The role of oral microbiome in respiratory health and diseases

Animal farming and the oral microbiome in the Agricultural Health Study

BACKGROUND

Raising farm animals imparts various exposures that may shape the human microbiome. The oral microbiome has been increasingly implicated in disease development. Animal farming has also been associated with certain chronic diseases such as cancer; however, underlying biological mechanisms are unclear. We investigated associations between raising farm animals and the oral microbiome in the Agricultural Health Study.

METHODS

This analysis included 1,245 participants (865 farmers and 380 spouses) who provided oral wash specimens and information on types and numbers of specific animals raised on their farms within 2 years before sample collection. The oral microbiome was measured by sequencing the V4 region of the 16S ribosomal RNA gene. We evaluated associations of farm animal exposures with alpha and beta diversity metrics (within- and between-sample diversity, respectively), as well as presence and relative abundance of specific bacterial genera. All analyses adjusted for potential confounders (e.g., age, sex, smoking, alcohol consumption).

RESULTS

Overall, 63 % of participants raised farm animals, most commonly cattle (46 %) and hogs (20 %). Those who raised a large number of hogs (≥2,000 vs. no hogs) had higher alpha diversity. Conversely, raising sheep/goats and raising larger numbers of poultry were associated with lower alpha diversity. Beta diversity was not significantly different between participants with and without any farm animals. Participants raising any farm animals had higher relative abundance of Porphyromonas and lower relative abundances of Prevotella and Ruminococcaceae UCG-014. Several genera were more likely to be absent with specific animal exposures (e.g., Capnocytophaga for cattle and sheep/goats; Corynebacterium, Dialister, Stomatobaculum, and Solobacterium for sheep/goats and poultry).

CONCLUSIONS

This was the largest study of farm animal exposures and the human microbiome to date. Findings suggest that raising specific farm animals may influence the oral microbiome, supporting the need to further investigate the potential role of animal farming in disease etiology.

Association between oral microbiome and depression: A population-based study

OBJECTIVE

Depression is a global mental health issue, particularly affecting adolescents and young adults. While the role of gut microbiota in depression has been extensively studied, the influence of the oral microbiome remains underexplored. Recent studies suggest that the oral microbiome may affect systemic and brain health through the oral-brain axis. This study aimed to investigate the relationship between oral microbiome diversity and depression using data from 6212 participants in the National Health and Nutrition Examination Survey (NHANES) 2009-2012.

METHODS

Oral microbiome diversity was assessed through oral rinse samples using 16S rRNA sequencing, focusing on α-diversity metrics (observed ASVs and Faith's phylogenetic diversity) and β-diversity measures. Depressive symptoms were evaluated with the Patient Health Questionnaire (PHQ-9). Weighted logistic regression models were employed to assess associations between α-diversity and depression, while linear regression was used to examine the relationship between α-diversity and PHQ-9 scores. β-diversity differences were analyzed via permutational analysis of variance (PERMANOVA).

RESULTS

10.03% of the participants were diagnosed with depression. Higher α-diversity in the oral microbiome was negatively correlated with depression: observed ASVs (OR: 0.713 [CI: 0.508-0.999], P = 0.050) and Faith's phylogenetic diversity (OR: 0.584 [CI: 0.367-0.931], P = 0.025). Linear regression indicated that greater α-diversity was associated with lower PHQ-9 scores, reflecting fewer depressive symptoms. Furthermore, β-diversity analysis revealed significant differences in the microbiome composition between depressed and non-depressed individuals.

CONCLUSION

Reduced oral microbiome diversity is associated with an increased risk and severity of depression. The study underscores the importance of exploring the oral-brain axis and highlights the need for further research into the mechanisms and therapeutic strategies targeting this relationship.

Effect of Stimulated Salivary Volume on Dysbiosis of the Salivary Microbiome in Children and Young Adults

OBJECTIVES

This study aimed to determine the salivary factors that influence salivary bacterial counts and the microbiome composition in children and young adults.

METHODS

This cross-sectional study included 382 patients who visited the dental clinic in Hiroshima University Hospital. All participants underwent a saliva test and were divided into high- and low-bacterial-count groups based on the median bacterial count. Salivary factors and clinical variables, including the total number of teeth and plaque control record, were analyzed to determine their association with salivary bacterial counts. Furthermore, a comprehensive analysis of microbiome diversity and composition was performed using 16S rRNA sequencing.

RESULTS

Univariate and multivariate analyses identified stimulated saliva volume (SSV) and plaque control record as independent factors influencing salivary bacterial counts. Principal coordinate analysis revealed a significant decrease in beta diversity in the high-bacterial-count group. LEfSe analysis revealed Prevotella, Veillonella, Megafaella, Selenomonas, and TM7X as the 5 most abundant bacteria. The relative abundance of the 35 KEGG pathways exhibited significant differences. Furthermore, Prevotella and Veillonella were strongly associated with 25 functional pathways.

CONCLUSION

Oral hygiene instruction is necessary even for children and young adults with relatively adequate SSV to maintain a healthy oral microbiome.

The Effects of Electronic Cigarettes on Oral Microbiome and Metabolome in 3D Tissue-Engineered Models

BACKGROUND AND AIM

Recent studies have shown that electronic cigarettes (ECs) use disrupts the oral microbiome composition and diversity, impairing the metabolic pathways of the mucosal cells. However, to date, no reports have evaluated the role of EC exposure in the context of oral metabolome. Hence, the aim of this study was to investigate the role of EC aerosol exposure in the dysregulation of the oral microbiome and metabolome profile using in vitro 3D organotypic models of human oral mucosa.

METHODS

3D tissue-engineered human oral mucosa models were generated and infected with oral microbes obtained from saliva of a healthy donor. The epithelial surface of the oral mucosal models was exposed directly to the EC aerosol (flavoured; with and without nicotine) as it came out of a simulated activated device that mimicked the clinical situation. A comprehensive assessment of oral microbiome community composition by bacterial 16S rRNA gene sequencing was performed. A gas chromatography-based mass spectrometry analysis was also conducted to identify the effect of vaping on the oral metabolome profile.

RESULTS

A higher alpha diversity in flavoured EC with nicotine groups was observed compared to controls, with notable differences in bacterial taxa abundance. Metabolomics analysis further demonstrated distinct clustering of control, EC with flavoured nicotine, and flavoured EC groups, confirming 13 metabolites that were statistically higher in levels in flavoured EC with nicotine group, indicating the adverse effects of nicotine on the oral mucosa model. Altered metabolites were mainly enriched in pathways associated with oral cancer progression.

CONCLUSION

This study underscores the significant impact of EC use on oral health, highlighting alterations in the oral microbiome, bacterial composition, and metabolite profiles via a clinically relevant in vitro 3D organotypic model of human oral mucosa.

Professional dental care and survival rates in long-term care recipients: A cohort study of 1 459 163 individuals in South Korea

OBJECTIVES

To determine the dental care pattern and survival rates of participants who received long-term care (LTC) and a matched control cohort in South Korea.

BACKGROUND

Global ageing trends and the development of superaged societies pose healthcare challenges. South Korea's LTC system aids those with chronic illnesses and disabilities. Despite the link between oral health and systemic diseases, providing dental care in LTC facilities often reflects social neglect.

METHODS

We identified 1 459 163 individuals eligible for LTC insurance in the Korean National Health Insurance Service database from July 2008 to 2015 (LTC cohort) and 1 459 544 individuals matched through propensity-score matching (matched cohort). The LTC recipients were further categorised into subgroups based on their care type (institutional, home or mixed care). Population of utilising dental services and the average number of dental visits were counted in each cohort, and the survival rate of the LTC cohort was determined according to dental utilisation.

RESULTS

Population of utilising dental services increased steadily in all cohorts except for institutional care, with the highest utilisation (around 30%) observed in the matched cohort. Lower independence in LTC cohorts was associated with lower dental utilisation: 18-27% for home care, 12-18% for mixed care, and 10% for institutional care. The survival rates in the LTC cohort were significantly lower than in the matched cohort (P < .0001), with 28.1% survival in LTC vs 59.3% in the matched cohort.

CONCLUSION

Long-term care recipients experience social neglect for oral care, while higher survival rates were observed in those utilised dental services.

Association between oral microbiome diversity and chronic obstructive pulmonary disease in the US population

BACKGROUND

There is a dearth of population-based studies on the association between the diversity of the oral microbiome and the risk of chronic obstructive pulmonary disease (COPD). The study aims to investigate the association between oral microbiome diversity and COPD.

METHODS

In this cross-sectional study, data from the National Health and Nutrition Examination Survey (NHANES 2009-2012) were analyzed. The association between the oral microbiome α-diversity and COPD risk was examined via multivariable logistic regression, with Restricted cubic splines revealing potential non-linear trends. The β-diversity disparities between COPD and non-COPD groups were delineated using Principal Coordinate Analysis (PCoA) and Permutational Multivariate Analysis of Variance (PERMANOVA).

