Smoking and microbiome in oral, airway, gut and some systemic diseases

Artesunate ameliorates diabetic xerostomia in rats through regulating oral microbiota and metabolic profile in salivary gland based on NF-κB/NLRP3 signaling pathway

BACKGROUND

Artemisia annua. L, as a valuable Chinese medicine, has been applied for millennia in China. Its major active ingredient, artemisinin, has demonstrated diverse pharmacological properties, including anti-inflammatory, antioxidant, and anti-diabetic effects. Recent studies suggest that artesunate (ART), an artemisinin derivative, exhibits promising therapeutic effects on diabetic complications. Nevertheless, the role and underlying mechanisms of ART in the treatment of diabetic xerostomia (DX) remain unclear.

AIM

This study aimed to elucidate the effects of ART on DX in a type 2 diabetes mellitus (T2DM) rat model, primarily from the perspective of oral microbiota and salivary gland (SG) metabolism, and to further explore potential mechanisms involved.

METHODS

Various assessments including blood levels, insulin resistance (IR), saliva flow rate, as well as histological analyses through hematoxylin and eosin and Masson staining were performed to verify the reliability of DX model and protective effects of ART on the DX. Untargeted metabolomics and 16S rDNA sequencing were employed to respectively evaluate effects of ART on metabolite changes in SG and oral microbiota in the DX rats. Network pharmacology was employed to predict key pathways and targets with critical roles in ART's therapeutic effect on DX. Additionally, molecular docking and molecular dynamics (MD) simulations were utilized to evaluate interactions between ART and the identified key pathway targets. Surface plasmon resonance (SPR) experiment was performed to verify our computational predictions. Finally, molecular biology experiments were conducted to further validate the identified key pathway targets.

RESULTS

ART treatment ameliorated the hyperglycemia, IR and hyposalivation, and ameliorated pathological changes and oxidative stress of SGs in the DX rats. Besides, 16S rDNA sequencing suggested that ART alleviated the perturbation of oral microbiota (such as Veillonella, Lactobacillus, Clostridium sensu stricto 1, Escherichia-Shigella, and Dubosiella). Untargeted metabolomics revealed that steroid hormone biosynthesis, taurine and hypotaurine metabolism of SGs in the DX rats were partially corrected by ART treatment. Correlation analysis demonstrated an obvious association between the oral microbiota species and SG metabolites. Network pharmacology analysis identified NF-κB pathway as a critical pathway of ART in treating DX. Meanwhile, molecular docking and MD simulation suggested stable binding of ART to NF-κB/NLRP3 pathway targets, particularly NLRP3. Furthermore, SPR confirmed a stable binding of ART to NLRP3, a key target in the NF-κB/NLRP3 pathway. Oxidative stress indicators involved in NF-κB pathway, including MDA and SOD levels, were significantly reduced after ART intervention. Western blotting and qRT-PCR experiments further revealed that ART inhibited increase of NF-κB/NLRP3 pathway related targets expression, including NF-κB, NLRP3, Caspase1, IL-1β, IL-18, TNF-α, and IL-6 in the SGs of DX rats.

CONCLUSION

ART exerted beneficial therapeutic effects on DX by modulating oral microbiota dysbiosis and restoring SG's metabolic profiles, and inhibiting activation of NF-κB/NLRP3 pathway, suggesting its potential novel application in DX treatment.

Trimethylamine N-Oxide and Smoking Are Associated With the Progression of Thromboangiitis Obliterans

INTRODUCTION

Thromboangiitis obliterans (TAO) is potentially associated with smoking, although its precise pathogenesis remains unclear. Trimethylamine N-oxide (TMAO) has been implicated in the induction of various cardiovascular and cerebrovascular diseases. However, the role of TMAO in TAO has not been reported. This study aimed to investigate the relationship between smoking, TMAO, and TAO.

MATERIALS AND METHODS

Thirty-three patients diagnosed with TAO and hospitalized for treatment between January 2018 and July 2024 were included in the study. Healthy smokers (n = 38) and nonsmokers (n = 35) were randomly recruited and matched for age, sex, and education level as controls. Subsequently, we analyzed their clinical characteristics, levels of TMAO, and immune and inflammatory markers.

RESULTS

Patients with TAO exhibited significantly higher levels of TMAO, Toll-like receptor 4 (TLR4), receptor for advanced glycation end products, interleukin (IL)-1β, IL-18, tumor necrosis factor-alpha, high mobility group box 1, nuclear factor-κB (NF-κB), and phosphorylated NF-κB (pNF-κB) than those in the smoking and nonsmoking control groups (all P < 0.05). The smoking control group also exhibited significantly higher levels of TMAO, TLR4, IL-1β, NF-κB, and pNF-κB (all P < 0.05) than the nonsmoking control group. TMAO, IL-1β, and tumor necrosis factor-alpha levels were significantly higher in the underage smoking group (all P < 0.05) than in the adult smoking group. The level of TMAO was significantly correlated with the Rutherford classification in patients with TAO, patients' smoking status (including total years of smoking and average daily cigarette consumption), and immune and inflammatory markers (all P < 0.05).

CONCLUSIONS

These findings indicate that gut microbiota plays a significant role in the pathogenesis of TAO. TMAO is likely involved in the pathogenesis and progression of TAO, with smoking acting as a contributing factor. The underlying mechanism may involve the activation of immune-inflammatory pathways, specifically the high mobility group box 1-receptor for advanced glycation end products/TLR4-NF-κB pathway.

Lifestyles associated with complete tooth loss in elderly people in Brazil, 2019

OBJECTIVE

This study aimed to assess types of lifestyle that may contribute to total tooth loss in the elderly.

