Oral Microorganisms Research Articles

Evaluation of the Role of Oral Microbes in Pathogenesis of Oral Lichen Planus.

The pathophysiology and etiology of oral lichen planus (OLP) are still unknown, despite the fact that the condition's progression has been connected to a T-cell-based immune response. Research has focused on variables, such as oral bacteria, that may cause an autoimmune reaction with conflicting results. This study was conducted to evaluate the role of oral microorganisms in the pathogenesis of OLP. In this study, 82 formalin-fixed paraffin-embedded specimens of histopathologically confirmed cases of OLP and 20 such specimens of normal healthy subjects were obtained. Immunohistochemistry was carried out for the identification of microorganisms. Candida albicans was observed in 47.12% of OLP cases and 9.43% of healthy controls. Helicobacter pylori was discovered in 45.21% of OLP cases and 13.46% of healthy controls. Periodontopathogenic bacteria was found in 33.14% of OLP cases and 13.45% of healthy controls. Human papillomavirus (HPV)-16 was noticed in 38.12% of OLP cases and 11.24% in the control group. HPV-18 was found in 32.43% of OLP patients and 11.43% in the control group. Mycoplasma salivarium was found in 46.47% of OLP patients and 6.45% in control. It was observed that several microorganisms like H. pylori, C. albicans, M. salivarium, periodontopathogenic bacteria, HPV-16, and HPV-18 were found to be related to OLP.

Saliva‑microbiome‑derived signatures: expected to become a potential biomarker for pulmonary nodules (MCEPN-1).

Oral microbiota imbalance is associated with the progression of various lung diseases, including lung cancer. Pulmonary nodules (PNs) are often considered a critical stage for the early detection of lung cancer; however, the relationship between oral microbiota and PNs remains unknown. We conducted a 'Microbiome with pulmonary nodule series study 1' (MCEPN-1) where we compared PN patients and healthy controls (HCs), aiming to identify differences in oral microbiota characteristics and discover potential microbiota biomarkers for non-invasive, radiation-free PNs diagnosis and warning in the future. We performed 16S rRNA amplicon sequencing on saliva samples from 173 PN patients and 40 HCs to compare the characteristics and functional changes in oral microbiota between the two groups. The random forest algorithm was used to identify PN salivary microbial markers. Biological functions and potential mechanisms of differential genes in saliva samples were preliminarily explored using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cluster of Orthologous Groups (COG) analyses. The diversity of salivary microorganisms was higher in the PN group than in the HC group. Significant differences were noted in community composition and abundance of oral microorganisms between the two groups. Neisseria, Prevotella, Haemophilus and Actinomyces, Porphyromonas, Fusobacterium, 7M7x, Granulicatella and Selenomonas were the main differential genera between the PN and HC groups. Fusobacterium, Porphyromonas, Parvimonas, Peptostreptococcus and Haemophilus constituted the optimal marker sets (area under curve, AUC = 0.80), which can distinguish between patients with PNs and HCs. Further, the salivary microbiota composition was significantly correlated with age, sex, and smoking history (P < 0.001), but not with personal history of cancer (P > 0.05). Bioinformatics analysis of differential genes showed that patients with PN showed significant enrichment in protein/molecular functions related to immune deficiency and energy metabolisms, such as the cytoskeleton protein RodZ, nicotinamide adenine dinucleotide phosphate dehydrogenase (NADPH) dehydrogenase, major facilitator superfamily transporters and AraC family transcription regulators. Our study provides the first evidence that the salivary microbiota can serve as potential biomarkers for identifying PN. We observed a significant association between changes in the oral microbiota and PNs, indicating the potential of salivary microbiota as a new non-invasive biomarker for PNs. Clinical trial registration number: ChiCTR2200062140; Date of registration: 07/25/2022.

Oral Mycobiota: A Narrative Review.