RESULTS

A total of 6061 participants were included in this study. For α-diversity, the observed ASVs were significantly associated with COPD risk (OR = 0.964, 95%CI: 0.936-0.993, P = 0.016). Similarly, Faith's phylogenetic Diversity showed a significant association with COPD risk (OR = 0.955, 95%CI: 0.919-0.993, P = 0.020). The Shannon-Weiner index was also associated with COPD risk (OR = 0.829, 95%CI: 0.702-0.981, P = 0.029). For β-diversity, PCoA and PERMANOVA analysis showed statistically significant differences in Bray-Curtis, unweighted, and weighted UniFrac distances (all P < 0.01) between the COPD and non-COPD groups.

CONCLUSIONS

Significant differences in oral microbiome α-diversity and β-diversity were found between COPD and non-COPD populations, with α-diversity (observed ASVs, Faith's Phylogenetic Diversity, Shannon-Weiner index) being negatively associated with the risk of COPD.

Association between oral dysbiosis and Parkinson's disease: a systematic review

The oral cavity serves as the gateway to the human organism, hosting a diverse community of microorganisms that coexist in a state of symbiosis. Disruption of this balance leads to oral dysbiosis, a condition associated with infections and oral pathologies, which may contribute to the etiopathogenesis of systemic disorders such as Parkinson's disease, a neurodegenerative movement disorder characterized by resting tremor, rigidity, and bradykinesia. While oral dysbiosis is recognized as a risk factor and an aggravating element for Parkinson's disease, it is not regarded as a direct cause. This systematic review aims to synthesize existing research exploring the potential relationship between oral dysbiosis and the development of Parkinson's disease. Following a comprehensive analysis, 12 studies were selected, comprising 11 case-control studies and one observational analytical study. These studies investigated the composition of oral microbiota in different sample groups, revealing a higher abundance of pathogenic oral bacteria in individuals diagnosed with Parkinson's disease. The findings suggest that oral dysbiosis may influence both the onset of Parkinson's disease and the progression of symptoms such as cognitive decline. These results pave the way for future research, particularly regarding alterations in oral microbiota as potential biomarkers for early diagnosis and disease monitoring.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024540056.

Animal models of oral infectious diseases

Oral infectious diseases, including caries, pulpitis, periodontitis, and oral candidiasis, are caused by plaque biofilm or dysbiosis. These conditions affect over two billion people worldwide, imposing a significant burden on healthcare systems and economies. Developing suitable animal models is crucial for investigating the underlying mechanisms of these diseases and evaluating potential therapeutic strategies. Currently, most animal models of oral infectious diseases are built via inoculating a single pathogenic bacterium. However, these models often fail to fully replicate the complex disease processes observed in humans. As a result, alternative methods are needed to explore more accurate animal models that better represent the progression of oral infectious diseases. Herein, this mini-review provides a concise overview of strategies for constructing animal models of oral infectious diseases, focusing on four representative conditions: caries, pulpitis, periodontitis, and oral candidiasis. The goal is to offer valuable insights and references for researchers working in the field of animal model development for oral health.

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.

Photobiomodulation and the oral-gut microbiome axis: therapeutic potential and challenges

This Perspective article explores the challenges associated with the direct application of photobiomodulation (PBM) to the gut and presents a novel hypothesis for indirect gut health modulation through oral microbiome alteration. Given the difficulties in delivering PBM effectively to deep gastrointestinal tissues, an alternative approach involves targeting the oral microbiome, which has a demonstrated relationship with the gut microbiome. Research indicates that PBM applied to the oral cavity could selectively alter microbial composition. This alteration may, via the oral-gut microbiome axis, indirectly impact gut health. This hypothesis, supported by preliminary studies, suggests that oral PBM could offer a promising non-invasive strategy for managing gut-related disorders. Furthermore, there may be a link between the oral microbiome and brain diseases. Given the proximity to the brain, PBM-induced changes in the oral microbiota could indirectly help prevent neurological disorders. However, further investigation is necessary to comprehensively elucidate the underlying mechanisms and therapeutic implications of this approach.

Association between lipid accumulation product (LAP) index and self-reported oral health outcomes: a cross-sectional study

BACKGROUND

Lipid Accumulation Product (LAP) is a biomarker associated with excessive lipid accumulation and various metabolic diseases. Despite the well-established link between oral and systemic health, the association between LAP and oral health remains largely unexplored.

METHODS

Data from 7,124 participants aged over 18 years from the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2014 were analyzed. Multivariate logistic regression models were applied to evaluate the independent association between LAP and self-reported oral health outcomes, adjusting for potential confounders.

RESULTS

There was a significant correlation between increasing LAP levels and deteriorating oral health status (β = 0.26, 95% CI: 0.20 to 0.32, P < 0.0001). Subgroup analyses revealed that the negative correlation between LAP and self-reported oral health outcomes was more pronounced in younger individuals and those with higher education levels. A non-linear relationship was identified, with oral health deteriorating significantly as LAP increased up to a threshold of 83, after which the relationship became non-significant.

CONCLUSIONS

This study demonstrates a robust association between LAP and self-reported oral health outcomes, suggesting that LAP could be a reliable indicator for assessing oral health status. The findings highlight the importance of targeted health interventions for populations with higher LAP indices to prevent oral health deterioration and potential systemic health issues.

Caries in a cohort of adults with cystic fibrosis: a cross-sectional study

Objectives To measure past dental caries experience in people with cystic fibrosis and to compare the results with a control group of people without cystic fibrosis.Methods A cross-sectional study of 92 adults with cystic fibrosis and 92 adults without cystic fibrosis was undertaken in Cork University Dental School and Hospital. The median age for study group and control group participants was 31 years and 27 years, respectively. All participants completed a detailed questionnaire before undergoing a clinical examination that recorded demographic, social and oral health variables. Caries was recorded using the Decayed, Missing and Filled Teeth (DMFT) index. All data were statistically analysed using the Wilcoxon rank-sum test, chi-squared test and Fisher's test. Negative binomial models were also used to analyse data.Results The study group had a higher mean DMFT score compared to the control group (6.52, 0.99, 0.41, 3.89 versus 5.33, 0.18, 0.11, 3.68). While the study group had a higher DMFT, the only component that was statistically significant between the groups was the Decayed Teeth component (p <0.001).Conclusion In this study, the cohort of people with cystic fibrosis had more caries than people without cystic fibrosis. Further research is required to establish if underlying systemic conditions, social and behavioural factors, or a combination of the aforementioned are responsible for a higher caries experience in this study group.

Effects of Zataria multiflora mouthwash and chlorhexidine compared to chlorhexidine alone on the incidence of ventilator-associated pneumonia in patients admitted to intensive care units

BACKGROUND AND PURPOSE

Ventilator-associated pneumonia (VAP) is the most prevalent nosocomial infection in intensive care units (ICUs). To prevent VAP, several strategies are employed, including oral care with mouthwashes. This study sought to compare the effects of Zataria multiflora essential oil mouthwash combined with chlorhexidine (ZM + CHG) against chlorhexidine (CHG) alone in reducing the incidence of VAP among ICU patients.

MATERIALS AND METHODS

This study is a single-blind clinical trial involving 120 mechanically ventilated ICU patients. They were randomly assigned into two groups. One group received Zataria multiflora 0.2 % mouthwash and chlorhexidine gluconate 0.2 % mouthwash (ZM + CHG group), while the control group received chlorhexidine gluconate 0.2 % mouthwash (CHG group), both administered twice daily for five days. Clinical pulmonary infection, oral health, and oral mucosal-plaque condition were assessed using the clinical pulmonary infection score (CPIS), Beck oral assessment scale (BOAS), and mucosal-plaque score (MPS), respectively.

RESULTS

Both ZM + CHG and CHG were effective in reducing the incidence of VAP, with ZM + CHG demonstrating superior effectiveness (p < 0.05). Moreover, ZM + CHG led to a significant improvement in oral and dental health scores and oral mucosal plaque condition compared to CHG (p < 0.05). This study found no significant complications from using either mouthwash, although the follow-up period was relatively short.

CONCLUSION

ZM + CHG reduced the incidence of VAP in ICU patients more effectively than CHG. It also improved oral health and mucosal-plaque condition in mechanically ventilated patients. Thus, ZM + CHG could serve as an alternative to CHG in ICU patients under mechanical ventilation. However, additional studies are needed to confirm its impact on VAP incidence.

Effect of oral healthcare prevention program on oral hygiene in post-stroke patients: A systematic review and meta-analysis

OBJECTIVES

The global burden of stroke is increasing every year. Residual impairments from stroke reduce the future independence of affected patients while also increasing their susceptibility to oral health-related diseases. Oral healthcare prevention programs (OHCP) are vital in maintaining acceptable oral hygiene during rehabilitation. Dysphagia among stroke elevates the risk of ingesting oral opportunistic pathogens, potentially leading to severe conditions.

DATA SOURCES

A systematic search was conducted in three main databases (Medline, EMBASE, CENTRAL) until November 29th, 2022.