METHODS

This is a cross-sectional and population-based study, having as its target population elderly individuals aged 60 years or older. We used the database of the most recent edition of the National Health Survey, conducted in Brazil in 2019. Initially, the chi-square test was used and then the prevalence ratios were adjusted using the Poisson multiple regression model in order to identify associations between the variables.

RESULTS

The final sample analyzed consisted of 22,728 elderly individuals. Prevalence of complete tooth loss was 31.7% (95% confidence interval [95%CI] 31.1; 32.3). Multivariate analysis revealed that this condition was higher in females (p-value<0.001; prevalence ratio [PR] 1.05; 95%CI 1.04; 1.07), in the oldest old (p-value<0.001; PR 1.54; 95%CI 1.43; 1.61), in those without formal education (p-value<0.001; PR 1.06; 95%CI 1.04; 1.08), in those without dental insurance (p-value<0.001; PR 1.07; 95%CI 1.05; 1.09), in smokers (p-value<0.001; PR 1.04; 95%CI 1.02; 1.06), in individuals who consume soft drinks with high sugar content (p-value<0.001; PR 1.05; 95%CI 1.03; 1.07) and in those who do not do physical activities (p-value<0.001; PR 1.05; 95%CI 1.03; 1.06).

CONCLUSION

We concluded that complete tooth loss was greater in elderly people with unfavorable socioeconomic conditions, those who smoke, those who consume soft drinks with high sugar content and those who do not do physical activities regularly.

Lung Microbiome in Autoimmune-Associated Interstitial Lung Disease

The lung microbiome is a diverse mucosal environment that has been shown to be implicated in the pathogenesis of various chronic lung diseases including insterstitial lung diseases (ILD) such as idiopathic pulmonary fibrosis (IPF). ILD is a well-established manifestation of several types of autoimmune diseases. This review will highlight recent work exploring the role of the lung microbiome in the pathogenesis of autoimmune-related ILD.

Gut Microbiome Signature in Predisease Phase of Inflammatory Bowel Disease: Prediction to Pathogenesis to Prevention

Advances in understanding the pathogenesis of inflammatory bowel disease (IBD) point toward a key role of the gut microbiome. We review the data describing the changes in the gut microbiome from IBD case-control studies and compare these findings with emerging data from studies of the preclinical phase of IBD. What is apparent is that assessing changes in the composition and function of the gut microbiome during the preclinical phase helps address confounding factors, such as disease activity and drug therapy, which can directly influence the gut microbiome. Understanding these changes in the predisease phase provides a means of predicting IBD in high-risk populations and offers insights into possible mechanisms involved in disease pathogenesis. Finally, we discuss strategies to use this information to design interventions aimed at modulating the microbiome as a means of preventing or delaying the onset of IBD.

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.

Nasal production of IL-26 involving T cells in smokers with and without chronic obstructive pulmonary disease

BACKGROUND

Novel specific therapy in chronic obstructive pulmonary disease (COPD) will require accessible targets for endotyping to identify responsive patients. It is therefore of interest that IL-26 in the bronchoalveolar space is enhanced and associates with bronchoalveolar pathology among long-term smokers (LTS) with and without COPD.

OBJECTIVE

We determined whether IL-26 in the nasal cavity can be produced by T cells and associates with bronchoalveolar pathology and clinical symptoms in LTS with and without COPD.

METHODS

We characterized LTS with and without COPD plus healthy nonsmokers by radiology, spirometry, modified Medical Research Council scale, and St George Respiratory Questionnaire. We determined extracellular IL-26 concentrations (via ELISA) in nasal (NAL) and bronchoalveolar lavage (BAL) samples, BAL neutrophil counts, and NAL IL-26+ T-cell expression (via flow cytometry).

RESULTS

The NAL IL-26 concentrations were higher in LTS with COPD than in healthy nonsmokers. These enhanced IL-26 concentrations displayed a positive correlation with forced expiratory volume in 1 second/forced vital capacity ratio. The IL-26 protein was expressed in CD4+ and CD8+ T cells, but only a small portion of these cells coexpressed IL-15, IL-17A, or IL-22 in LTS with COPD. In this group, IL-26+ CD3+ T cells displayed a negative correlation with forced expiratory volume in 1 second, as did with extracellular NAL IL-26 concentrations. The relative mean fluorescence intensity for CD8+ T cells displayed a negative correlation with modified Medical Research Council and St George Respiratory Questionnaire score.

CONCLUSION

In the nasal cavity, IL-26 can be produced by local T cells. This IL-26 reflects bronchoalveolar pathology and clinical symptoms, thereby constituting an accessible target with potential for clinically relevant endotyping in COPD.

Contamination rates in serially sampled sputum specimens obtained during tuberculosis treatment to capture culture conversion

Sputum cultures are the gold standard for tuberculosis (TB) diagnosis and treatment monitoring. However, cultures in MGIT liquid media are susceptible to microbial contamination, often rendering them uninterpretable. Research has shown that maintaining strict cold chains and supervised sample collection can reduce contamination rates, but few longitudinal studies with weekly sampling have explored this. Here we evaluated whether (1) the time between specimen collection and laboratory processing and (2) unsupervised specimen collection are associated with contamination rates. Additionally, we estimated contamination rates over the first 12 weeks of treatment and assessed clinical and behavioral predictors of contamination. We collected 3155 sputum specimens from 301 participants undergoing TB treatment. Contamination was lowest (12.3%) at treatment initiation, increased over the first few weeks, and stabilized around 30% from week 8 onwards. Samples collected without supervision were more likely to be contaminated at treatment initiation (p=0.048) and over the 12 weeks (p=0.028). We observed an inverse relationship between smear grade and contamination risk throughout the sampling period. These findings underscore the importance of supervised sputum collection to reduce contamination and provide ways to enhance the clinical and research value of weekly cultures, particularly those collected later in treatment. This is especially relevant for community-collected specimens used in monitoring treatment response.