Numerous studies have proven the important role of the oral microbiota in health and disease. The dysfunctionality of the oral microbiota, known as dysbiosis, is incriminated in dental caries, periodontal disease, oral infectious diseases, oral cancer, and systemic disease. The lesser-known component of the oral microbiota, the mycobiota, is now assiduously investigated. Recent technological developments have helped foster the identification of new fungal species based on genomic research. Next-generation sequencing has expanded our knowledge about the diversity, architecture, and relationships of oral microorganisms within the oral cavity. The mycobiome structure and relationships with the bacteriome have been studied to identify a mycobiotic signature. This review aimed to emphasize the latest knowledge of the oral mycobiome.

The potential of EGCG in modulating the oral-gut axis microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a recurrent chronic intestinal disorder that includes ulcerative colitis (UC) and Crohn's disease (CD). Its pathogenesis involves intricate interactions between pathogenic microorganisms, native intestinal microorganisms, and the intestinal immune system via the oral-gut axis. The strong correlation observed between oral diseases and IBD indicates the potential involvement of oral pathogenic microorganisms in IBD development. Consequently, therapeutic strategies targeting the proliferation, translocation, intestinal colonization and exacerbated intestinal inflammation of oral microorganisms within the oral-gut axis may partially alleviate IBD. Tea consumption has been identified as a contributing factor in reducing IBD, with epigallocatechin gallate (EGCG) being the primary bioactive compound used for IBD treatment. However, the precise mechanism by which EGCG mediates microbial crosstalk within the oral-gut axis remains unclear. In this review, we provide a comprehensive overview of the diverse oral microorganisms implicated in the pathogenesis of IBD and elucidate their colonization pathways and mechanisms. Subsequently, we investigated the antibacterial properties of EGCG and its potential to attenuate microbial translocation and colonization in the gut, emphasizing its role in attenuating exacerbations of IBD. We also elucidated the toxic and side effects of EGCG. Finally, we discuss current strategies for enhancing EGCG bioavailability and propose novel multi-targeted nano-delivery systems for the more efficacious management of IBD. This review elucidates the role and feasibility of EGCG-mediated modulation of the oral-gut axis microbiota in the management of IBD, contributing to a better understanding of the mechanism of action of EGCG in the treatment of IBD and the development of prospective treatment strategies.

Insights into microorganisms, associated factors, and the oral microbiome in infective endocarditis patients.

Infective Endocarditis (IE) is a rare, life-threatening infection of the endocardium with multisystem effects. Culprit microorganisms derived from different niches circulate through the bloodstream and attach to the endocardium, particularly the heart valves. This study aimed to investigate culprit microorganisms among a cross-sectional cohort of IE patients, their associated factors, and to explore the potential relationship to the oral microbiome. In this observational study, we undertook a cross-sectional analysis of 392 medical records from patients diagnosed with IE. The primary outcome of this study was to analyse the association between the IE culprit microorganisms and the underlying anatomical types of IE (native valve (NVE), prosthetic valve (PVE), or cardiac device-related (CDE)). Secondary outcomes encompassed a comparative analysis of additional factors, including: the treatment approaches for IE, and the categorisation of blood cultures, extending to both genus and species levels. Additionally, we cross-referenced and compared the species-level identification of IE bacteraemia outcome measures with data from the expanded Human Oral Microbiome Database (eHOMD). A culprit microorganism was identified in 299 (76.28%) case participants. Staphylococcal infections were the most common (p < 0.001), responsible for 130 (33.16%) hospitalisations. There were 277 (70.66%) cases of NVE, 104 (26.53%) cases of PVE, and 11 (2.81%) cases of CDE. The majority of PVE occurred on prosthetic aortic valves (78/104, 75%), of which 72 (93.5%) were surgical aortic valve replacements (SAVR), 6 (7.8%) were transcatheter aortic valve implants, and one transcatheter pulmonary valve implant. Overall, underlying anatomy (p = 0.042) as well as the treatment approaches for IE (p < 0.001) were significantly associated with IE culprit microorganisms. Cross-reference between IE bacteraemia outcomes with the eHOMD was observed in 267/392 (68.11%) cases. This study demonstrated that IE patients with a history of stroke, smoking, intravenous drug use, or dialysis were more likely to be infected with Staphylococcus aureus. CDE case participants and patients who had previous SAVR were most associated with Staphylococcus epidermidis. IE patients aged 78+ were more likely to develop enterococci IE than other age groups. Oral microorganisms indicated by the eHOMD are significantly observed in the IE population. Further research, through enhanced dental and medical collaboration, is required to correlate the presence of oral microbiota as causative factor for IE.