STUDY SELECTION

We included randomized clinical trials that measure the effect of OHCP on oral health and oral opportunistic pathogens. After the systematic search (7608 articles), we conducted title/abstract selection by two independent authors, followed by full-text selection. In both cases, Cohen's kappa was calculated. Finally, we found 15 articles that were eligible for analysis.

RESULTS

The plaque index showed a slight but non-significant reduction with the OHCP program (SMD= -2.77, CI:6.6-1.06). In terms of the risk of oral yeast detection, there was a statistically non-significant difference between the intervention and control groups at short-term and after a 3-month follow-up (RR: 1.06, 95 % CI: 0.20;5.69; RR:0.98 CI: 0.33; 2.93), respectively. For S.aureus and AGNB, there was no statistically significant difference in short-term evaluation (RR: 0.89 CI: 0.07; 11.99; RR:0.77 CI: 0.00; 888.18), respectively.

CONCLUSIONS

Current evidence did not identify that regular OHCP had a beneficial effect on oral pathogen-related diseases.

PROSPERO REGISTRATION

CRD42022346788 CLINICAL SIGNIFICANCE: Regular oral health care, including assistance from a dental hygienist in stroke units, is essential for preventing oral health-related diseases. Integrating into post-stroke rehabilitation can enhance overall quality of life and well-being.

Oral and fecal microbiota as accurate non-invasive tools for detection of pancreatic cancer in the Chinese population

Pancreatic cancer (PCA), a leading cause of cancer-related deaths, has limited non-invasive diagnostic methods. We aimed to identify oral and fecal microbiome biomarkers and construct diagnostic classifiers. Oral and fecal samples from 97 PCA patients and 90 healthy controls underwent 16S rRNA sequencing. Samples were randomly divided into training and validation cohorts in a 7:3 ratio. Random forest models were constructed using training cohort and validated internally and externally in Chinese, Japanese, and Spanish populations. Results revealed significant dysbiosis of the oral and fecal microbiota of PCA patients. Most of the differential taxa shared between oral and fecal samples showed similar changes. Relative abundances of Streptococcus in oral samples, and of Bifidobacterium, Klebsiella and Akkermansia in fecal samples, were enriched in PCA. The fecal Firmicutes to Bacteroidota ratio was higher in PCA patient samples. Oral and fecal microbiome classifiers based on the top 20 contributing genera were constructed, and internal validation showed that the area under the curve (AUC) values were 0.963 and 0.890, respectively. The fecal microbiome classifier performed well in the external Chinese population, with an AUC of 0.878, but poorly in the Japanese and Spanish populations. Furthermore, fecal microbiomes could predict metastasis status in PCA patients, with an AUC of 0.804. In conclusion, oral and fecal microbiota were dysbiotic in PCA patients. Fecal microbiome classifier provides a feasible, non-invasive, and cost-effective tool with high precision for PCA screening in China; oral microbiome classifier requires further validation in external populations sampled with the same simple and convenient methods.

Nanotherapies Based on ROS Regulation in Oral Diseases

Oral diseases rank among the most prevalent clinical conditions globally, typically involving detrimental factors such as infection, inflammation, and injury in their occurrence, development, and outcomes. The concentration of reactive oxygen species (ROS) within cells has been demonstrated as a pivotal player in modulating these intricate pathological processes, exerting significant roles in restoring oral functionality and maintaining tissue structural integrity. Due to their enzyme-like catalytic properties, unique composition, and intelligent design, ROS-based nanomaterials have garnered considerable attention in oral nanomedicine. Such nanomaterials have the capacity to influence the spatiotemporal dynamics of ROS within biological systems, guiding the evolution of intra-ROS to facilitate therapeutic interventions. This paper reviews the latest advancements in the design, functional customization, and oral medical applications of ROS-based nanomaterials. Through the analysis of the components and designs of various novel nanozymes and ROS-based nanoplatforms responsive to different stimuli dimensions, it elaborates on their impacts on the dynamic behavior of intra-ROS and their potential regulatory mechanisms within the body. Furthermore, it discusses the prospects and strategies of nanotherapies based on ROS scavenging and generation in oral diseases, offering alternative insights for the design and development of nanomaterials for treating ROS-related conditions.

Effectiveness of Herbal Medicines with Anti-Inflammatory, Antimicrobial, and Antioxidant Properties in Improving Oral Health and Treating Gingivitis and Periodontitis: A Systematic Review

OBJECTIVES

This systematic review investigates the effectiveness of natural extracts with anti-inflammatory properties for improving oral health, particularly in managing gingivitis and periodontal disease (PD). With PD being a major global health issue, exacerbated by microbial dysbiosis and oxidative stress, the integration of phytochemicals and herbal formulations into periodontal therapy offers a promising avenue for adjunctive treatments.

METHODS

A systematic review was conducted following PRISMA guidelines and registered under the International Prospective Register of Systematic Reviews (ID: 641944). Databases, including PubMed, Scopus, and Web of Science, were searched between 18-24 December 2024, using Boolean keywords combining terms such as "herbal medicine", "plant extracts", "anti-inflammatory", and "periodontal therapy". Studies involving animal models, in vitro data, or non-peer-reviewed articles were excluded.

RESULTS

Seventeen studies met inclusion criteria. Polyherbal formulations and single-component extracts (e.g., Camellia sinensis, Punica granatum, Zingiber officinale, and Rosmarinus officinalis) demonstrated comparable efficacy to conventional agents like chlorhexidine (CHX). Polyherbal rinses, camellia sinensis gels, and extracts like Punica granatum reduced inflammation, improved gingival health, and showed antimicrobial properties, offering effective natural alternatives.

CONCLUSIONS

Natural products, including single extracts and polyherbal formulations, provide effective and safe alternatives for managing gingivitis and PD. Their anti-inflammatory, antimicrobial, and antioxidant properties support their adjunctive role alongside with scaling and root planning therapy (SRP) in periodontal therapy. However, further large-scale, long-term studies are needed to standardize formulations and establish optimal protocols.

Salivary microbiota characterization of Yerba Mate consumers in Uruguay

INTRODUCTION

Yerba Mate (YM) is a green-colored infusion, derived from the Ilex paraguariensis plant, very popular and commonly consumed in Latin American countries (southern Brazil, Argentina, Paraguay, and Uruguay), rapidly gaining penetration in global markets, It's a beverage rich in polyphenols, alkaloids, and saponins, making its impact on the oral microbiome particularly interesting.

OBJECTIVES

This study aimed to characterize the composition of salivary microbiota in Uruguayan YM consumers and non-consumers, exploring potential implications for oral health.

MATERIALS AND METHODS

Salivary samples were collected from 24 YM consumers and 28 non-consumers in Uruguay (n = 52). Participants were dentistry students, aged 18 to 35, with no reported pathologies and who had no oral conditions after visual inspection. 16S rRNA gene metabarcoding Illumina sequencing was employed to analyze their microbial composition. Bioinformatic analysis was conducted to identify and compare microbial taxa between the two groups. Relevant demographic and dietary data were also collected and analyzed.

RESULTS

The salivary microbiome of YM consumers is not completely different from non-consumers, however, several particular characteristics were found in each group. Both YM consumers and non-consumers exhibited a high relative abundance of Streptococcus species, with Streptococcus oralis being more abundant in a subset of non-consumers suggesting that YM may help maintain a balanced oral microbiota. Although no significant differences were observed in the Shannon diversity index, YM consumers might have a more diverse microbiome than non-consumers (YM consumers showed significantly higher species richness (Chao1 index), a greater number of amplicon sequence variants (ASVs), and broader microbial diversity, as confirmed by multivariate analyses). While the presence of Prevotella spp. in YM consumers aligns with previous research on polyphenol-rich beverages, its role in oral health warrants further investigation.

CONCLUSIONS

This study highlights the influence of YM consumption on salivary microbiota composition and diversity. YM consumption was associated with increased microbial diversity and species richness, which may contribute to oral microbiome resilience and health. These findings underscore the impact of dietary habits on oral microbial communities and their potential implications for oral health management and disease prevention.

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.

Oral microbiota as a biomarker for predicting the risk of malignancy in indeterminate pulmonary nodules: a prospective multicenter study

BACKGROUND

Determining the benign or malignant status of indeterminate pulmonary nodules (IPN) with intermediate malignancy risk is a significant clinical challenge. Oral microbiota-lung cancer (LC) interactions have qualified oral microbiota as a promising non-invasive predictive biomarker in IPN.

MATERIALS AND METHODS

Prospectively collected saliva, throat swabs, and tongue coating samples from 1040 IPN patients and 70 healthy controls across three hospitals. Following up, the IPNs were diagnosed as benign (BPN) or malignant pulmonary nodules (MPN). Through 16S rRNA sequencing, bioinformatics analysis, fluorescence in situ hybridization (FISH), and seven machine learning algorithms (support vector machine, logistic regression, naïve Bayes, multi-layer perceptron, random forest, gradient-boosting decision tree, and LightGBM), we revealed the oral microbiota characteristics at different stages of HC-BPN-MPN, identified the sample types with the highest predictive potential, constructed and evaluated the optimal MPN prediction model for predictive efficacy, and determined microbial biomarkers. Additionally, based on the SHAP algorithm interpretation of the ML model's output, we have developed a visualized IPN risk prediction system on the web.