Smoking-induced gut microbial dysbiosis mediates cancer progression through modulation of anti-tumor immune response

Cigarette smoke exposure (CSE) increases the risk for a plethora of cancers. Recent evidence indicates that the gut microbiome can influence cancer progression by immune system modulation. Since CSE alters the gut microbiome, we hypothesized that the gut microbiome serves as a causative link between smoking and cancer growth. Through a combination of syngeneic animal models and fecal microbiota transplantation studies, we established an essential role for smoke-induced dysbiosis in cancer growth. 16s rRNA sequencing and liquid chromatography-mass spectrometry indicated a unique CSE-associated microbial and metabolomic signature. Immunophenotyping of tumor specimens and experiments in Rag1-KO and CD8-KO demonstrated that smoke-induced tumor growth requires functional adaptive immunity. Finally, utilizing gut microbial ablation strategies with broad- and narrow-spectrum antibiotics, we demonstrated the reversal of phenotypic effects of CSE. Our study provides evidence for gut microbiome as an actionable target to mitigate CSE-induced tumor promotion.

Smoking-related gut microbiota alteration is associated with obesity and obesity-related diseases: results from two cohorts with sibling comparison analyses

BACKGROUND

Individuals who smoke tend to have a lower body mass index (BMI) but face an increased risk of obesity-related diseases. This study investigates this paradox from the perspective of gut microbiota.

METHODS

We conducted microbiome analyses to identify smoking-related microbial genera and created a smoking-related microbiota index (SMI) using 16S rRNA sequencing data from 4000 male participants in WELL-China cohort and Lanxi cohort. We employed logistic regression to explore the association between SMI and obesity indices derived from dual-energy X-ray absorptiometry. Cox regression analyses were conducted to explore the association of SMI with incident of obesity-related diseases. To further control for unmeasured familial confounders, sibling comparison analyses were conducted using between-within (BW) model.

RESULTS

The smoking-related microbiota index (SMI) showed a positive association with BMI and other obesity indices. Further analyses revealed that SMI is linked to obesity-related diseases, with hazard ratios (95% confidence intervals) of 1.97 (1.41-2.75) for incident diabetes, 1.31 (1.01-1.71) for major adverse cardiovascular events, and 1.70 (1.05-2.75) for obesity-related cancers. Results from sibling comparison analyses reinforced these findings.

CONCLUSIONS

While smoking may reduce weight through various mechanisms, alterations in gut microbiota related to smoking are associated with weight gain. Further research is required to determine if changes in the smoking-related microbiome contribute to weight gain following smoking cessation.

Deciphering the tripartite interaction of urbanized environment, gut microbiome and cardio-metabolic disease

The world is experiencing a sudden surge in urban population, especially in developing Asian and African countries. Consequently, the global burden of cardio-metabolic disease (CMD) is also rising owing to gut microbiome dysbiosis due to urbanization factors such as mode of birth, breastfeeding, diet, environmental pollutants, and soil exposure. Dysbiotic gut microbiome indicated by altered Firmicutes to Bacteroides ratio and loss of beneficial short-chain fatty acids-producing bacteria such as Prevotella, and Ruminococcus may disrupt host-intestinal homeostasis by altering host immune response, gut barrier integrity, and microbial metabolism through altered T-regulatory cells/T-helper cells balance, activation of pattern recognition receptors and toll-like receptors, decreased mucus production, elevated level of trimethylamine-oxide and primary bile acids. This leads to a pro-inflammatory gut characterized by increased pro-inflammatory cytokines such as tumour necrosis factor-α, interleukin-2, Interferon-ϒ and elevated levels of metabolites or metabolic endotoxemia due to leaky gut formation. These pathophysiological characteristics are associated with an increased risk of cardio-metabolic disease. This review aims to comprehensively elucidate the effect of urbanization on gut microbiome-driven cardio-metabolic disease. Additionally, it discusses targeting the gut microbiome and its associated pathways via strategies such as diet and lifestyle modulation, probiotics, prebiotics intake, etc., for the prevention and treatment of disease which can potentially be integrated into clinical and professional healthcare settings.

Current Smoker: A Clinical COPD Phenotype Affecting Disease Progression and Response to Therapy

Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition of the lungs, characterized by chronic respiratory symptoms, primarily dyspnea, cough, and sputum production, due to airway and/or alveoli abnormalities that cause persistent, and often progressive, airflow obstruction. Although the underlying mechanisms responsible for COPD remain poorly understood, over the last several decades, clinical phenotypes and endotypes have been suggested. These include frequent exacerbator and eosinophilic groups that guide tailored therapies for patients with that clinical expression. In the developed world, smoking is the main known cause of COPD, responsible for ~80% of cases. Active smokers have more severe disease, with more rapid lung function decline and impaired quality of life, than former smokers. Unfortunately, smoking is still highly prevalent. Rates range between 3% and 37% globally, with factors including sex, age, race, education level, and geography influencing the rate of addiction. Importantly, several studies have shown that smoking detrimentally affects treatment efficacy of COPD medications; this is particularly true of inhaled corticosteroids and macrolides. In this review, we discuss the effects of smoking on the pathophysiology of COPD and the clinical impact of smoke exposure in patients with COPD. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Human reference microbiome profiles of different body habitats in healthy individuals

Introduction

This study aimed to establish the human reference microbiome profiles in blood, saliva, and stool of healthy individuals, serving as reference values to identify microbiome alterations in human disease.