The Associations between Snack Intake and Cariogenic Oral Microorganism Colonization in Young Children of a Low Socioeconomic Status.

Cariogenic microorganisms are crucial pathogens contributing to the development of early childhood caries. Snacks provide fermentable carbohydrates, altering oral pH levels and potentially affecting microorganism colonization. However, the relationship between snack intake and cariogenic microorganisms like Candida and Streptococcus mutans in young children is still unclear. This study aimed to assess this association in a prospective underserved birth cohort. Data from children aged 12 to 24 months, including oral microbial assays and snack intake information, were analyzed. Sweet and non-sweet indices based on the cariogenic potential of 15 snacks/drinks were created. Mixed-effects models were used to assess the associations between sweet and non-sweet indices and S. mutans and Candida carriage. Random forest identified predictive factors of microorganism carriage. Higher non-sweet index scores were linked to increased S. mutans carriage in plaques (OR = 1.67, p = 0.01), potentially strengthening with age. Higher sweet index scores at 12 months were associated with increased Candida carriage, reversing at 24 months. Both indices were top predictors of S. mutans and Candida carriage. These findings underscore the associations between snack intake and cariogenic microorganism carriage and highlight the importance of dietary factors in oral health management for underserved young children with limited access to dental care and healthy foods.

Cellulose Nanocrystals Show Anti-Adherent and Anti-Biofilm Properties against Oral Microorganisms.

Cellulose nanocrystals (CNCs) are cellulose-derived nanomaterials that can be easily obtained, e.g., from vegetable waste produced by circular economies. They show promising antimicrobial activity and an absence of side effects and toxicity. This study investigated the ability of CNCs to reduce microbial adherence and biofilm formation using in vitro microbiological models reproducing the oral environment. Microbial adherence by microbial strains of oral interest, Streptococcus mutans and Candida albicans, was evaluated on the surfaces of salivary pellicle-coated enamel disks in the presence of different aqueous solutions of CNCs. The anti-biofilm activity of the same CNC solutions was tested against S. mutans and an oral microcosm model based on mixed plaque inoculum using a continuous-flow bioreactor. Results showed the excellent anti-adherent activity of the CNCs against the tested strains from the lowest concentration tested (0.032 wt. %, p < 0.001). Such activity was significantly higher against S. mutans than against C. albicans (p < 0.01), suggesting a selective anti-adherent activity against pathogenic strains. At the same time, there was a minimal, albeit significant, anti-biofilm activity (0.5 and 4 wt. % CNC solution for S. mutans and oral microcosm, respectively, p = 0.01). This makes CNCs particularly interesting as anticaries agents, encouraging their use in the oral field.

Preparation and Characterization of Ginseng Gel and In Vivo Evaluation of Its Clinical Efficacy in Generalized Chronic Gingivitis Patients.