RESULTS

Saliva, tongue coating, and throat swab microbiotas exhibit site-specific characteristics, with saliva microbiota being the optimal sample type for disease prediction. The saliva-LightGBM model demonstrated the best predictive performance (AUC = 0.887, 95%CI: 0.865-0.918), and identified Actinomyces, Rothia, Streptococcus, Prevotella, Porphyromonas , and Veillonella as biomarkers for predicting MPN. FISH was used to confirm the presence of a microbiota within tumors, and external data from a LC cohort, along with three non-IPN disease cohorts, were employed to validate the specificity of the microbial biomarkers. Notably, coabundance analysis of the ecological network revealed that microbial biomarkers exhibit richer interspecies connections within the MPN, which may contribute to the pathogenesis of MPN.

CONCLUSION

This study presents a new predictive strategy for the clinic to determine MPNs from BPNs, which aids in the surgical decision-making for IPN.

Significance of Multidisciplinary Teams for Patients with Oral and Maxillofacial Surgical Diseases: An Observational Retrospective Study in a General Hospital in China

Objective

The multidisciplinary team (MDT) approach is increasingly being utilized in the management of complex head and neck diseases. This study analyzed the benefits of MDT for patients with head and neck diseases as primary or secondary conditions and categorized MDT meetings into two types: head and neck surgery initiation (HNI) and head and neck surgery participation (HNP). The study further explored the characteristics of these MDT meetings and the factors influencing patient compliance, aiming to optimize MDT treatment models to maximize patient benefits.

Design

Retrospective analysis.

Methods

MDT meetings from January 2021 to December 2023 were reviewed. The meetings and patients were classified into the HNI group and the HNP group. Various factors, including general patient conditions, disease characteristics et al were analyzed using chi-square tests and point biserial correlation tests. P-values < 0.05 were considered statistically significant.

Results

A total of 292 MDT cases were analyzed, comprising 127 cases in the HNI group and 165 cases in the HNP group. In the HNI group, the initial diagnosis was modified in 11 cases (8.7%), with 92 patients (72.4%) receiving major recommendations for their treatment plans. In the HNP group, the initial diagnosis was modified in 28 cases (17.0%). The head and neck surgeons had a major impact on treatment plans in 47 cases (28.5%). Notably, patients with head and neck tumors received more major recommendations (p<0.05) in the HIN group, and patients who had tumors (p<0.05) and from outpatient departments (p<0.05) exhibited poor compliance with recommendations.

Conclusion

The MDT approach in general hospitals has improved the rationality of medical decision-making, especially in rare diseases, tumors, and systematic conditions compared to MDT in a single center, with head and neck surgeons playing vital roles. MDT models can be further explored and established.

The oral-gut microbiome axis in health and disease

The human body hosts trillions of microorganisms throughout many diverse habitats with different physico-chemical characteristics. Among them, the oral cavity and the gut harbour some of the most dense and diverse microbial communities. Although these two sites are physiologically distinct, they are directly connected and can influence each other in several ways. For example, oral microorganisms can reach and colonize the gastrointestinal tract, particularly in the context of gut dysbiosis. However, the mechanisms of colonization and the role that the oral microbiome plays in causing or exacerbating diseases in other organs have not yet been fully elucidated. Here, we describe recent advances in our understanding of how the oral and intestinal microbiota interplay in relation to their impact on human health and disease.

The Variability of the Salivary Antimicrobial Peptide Profile: Impact of Lifestyle

Saliva is crucial in maintaining oral health; its composition reflects the body's physiological and diseased state. Among salivary components, antimicrobial peptides (AMPs) stand out for their broad antimicrobial activities and role in modulating the oral microbiota and innate immune response. Local and systemic diseases can affect the levels of AMPs in saliva, making them attractive biomarkers. However, the large variability in their concentrations hampers their use in diagnostics. Knowledge of the various factors influencing the profile of salivary AMPs is essential for their use as biomarkers. Here, we examine how lifestyle factors such as physical activity, dietary supplementation, tobacco smoking, and psychological stress impact salivary AMP levels. By understanding these sources of variability, we can take a step forward in using AMPs for diagnostics and prognostics and develop new tailored and preventative approaches.

Subgingival biofilm microbiome in individuals with asthma and periodontitis: Metagenomic analysis

OBJECTIVE

This observational study aimed to explore the metagenomics of subgingival biofilms in individuals with varying degrees of asthma, from severe to none, to elucidate the association between the subgingival microbiome and asthma.

MATERIALS AND METHODS

Subgingival biofilm samples were collected from thirty participants at the Asthma Control Program Outpatient Clinic in Bahia (ProAR). These samples were categorized into six groups based on the severity of asthma and the presence or absence of periodontitis. We employed next-generation sequencing (Illumina MiSeq), targeting the 16S rRNA gene, to characterize the microbial communities present. Our analysis included descriptive statistics and sequencing data, evaluated using multivariate statistical methods such as the Shannon index, principal coordinate analysis, and the Bray-Curtis dissimilarity.

RESULTS

Our findings indicate a higher prevalence of periodontally detrimental bacterial genera in individuals with severe asthma and periodontitis. Additionally, individuals with asthma, but without periodontitis, exhibited a tendency toward dysbiosis, particularly in cases of severe asthma.

CONCLUSION

This research provides new insights into the composition of the subgingival microbiome in individuals with varying severities of asthma and periodontitis. The genera identified in this study underscore the need for further investigations to build upon these findings.

Examining the link between gut microbiota and periodontitis in East Asians using Mendelian randomization

Objective

This study explores the possible connection between periodontitis and gut microbiota in East Asians, a relationship that has been largely unexplored until now.

Methods

Using publicly available genome-wide association study (GWAS) data, we performed Mendelian randomization (MR). We analyzed GWAS summary statistics to assess if gut microbiota could causally influence periodontitis risk. We applied methods such as MR-Egger, weighted median, inverse variance weighting, and simple MR, and conducted sensitivity analyses to confirm our findings.

Results

Utilizing the Inverse-Variance Weighted approach, we identified potential causal relationships between 17 host-genetically influenced gut microbiota characteristics and periodontitis, including Granulicatella adiacens, Bilophila wadsworthia, and Thermosinus. Specifically, G. adiacens was linked to an increased risk of periodontitis (odds ratios [OR] 1.07, 95% confidence interval [CI] 1.02-1.15, p = 0.0004), while B. wadsworthia was linked to a decreased likelihood of tooth loss (OR 0.98, 95% CI 0.96-0.99, p = 0.0005). No evidence of pleiotropy or heterogeneity was observed across sensitivity analyses.

Conclusion

This study reveals a causal relationship between specific microorganisms and periodontitis in the Asian population, shedding light on the influence of gut microbiota on periodontitis.

Oral health among refugees and asylum seekers utilizing Médecins du Monde clinics in mainland Greece, 2016-2017

BACKGROUND

The oral health of refugees and asylum seekers is understudied. However, oral health has important implications for overall health and wellbeing. This study addresses this gap by characterizing oral health care utilization in Médecins du Monde (MdM) clinics across mainland Greece from 2016 - 2017.

METHODS

A retrospective cross-sectional study design was used to estimate proportional morbidities for caries, extraction, developmental, periodontal disease, preventive, and other oral health outcomes. The association between physical health conditions and consultations of interest - upper respiratory tract infections (URTIs) and reproductive health consultations - and oral health were compared using odds ratios (OR) and 95% confidence intervals (CIs). Oral health outcomes between Afghans and Syrians were compared using odds ratios and 95% CIs.

RESULTS

Caries (39.44%) and extractions (28.99%) were highly prevalent in our study population. The utilization of preventive dental consultations (37.10%) was high, particularly among males. Individuals with at least one upper respiratory tract infection (OR = 1.52; 95% CI: 1.30 - 1.77; Or = 1.90; 95% CI: 1.53 - 2.36) and women and girls with reproductive health consultations (OR = 1.30; 95% CI: 1.03 - 1.66; OR = 2.03; 95% CI: 1.49 - 2.76) were more likely to have any dental or caries specific consultations. The observed patterns in oral health needs differed between Afghans and Syrians, with Afghans more likely to have preventive screenings and less likely to have caries, extractions, or other conditions.

CONCLUSIONS

Displaced populations utilizing MdM dental clinics had high levels of oral health needs, particularly for caries and extractions. The connection between oral and overall health was seen in the study population, and these findings reinforce the public health importance of oral health for improving health and wellbeing of displaced populations. Evidence-informed policy, practice, and programming inclusive of oral health are needed to address both oral and overall health of refugees and asylum seekers in Greece. Future research should investigate not only oral health care needs but also knowledge and beliefs that inform utilization patterns among displaced populations.