Methods

The study population consisted of a reference group of healthy adults and a second group consisting of adults with periodontal disease (PD). Blood, saliva, and stool samples were subjected to 16S rRNA sequencing. Reference intervals of alpha diversity indices were calculated. To reduce the effects of inherent limitations of microbiome data, the taxonomic profiles of the reference group were estimated as log-scaled fold change (logFC) in the abundance of microorganisms between two habitats within the subjects.

Results

For stool and saliva microbiomes, differences in the abundances of Firmicutes, Patescibacteria, and Verrucomicrobia distinguished healthy from PD subjects (95% confidence interval (CI) of logFC: [-0.18, 0.31], [-1.19, -0.34], and [-3.68, -2.90], respectively). Differences in the abundances of Cyanobacteria, Fusobacteria, and Tenericutes in stool and blood microbiome of healthy subjects fell within 95% CI of logFC [-0.38, 0.61], [-4.14, -3.01], and [1.66, 2.77], respectively. In saliva and blood, differences in the abundances of Epsilonbacteraeota, Firmicutes, Fusobacteria, and Proteobacteria could be used as reference values (95% CI of logFC: [-3.67, -2.47], [-0.35, 0.49], [-4.59, -3.26], and [-1.20, 0.07], respectively).

Discussion

As the reference microbiome profiles could discern healthy subjects and individuals with PD, a relatively mild disease state, they can be applied as reference values representing the healthy status of the microbiome and for screening of disease states, preferably in preclinical stages.

Microbial dysbiosis in periodontitis and peri-implantitis: pathogenesis, immune responses, and therapeutic

The oral microbiome comprises over 700 distinct species, forming complex biofilms essential for maintaining oral and systemic health. When the microbial homeostasis in the periodontium is disrupted, pathogens within the biofilm can cause periodontitis and peri-implantitis, inducing host immune responses. Understanding the role of microbial communities and the immune mechanisms in oral health and disease is crucial for developing improved preventive, diagnostic and therapeutic strategies. However, many questions remain about how changes in bacterial populations contribute to the development and progression of these conditions. An electronic and manual literature search was conducted using PubMed, Excerpta Medica, Frontiers Reports and the Wiley Online Library databases for relevant articles. Data from these publications were extracted and the overall findings were summarized in a narrative manner. The variations in microbial communities and immune responses of periodontitis and peri-implantitis are explored. Dysbiosis of the subgingival microbiome-characterized by an increase in pathogenic bacteria such as Porphyromonas gingivalis, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans-plays a pivotal role in the initiation and progression of periodontitis. As for peri-implantitis, alterations include a higher abundance of opportunistic pathogens and reduced microbial diversity around implants. Moreover, oral dysbiosis potentially influencing systemic health through immune-mediated pathways. Regional immunity of periodontium involving neutrophils, T helper cells-17, and immune-related cytokines is crucial for maintaining periodontal homeostasis and responding to microbial imbalances. Additionally, the impact of non-mechanical treatments-such as probiotics and laser therapy-on the oral microbiome is discussed, demonstrating their potential in managing microbial dysbiosis. These findings underscore that bacterial dysbiosis is a central factor in the development of periodontitis and peri-implantitis. Maintaining microbial balance is essential for preventing these diseases, and interventions targeting the microbiome could enhance treatment outcomes. Strategies focusing on controlling pathogenic bacteria, modulating immune responses, and promoting tissue regeneration are key to restoring periodontal stability. Further research is needed to clarify the mechanisms underlying the transition from peri-implant mucositis to peri-implantitis and to optimize prevention and treatment approaches, considering the complex interactions between the microbiome and host immunity.

The role of the microbiome in head and neck squamous cell cancers

The human microbiome has garnered tremendous interest in the field of oncology, and microbiota studies in head and neck oncology has also flourished. Given the increasing incidence and mortality of HNSCC, as well as the suboptimal outcomes of available treatments, there is an urgent need for innovative approaches involving the microbiome. This review evaluates the intricate relationship between the microbiome and HNSCC, highlighting the potential of the microbiome as a marker for cancer detection, its role in malignancy, and its impact on the efficacy of conventional treatments like chemotherapy and radiotherapy. The review also explores the effects of treatment modalities on the microbiome and discusses the potential of microbiome alterations to predict and influence treatment toxicities such as mucositis and xerostomia. Further research is warranted to characterize the microbiome-HNSCC association, which holds promise for advancing early diagnosis, enhancing prognostic accuracy, and personalizing treatment strategies to improve patient outcomes. The exploration of the microbiome in clinical trials indicates a burgeoning subject of microbiome-focused therapies, heralding a new frontier in most cancer care.

The implication of microbiome in lungs cancer: mechanisms and strategies of cancer growth, diagnosis and therapy

Available evidence illustrates that microbiome is a promising target for the study of growth, diagnosis and therapy of various types of cancer. Lung cancer is a leading cause of cancer death worldwide. The relationship of microbiota and their products with diverse pathologic conditions has been getting large attention. The novel research suggests that the microbiome plays an important role in the growth and progression of lung cancer. The lung microbiome plays a crucial role in maintaining mucosal immunity and synchronizing the stability between tolerance and inflammation. Alteration in microbiome is identified as a critical player in the progression of lung cancer and negatively impacts the patient. Studies suggest that healthy microbiome is essential for effective therapy. Various clinical trials and research are focusing on enhancing the treatment efficacy by altering the microbiome. The regulation of microbiota will provide innovative and promising treatment strategies for the maintenance of host homeostasis and the prevention of lung cancer in lung cancer patients. In the current review article, we presented the latest progress about the involvement of microbiome in the growth and diagnosis of lung cancer. Furthermore, we also assessed the therapeutic status of the microbiome for the management and treatment of lung cancer.

