken antiviral resistance, and heightens susceptibility to SARS-CoV-2 infection. This immune dysfunction also increases the risk of additional viral infections, exacerbating oral conditions like periodontal and endodontic diseases. These persistent oral health issues can contribute to systemic inflammation, creating bidirectional effects between oral and non-oral tissues, potentially leading to Post-Acute Sequelae of COVID-19 (PASC).

Herbal remedies for oral and dental health: a comprehensive review of their multifaceted mechanisms including antimicrobial, anti-inflammatory, and antioxidant pathways

Across diverse cultures, herbal remedies have been used to alleviate oral discomfort and maintain dental hygiene. This review presents studies on herbal remedies with remarkable antimicrobial, anti-inflammatory, antioxidant, anticancer, anticaries, analgesic, and healing properties. The manuscripts demonstrate the depth of scientific inquiry into herbal remedies used for the management of various oral and dental health conditions. These include gingivitis, oral ulcers, mucositis, periodontitis, oral pathogens, carcinoma, xerostomia, and dental caries. Researchers have investigated the phytochemical and pharmacological properties of plant-derived compounds and their extracts evaluated their interactions with oral pathogens and inflammatory processes. The convergence of traditional knowledge and rigorous scientific investigation offers a compelling narrative, fostering a deeper understanding of herbal remedies as viable alternatives to conventional dental interventions. This work has the potential to provide patients with access to gentle, yet effective solutions, and simultaneously offer dental health professionals the opportunity to enrich their knowledge, and ability to provide personalized, holistic care. This review highlights the symbiotic relationship between herbal medicine and scientific understanding, emphasizing the importance of disseminating this knowledge to benefit both practitioners and patients, enabling evidence-based decision-making in dental care. The exploration of herbal remedies offers a promising alternative, potentially mitigating some of these side effects while promoting oral health in a more natural and holistic manner.

Revealing the viral culprits: the hidden role of the oral virome in head and neck cancers

The oral viral microbiome (or virome), encompassing a diverse community of viruses within the oral cavity, has emerged as a significant yet underexplored factor in head and neck cancers (HNCs). This review synthesizes recent evidence linking the oral virome to head and neck carcinogenesis, particularly oropharyngeal and nasopharyngeal carcinomas-the most common virus-associated subtypes of HNCs. Beyond pathogenesis, the diagnostic and therapeutic implications of the oral virome are explored, including non-invasive salivary detection of viral biomarkers for early cancer diagnosis, the development of targeted antiviral therapies, and preventive vaccination strategies-exemplified by the success of HPV vaccines in reducing the incidence of oropharyngeal cancers. Despite these advancements, challenges persist, including technical limitations, the need for longitudinal studies, and the integration of multi-omics approaches. A comprehensive understanding of the oral virome could revolutionize cancer diagnostics, therapeutics, and prevention. Moving forward, collaborative interdisciplinary efforts will be essential to fully leverage virome research for improving HNC outcomes.

How Should We Manage the Impact of Antimicrobial Resistance in Patients With Cancer? An Oncological and Infectious Disease Specialist Point of View

Patients with solid tumors present a higher risk of infectious diseases with worse outcomes compared with immunocompetent patients. Prolonged treatment of prophylactic and empirically chosen antibiotics and health care-acquired infections can predispose patients with cancer to infections with antimicrobial-resistant (AMR) organisms. AMR is a global health priority and can affect patients with cancer. The outcome of patients with cancer worsens dramatically if multidrug-resistant (MDR) microorganisms cause infections. Moreover, the emergence of MDR organisms increases health care costs. Antimicrobial stewardship programs can be useful to monitor and improve the use of antibiotics in all oncological settings, including the palliative setting. Awareness of the magnitude of these issues is still low, so it is important to inform and educate oncologists. This narrative review aims to illustrate the main evidence on infections caused by AMR organisms in patients with cancer and the tools that oncologists should have to enhance their multidisciplinary management.

Evaluating the Impact of Kefir Consumption on Dental Caries and Periodontal Disease: A Narrative Review

Background/Objectives: Dental caries and periodontal diseases are the most common illnesses in the oral cavity and represent a public health concern globally. In recent decades, diverse studies showed that Kefir, a traditional beverage that can be milk- or water-based, contains a complex microbial community and has health benefits. The goal of this review was to update the current knowledge of kefir consumption and its impact on oral health. Methods: The search of a combination of keywords-kefir; dental caries; probiotics; microbiota; periodontal diseases; biofilm; and oral health-was conducted using PubMed, Google Scholar, and Web of Science databases for studies in human subjects. Discussion: The research suggests that kefir consumption may aid in decreasing counts of microorganisms typically associated with oral illness. Conclusions: Kefir has the potential to inhibit certain oral pathogens and reduce biofilm formation by promoting diversity within the oral microbiota, suggesting that kefir could be a promising adjuvant treatment for dental caries and periodontal diseases by improving oral health.