Financial Burden of Dental Care Among Patients With Head and Neck Cancer

Importance

Patients undergoing treatment for head and neck cancer (HNC) experience oral complications requiring substantial dental treatment. This treatment is commonly not reimbursed by medical insurers, presenting a potential financial burden for patients.

Objective

To characterize the dental care needs and associated cost burden for patients with HNC.

Design, Setting, and Participants

This survey study included Head and Neck Cancer Alliance (HNCA) members who were surveyed from March 23 to October 27, 2023, using Qualtrics. The survey was promoted using the HNCA's social media and email list. Data analysis was performed between October 2023 and May 2024.

Main Outcomes and Measures

Main outcomes were oral and dental complications of cancer treatment among patients with HNC, the association of cancer treatment with dental care use, and costs of associated dental treatment.

Results

Of 100 individuals administered the survey, 85 (85%) completed all required questions and were included in the analysis. Of 84 participants with age and sex data, 51 (61%) were aged 65 years or older and 45 (54%) were female. Of 85 respondents, 59 (70%) indicated that their current oral health was worse than before cancer treatment. Most respondents (73 of 85 [86%]) endorsed oral complications from cancer treatment, including xerostomia (66 of 73 [90%]), caries (35 of 73 [48%]), and oral mucositis (29 of 73 [40%]); 64 of 73 respondents (88%) required follow-up dental treatment. Overall, 4 of 28 (14%) before HNC treatment and 17 of 53 (32%) after treatment reported finances as the reason that not all recommended dental care was received. A total of 33 of the 85 respondents (39%) said that their postcancer dental care had caused them financial hardship. Individuals who were less likely to endorse financial hardship were more likely to have greater educational attainment (odds ratio [OR], 0.20; 95% CI, 0.06-0.58), higher income (OR, 0.33; 95% CI, 0.11-0.94), increased pre-HNC dental visit frequency (OR, 0.30; 95% CI, 0.10-0.86), same or better oral health after HNC (OR, 0.13; 95% CI, 0.02-0.50), and lower out-of-pocket dental expenses after HNC (OR, 0.09; 95% CI, 0.03-0.29).

Conclusions and Relevance

In this survey study, most patients undergoing treatment for HNC required extensive dental treatment throughout cancer treatment; this treatment presented a financial burden for 39% of patients that was a limiting barrier to care. Since most private medical insurers do not reimburse for dental treatment, more comprehensive coverage deserves policy attention.

Mechanisms underlying the effects, and clinical applications, of oral microbiota in lung cancer: current challenges and prospects

The oral cavity contains a site-specific microbiota that interacts with host cells to regulate many physiological processes in the human body. Emerging evidence has suggested that changes in the oral microbiota can increase the risk of lung cancer (LC), and the oral microbiota is also altered in patients with LC. Human and animal studies have shown that oral microecological disorders and/or specific oral bacteria may play an active role in the occurrence and development of LC through direct and/or indirect mechanisms. These studies support the potential of oral microbiota in the clinical treatment of LC. Oral microbiota may therefore be used in the prevention and treatment of LC and to improve the side effects of anticancer therapy by regulating the balance of the oral microbiome. Specific oral microbiota in LC may also be used as screening or predictive biomarkers. This review summarizes the main findings in research on oral microbiome-related LC and discusses current challenges and future research directions.

The impact of oral diseases on respiratory health and the influence of respiratory infections on the oral microbiome

OBJECTIVE

The objective of this review is to examine the relationship between oral diseases and respiratory health, investigating how oral microbiome disruptions contribute to respiratory tract infections. Additionally, it aims to explore the impact of respiratory disease symptoms and treatments on the oral microbiome.

DATA SOURCES

The literature utilized in this review was sourced from studies focusing on the correlation between oral health and respiratory infections, spanning a period of 40 years. Various databases and scholarly sources were likely consulted to gather relevant research articles, reviews, and clinical studies.

STUDY SELECTION

This review summarizes four decades-long research, providing insights into the intricate relationship between oral and respiratory health. It delves into how oral diseases influence respiratory tract conditions and vice versa. The selection process likely involved identifying studies that addressed the interaction between oral microbiome disruptions and respiratory complications.

CONCLUSION

Oral diseases or poor oral habits have been known to increase the risk of getting respiratory infections. Modern techniques have demonstrated the relationship between oral disease and respiratory tract infections like influenza, chronic obstructive pulmonary diseases, asthma, and Pneumonia. Apart from that, the medications used to treat respiratory diseases affect oral physiological factors like the pH of saliva, and saliva flow rate, which can cause significant changes in the oral microbiome. This review provides regular oral hygiene and care that can prevent respiratory health and respiratory infections.

CLINICAL SIGNIFICANCE

Understanding the intricate relationship between oral health and respiratory infections is crucial for healthcare providers. Implementing preventive measures and promoting good oral hygiene habits can reduce respiratory tract infections and improve overall respiratory health outcomes.

Advances in the application and mechanism of bioactive peptides in the treatment of inflammation

Inflammation is a normal immune response in organisms, but it often triggers chronic diseases such as colitis and arthritis. Currently, the most widely used anti-inflammatory drugs are non-steroidal anti-inflammatory drugs, albeit they are accompanied by various adverse effects such as hypertension and renal dysfunction. Bioactive peptides (BAPs) provide therapeutic benefits for inflammation and mitigate side effects. Herein, this review focuses on the therapeutic effects of various BAPs on inflammation in different body parts. Emphasis is placed on the immunomodulatory mechanisms of BAPs in treating inflammation, such as regulating the release of inflammatory mediators, modulating MAPK and NF-κB signaling pathways, and reducing oxidative stress reactions for immunomodulation. This review aims to provide a reference for the function, application, and anti-inflammation mechanisms of BAPs.

The clinical impacts of lung microbiome in bronchiectasis with fixed airflow obstruction: a prospective cohort study

BACKGROUND

Airflow obstruction is a hallmark of disease severity and prognosis in bronchiectasis. The relationship between lung microbiota, airway inflammation, and outcomes in bronchiectasis with fixed airflow obstruction (FAO) remains unclear. This study explores these interactions in bronchiectasis patients, with and without FAO, and compares them to those diagnosed with chronic obstructive pulmonary disease (COPD).

METHODS

This prospective observational study in Taiwan enrolled patients with either bronchiectasis or COPD. To analyze the lung microbiome and assess inflammatory markers, bronchoalveolar lavage (BAL) samples were collected for 16S rRNA gene sequencing. The study cohort comprised 181 patients: 86 with COPD, 46 with bronchiectasis, and 49 with bronchiectasis and FAO, as confirmed by spirometry.

RESULTS

Patients with bronchiectasis, with or without FAO, had similar microbiome profiles characterized by reduced alpha diversity and a predominance of Proteobacteria, distinctly different from COPD patients who exhibited more Firmicutes, greater diversity, and more commensal taxa. Furthermore, compared to COPD and bronchiectasis without FAO, bronchiectasis with FAO showed more severe disease and a higher risk of exacerbations. A significant correlation was found between the presence of Pseudomonas aeruginosa and increased airway neutrophilic inflammation such as Interleukin [IL]-1β, IL-8, and tumor necrosis factor-alpha [TNF]-α, as well as with higher bronchiectasis severity, which might contribute to an increased risk of exacerbations. Moreover, in bronchiectasis patients with FAO, the ROSE (Radiology, Obstruction, Symptoms, and Exposure) criteria were employed to classify individuals as either ROSE (+) or ROSE (-), based on smoking history. This classification highlighted differences in clinical features, inflammatory profiles, and slight microbiome variations between ROSE (-) and ROSE (+) patients, suggesting diverse endotypes within the bronchiectasis with FAO group.

CONCLUSION

Bronchiectasis patients with FAO may exhibit two distinct endotypes, as defined by ROSE criteria, characterized by greater disease severity and a lung microbiome more similar to bronchiectasis without FAO than to COPD. The significant correlation between Pseudomonas aeruginosa colonization and increased airway neutrophilic inflammation, as well as disease severity, underscores the clinical relevance of microbial patterns. This finding reinforces the potential role of these patterns in the progression and exacerbations of bronchiectasis with FAO.

Relationship between human oral microbiome dysbiosis and neuropsychiatric diseases: An updated overview

The role of the gut-brain axis in mental health disorders has been extensively studied. As the oral cavity is the starting point of the digestive tract, the role that the oral microbiota plays in mental health disorders has gained recent attention. Oral microbiota can enter the bloodstream and trigger inflammatory responses or translocate to the brain through the trigeminal nerve or olfactory system. Hence, the concept of the oral microbiota-brain axis has emerged. Several hypotheses have been suggested that the oral microbiota can enter the gastrointestinal tract and affect the gut-brain axis; however, literature describing oral-brain communication remains limited. This review summarizes the characteristics of oral microbiota and its mechanisms associated with mental health disorders. Through a comprehensive examination of the relationship between oral microbiota and various neuropsychiatric diseases, such as anxiety, depression, schizophrenia, autism spectrum disorder, epilepsy, Parkinson's disease, and dementia, this review seeks to identify promising avenues of future research.