Aim The aim of the present study was to prepare and characterize ginseng gel and then to evaluate its clinical efficacy in terms of plaque index (PI), gingival index (GI) among generalized chronic gingivitis patients. Materials and methods Ginseng gel was prepared using 250 g of ginseng powder. The antimicrobial activity of prepared ginseng gel and chlorhexidine gel was checked at various concentrations (25, 50, 75, 100, 125, 150, 175, 200, 225, 250 and 275 µg) against anaerobic organisms to find the concentration with maximum antimicrobial activity. The concentration with highest antimicrobial activity was subjected to in vivo analysis. A total of 30 generalized chronic gingivitis patients were subjected to scaling and then divided into two groups for intraoral gel application - Group I (ginseng gel) and Group II (chlorhexidine gel) for one month. The clinical parameters PI, GI were measured at baseline (pre scaling) and one month (post scaling) comparing ginseng gel and chlorhexidine gel (Hexigel - chlorhexidine gluconate 1.0% w/w). Independent t test and paired t test were done for statistical analysis. Results At 275 µg, ginseng gel showed highest antibacterial action against anaerobic oral microorganisms. In Group I, the reduction in PI from baseline was (2.52±0.02) to follow up after one month (0.75±0.05), GI from baseline (2.2±0.35) to follow up after one month (0.9±0.02). In Group II, the reduction in PI from baseline was (2.54±0.01) to follow up after one month (0.79±0.02), GI from baseline (2.1±0.42) to follow up after one month (0.8±0.01). Conclusion Ginseng gel showed equal clinical efficacy to chlorhexidine gel in terms of PI and GI. Though chlorhexidine was effective in lower concentrations, it has considerable adverse effects such as taste alteration. Hence it is better to encourage the use of herbal-based products for the management of gingivitis to prevent side effects of synthetic preparations.

The Physical Properties of Vanillin-Incorporated Irreversible Hydrocolloid Impression Material

Irreversible hydrocolloid impression material is extensively used in dentistry to record and duplicate the details of tooth structure, surrounding tissue, and other intraoral structures. The materials allow dentists to work more easily and perform better diagnosis and treatment planning. When used, the material is exposed to oral microorganisms, some are pathogens, from the patient’s teeth, mucosa, blood, and saliva. These pathogens can be absorbed into the material and transmitted to dentists and other dental workers. Hydrocolloid impression material incorporated with vanillin has been shown to exhibit antimicrobial potential, however, its physical properties have not been performed. Therefore, this study aims to investigate the physical properties of a vanillin-incorporated irreversible hydrocolloid impression material on four different physical properties: working time, setting time, elastic recovery, and strain-in compression. The impression powder was mixed with varying concentrations of vanillin (0.1%, 0.5%, and 1.0% w/w) using the electric vacuum mixer. The impression material without vanillin was used as a control. All the tests were done following the ISO specification 21563: 2021 for dental materials with 15 specimens for each test. The result showed that at concentrations of 0%, 0.1%, and 0.5% w/w vanillin, no significant change in the four physical properties has been observed. However, the working time and setting time values of impression material with 1% vanillin were reduced significantly and did not meet the ISO standard. In conclusion, the incorporation of 0.1%, 0.5%, and 1% w/w vanillin into irreversible hydrocolloid impression material showed a significant reduction in setting time and working time. However, when considering the ISO standard specifications, the 0.1% and 0.5% w/w vanillin-added materials can still be used due to their acceptable values of all physical properties (setting time, working time, elastic recovery, and strain-in compression). These impression materials will be valuable for use in clinical settings to reduce the disinfection procedure and the risk of cross-contamination.