Exploration of oral microbiota alteration and AI-driven non-invasive hyperspectral imaging for CAD prediction

BACKGROUND

Oral microbiome dysbiosis is an important risk factor affecting the occurrence and progression of coronary artery disease (CAD). However, the dysbiosis on the tongue in patients with CAD is still unclear, and whether the oral alteration caused by these disorders can be identified by other tools for CAD diagnosis needs to be further explored. Hyperspectral imaging (HSI) is characterized as high spectral resolution, broad spectral range, and superior spatial resolution. Hyperspectral images contain high-dimensional data that generally require machine learning algorithms for feature identification and model construction. Therefore, this study aims to investigate the variation of tongue microbiota and the effectiveness of HSI models in CAD diagnosis.

METHODS

Between 2023 and 2024, we prospectively approached 276 patients with chest pain and exhibiting risk for CAD who underwent coronary artery angiography (CAG). And 190 patients were enrolled in this study. Tongue dorsum swabs were collected for subsequent 16sRNA sequencing and microbiome analysis. Tongue dorsum features were extracted from hyperspectral images. The HSI analysis incorporated a total of 4750 hyperspectral images from all patients. All images are divided into training set (N = 2555), internal test set (N = 1095) and external test set (N = 1095). A total of 31 models were constructed. 30 single machine learning algorithms were used to construct and test the CAD prediction models. Furthermore, the best performing fusion model was established. The efficacy of the model was evaluated employing several metrics, including area under the curve (AUC), decision curve analysis (DCA), calibration curve, accuracy (ACC), sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and F1 score.

RESULTS

The 16sRNA sequencing results indicated significant dysbiosis in the oral microbiota of patients with CAD, with decreased microbial abundance, network complexity and stability. The fusion model (GP-GB-SVM) demonstrated the highest performance, achieving an AUC of 0.92, ACC of 0.82, SE of 0.70, SP of 0.92, PPV of 0.88 and NPV of 0.79 in the internal test set and AUC of 0.86, ACC of 0.70, SE of 0.90, SP of 0.46, PPV of 0.60 and NPV of 0.90 in the external test set.

CONCLUSION

These findings not only emphasize the significant alteration of microbiome colonized on the tongue dorsum in CAD patients but also demonstrate the tongue features associated with microbiome dysbiosis can be identified in hyperspectral images. Thereby the integration of HSI and machine learning provides novel insights into non-invasive diagnosis of CAD.

Structural and functional changes in the oral microbiome of patients with craniofacial microsomia

Craniofacial microsomia (CFM) is the second most common congenital craniofacial deformity, presenting diverse clinical manifestations and treatments that may influence oral bacteria dysbiosis (OBD). However, research linking CFM to OBD is limited. Saliva samples were collected from 20 patients with CFM and 24 controls. We compared oral microflora and gene function using 16 S ribosomal RNA sequencing and metagenomics. We also evaluated the correlation between CFM clinical phenotypes and microbiota community structure. Patients with CFM demonstrated greater richness and evenness in their oral microflora. The dominant genera included several pathogenic species, such as Actinomyces, Fusobacterium, and Prevotella. Notably, the severity of CFM correlated positively with the abundance of Neisseria and Porphyromonas. Upregulated pathways were primarily linked to biotin and amino acid metabolism, such as Tryptophan metabolism and Lysine degradation, and further underscored the need for focused oral health interventions in this population. This study is the first to indicate that CFM patients exhibit unique oral bacterial dysbiosis, marked by a higher presence of opportunistic pathogens and increased pathways related to oral and systemic health. These findings highlight the importance of monitoring oral health in patients with CFM.

Microbial signatures in head and neck squamous cell carcinoma: an in silico study

OBJECTIVES

The oral cavity harbors a plethora of bacterial species. Dysbiosis of oral and gut microbiota is associated with several oral and systemic pathologies, such as cancer, obesity, diabetes, atherosclerosis and gastrointestinal diseases. Imbalance in the oral-gut microbial axis has been associated with head and neck squamous cell carcinoma (HNSCC). This study aims to analyze the bacterial profile of HNSCC across various taxonomic units, investigate molecular patterns associated with prevalent bacterial phylum in HNSCC, and compare the bacterial profile in HNSCC and gastrointestinal (GI) carcinoma using computational analysis.

METHODOLOGY

The microbe-host transcriptomic, proteomic, and epigenetic analyses of HNSCC and GI carcinomas were performed using The Cancer Microbiome Atlas (TCMA) database. The differential expression of the host's mRNA transcripts and proteins associated with tumor microbiome were analyzed using The University of Alabama at Birmingham Cancer data analysis (UALCAN) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) websites.