Systematic review and meta-analysis on the prevalence and risk factors of oral frailty among older adults

Objectives

The present study aim to systematically review the prevalence and influencing factors of oral frailty in older people.

Methods

A search strategy was developed and implemented to systematically review literature across PubMed, Embase, Web of Science, MEDLINE (via EBSCOhost), CINAHL, the Cochrane Library, Scopus, China Knowledge Resource Integrated Database (CNKI), Wanfang Data, Chinese Biomedical Database (CBM), and Weipu Database (VIP), in accordance with the PRISMA 2020 guidelines. Our search encompassed studies published up to June 28, 2024, that investigated the prevalence or risk factors of oral frailty among older adults. Literature screening, data extraction, and quality assessment were independently performed by two researchers, followed by data analysis using Stata 17 software. This study has been registered with PROSPERO.

Results

A total of 35 studies involving 202,864 participants were analyzed. The overall prevalence of oral frailty among older adults was 34.0% (95% CI: 27.9-40.1%, I 2 = 99.7%, p < 0.001). Subgroup analyses revealed statistically significant differences in the prevalence of oral frailty among different assessment tools and age groups (p < 0.05). Univariate meta-regression analysis indicated that the age was related to heterogeneity in the study (p < 0.05). Factors such as age, gender, physical frailty, pre-frailty, and unattached were identified as key risk factors for oral frailty in older adults (all p < 0.05).

Conclusion

The incidence of oral frailty among older adults is notably high and influenced by a variety of factors. Healthcare professionals are encouraged to actively implement preventive and treatment measures addressing the controllable factors associated with oral frailty. Such proactive efforts are essential for early identification of high-risk individuals, which can help reduce the prevalence of oral frailty among older adults and enhance their quality of life.

Systematic Review Registration

PROSPERO (CRD42023488653: https://www.crd.york.ac.uk/prospero/).

Potential roles of cigarette smoking on gut microbiota profile among Chinese men

BACKGROUND

Cigarette smoking is posited as a potential factor in disrupting the balance of the human gut microbiota. However, existing studies with limited sample size have yielded inconclusive results.

METHODS

Here, we assessed the association between cigarette smoking and gut microbial profile among Chinese males from four independent studies (N total = 3308). Both 16S rRNA and shotgun metagenomic sequencing methods were employed, covering 206 genera and 237 species. Microbial diversity and abundance were compared among non-smokers, current smokers, and former smokers.

RESULTS

Actinomyces[g], Atopobium[g], Haemophilus[g], Turicibacter[g], and Lachnospira[g] were found to be associated with smoking status (current smokers vs. non-smokers). Metagenomic data provided a higher resolution at the species level, particularly for the Actinomyces[g] branch. Additionally, serum γ-glutamylcysteine (γ-Glu-Cys) was found to have a potential role in connecting smoking and Actinomyces[g]. Furthermore, we revealed putative mediation roles of the gut microbiome in the associations between smoking and common diseases including cholecystitis and type 2 diabetes.

CONCLUSIONS

We characterized the gut microbiota profile in male smokers and further revealed their potential involvement in mediating the impact of smoking on health outcomes. These findings advance our understanding of the intricate association between cigarette smoking and the gut microbiome.

A human oral commensal-mediated protection against Sjögren's syndrome with maintenance of T cell immune homeostasis and improved oral microbiota

Sjögren's syndrome (SS) is a prevalent systemic autoimmune disease with substantial impacts on women's health worldwide. Although oral Haemophilus parainfluenzae is reduced in SS, its significance remains unclear. This study aimed to elucidate the pathophysiological role of H. parainfluenzae in SS. Reduced salivary H. parainfluenzae levels in SS patients were confirmed through quantitative PCR. Oral H. parainfluenzae inoculation in NOD mice alleviated focal sialadenitis, improved salivary function, and reduced IFN-γ+CD3+ and IFN-γ+CD8+ T cells in salivary gland-draining lymph nodes, maintaining immune homeostasis against a biased type 1 response. Inoculation also enhanced salivary microbiota diversity, balanced the Firmicutes-to-Proteobacteria ratio, and reduced the overwhelming presence of Pseudomonas mendocina. In vitro, H. parainfluenzae-preconditioned A253 cells limited CD8 T cell expansion with reduced IFN-γ production. These findings suggest that H. parainfluenzae improves oral microbial diversity, promotes homeostatic T-cell immunity, and protects against SS, supporting its potential as a next-generation probiotic.

Elimination of oral foci of infection might lead to clinical improvement of Graves' orbitopathy

PURPOSE

Graves' disease (GD) and Graves' orbitopathy (GO) are multifactorial disorders with links to the gut microbiome and autoimmunity. It is observed that patients with GD exhibit altered gut microbiome diversity. However, little is known about the role of oral microbiota in GD and GO. This study aims to investigate the impact of oral health and oral sanitation on the clinical course of GO in patients disqualified from glucocorticoid treatment due to oral infections.

METHODS

We reviewed 188 admissions of 127 patients with GO, hospitalized in a tertiary university hospital. Clinical, biochemical, imaging, ophthalmological, and oral health assessment data from each admission were analyzed. Patients excluded from the glucocorticoids (GCs) therapy due to oral foci of infection had the clinical activity score (CAS) reassessed after three months, and they were divided into two groups: with and without improvement.