APPLICATION OF ANTIMICROBIAL NANOPARTICLES OF METALS AND THEIR OXIDES IN IMPROVING DENTAL PROSTHESES

Many nanoparticles of metals and their oxides, including silver, titanium, zinc, copper, zirconium, have antimicrobial properties. These nanoparticles are a promising strategy for the treatment and prevention of oral cavity infections and can be used in various fields of dentistry. The purpose of the work is to present a literature review on the application of applying antimicrobial nanoparticle of metals and their oxides in orthopedic dentistry, in particular, in the improvement of materials for the prosthetics of dentition defects. Literature sources were searched in the PubMed database. Articles for the years 2013–2023 were selected for their involvement in orthodontic dentistry and for the availability of microbiological test data. Recent trends indicate a shift towards enhancing the composition of fundamental materials used in dental prostheses. To mitigate infectious complications, a modification of the base plastic by incorporating nanoparticles with antimicrobial properties is proposed. Silver nanoparticles are widely utilized to modify denture materials and, when combined with polymers or applied as a surface coating on biomaterials, exhibit antimicrobial properties against oral pathogens, along with an anti-biofilm effect. Zinc oxide nanoparticles, recognized for their biocompatibility and non-toxic nature, possess significant biocidal properties effective against a broad spectrum of bacteria and fungi. They demonstrate the ability to inhibit biofilm formation by oral cavity microorganisms, not only on acrylic prostheses but also on surfaces like glass, polystyrene, and silicone. Titanium oxide nanoparticles contribute to reducing microorganism adhesion on various prosthetic materials, including acrylic resins, ceramic glass, and stainless steel. Zirconium oxide nanoparticles, distinct from other metal oxide counterparts, do not compromise the aesthetics of dentures. Simultaneously, they enhance density and reduce polymethylmethacrylate porosity, thereby decreasing candida adhesion and proliferation in the samples. Copper oxide nanoparticles exhibit dose-dependent inhibition of C. albicans and Streptococcus spp. growth, along with biofilm formation, and show cytotoxic effects only at high concentrations. Thus, there are metal and metal oxide nanoparticles that can improve the antimicrobial properties of prosthetic materials for orthopedic dentistry and thus ensure the prevention of infectious complications when using dental prostheses, but for their clinical use, the gap between experiment and practice has yet to be bridged.

Microbial Symphony: Navigating the Intricacies of the Human Oral Microbiome and Its Impact on Health.

This comprehensive review delves into the forefront of research on the human oral microbiome, exploring recent advancements that span microbial colonization, state-of-the-art detection methodologies, and the complex interplay involved in disease progression. Through an exhaustive analysis of the contemporary literature, we illuminate the dynamic orchestration of microbial communities within the oral cavity, underscoring their pivotal role in health and disease. Cutting-edge detection techniques, including metagenomics and high-throughput sequencing, are discussed regarding their transformative impact on understanding the intricacies of oral microbial ecosystems. As we stand on the cusp of a new decade, this review anticipates a paradigm shift in the field, emphasizing the potential for rapid identification and targeted management of detrimental oral microorganisms. Insights gained from this exploration not only contribute to our fundamental understanding of the oral microbiome but also hold promise for the development of innovative therapeutic strategies to maintain oral health. This article aims to serve as a valuable resource for researchers, clinicians, and public health professionals engaged in unraveling the mysteries of the microbial symphony within the human oral cavity.

An integrated sample-to-answer graphene microchip for ultrafast detection of multiple microorganisms

The integrated detection of nucleic acids is a molecular biological technology integrating the entire process of nucleic acid detection into a “sample-to-answer” system, which is widely used in microbial identification and disease diagnosis. Although the integrated detection of nucleic acids has the advantages of fully-enclosed system and simple operation, it still faces challenges like dependence on bulky equipment, complex design, and long detection time. To address these challenges, we have proposed and fabricated an integrated graphene microchip for ultra-fast detection of multiple microorganisms. This microchip is composed of two main regions: the electrolysis-extraction region and the isothermal amplification-detection region. In the electrolysis-extraction region, the microchip was equipped with the micron-structured graphene interdigital electrode and a regular battery for power supply, and the nucleic acids of H. pylori were extracted only in 1.0 s by electrolysis. Then in the isothermal amplification-detection region, the nucleic acids of H. pylori were detected in less than 9 min at a concentration of 10 CFU/µL. As a result, the detection time of the whole process were controlled in merely 9 min. In addition, this integrated graphene microchip has three parallel channels for simultaneous detection of oral microorganisms, e.g., C. albicans, S. aureus and H. pylori. These characteristics make our integrated graphene microchip promising to contribute to the development in integrated technology of nucleic acid detection and be widely used at various medical structures or on-site environments such as home testing.

The multispecies microbial cluster of Fusobacterium, Parvimonas, Bacteroides and Faecalibacterium as a precision biomarker for colorectal cancer diagnosis.