RESULTS

A decrease in Actinobacteria and an enrichment of Flavobacteria at the class level, Neisseriales, Pasteurellales, and Campylobacterales at the order level, Pasteurellaceae, Flavobacteriaceae, Campylobacteraceae, and Peptoniphilaceae at the family level, and Hemophilus, Porphyromonas, and Leptotrichia at the genus level were observed in HNSCC compared to the normal mucosa. RICTOR protein, mRNA transcripts (HIST1H2BB, SCARNA11, TBC1D21 gene), and hsa-miR-200a-5p miRNA were significantly correlated with prevalent bacterial species in HNSCC. A major increase in Actinobacteria, Fusobacteria, and Spirochaetes was observed in HNSCC compared to GI carcinoma.

CONCLUSION

The oral-gut microbial dysbiosis, as reflected by the differential abundance of bacterial species in oral and GI carcinomas, suggests the implication of tumor microbiome and their genomic interactions with the host in carcinogenesis.

Emerging therapeutic strategies targeting bone signaling pathways in periodontitis

Periodontitis is a multifactorial immune-mediated disease exacerbated by dysregulated alveolar bone homeostasis. Timely intervention is crucial for disease management to prevent tooth loss. To successfully manage periodontitis, it is imperative to understand the cellular and molecular mechanisms involved in its pathogenesis to develop novel treatment modalities. Non-surgical periodontal therapy (NSPT) such as subgingival instrumentation/debridement has been the underlying treatment strategy over the past decades. However, new NSPT approaches that target key signaling pathways regulating alveolar bone homeostasis have shown positive clinical outcomes. This narrative review aims to discuss endogenous bone homeostasis mechanisms impaired in periodontitis and highlight the clinical outcomes of preventive periodontal therapy to avoid invasive periodontal therapies. Although the anti-resorptive therapeutic adjuncts have demonstrated beneficial outcomes, adverse events have been reported. Diverse immunomodulatory therapies targeting the osteoblast/osteoclast (OB/OC) axis have shown promising outcomes in vivo. Future controlled randomized clinical trials (RCT) would help clinicians and patients in the selection of novel preventing therapies targeting key molecules to effectively treat or prevent periodontitis.

Levilactobacillus brevis CD2 as a multifaceted probiotic to preserve oral health: results of a double-blind, randomized, placebo-controlled trial in healthy adults

BACKGROUND

A growing number of in vitro and in vivo studies suggest the application of probiotics as a natural approach to maintaining oral health. This double-blind, randomized controlled trial aimed to evaluate the efficacy of Levilactobacillus brevis CD2 (CNCM I-5566), a multifunctional probiotic frequently used in oral medicine, in preserving or improving several recognized oral health indicators.

METHODS

Thirty consenting healthy adults were randomized to receive four lozenges per day of L. brevis CD2 probiotic (n = 15) or placebo (n = 15) over four weeks. Clinical parameters (full-mouth bleeding on probing (BoP) and plaque index (PI) scores) were recorded. Unstimulated saliva was collected to measure salivation rate, pH, and buffer capacity. Salivary biomarkers were analyzed, including glucose, D-lactate, and secretory immunoglobulins A (sIgA). Clinical and salivary parameters were assessed at baseline, after four weeks of intervention, and two weeks post-intervention. Wilcoxon rank-sum test and robust regression analysis were used for statistical comparisons. The possible mediating effect of PI on BoP changes was assessed.

RESULTS

After four weeks, the probiotic group showed significant improvements in BoP and PI compared to baseline and placebo. The probiotic group had a higher salivation rate than baseline and placebo after four weeks of treatment and washout. While changes in salivary pH were not significant, buffering capacity increased in the probiotic group after four weeks of treatment and washout. Salivary glucose and D-lactate levels were lower in the probiotic group post-treatment and after washout. sIgA values increased and remained stable after washout in the probiotic group. No adverse effects were reported.

CONCLUSIONS

The treatment with L. brevis CD2 significantly improved clinical and salivary parameters, supporting its efficacy as a probiotic for oral health.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT06457724; Registered 7 June 2024 - Retrospectively registered; https://clinicaltrials.gov/study/NCT06457724?viewType=Table&page=452&rank=4512#study-overview .

Imbalance of oral microbiome homeostasis: the relationship between microbiota and the occurrence of dental caries

BACKGROUND

Streptococcus mutans is recognized as a key pathogen responsible for the development of dental caries. With the advancement of research on dental caries, the understanding of its pathogenic mechanism has gradually shifted from the theory of a single pathogenic bacterium to the theory of oral microecological imbalance. Acidogenic and aciduric microbial species are also recognized to participate in the initiation and progression of dental caries. This study is designed to elucidate the relationship between oral microbiome dysregulation and the initiation of dental caries.