RESULTS

Finishing dental treatment in the meantime was the only factor significantly correlated with improvement in these patients (p = 0.041). The secondary finding was that anti-thyroid peroxidase antibodies titer was significantly higher in the group with oral foci of infection considered as a contraindication for GCs (medians 28.50 vs 128.00; p = 0.026), and those patients were more likely to smoke than the group without oral issues (p = 0.024).

CONCLUSIONS

The results of our study suggest that monitoring and treating oral diseases may be pertinent in patients with GO and might serve as a supportive treatment strategy for managing the condition.

KEY MESSAGES

What is known: There is a recognized link between gut dysbiosis and the autoimmune processes in Graves' Disease (GD) and Graves' Orbitopathy (GO).

WHAT IS NEW

Elevated levels of TPOAb have been observed in patients with GO who also have oral foci of infection. Dental treatment has been shown to lead to significant clinical improvements in patients with GO. Maintaining oral hygiene might serve as a supportive treatment strategy for managing GO.

Heterogeneity and individualized therapy for eosinophilic granulomatosis with polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA), as a heterogeneous component of antineutrophil cytoplasmic antibody-associated vasculitis, may be induced by a series of environmental and genetic factors, involved with a variety of immune cells and immune components, and presented with various clinical manifestations, with multiple organs and systems (respiratory, skin, heart, kidney, nerve, etc.) involved. The choice of glucocorticoid (GC) dosage and immunosuppressant in traditional treatment strategies varies greatly from individual to individual and is not universally applicable in all the EGPA phenotype spectrum, especially in relapsing or refractory diseases. With the understanding of the heterogeneity of EGPA, a variety of therapeutic approaches are emerging and improving the traditional treatment model. In this review, we summarized the heterogeneity of EGPA etiology and pathogenesis. Clinical and pathological manifestations of the same organ involved also show significant differences and there are even gender differences. Biological treatments that mainly target type 2 inflammatory pathways are widely used in clinical practice for remission induction and maintenance of EGPA. Targeted biological therapy has shown excellent performance in reducing GC dosage and controlling symptoms and recurrence. However, a large number of high-quality randomized controlled studies are still under research for relapsing or refractory EGPA with special organ involvement. We believe that EGPA has a highly heterogeneous phenotype spectrum, and the treatment patterns targeting key molecules in the pathogenesis are of great value for individual treatment of EGPA.

The Oral Microbiome: A Key Determinant of Oral Health

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

Cigarette smoke-induced disordered microbiota aggravates the severity of influenza A virus infection

Cigarette smoke (CS) promotes the development of chronic pulmonary disease and has been associated with increased risk for influenza-related illness. Here, we directly addressed the impact of CS disordered microbiota on the severity of influenza A virus (IAV) infection. Specific and opportunistic pathogen-free (SOPF) C57BL/6J mice were exposed to CS or room air (RA) for 5.5 months. Each exposed mouse was then cohoused with a group of recipient germ-free (GF) mice for 1 month for microbial transfer. Colonized GF mice were then infected intranasally with IAV and disease development was monitored. Upper and lower airway and fecal microbiota were longitudinally investigated by 16S rRNA gene sequencing and bacterial cultures in donor and recipient mice. The bacterial family Streptococcaceae accounted for the largest difference between CS- and RA-exposed microbiota in the oropharynx. Analysis of the oropharynx and fecal microbiota indicated an efficient transfer to coprophagic recipient mice, which replicated the differences in microbiota composition observed in donor mice. Subsequent IAV infection revealed significantly higher weight loss for CS microbiota recipient mice at 8-10 days post infection (dpi) compared to control recipient mice. In addition, H1N1 infection inflicted substantial changes in the microbiota composition, especially at days 4 and 8 after infection. In conclusion, mice with a CS-associated microbiota suffer from higher disease severity upon IAV infection compared to mice colonized with a normal SOPF microbiota. Our data suggest that independently of CS exposure and concomitant structural lung damage, microbial distortion due to CS exposure may impact the severity of IAV disease course.IMPORTANCEIt has been reported that chronic exposure to CS is associated with a disordered microbiota composition. In this study, we colonized germ-free (GF) mice with the microbiota from SOPF mice which were chronically exposed to CS or RA. This allowed disentangling the effect of the disordered microbiota from the immune-modulating effects of actual CS exposure. We observed a successful transfer of the microbiotas after cohousing including specific microbiota differences induced by CS exposure in formerly GF mice, which were never exposed to CS. We then investigated the effects of IAV infection on the disease course and microbiotas of formerly GF mice. We found that mice with CS-associated microbiota reveal worse disease course compared to the control group. We hypothesize that CS-induced disordering of the microbiota may, indeed, impact the severity of influenza A disease.

Influence of gut and lung dysbiosis on lung cancer progression and their modulation as promising therapeutic targets: a comprehensive review

Lung cancer (LC) continues to pose the highest mortality and exhibits a common prevalence among all types of cancer. The genetic interaction between human eukaryotes and microbial cells plays a vital role in orchestrating every physiological activity of the host. The dynamic crosstalk between gut and lung microbiomes and the gut-lung axis communication network has been widely accepted as promising factors influencing LC progression. The advent of the 16s rDNA sequencing technique has opened new horizons for elucidating the lung microbiome and its potential pathophysiological role in LC and other infectious lung diseases using a molecular approach. Numerous studies have reported the direct involvement of the host microbiome in lung tumorigenesis processes and their impact on current treatment strategies such as radiotherapy, chemotherapy, or immunotherapy. The genetic and metabolomic cross-interaction, microbiome-dependent host immune modulation, and the close association between microbiota composition and treatment outcomes strongly suggest that designing microbiome-based treatment strategies and investigating new molecules targeting the common holobiome could offer potential alternatives to develop effective therapeutic principles for LC treatment. This review aims to highlight the interaction between the host and microbiome in LC progression and the possibility of manipulating altered microbiome ecology as therapeutic targets.