Detection of trichomonads in patients with lung cancer and transcription analysis on the response of human pulmonary epithelial cells to Trichomonas tenax invasion

INTRODUCTION

Lung cancer is one of the most prevalent malignancies worldwide. Substantial research has illuminated the intricate interplay between microorganisms and human health, revealing their role in disease regulation. Trichomonads is a flagellated protozoan in the human cavity and have been previously identified as a pathogen associated with pneumonia, contributing to tissue chronic inflammation and carcinogenesis.

METHODS

Nested polymerase chain reaction methods were employed to scrutinize the prevalence of trichomonads in the bronchovesicular fluid of patients diagnosed with lung cancer. Subsequently, the influence of Trichomonas tenax invasion on lung cancer cells was elucidated through proliferation assays, migration assays, and transcription analysis.

RESULTS

Bronchoalveolar fluid samples from lung cancer patients yielded positive nested PCR results for eight out of twenty-seven samples. Seven of these samples were identified as Trichomonas tenax, while one was identified as Tetratrichomonas spp. Our findings revealed a significant upregulation of pathways associated with carcinogenesis, including cellular proliferation, migration, and drug resistance, in response to T. tenax invasion.

CONCLUSIONS

This study underscores the importance of recognizing the presence of trichomonads and the influence of T. tenax invasion on host responses to respiratory diseases. The identified pathways implicated in cancer development may pave the way for developing targeted treatment strategies for pulmonary diseases. These findings hold promise for informing and improving the precision of therapeutic interventions in the context of pulmonary ailments.

Differential Patterns of Gut and Oral Microbiomes in Hispanic Individuals with Cognitive Impairment

Alzheimer's disease and related dementias (ADRD) have been associated with alterations in both oral and gut microbiomes. While extensive research has focused on the role of gut dysbiosis in ADRD, the contribution of the oral microbiome remains relatively understudied. Furthermore, the potential synergistic interactions between oral and gut microbiomes in ADRD pathology are largely unexplored. This study aims to evaluate distinct patterns and potential synergistic effects of oral and gut microbiomes in a cohort of predominantly Hispanic individuals with cognitive impairment (CI) and without cognitive impairment (NC). We conducted 16S rRNA gene sequencing on stool and saliva samples from 32 participants (17 CI, 15 NC; 62.5% female, mean age = 70.4 ± 6.2 years) recruited in San Antonio, Texas, USA. Correlation analysis through MaAslin2 assessed the relationship between participants' clinical measurements (e.g., fasting glucose and blood cholesterol) and their gut and saliva microbial contents. Differential abundance analysis evaluated taxa with significant differences between CI and NC groups, and alpha and beta diversity metrics assessed within-sample and group compositional differences. Our analyses revealed no significant differences between NC and CI groups in fasting glucose or blood cholesterol levels. However, a clear association was observed between gut microbiome composition and levels of fasting glucose and blood cholesterol. While alpha and beta diversity metrics showed no significant differences between CI and NC groups, differential abundance analysis revealed an increased presence of oral genera such as Dialister , Fretibacterium , and Mycoplasma in CI participants. Conversely, CI individuals exhibited a decreased abundance of gut genera, including Shuttleworthia , Holdemania , and Subdoligranulum , which are known for their anti-inflammatory properties. No evidence was found for synergistic contributions between oral and gut microbiomes in the context of ADRD. Our findings suggest that similar to the gut microbiome, the oral microbiome undergoes significant modifications as individuals transition from NC to CI. Notably, the identified oral microbes have been previously associated with periodontal diseases and gingivitis. These results underscore the necessity for further investigations with larger sample sizes to validate our findings and elucidate the complex interplay between oral and gut microbiomes in ADRD pathogenesis.

Causal association between air pollution and allergic rhinitis, asthma: a Mendelian randomization study

Backgrounds

Observational studies suggest that air pollutants, including particulate matter and nitrogen compounds, could elevate asthma and allergic rhinitis health risks. Nevertheless, the exact nature of the causal relationship between air pollution and asthma and allergic rhinitis remains unknown. This study utilizes the Mendelian randomization (MR) technique to explore the potential causal links between air pollution components (PM2.5, PM2.5-10, PM10, NO₂, and nitrogen dioxide) and the incidence of allergic rhinitis and asthma.

Methods

A MR study utilized summary statistics from GWAS that are publicly accessible. The inverse variance weighting (IVW) approach served as the foundational analysis technique. To ensure robustness, supplementary methodologies such as the weighted median, MR-Egger regression, simple mode, and weighted model were also applied. Heterogeneity was evaluated using Cochran's Q test, and the presence of pleiotropy was determined through MR-Egger regression. The MR-PRESSO test was employed for outlier detection, and the analysis's sensitivity was scrutinized via a leave-one-out strategy.

Results

The IVW technique showed a strong correlation between PM10 and asthma (OR = 0.625, 95% CI = 0.396-0.988, p = 0.044). No significant associations were found between asthma and other air pollutants such as PM2.5, PM2.5-10, NO₂, or nitrogen dioxide. Similarly, allergic rhinitis showed no causal relationships with any studied air pollution metrics. Pleiotropy was absent in the findings. Sensitivity analyses, employing the leave-one-out method, confirmed the stability of these results, unaffected by individual single nucleotide polymorphisms (SNPs).

Conclusion

This Mendelian randomization study establishes a causal link between PM10 exposure and asthma, suggesting that interventions to reduce air pollution may decelerate the adverse progression of asthma.

Effect of oral health interventions for dependent older people-A systematic review

BACKGROUND

There is an increasing proportion of older people in the population worldwide, with a large group being dependent on the care of others. Dependent older people are more vulnerable to oral diseases, which can heavily impact their quality of life (OHRQoL) and general health.

OBJECTIVE

The purpose of this systematic review was to comprehensively assess interventions to improve oral health or guarantee access and adherence to dental treatment of dependent older people.

METHODS

We searched MEDLINE, EMBASE, CENTRAL and clinical trial registries. Two reviewers performed the selection, data extraction, risk of bias evaluation using the Cochrane Risk of Bias tool and assessment of certainty of the evidence. When possible, we conducted a meta-analysis to calculate effect estimates and their 95%CIs. Primary outcomes were OHRQoL, oral/dental health, and use of the oral care system.

RESULTS

We included a total of 30 randomised clinical trials assessing educational and non-educational interventions for community-dwelling older people (n = 2) and those residing in long-term care facilities (n = 28). Most studies assessed oral hygiene and showed that interventions may result in a reduction in dental plaque in the short term (with low certainty of evidence), but there is limited evidence for long-term effectiveness. Only one study assessed OHRQoL, and none evaluated changes in the use of the oral health care system.

CONCLUSION

Our findings do not provide strong conclusions in favour of any specific intervention, mainly due to study quality and imprecision. There is limited information about the long-term effect of interventions, and further research is needed, especially targeting community-dwelling older people.

PROSPERO ID

CRD42021231721.

An insight into the last 5-year patents on Porphyromonas gingivalis and Streptococcus mutans, the pivotal pathogens in the oral cavity

INTRODUCTION

The oral cavity harbors an extensive array of over 700 microorganisms, forming the most complex biome of the entire human body, with bacterial species being the most abundant. Oral diseases, e.g. periodontitis and caries, are strictly associated with bacterial dysbiosis. Porphyromonas gingivalis and Streptococcus mutans stand out among bacteria colonizing the oral cavity.

AREAS COVERED

After a brief overview of the bacterial populations in the oral cavity and their roles in regulating (flora) oral cavity or causing diseases like periodontal and cariogenic pathogens, we focused our attention on P. gingivalis and S. mutans, searching for the last-5-year patents dealing with the proposal of new strategies to fight their infections. Following the PRISMA protocol, we filtered the results and analyzed over 100 applied/granted patents, to provide an in-depth insight into this R&D scenario.

EXPERT OPINION

Several antibacterial proposals have been patented in this period, from both chemical - peptides and small molecules - and biological - probiotics and antibodies - sources, along with natural extracts, polymers, and drug delivery systems. Most of the inventors are from China and Korea and their studies also investigated anti-inflammatory and antioxidant effects, being beneficial to oral health through a prophylactic, protective, or curative effect.

A comparison of the prevalence of respiratory pathogens and opportunistic respiratory pathogenic profile of 'clean' and 'unclean' removable dental prostheses

OBJECTIVES

To determine and compare the opportunistic respiratory pathogenic index (ORPI) and prevalence of respiratory pathogens between clean and unclean removable prostheses.

METHODS

A cross-sectional study was conducted among 97 removable prosthesis wearers at a teaching dental hospital. Participants' prosthesis hygiene was grouped into clean and unclean. After prosthesis plaque samples were sequenced using the Type IIB Restriction-site Associated DNA Sequencing for Microbiome method, the prevalence was assessed for the presence of respiratory pathogens on each sample. The ORPIs for clean and unclean prostheses were quantified based on the sum of the relative abundance of respiratory pathogenic bacteria in a microbiome using a reference database that contains opportunistic respiratory pathogens and disease-associated information.