RESULTS

16 S rRNA gene sequencing of saliva and dental plaque from the Specific Pathogen Free Control group and the Specific Pathogen Free sucrose diet group revealed that a sucrose diet significantly influenced the composition of the oral microbiome. At the phylum level, the dominant microbial communities in both groups of mice were Firmicutes, Proteobacteria, Unclassified Bacteria, Actinobacteria, and Bacteroidetes. At the genus level, statistical analysis identified significant differences in the abundance of 18 genera between the two groups. The relative abundance of the Gemella genus was significantly increased in the SPF Sucrose group. The SPF Control group and the Germ-free Control group have no differential bacterial genera in the oral microbiome. Micro-CT examination of the mandibles revealed the development of dental caries in both the SPF Sucrose group and the Germ-free Sucrose group.

CONCLUSIONS

This study indicates that a dysbiotic microbial community can lead to the development of caries. Lays the foundation for further research into the etiology of dental caries.

Impact of Periodontitis and Oral Dysbiosis Metabolites in the Modulation of Accelerating Ageing and Human Senescence

Periodontitis, a chronic multifactorial inflammatory condition of the periodontium, is originated by a dysbiotic oral microbiota and is negatively correlated with several systemic diseases. The low-chronic burden of gingival inflammation not only exacerbates periodontitis but also predisposes individuals to a spectrum of age-related conditions, including cardiovascular diseases, neurodegenerative disorders, and metabolic dysfunction, especially related to ageing. In this regard, over the local periodontal treatment, lifestyle modifications and adjunctive therapies may offer synergistic benefits in ameliorating both oral and systemic health in ageing populations. Elucidating the intricate connections between periodontitis and senescence is important for understanding oral health's systemic implications for ageing and age-related diseases. Effective management strategies targeting the oral microbiota and senescent pathways may offer novel avenues for promoting healthy ageing and preventing age-related morbidities. This review will analyze the current literature about the intricate interplay between periodontitis, oral dysbiosis, and the processes of senescence, shedding light on their collective impact on the modulation and accelerated ageing and age-related diseases. Lastly, therapeutic strategies targeting periodontitis and oral dysbiosis to mitigate senescence and its associated morbidities will be discussed.

Periodontal pathogens and obesity in the context of cardiovascular risks across age groups

Background

Cardiovascular diseases (CVDs) are the leading cause of mortality and morbidity among noncommunicable diseases. Over the past decade, there has been a notable increase in the prevalence of CVDs among young individuals. Obesity, a well-known risk factor for CVDs, is also associated with various comorbidities that may contribute to cardiovascular risk. The relationship between periodontal pathogens and CVD risk factors, including obesity, smoking, lipid metabolism disorders, and inflammatory markers, remains underexplored.

Methods

This study examined the relationship between six periodontal pathogens (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia, Prevotella intermedia, and Fusobacterium nucleatum) and CVD risk factors among 189 subjects stratified by age and body mass index (BMI). Body composition was assessed via bioimpedance analysis, and blood samples were analyzed for lipid profiles, glucose, and proinflammatory cytokines. Oral samples were collected for polymerase chain reaction (PCR) analysis to identify periodontal pathogens. Cardiovascular and diabetes risk scores were calculated using the SCORE and FINDRISC scales.

Results

The prevalence of periodontal pathogens in the population was 33.0% for P. gingivalis, 47.8% for P. intermedia, 63.4% for A. actinomycetemcomitans, 46.6% for T. forsythia, 46.6% for T. denticola, and 89.2% for F. nucleatum. Significant age- and BMI-related differences were observed in pathogen prevalence, particularly with P. gingivalis, P. intermedia, and T. denticola. Young obese individuals exhibited a higher prevalence of P. intermedia and T. forsythia. P. gingivalis was found to be associated with hypertension and dyslipidemia, while P. intermedia was linked to hypertension and obesity. T. denticola was associated with obesity, dyslipidemia and smoking, whereas T. forsythia was linked to dyslipidemia alone.

Conclusions

This study highlights the potential connection between periodontal pathogens and risk factors associated with cardiovascular disease, including smoking, elevated BMI, increased adipose tissue, hypertension, and dyslipidemia. Further research is required to determine the causal relationships between oral microbiome dysbiosis, obesity and, systemic diseases and to develop an effective strategy for preventing oral health-related CVD risk factors in young adults.