The salivary microbiome and oral health status in HBeAg-negative chronic hepatitis B

Background/purpose

Dysbiosis of oral microbiota has been reported in late stage of chronic hepatitis B (CHB) infection with cirrhosis. CHB is characterized by the constant virus-induced liver injury which may lead to liver cirrhosis and hepatocellular carcinoma (HCC). However, some patients show normal liver function without antiviral treatment, associating with favourable prognosis. The oral microbiota composition and oral health status in these patients is unidentified.

Materials and methods

The study focuses on the composition of oral microbiota and oral health status in individuals with CHB and HBV vaccinees as controls. The CHB patients were hepatitis B 'e' antigen (HBeAg)-negative, with or without elevated liver enzyme increase at time of sampling, The 16S rRNA high-throughput sequencing and bioinformatic analysis were applied to investigate oral bacterial diversity, and oral examination including decay-missing-filled teeth (DMFT) index, probing depth (PD) and mucosal status was performed, along with oral health questionnaire, to assess the oral health status in CHB patients and healthy controls.

Results

Our results indicate that their oral microbiome compositions are not significantly different though some have increased ALT/AST liver enzyme levels at the time of sampling, compared to the healthy control participants who are vaccinated e.g. protected from this viral disease. CHB patients here bore a good oral health status and life-style habits as comparing to healthy controls.

Conclusion

These findings suggest that a health-associated salivary microflora is present in CHB without severe liver injury. Continued regular dental health and lifestyle support in liver disease patients is therefore justified.

Causal effects of gut microbiota on gout and hyperuricemia: insights from genome-wide Mendelian randomization, RNA-sequencing, 16S rRNA sequencing, and metabolomes

BACKGROUND

This study investigated the causal relationship between gut microbiota (GM), serum metabolome, and host transcriptome in the development of gout and hyperuricemia (HUA) using genome-wide association studies (GWAS) data and HUA mouse model experiments.

METHODS

Mendelian randomization (MR) analysis of GWAS summary statistics was performed using an inverse variance weighted (IVW) approach to determine or predict the causal role of the GM on gout. The HUA mouse model was used to characterize changes in the gut microbiome, host metabolome, and host kidney transcriptome by integrating cecal 16S rRNA sequencing, untargeted serum metabolomics, and host mRNA sequencing.

RESULTS

Our analysis demonstrated causal effects of seven GM taxa on gout, including genera of Ruminococcus, Odoribacter, and Bacteroides. Thirty eight immune cell traits were associated with gout. Dysbiosis of Dubosiella, Lactobacillus, Bacteroides, Alloprevotella, and Lachnospiraceae_NK4A136_group genera were associated with changes in the serum metabolites and kidney transcriptome of the HUA model mice. The changes in the gut microbiome of the HUA model mice correlated significantly with alterations in the levels of serum metabolites such as taurodeoxycholic acid, phenylacetylglycine, vanylglycol, methyl hexadecanoic acid, carnosol, 6-aminopenicillanic acid, sphinganine, p-hydroxyphenylacetic acid, pyridoxamine, and de-o-methylsterigmatocystin, and expression of kidney genes such as CNDP2, SELENOP, TTR, CAR3, SLC12A3, SCD1, PIGR, CD74, MFSD4B5, and NAPSA.

CONCLUSION

Our study demonstrated a causal relationship between GM, immune cells, and gout. HUA development involved alterations in the vitamin B6 metabolism because of GM dysbiosis that resulted in altered pyridoxamine and pyridoxal levels, dysregulated sphingolipid metabolism, and excessive inflammation.

Dietary Habits, Nutrition Intake, and Alcohol Consumption Based on Types of Smoking and Smoking Status: A Cross-Sectional Study

BACKGROUND/OBJECTIVES

Smoking increases the risk for multiple lifestyle-related diseases. In Japan, consumption of heated tobacco products (HTPs), a novel cigarette type, is rising. However, no studies have yet compared dietary habits among HTP smokers. This study assessed food and nutrient intake and alcohol consumption by smoking status (non-smokers, cigarette smokers, HTP smokers).

METHODS

This cross-sectional study included 237 HTP smokers, 242 cigarette smokers, and 178 non-smokers (50% each male and female). The Brief Self-Administered Diet History Questionnaire was administered as a nutritional survey, and smokers were asked about their smoking status, including smoking history and the number of puffs smoked per day.

RESULTS

A significantly higher intake of meat was seen in HTP smokers than in cigarette smokers (p = 0.038), and HTP smokers showed the lowest intake of vitamin D in all groups. HTP and cigarette smokers had a lower intake of certain vitamins, minerals, and dietary fiber compared with non-smokers. The rate of habitual drinkers (at least one drink a month) and their alcohol consumption (g/day) were significantly lower in non-smokers (58%, 1.3 g) than in HTP smokers (67%, 4.8 g) and cigarette smokers (70%, 7.1 g) (p = 0.031). Additionally, after adjusting for sex and smoking status in a multiple regression analysis, the number of puffs was a significant contributor to alcohol intake in HTP smokers (β = 0.296, p < 0.001).

CONCLUSIONS

This study identified significant dietary, nutritional, and alcohol consumption differences based on smoking status, underscoring the need to consider both diet and smoking type in nutritional counseling and smoking cessation guidance.