RESULTS

A total of 30 opportunistic respiratory pathogens were identified on the removable prostheses. Eighty-one (83.5 %) removable prostheses harboured respiratory pathogenic bacteria. Stenotrophomonas maltophilia (34.0 %), Pseudomonas aeruginosa (27.8 %), and Streptococcus agalactiae (27.8 %) were the top three prevalent respiratory pathogens detected in plaque samples. There was a significantly higher prevalence of respiratory pathogens residing on unclean than clean prostheses (P = 0.046). However, the ORPIs in both groups showed no statistically significant difference (P = 0.516).

CONCLUSIONS

The ORPIs for both clean and unclean prostheses demonstrated a similar abundance of respiratory pathogens. However, the high prevalence of respiratory pathogens residing on unclean prostheses should not be underestimated. Therefore, maintaining good prosthesis hygiene is still important for overall oral and systemic health, even though the direct link between prosthesis cleanliness and reduced abundance of respiratory pathogens has not been established.

CLINICAL SIGNIFICANCE

The association between the prevalence of respiratory pathogens and unclean removable prostheses has been demonstrated and might increase the theoretical risk of respiratory disease development.

Oropharyngeal microbial ecosystem perturbations influence the risk for acute respiratory infections in common variable immunodeficiency

Background

The respiratory tract microbiome is essential for human health and well-being and is determined by genetic, lifestyle, and environmental factors. Patients with Common Variable Immunodeficiency (CVID) suffer from respiratory and intestinal tract infections, leading to chronic diseases and increased mortality rates. While CVID patients' gut microbiota have been analyzed, data on the respiratory microbiome ecosystem are limited.

Objective

This study aims to analyze the bacterial composition of the oropharynx of adults with CVID and its link with clinical and immunological features and risk for respiratory acute infections.

Methods

Oropharyngeal samples from 72 CVID adults and 26 controls were collected in a 12-month prospective study. The samples were analyzed by metagenomic bacterial 16S ribosomal RNA sequencing and processed using the Quantitative Insights Into Microbial Ecology (QIME) pipeline. Differentially abundant species were identified and used to build a dysbiosis index. A machine learning model trained on microbial abundance data was used to test the power of microbiome alterations to distinguish between healthy individuals and CVID patients.

Results

Compared to controls, the oropharyngeal microbiome of CVID patients showed lower alpha- and beta-diversity, with a relatively increased abundance of the order Lactobacillales, including the family Streptococcaceae. Intra-CVID analysis identified age >45 years, COPD, lack of IgA, and low residual IgM as associated with a reduced alpha diversity. Expansion of Haemophilus and Streptococcus genera was observed in patients with undetectable IgA and COPD, independent from recent antibiotic use. Patients receiving azithromycin as antibiotic prophylaxis had a higher dysbiosis score. Expansion of Haemophilus and Anoxybacillus was associated with acute respiratory infections within six months.

Conclusions

CVID patients showed a perturbed oropharynx microbiota enriched with potentially pathogenic bacteria and decreased protective species. Low residual levels of IgA/IgM, chronic lung damage, anti antibiotic prophylaxis contributed to respiratory dysbiosis.

Periodontal disease increases the severity of chronic obstructive pulmonary disease: a Mendelian randomization study

BACKGROUND

Recent research suggests that periodontitis can increase the risk of chronic obstructive pulmonary disease (COPD). In this study, we performed two-sample Mendelian randomization (MR) and investigated the causal effect of periodontitis (PD) on the genetic prediction of COPD. The study aimed to estimate how exposures affected outcomes.

METHODS

Published data from the Gene-Lifestyle Interaction in the Dental Endpoints (GLIDE) Consortium's genome-wide association studies (GWAS) for periodontitis (17,353 cases and 28,210 controls) and COPD (16,488 cases and 169,688 controls) from European ancestry were utilized. This study employed a two-sample MR analysis approach and applied several complementary methods, including weighted median, inverse variance weighted (IVW), and MR-Egger regression. Multivariable Mendelian randomization (MVMR) analysis was further conducted to mitigate the influence of smoking on COPD.

RESULTS

We chose five single-nucleotide polymorphisms (SNPs) as instrumental variables for periodontitis. A strong genetically predicted causal link between periodontitis and COPD, that is, periodontitis as an independent risk factor for COPD was detected. PD (OR = 1.102951, 95% CI: 1.005-1.211, p = 0.039) MR-Egger regression and weighted median analysis results were coincident with those of the IVW method. According to the sensitivity analysis, horizontal pleiotropy's effect on causal estimations seemed unlikely. However, reverse MR analysis revealed no significant genetic causal association between COPD and periodontitis. IVW (OR = 1.048 > 1, 95%CI: 0.973-1.128, p = 0.2082) MR Egger (OR = 0.826, 95%CI:0.658-1.037, p = 0.1104) and weighted median (OR = 1.043, 95%CI: 0.941-1.156, p = 0.4239). The results of multivariable Mendelian randomization (MVMR) analysis, after adjusting for the confounding effect of smoking, suggest a potential causal relationship between periodontitis and COPD (P = 0.035).

CONCLUSION

In this study, periodontitis was found to be independent of COPD and a significant risk factor, providing new insights into periodontitis-mediated mechanisms underlying COPD development.

SARS-CoV-2, periodontal pathogens, and host factors: The trinity of oral post-acute sequelae of COVID-19

COVID-19 as a pan-epidemic is waning but there it is imperative to understand virus interaction with oral tissues and oral inflammatory diseases. We review periodontal disease (PD), a common inflammatory oral disease, as a driver of COVID-19 and oral post-acute-sequelae conditions (PASC). Oral PASC identifies with PD, loss of teeth, dysgeusia, xerostomia, sialolitis-sialolith, and mucositis. We contend that PD-associated oral microbial dysbiosis involving higher burden of periodontopathic bacteria provide an optimal microenvironment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These pathogens interact with oral epithelial cells activate molecular or biochemical pathways that promote viral adherence, entry, and persistence in the oral cavity. A repertoire of diverse molecules identifies this relationship including lipids, carbohydrates and enzymes. The S protein of SARS-CoV-2 binds to the ACE2 receptor and is activated by protease activity of host furin or TRMPSS2 that cleave S protein subunits to promote viral entry. However, PD pathogens provide additional enzymatic assistance mimicking furin and augment SARS-CoV-2 adherence by inducing viral entry receptors ACE2/TRMPSS, which are poorly expressed on oral epithelial cells. We discuss the mechanisms involving periodontopathogens and host factors that facilitate SARS-CoV-2 infection and immune resistance resulting in incomplete clearance and risk for 'long-haul' oral health issues characterising PASC. Finally, we suggest potential diagnostic markers and treatment avenues to mitigate oral PASC.

Comparative Lipidomics of Oral Commensal and Opportunistic Bacteria

The oral cavity contains a vast array of microbes that contribute to the balance between oral health and disease. In addition, oral bacteria can gain access to the circulation and contribute to other diseases and chronic conditions. There are a limited number of publications available regarding the comparative lipidomics of oral bacteria and fungi involved in the construction of oral biofilms, hence our decision to study the lipidomics of representative oral bacteria and a fungus. We performed high-resolution mass spectrometric analyses (<2.0 ppm mass error) of the lipidomes from five Gram-positive commensal bacteria: Streptococcus oralis, Streptococcus intermedius, Streptococcus mitis, Streptococcus sanguinis, and Streptococcus gordonii; five Gram-positive opportunistic bacteria: Streptococcus mutans, Staphylococcus epidermis, Streptococcus acidominimus, Actinomyces viscosus, and Nanosynbacter lyticus; seven Gram-negative opportunistic bacteria: Porphyromonas gingivalis. Prevotella brevis, Proteus vulgaris, Fusobacterium nucleatum, Veillonella parvula, Treponema denticola, and Alkermansia muciniphila; and one fungus: Candida albicans. Our mass spectrometric analytical platform allowed for a detailed evaluation of the many structural modifications made by microbes for the three major lipid scaffolds: glycerol, sphingosine and fatty acyls of hydroxy fatty acids (FAHFAs).

A Holistic Approach for Ethics and Sustainability in the Food Chain: The Gateway to Oral and Systemic Health

Food production is a complex matter, affecting people's lives, organizations' profits, and the well-being of the whole planet, and has multifaceted ethical considerations surrounding its production, distribution, and consumption. This paper addresses the pressing need to confront ethical challenges within the food system, encompassing issues such as environmental sustainability, food security, and individual food choices for better oral and systemic health of all individuals around the globe. From agricultural practices to global trade and food waste, ethical implications are addressed across various domains, highlighting the interconnectedness of ethical decision-making in the food industry. Central themes explored include the ethical dimensions of food production methods, the impact of global trade on food ethics, and the role of individuals in making ethically informed food choices. Additionally, this paper considers the spiritual and physical significance of food, particularly through the lens of oral health as a gateway to holistic well-being. Recognizing the complexity of the food and mouth ecosystem, this paper calls for serious interventions in legislation and economics to promote ethical protocols and techniques for sustainability reasons. It emphasizes the importance of ethical considerations in food safety management systems, regulatory frameworks, and quality standards. Moreover, this paper underlines the need for a comprehensive approach to address ethical dilemmas and moral values inherent in the food industry and oral health policies, adopting the precautionary principle and ethical decision-making frameworks. This article finally aims to serve as a call to action for stakeholders across the food industry and the healthcare sector, to prioritize ethical practices, promote transparency, rearrange economic parameters, and work towards a more sustainable and equitable food system for inner and outer oral and systemic health and human sustainability for all.