Host-microbe computational proteomic landscape in oral cancer revealed key functional and metabolic pathways between Fusobacterium nucleatum and cancer progression

Oral squamous cell carcinoma (OSCC) is the most common manifestation of oral cancer. It has been proposed that periodontal pathogens contribute to OSCC progression, mainly by their virulence factors. However, the main periodontal pathogen and its mechanism to modulate OSCC cells remains not fully understood. In this study we investigate the main host-pathogen pathways in OSCC by computational proteomics and the mechanism behind cancer progression by the oral microbiome. The main host-pathogen pathways were analyzed in the secretome of biopsies from patients with OSCC and healthy controls by mass spectrometry. Then, functional assays were performed to evaluate the host-pathogen pathways highlighted in oral cancer. Host proteins associated with LPS response, cell migration/adhesion, and metabolism of amino acids were significantly upregulated in the human cancer proteome, whereas the complement cascade was downregulated in malignant samples. Then, the microbiome analysis revealed large number and variety of peptides from Fusobacterium nucleatum (F. nucleatum) in OSCC samples, from which several enzymes from the L-glutamate degradation pathway were found, indicating that L-glutamate from cancer cells is used as an energy source, and catabolized into butyrate by the bacteria. In fact, we observed that F. nucleatum modulates the cystine/glutamate antiporter in an OSCC cell line by increasing SLC7A11 expression, promoting L-glutamate efflux and favoring bacterial infection. Finally, our results showed that F. nucleatum and its metabolic derivates promote tumor spheroids growth, spheroids-derived cell detachment, epithelial-mesenchymal transition and Galectin-9 upregulation. Altogether, F. nucleatum promotes pro-tumoral mechanism in oral cancer.

The effect of antireaction medications on the association between periodontitis and leprosy reactions: An important methodological issue in periodontal medicine

BACKGROUND

The treatment of leprosy reactions (LRs) involves thalidomide, corticosteroids, and other immunomodulatory medications. This study evaluated the effect of these treatments on the association between periodontitis and LRs, as well as factors associated with LRs.

METHODS

This case-control study was conducted on 283 individuals followed at a leprosy outpatient clinic in Brazil. The case group was comprised of 158 individuals presenting type 1 or type 2 LRs, and the control group of 125 leprosy individuals without reactions. A complete oral examination was performed to diagnose periodontitis, the independent variable. Antireaction medication used was collected from medical records, and participants were classified according to the use of prednisone and/or thalidomide, time of use, or non-use of medication. Socioeconomic-demographic, clinical, and lifestyle covariables were collected by interview. Unconditional logistic regression analysis by subgroups evaluated the effect of antireaction medication on the association between periodontitis and LRs, estimating the odds ratio with a 95% confidence interval (OR; 95% CI).

RESULTS

A relationship between periodontitis and LRs was observed only in the subgroup using the association prednisone and thalidomide: ORadjusted = 0.32; 95% CI = 0.11-0.95. Conversely, more severe periodontal clinical parameters were observed in cases versus controls. Several socioeconomic, health conditions, and lifestyle factors were associated with the presence of LRs.

CONCLUSIONS

Although periodontal disease indicators were worse among the cases, the findings showed a negative relationship between periodontitis and LRs in individuals receiving associated prednisone and thalidomide. These medications appear to influence the inflammatory cascade between diseases, modifying and masking the manifestations of periodontitis.

The Oral Microbiome: A Key Determinant of Oral Health

As the second largest reservoir of human microbes, the oral cavity is colonized by millions of tiny creatures collectively named as oral microbiome. Species detected in human mouth are diverse, including bacteria, fungi, viruses, and protozoa. Active bidirectional interaction exists between the oral microbiome and the host. Stresses from hosts shape the composition, distribution pattern, and the community behaviors of the oral microbiome, while any changes occurring on the oral microbiome may disrupt its symbiosis relationship with the host and ultimately lead to oral and systemic diseases that jeopardize the host's health. In this chapter, the latest understanding about the role of oral microbiome in common oral diseases, including dental caries, periodontal disease, oral candidiasis, and hyposalivation, is discussed.

Interaction of the Systemic Inflammatory State, Inflammatory Mediators, and the Oral Microbiome

Humans are biological units that host numerous microbial symbionts and their genomes, which together form a superorganism or holobiont. Changes in the balance of the oral ecosystem can have consequences for both general and oral health, such as cavities, gingivitis, and periodontitis. Periodontitis is initiated by a synergistic and dysbiotic microbial community that causes local inflammation and destruction of the tooth's supporting tissues, potentially leading to systemic inflammation. This inflammation caused by periodontal disease has been associated with various systemic alterations, and the immune system is largely responsible for the body's exacerbated response, which can induce and exacerbate chronic conditions. Studies indicate that subgingival microorganisms found in periodontitis reach the bloodstream and are distributed throughout the body and, therefore, can be found in distant tissues and organs. Among all diseases associated with periodontal disease, diabetes mellitus presents the strongest and most elucidated link, and its bidirectional relationship has already been demonstrated. Chronic hyperglycemia favors the worsening of periodontal parameters, while the aggravation of periodontal parameters can promote an increase in glycemic indexes. Other systemic diseases have been related to periodontitis, such as Alzheimer's, chronic kidney disease, atherosclerosis, and respiratory diseases. The importance of periodontal control may suggest a reduction in the chances of developing chronic inflammatory diseases because these two alterations often share inflammatory pathways and, for this reason, may influence each other.