The incidence of colorectal cancer (CRC) has increased worldwide, and early diagnosis is crucial to reduce mortality rates. Therefore, new noninvasive biomarkers for CRC are required. Recent studies have revealed an imbalance in the oral and gut microbiomes of patients with CRC, as well as impaired gut vascular barrier function. In the present study, the microbiomes of saliva, crevicular fluid, feces, and non-neoplastic and tumor intestinal tissue samples of 93 CRC patients and 30 healthy individuals without digestive disorders (non-CRC) were analyzed by 16S rRNA metabarcoding procedures. The data revealed that Parvimonas, Fusobacterium, and Bacteroides fragilis were significantly over-represented in stool samples of CRC patients, whereas Faecalibacterium and Blautia were significantly over-abundant in the non-CRC group. Moreover, the tumor samples were enriched in well-known periodontal anaerobes, including Fusobacterium, Parvimonas, Peptostreptococcus, Porphyromonas, and Prevotella. Co-occurrence patterns of these oral microorganisms were observed in the subgingival pocket and in the tumor tissues of CRC patients, where they also correlated with other gut microbes, such as Hungatella. This study provides new evidence that oral pathobionts, normally located in subgingival pockets, can migrate to the colon and probably aggregate with aerobic bacteria, forming synergistic consortia. Furthermore, we suggest that the group composed of Fusobacterium, Parvimonas, Bacteroides, and Faecalibacterium could be used to design an excellent noninvasive fecal test for the early diagnosis of CRC. The combination of these four genera would significantly improve the reliability of a discriminatory test with respect to others that use a single species as a unique CRC biomarker.

Oral_voting_transfer: classification of oral microorganisms' function proteins with voting transfer model.

The oral microbial group typically represents the human body's highly complex microbial group ecosystem. Oral microorganisms take part in human diseases, including Oral cavity inflammation, mucosal disease, periodontal disease, tooth decay, and oral cancer. On the other hand, oral microbes can also cause endocrine disorders, digestive function, and nerve function disorders, such as diabetes, digestive system diseases, and Alzheimer's disease. It was noted that the proteins of oral microbes play significant roles in these serious diseases. Having a good knowledge of oral microbes can be helpful in analyzing the procession of related diseases. Moreover, the high-dimensional features and imbalanced data lead to the complexity of oral microbial issues, which can hardly be solved with traditional experimental methods. To deal with these challenges, we proposed a novel method, which is oral_voting_transfer, to deal with such classification issues in the field of oral microorganisms. Such a method employed three features to classify the five oral microorganisms, including Streptococcus mutans, Staphylococcus aureus, abiotrophy adjacent, bifidobacterial, and Capnocytophaga. Firstly, we utilized the highly effective model, which successfully classifies the organelle's proteins and transfers to deal with the oral microorganisms. And then, some classification methods can be treated as the local classifiers in this work. Finally, the results are voting from the transfer classifiers and the voting ones. The proposed method achieved the well performances in the five oral microorganisms. The oral_voting_transfer is a standalone tool, and all its source codes are publicly available at https://github.com/baowz12345/voting_transfer.

Efficacy of Ceragenins in Controlling the Growth of Oral Microorganisms: Implications for Oral Hygiene Management.

Ensuring proper dental hygiene is of paramount importance for individuals' general well-being, particularly for patients receiving medical care. There is a prevailing utilization of conventional oral hygiene items, including toothbrushes and mouthwashes, which have gained widespread acceptance; nevertheless, their limitations encourage investigating novel options in this domain. Our study indicates that ceragenins (CSAs) being lipid analogs of host defense peptides, well-recognized for their wide-ranging antimicrobial properties, may be a potentially efficacious means to augment oral hygiene in hospitalized individuals. We demonstrate that ceragenins CSA-13, CSA-44, and CSA-131 as well as undescribed to date CSA-255 display potent antimicrobial activities against isolates of fungi, aerobic, and anaerobic bacteria from Candida, Streptococcus, Enterococcus, and Bacteroides species, which are well-recognized representatives of microbes found in the oral cavity. These effects were further confirmed against mono- and dual-species fungal and bacterial biofilms. While the ceragenins showed similar or slightly diminished efficacy compared to commercially available mouthwashes, they demonstrated a highly favorable toxicity profile toward host cells, that may translate into better maintenance of host mucosal membrane stability. This suggests that incorporating ceragenins into oral hygiene products could be a valuable strategy for reducing the risk of both oral cavity-localized and secondary systemic infections and for improving the overall health outcomes of individuals receiving medical treatment.