Association between oral microbiome and five types of respiratory infections: a two-sample Mendelian randomization study in east Asian population

Objective

To explore the causal relationship between the oral microbiome and specific respiratory infections including tonsillitis, chronic sinusitis, bronchiectasis, bronchitis, and pneumonia, assessing the impact of genetic variations associated with the oral microbiome.

Methods

Mendelian randomization was used to analyze genetic variations, leveraging data from genome-wide association studies in an East Asian cohort to identify connections between specific oral microbiota and respiratory infections.

Results

Our analysis revealed that Prevotella, Streptococcus, Fusobacterium, Pauljensenia, and Capnocytophaga play crucial roles in influencing respiratory infections. Prevotella is associated with both promoting bronchitis and inhibiting pneumonia and tonsillitis, with a mixed effect on chronic sinusitis. Streptococcus and Fusobacterium show varied impacts on respiratory diseases, with Fusobacterium promoting chronic sinusitis, bronchiectasis, and bronchitis. Conversely, Pauljensenia and Capnocytophaga are linked to reduced bronchitis and tonsillitis, and inhibited pneumonia and bronchitis, respectively.

Discussion

These findings underscore the significant impact of the oral microbiome on respiratory health, suggesting potential strategies for disease prevention and management through microbiome targeting. The study highlights the complexity of microbial influences on respiratory infections and the importance of further research to elucidate these relationships.

Antimicrobial Prophylaxis With Ampicillin-sulbactam Compared With Cefazolin for Esophagectomy: Nationwide Inpatient Database Study in Japan

OBJECTIVE

To assess the effect of antimicrobial prophylaxis with ampicillin-sulbactam (ABPC/SBT) compared with cefazolin (CEZ) on the short-term outcomes after esophagectomy.

BACKGROUND

CEZ is widely used for antimicrobial prophylaxis in esophagectomy without procedure-specific evidence, whereas ABPC/SBT is preferred in some hospitals to target both aerobic and anaerobic oral bacteria.

METHODS

Data of patients who underwent esophagectomy for cancer between July 2010 and March 2019 were extracted from a nationwide Japanese inpatient database. Overlap propensity score weighting was conducted to compare the short-term outcomes [including surgical site infection (SSI), anastomotic leakage, and respiratory failure] between antimicrobial prophylaxis with CEZ and ABPC/SBT after adjusting for potential confounders. Sensitivity analyses were also performed using propensity score matching and instrumental variable analyses.

RESULTS

Among 17,772 eligible patients, 16,077 (90.5%) and 1695 (9.5%) patients were administered CEZ and ABPC/SBT, respectively. SSI, anastomotic leakage, and respiratory failure occurred in 2971 (16.7%), 2604 (14.7%), and 2754 patients (15.5%), respectively. After overlap weighting, ABPC/SBT was significantly associated with a reduction in SSI [odds ratio 0.51 (95% CI: 0.43-0.60)], anastomotic leakage [0.51 (0.43-0.61)], and respiratory failure [0.66 (0.57-0.77)]. ABPC/SBT was also associated with reduced respiratory complications, postoperative length of stay, and total hospitalization costs. The proportion of Clostridioides difficile colitis and noninfectious complications did not differ between the groups. Propensity score matching and instrumental variable analyses demonstrated equivalent results.

CONCLUSIONS

The administration of ABPC/SBT as antimicrobial prophylaxis for esophagectomy was associated with better short-term postoperative outcomes compared with CEZ.

The human microbiome and benign prostatic hyperplasia: Current understandings and clinical implications

The research of the human microbiome in the preceding decade has yielded novel perspectives on human health and diseases. Benign prostatic hyperplasia (BPH) is a common disease in middle-aged and elderly males, which negatively affects the life quality. Existing evidence has indicated that the human microbiome, including urinary, intra-prostate, gut, oral and blood microbiome may exert a significant impact on the natural progression of BPH. The dysbiosis of the microbiome may induce inflammation at either a local or systemic level, thereby affecting the BPH. Moreover, metabolic syndrome (MetS) caused by the microbiome can also be involved in the development of BPH. Additionally, alterations in the microbiome composition during the senility process may serve as another cause of the BPH. Here, we summarize the influence of human microbiome on BPH and explore how the microbiome is linked to BPH through inflammation, MetS, and senility. In addition, we propose promising areas of investigation and discuss the implications for advancing therapeutic approaches.

Temporal stability of tongue microbiota in older patients - A pilot study

Background/purpose

Healthy states of human microbiota depend on a stable community of symbiotic microbes irrespective of external challenges from the environment. Thus, long-term stability of the oral microbiota is of importance, particularly for older patient populations.

Materials and methods

We used next-generation sequencing (NGS) to examine the tongue microbiota of 18 individuals receiving long-term care over a 10-month period.

Results

Beta diversity analysis demonstrated temporal stability of the tongue microbiota, as microbial compositions from all time points were indistinguishable from each other (P = 0.0887). However, significant individual variation in microbial composition (P = 0.0001) was observed, underscoring the presence of a unique microbial profile for each patient.

Conclusion

The temporal dynamics of tongue microbiota exhibit long-term stability, providing diagnostic implications for oral diseases within older patient populations.

Porphyromonas gingivalis triggers inflammation in hepatocyte depend on ferroptosis via activating the NF-κB signaling pathway

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by excessive fat deposition in hepatocytes caused by non-alcoholic liver injury. Porphyromonas gingivalis (P.g) is the main pathogen causing periodontitis, which can aggravate the progression of NAFLD in our previously study. The objective of this study was to further investigate the pathogenesis and moleculer michanisma of NAFLD aggravated by P.g.

METHODS

A mouse model of NAFLD was established, and the changes of inflammatory factors and NF-κB signaling pathway in liver tissue and L-02 cells were analyzed by transcriptome sequencing, Western blot, IHC and RT-PCR. In addition, the NF-κB signaling pathway inhibitor QNZ and ferroptosis inhibitor Fer-1 were used to analyze the relationship between NF-κB signaling pathway and ferroptosis in vitro.

RESULTS

In vivo and in vitro experiments, P.g can induce liver inflammation and activate NF-κB signaling pathway. At the same time, P.g promotes ferroptosis and inflammation in L-02 in vitro. QNZ alleviates ferroptosis and inflammatory activation in L-02. Fer-1 can relieve the L-02 inflammation caused by P.g products.

CONCLUSION

Porphyromonas gingivalis can induce ferroptosis and inflammation in hepatocytes and further worsen liver lesions. The mechanism of ferroptosis in hepatocytes depends on NF-κB signaling pathway, which provides a new strategy for clinical treatment and prevention of NAFLD.

The oral microbiome of newly diagnosed tuberculosis patients; a pilot study

BACKGROUND

Changes in oral microbiota composition (dysbiosis) have long been known to play a key role in the pathogenesis of oral and systemic diseases including respiratory diseases. However, till now, no study has assessed changes in oral microbiota following tuberculosis (TB) infection in humans.

AIMS

This is the first study of its kind that aimed to investigate oral microbial dysbiosis in newly diagnosed, treatment naïve, TB patients.

METHODS

Oral swab samples were collected from newly diagnosed TB patients (n = 20) and age, gender and ethnicity matched healthy controls (n = 10). DNA was extracted and microbiota analyzed by sequencing the hypervariable (V3-V4) region of the bacterial 16S rRNA gene using Illumina MiSeq platform. Bioinformatics and statistical analyses were performed using QIIME and R.

RESULTS

Bacterial richness, diversity and community composition were significantly different between TB patients and healthy controls. The two groups also exhibit differential abundance at phylum, class, genus and species levels. LEfSe analysis revealed enrichment (LDA scores (log10) >2, P < 0.05) of Firmicutes (especially Streptococcus) and Actinobacteriota (especially Rothia) in TB patients relative to healthy controls. Gene function prediction analysis showed upregulation of metabolic pathways related to carbohydrates (butanoate, galactose) and fatty acids metabolism, antibiotics biosynthesis, proteosome and immune system signaling.

CONCLUSION

These observations suggest significant variations in diversity, relative abundance and functional potential of oral microbiota of TB patients compared to healthy controls thereby suggesting potential role of oral bacterial dysbiosis in TB pathogenesis. However, longitudinal studies using powerful metagenomic and transcriptomic approaches are crucial to more fully understand and confrim these findings.