Association Between Dietary Patterns and Subgingival Microbiota: Results From the Oral Infections, Glucose Intolerance, and Insulin Resistance Study (ORIGINS)

OBJECTIVE

To study the association between dietary patterns and subgingival microbiota.

METHODS

Participants (n = 651) who were enrolled in the Oral Infections, Glucose Intolerance, and Insulin Resistance Study (ORIGINS) with subgingival plaque sampling (n = 890 plaques) and a dietary assessment were included. 16S rRNA gene amplicon sequences of subgingival plaque from sites with either probing depth <4 or ≥4 mm were processed separately and used to obtain α-diversity metrics (Faith, Shannon, Simpson, Observed) and taxa ratios (Red Complex to Corynebacterium [RCLR], Treponema to Corynebacterium [TCLR], and Treponema to Neisseria [TNLR]). Food frequency questionnaires (FFQs) were processed to calculate Alternate Healthy Eating Index (AHEI) and A Priori Diet Quality Score (APDQS) scores. Mixed regression models examined the mean levels of microbial metrics across quartiles of diet quality. Means ± standard errors are reported along with p-values.

RESULTS

In multivariable models assessing the association between diet scores and α-diversity metrics, higher AHEI values were significantly associated with lower Faith (p-value = 0.01) and Observed (p-value = 0.04) diversity values; similar findings were observed for APDQS (p-value = 0.01, p-value = 0.04). In multivariable models assessing the association between diet scores (AHEI and APDQS) and taxa ratios (RCLR, TCLR and TNLR), as the AHEI quartile increased, all taxa ratios decreased significantly as follows: -1.06 ± 0.093 in Q1 to -1.34 ± 0.099 in Q4 (RCLR), -0.43 ± 0.077 in Q1 to -0.64 ± 0.083 in Q4 (TCLR) and -0.09 ± 0.083 in Q1 to -0.38 ± 0.089 in Q4 (TNLR), respectively. In contrast, as the APDQS quartiles increased, only TNLR decreased significantly from -0.08 ± 0.085 in Q1 to -0.34 ± 0.091 in Q4.

CONCLUSION

Diets rich in fruits, vegetables, whole grains and other nutritionally rich plant foods are associated with lower oral microbial diversity and favourable ratios of pathogenic to commensal microbiota.

Alterations of oral microbiota in young children with autism: Unraveling potential biomarkers for early detection

OBJECTIVES

This study investigated the oral microbiota in young children with autism spectrum disorder (ASD) to determine possible alterations in microbial composition and identify potential biomarkers for early detection.

METHODS

Dental plaque samples from 25 children with ASD (aged 3-6 years; M = 4.79, SD = 0.83) and 30 age- and sex-matched typically developing (TD) children were analyzed using 16S rRNA sequencing.

RESULTS

The results showed lower bacterial diversity in children with ASD compared to controls, with distinct microbial compositions in the ASD and TD groups. Six discriminatory species (Microbacterium flavescens, Leptotrichia sp. HMT-212, Prevotella jejuni, Capnocytophaga leadbetteri, Leptotrichia sp. HMT-392, and Porphyromonas sp. HMT-278) were identified in the oral microbiota of ASD children, while five discriminatory species (Fusobacterium nucleatum subsp. polymorphum, Schaalia sp. HMT-180, Leptotrichia sp. HMT-498, Actinomyces gerencseriae, and Campylobacter concisus) were identified in TD controls. A model generated by random forest and leave-one-out cross-validation achieved an accuracy of 0.813. Receiver operating characteristic analysis yielded a sensitivity of 0.778, a specificity of 0.857, and an AUC (area under curve) of 0.937 (95 % CI: 0.82 - 1.00) for differentiating children with and without ASD.

CONCLUSION

The present study has unveiled significant disparities in the oral microbial composition between ASD and TD children.

SIGNIFICANCE

These findings contribute to understanding the microbiome-brain connection in ASD and its implications for early detection and management. Further research is needed to validate these oral bacterial biomarkers and explore their mechanistic association with ASD pathophysiology.

Human Herpesviruses, Bacteria, and Fungi in Gingivitis and Periodontitis Pediatric Subjects: A Systematic Review