Periodontium-Mimicking, Multifunctional Biomass-Based Hydrogel Promotes Full-Course Socket Healing.

Preserving stable tooth-periodontal tissue integration is vital for maintaining alveolar bone stability under physiological conditions. However, tooth extraction compromises this integration and impedes socket healing. Therefore, it becomes crucial to provide early stage coverage of the socket to promote optimal healing. Drawing inspiration from the periodontium, we have developed a quaternized methacryloyl chitosan/dopamine-grafted oxidized sodium alginate hydrogel, termed the quaternized methacryloyl chitosan/dopamine-grafted oxidized sodium alginate hydrogel (QDL hydrogel). Through blue-light-induced cross-linking, the QDL hydrogel serves as a comprehensive wound dressing for socket healing. The QDL hydrogel exhibits remarkable efficacy in closing irregular tooth extraction wounds. Its favorable mechanical properties, flexible formability, and strong adhesion are achieved through modifications of chitosan and sodium alginate derived from biomass sources. Moreover, the QDL hydrogel demonstrates a superior hemostatic ability, facilitating swift blood clot formation. Additionally, the inherent antibacterial properties of the QDL hydrogel effectively inhibit oral microorganisms. Furthermore, the QDL hydrogel promotes angiogenesis, which facilitates the nutrient supply for subsequent tissue regeneration. Notably, the hydrogel accelerates socket healing by upregulating the expression of genes associated with wound healing. In conclusion, the periodontium-mimicking multifunctional hydrogel exhibits significant potential as a clinical tooth extraction wound dressing.

The oral-brain axis: can periodontal pathogens trigger the onset and progression of Alzheimer's disease?

Alzheimer's disease (AD) is the most prevalent form of dementia, characterized by a progressive cognitive decline. Sporadic AD, accounting for more than 95% of cases, may arise due to the influence of environmental factors. It was reported that periodontitis, a common oral ailment, shares several risk factors with AD, including advanced age, smoking, diabetes, and hypertension, among others. Periodontitis is an inflammatory disease triggered by dysbiosis of oral microorganisms, whereas Alzheimer's disease is characterized by neuroinflammation. Many studies have indicated that chronic inflammation can instigate brain AD-related pathologies, including amyloid-β plaques, Tau protein hyperphosphorylation, neuroinflammation, and neurodegeneration. The potential involvement of periodontal pathogens and/or their virulence factors in the onset and progression of AD by the oral-brain axis has garnered significant attention among researchers with ongoing investigations. This review has updated the periodontal pathogens potentially associated with AD, elucidating their impact on the central nervous system, immune response, and related pathological processes in the brain to provide valuable insights for future research on the oral-brain axis.

Preparing and evaluating the anti-microbial effect of Allium jesdianum mouthwash on some of the most common oral microorganisms.

Due to the increasing resistance of bacteria to antibiotics and anti-bacterial compounds in plants, Allium jesdianum Boiss plant extract can be used in mouthwash compounds with its anti-microbial activity. The anti-bacterial and anti-fungal activity of A. jesdianum mouthwash was investigated on Streptococcus mutans, Streptococcus sanguis, S. salivarius and Candida albicans, and Candida tropicalis. To analyse the anti-microbial effect of this mouthwash, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the broth microdilution method. The average MIC and MBC of A. jesdianum mouthwash for S. mutans were 1.56 and 3.12 (mg/ml), respectively, for S. salivarius, 0.25 and 0.65 (mg/ml), and for S. sanguis, respectively, 0.25 and 0.65 (mg/ml). The highest MIC and MBC values were for S. mutans, and the MIC and MBC values were equal for S. sanguis and S. salivarius. Average MIC and MBC were determined as 2.41 and 4.16 (mg/ml) for C. albicans and 2.34 and 5.72 (mg/ml) for C. tropicalis, respectively. MIC values of mouthwash were higher for C. albicans and MBC values for C. tropicalis. Our results showed a promising anti-fungal-anti-bacterial effect of A. jesdianum extract. A. jesdianum extract may be used as an alternative to chemical mouthwashes.