Objectives: This systematic review assesses and compares the presence and relative abundance of periodontal pathogens, human herpesviruses (HHVs), and fungi in subgingival and/or saliva samples from pediatric subjects (≤18 years of age) with periodontally healthy status and with gingivitis and/or periodontitis. Methods: The study protocol was conducted under the PRISMA statement and registered on PROSPERO (CRD42024593007). Data from seven studies were descriptively analyzed and qualitatively assessed through the ROBINS-1 and JBI tools. Results: Pediatric subjects with clinically healthy periodontium exhibited a balanced microbiome, with early colonizers (Streptococcus species) supporting biofilm development and late colonizers like Fusobacterium nucleatum, Treponema denticola (82.35%), and Porphyromonas gingivalis (29.7%) present at low levels, suggesting subclinical dysbiosis. Viruses such as HSV-I (100%), CMV (17.8%), and EBV-I (22.09%) coexisted in a likely latent state, maintained by effective immune responses. In pediatric periodontitis, biofilms were more diverse and pathogenic, with increased prevalence of A. actinomycetemcomitans (56.09%), P. gingivalis (55.4%), and T. forsythia (35.9%). Generalized periodontitis showed higher CMV (36.36%) and EBV-I (36.24%) prevalence than gingivitis (HSV-I 18.75%). Coinfections were frequent in periodontitis, suggesting bacterial-viral synergy in exacerbating inflammation and tissue destruction. Fungi, although not studied, may also contribute under specific conditions. Conclusions: These findings highlight the role of microbial interactions in periodontal health and disease progression.

Anti-Porphyromonas gingivalis Antibody Levels in Patients With Stroke and Atrial Fibrillation: A Systematic Review and Meta-Analysis

OBJECTIVES

Atrial fibrillation (AF) and stroke are two highly related conditions, with periodontitis and periodontal pathogens, such as Porphyromonas gingivalis (Pg), appearing to be the most prominent common risk factors. In this study, we evaluated studies assessing Pg infection via serum/plasma anti-Pg antibodies in patients with AF and/or stroke.

MATERIAL AND METHODS

Online databases (PubMed, Scopus, Embase, and the Web of Science) were screened for studies showing the association between anti-Pg antibodies with stroke and/or AF. Relevant data were extracted, and a subsequent random-effects meta-analysis was performed to calculate the pooled odds ratio (OR) or standardized mean difference (SMD) and 95% confidence intervals (CIs) for Pg seropositivity or anti-Pg antibody levels in stroke patients compared to controls.

RESULTS

Sixteen studies were included in the systematic review. Based on the meta-analysis performed, there was no significant difference in Pg IgA and IgG levels between patients with stroke and controls (IgA: SMD 0.11, 95% CI -0.02 to 0.25, p = 0.1; IgG: SMD -0.12, 95% CI -1.24 to 0.99, p = 0.83). Similarly, no difference was observed between these groups in terms of Pg IgA and IgG seropositivity (IgA: OR 1.63, 95% CI 1.06-2.50, p = 0.026; IgG: OR 2.30, 95% CI 1.39-3.78, p < 0.001). Subsequently, we reviewed the results of six articles investigating serum or plasma IgG antibodies against Pg in patients with AF. Our results revealed a strict association between Pg infection and AF, with AF patients exhibiting either higher anti-Pg antibody levels or a higher prevalence of positive serum Pg antibodies.

CONCLUSIONS

Our study supports the clinical utility of Pg infection assessment in patients with periodontitis and those with AF and solicits more focused studies to corroborate its use in clinical settings to enhance overall outcomes, reduce the risk of complications like stroke, and help fine-tune personalized therapies.

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.

Revisiting the Concepts of Prebiotic and Prebiotic Effect in Light of Scientific and Regulatory Progress-A Consensus Paper From the Global Prebiotic Association

The term prebiotic has been used for almost 3 decades and has undergone numerous updates over the years. The scientific literature reveals that despite continuous efforts to establish a globally unified definition to guide jurisdictional regulations and product innovations, ambiguity continues to surround the terms prebiotic and prebiotic effect, leading to products that lack in full regulatory adherence being marketed worldwide. Thus, to reflect the current state of scientific research and knowledge and for the continuous advancement of the category, an update to the current prebiotic definition is warranted. This update includes removing the term selectivity, considering additional locations of action besides the gut, highlighting prebiotic performance benefits such as cognitive and athletic, and providing a clear standalone definition for prebiotic effect. The Global Prebiotic Association (GPA) is a leading information and industry hub committed to raising awareness about prebiotics, their emerging and well-established health benefits, and prebiotic product integrity and efficacy. In this position paper, GPA builds on previous prebiotic definitions to propose the following expanded definition for prebiotic: "a compound or ingredient that is utilized by the microbiota producing a health or performance benefit." In addition to prebiotic, GPA also defines prebiotic effect as "a health or performance benefit that arises from alteration of the composition and/or activity of the microbiota, as a direct or indirect result of the utilization of a specific and well-defined compound or ingredient by microorganisms." With these 2 definitions, GPA aims to paint a clearer picture for the term prebiotic, and by incorporating an industry point of view, these updated definitions may be used alongside current scientific and regulatory perspectives to move the category forward.

The oral microbial odyssey influencing chronic metabolic disease

INTRODUCTION

Since the oral cavity is the gateway to the gut, oral microbes likely hold the potential to influence metabolic disease by affecting the gut microbiota.