In-depth metaproteomics analysis of tongue coating for gastric cancer: a multicenter diagnostic research study

BackgroundOur previous study revealed marked differences in tongue images between individuals with gastric cancer and those without gastric cancer. However, the biological mechanism of tongue images as a disease indicator remains unclear. Tongue coating, a major factor in tongue appearance, is the visible layer on the tongue dorsum that provides a vital environment for oral microorganisms. While oral microorganisms are associated with gastric and intestinal diseases, the comprehensive function profiles of oral microbiota remain incompletely understood. Metaproteomics has unique strength in revealing functional profiles of microbiota that aid in comprehending the mechanism behind specific tongue coating formation and its role as an indicator of gastric cancer.MethodsWe employed pressure cycling technology and data-independent acquisition (PCT-DIA) mass spectrometry to extract and identify tongue-coating proteins from 180 gastric cancer patients and 185 non-gastric cancer patients across 5 independent research centers in China. Additionally, we investigated the temporal stability of tongue-coating proteins based on a time-series cohort. Finally, we constructed a machine learning model using the stochastic gradient boosting algorithm to identify individuals at high risk of gastric cancer based on tongue-coating microbial proteins.ResultsWe measured 1432 human-derived proteins and 13,780 microbial proteins from 345 tongue-coating samples. The abundance of tongue-coating proteins exhibited high temporal stability within an individual. Notably, we observed the downregulation of human keratins KRT2 and KRT9 on the tongue surface, as well as the downregulation of ABC transporter COG1136 in microbiota, in gastric cancer patients. This suggests a decline in the defense capacity of the lingual mucosa. Finally, we established a machine learning model that employs 50 microbial proteins of tongue coating to identify individuals at a high risk of gastric cancer, achieving an area under the curve (AUC) of 0.91 in the independent validation cohort.ConclusionsWe characterized the alterations in tongue-coating proteins among gastric cancer patients and constructed a gastric cancer screening model based on microbial-derived tongue-coating proteins. Tongue-coating proteins are shown as a promising indicator for identifying high-risk groups for gastric cancer.1cCPG45EGUX3nZjXKAFgvfVideo

Salivary microbiomes: a potent evidence in forensic investigations.

Saliva components combine with oral cavity microorganisms, blood cells, and airway secretions after entering the oral cavity via salivary ducts; these factors provide relevant information about persons' health state, quality of life, and lifestyle, in addition to their age and gender due to which salivary microbiome has emerged as a subject of significant interest in the forensic domain. This study aims to provide an extensive review of the possible applications of the salivary microbiome in characterizing the habit-specific microbiomes. Thirty-three relevant articles were selected for inclusion in this study. The study highlighted the influence of habits on the salivary microbiome suggesting smokers have distinct bacteria like Synergistetes, Streptococcus, Prevotella, and Veillonella in relation to age; people of higher age have more Prevotella; further, dental plaque can be corelated with Streptococci and Actinomycetes. Likewise, dietary habits, alcoholism, and consumption of coffee also affect bacteria types in oral cavities. The study underscores the added benefits of salivary microbiome profiling in forensics, as it is evident that microbial DNA profiling holds substantial promise for enhancing forensic investigations; it enables the characterization of an individual's habits, such as smoking, alcohol consumption, and dietary preferences; bacteria specific to these habits can be identified, thereby helping to narrow down the pool of potential suspects. In conclusion, the salivary microbiome presents a valuable avenue for forensic science, offering a novel approach which not only enhances the prospects of solving complex cases but also underscores the rich potential of microbiome analysis in the realm of forensic investigation.