METHOD

A thorough review of literature has been performed to link the alterations in oral microbiota with chronic metabolic disease by influencing the gut microbiota.

RESULT

A strong correlation exists between abnormalities in oral microbiota and several systemic disorders, such as cardiovascular disease, diabetes, and obesity, which likely initially manifest as oral diseases. Ensuring adequate oral hygiene practices and cultivating diverse oral microflora are crucial for the preservation of general well-being. Oral bacteria have the ability to establish and endure in the gastrointestinal tract, leading to the development of prolonged inflammation and activation of the immune system. Oral microbe-associated prophylactic strategies could be beneficial in mitigating metabolic diseases.

CONCLUSION

Oral microbiota can have a profound impact on the gut microbiota and influence the pathogenesis of metabolic diseases.

Current approaches to produce durable biomaterials: Trends in polymeric materials for restorative dentistry applications

Dental caries continues to be a public health issue, especially more evident in underserved populations throughout the U.S. Unfortunately, especially with an aging population, hundreds of thousands of resin composite restorations are replaced each year due to recurring decay and fracture. According to several cohort studies, the average life span of this type of restoration is 10 years or less, depending on the caries risk level of the patient and the complexity of the restorative procedure. Any new material development must depart from the simple restoration of form paradigm, in which the filling is simply inert/biocompatible. This review will discuss novel antibiofilm structures, based on a targeted approach specifically against dysbiotic bacteria. Biofilm coalescence can be prevented by using glycosyl transferase - GTF inhibitors, in a non-bactericidal approach. On the tooth substrate side, MMP-inhibiting molecules can improve the stability of the collagen in the hybrid layer. This review will also discuss the importance of testing the materials in a physiologically relevant environment, mimicking the conditions in the mouth in terms of mechanical loading, bacterial challenge, and the presence of saliva. Ultimately, the goal of materials development is to achieve durable restorations, capable of adapting to the oral environment and resisting challenges that go beyond mechanical demands. That way, we can prevent the unnecessary loss of additional tooth structure that comes with every re-treatment. CLINICAL SIGNIFICANCE: While proper restorative technique and patient education in terms of diet and oral hygiene are crucial factors in increasing the longevity of esthetic direct restorations, materials better able to resist and interact with the conditions of the oral environment are still needed. Reproducing the success of dental amalgams with esthetic materials continues to be the Holy Grail of materials development.

The Oral-Gut-Brain Axis: The Influence of Microbes as a Link of Periodontitis With Ischemic Stroke

Periodontitis, a non-communicable chronic inflammation disease resulting from dysbiosis of the oral microbiota, has been demonstrated to have a positive association with the risk of ischemic stroke (IS). The major periodontal pathogens contribute to the progression of stroke-related risk factors such as obesity, diabetes, atherosclerosis, and hypertension. Transcriptional changes in periodontitis pathogens have been detected in oral samples from stroke patients, suggesting a new conceptual framework involving microorganisms. The bidirectional regulation between the gut and the central nervous system (CNS) is mediated by interactions between intestinal microflora and brain cells. The connection between the oral cavity and gut through microbiota indicates that the oral microbial community may play a role in mediating complex communication between the oral cavity and the CNS; however, underlying mechanisms have yet to be fully understood. In this review, we present an overview of key concepts and potential mechanisms of interaction between the oral-gut-brain axis based on previous research, focusing on how the oral microbiome (especially the periodontal pathogens) impacts IS and its risk factors, as well as the mediating role of immune system homeostasis, and providing potential preventive and therapeutic approaches.

Salivary microbiome variations in type 2 diabetes mellitus patients with different stages of periodontitis

BACKGROUND

To investigate the difference of salivary microbiome composition in type 2 diabetes mellitus with different stages of periodontitis.

METHODS

105 patients diagnosed with T2DM were divided into four groups according to the Stage of periodontitis.The 16 S rDNA hypervariable regions V3-V4 were amplified by polymerase chain reaction (PCR) after saliva DNA was extracted. The library was constructed and Illumina sequencing was performed. The sequencing results were compared with the silva 138 database, and the salivary microbiome of the four groups of patients was studied by species composition analysis, species difference analysis, principal coordinate analysis, and correlation analysis.

RESULTS

There were significant differences in alpha diversity of salivary microbiome among the four groups, but no difference in Beta diversity. At the phylum level, there was one differential bacteria-Firmicutes, while at the genus level, there were 16 differential bacteria. Spearman's correlation analysis identified significant correlations between periodontal health indices (PLI, SBI, AL and PD) and the abundances of over 13 genera, including Streptococcus, Gemella and Capnocytophaga, etc. Additionally, the duration of diabetes exhibited a positive correlation with AL and PD.

CONCLUSIONS

There are differences in salivary microbial composition in patients with type 2 diabetes mellitus with different stages of periodontitis. There is a correlation between some saliva microbiota and periodontal inflammation.