The Effect of Dietary Types on Gut Microbiota Composition and Development of Non-Communicable Diseases: A Narrative Review

INTRODUCTION

The importance of diet in shaping the gut microbiota is well established and may help improve an individual's overall health. Many other factors, such as genetics, age, exercise, antibiotic therapy, or tobacco use, also play a role in influencing gut microbiota.

AIM

This narrative review summarizes how three distinct dietary types (plant-based, Mediterranean, and Western) affect the composition of gut microbiota and the development of non-communicable diseases (NCDs).

METHODS

A comprehensive literature search was conducted using the PubMed, Web of Science, and Scopus databases, focusing on the keywords "dietary pattern", "gut microbiota" and "dysbiosis".

RESULTS

Both plant-based and Mediterranean diets have been shown to promote the production of beneficial bacterial metabolites, such as short-chain fatty acids (SCFAs), while simultaneously lowering concentrations of trimethylamine-N-oxide (TMAO), a molecule associated with negative health outcomes. Additionally, they have a positive impact on microbial diversity and therefore are generally considered healthy dietary types. On the other hand, the Western diet is a typical example of an unhealthy nutritional approach leading to an overgrowth of pathogenic bacteria, where TMAO levels rise and SCFA production drops due to gut dysbiosis.

CONCLUSION

The current scientific literature consistently highlights the superiority of plant-based and Mediterranean dietary types over the Western diet in promoting gut health and preventing NCDs. Understanding the influence of diet on gut microbiota modulation may pave the way for novel therapeutic strategies.

From bench to bedside: an interdisciplinary journey through the gut-lung axis with insights into lung cancer and immunotherapy

This comprehensive review undertakes a multidisciplinary exploration of the gut-lung axis, from the foundational aspects of anatomy, embryology, and histology, through the functional dynamics of pathophysiology, to implications for clinical science. The gut-lung axis, a bidirectional communication pathway, is central to understanding the interconnectedness of the gastrointestinal- and respiratory systems, both of which share embryological origins and engage in a continuous immunological crosstalk to maintain homeostasis and defend against external noxa. An essential component of this axis is the mucosa-associated lymphoid tissue system (MALT), which orchestrates immune responses across these distant sites. The review delves into the role of the gut microbiome in modulating these interactions, highlighting how microbial dysbiosis and increased gut permeability ("leaky gut") can precipitate systemic inflammation and exacerbate respiratory conditions. Moreover, we thoroughly present the implication of the axis in oncological practice, particularly in lung cancer development and response to cancer immunotherapies. Our work seeks not only to synthesize current knowledge across the spectrum of science related to the gut-lung axis but also to inspire future interdisciplinary research that bridges gaps between basic science and clinical application. Our ultimate goal was to underscore the importance of a holistic understanding of the gut-lung axis, advocating for an integrated approach to unravel its complexities in human health and disease.

Gut-Brain Axis: Role of Microbiome, Metabolomics, Hormones, and Stress in Mental Health Disorders

The influence of gut microbiome, metabolites, omics, hormones, and stress on general and mental health is increasingly being recognized. Ancient cultures recognized the importance of diet and gut health on the overall health of an individual. Western science and modern scientific methods are beginning to unravel the foundations and mechanisms behind some of the ancient beliefs and customs. The gut microbiome, an organ itself, is now thought to influence almost all other organs, ranging from the brain to the reproductive systems. Gut microbiome, metabolites, hormones, and biological sex also influence a myriad of health conditions that range from mental health disorders, obesity, gastrointestinal disorders, and cardiovascular diseases to reproductive health. Here, we review the history and current understanding of the gut-brain axis bidirectional talk in various mental health disorders with special emphasis on anxiety and depressive disorders, whose prevalence has increased by over 50% in the past three decades with COVID-19 pandemic being the biggest risk factor in the last few years. The vagal nerve is an important contributor to this bidirectional talk, but other pathways also contribute, and most remain understudied. Probiotics containing Lactobacillus and Bifidobacterium species seem to have the most impact on improvement in mental health symptoms, but the challenge appears to be maintaining sustained levels, especially since neither Lactobacillus nor Bifidobacterium can permanently colonize the gut. Ancient endogenous retroviral DNA in the human genome is also linked to several psychiatric disorders, including depression. These discoveries reveal the complex and intricately intertwined nature of gut health with mental health disorders.

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.

The Effects of Nicotine Pouches and E-Cigarettes on Oral Microbes: A Pilot Study

It remains uncertain whether nicotine pouches and electronic cigarettes alter the oral environment and result in a high presence of periodontopathogenic bacteria in saliva, compared to that among cigarette users or non-tobacco users. In this study, saliva samples were collected from respondents using nicotine pouches, electronic cigarettes, and conventional cigarettes, alongside a control group of non-tobacco users. Polymerase chain reaction was used to identify clinical isolates of the following periodontal bacteria: Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Fusobacterium nucleatum, Fusobacterium periodonticum, Porphyromonas endodontalis, and Rothia mucilaginosa. The presence of some periodontal pathogens was detected in the saliva samples from users of nicotine pouches, electronic cigarettes, and conventional cigarettes but not in samples taken from the control group. Therefore, the initial results of this pilot study suggest that the presence of periodontopathogenic bacteria in the saliva of nicotine pouch and electronic cigarette users could alter the oral microbiome, leading to periodontal diseases. However, further quantitative investigation is needed.

Gut virome alterations in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the primary causes of mortality and morbidity worldwide. The gut microbiome, particularly the bacteriome, has been demonstrated to contribute to the progression of COPD. However, the influence of gut virome on the pathogenesis of COPD is rarely studied. Recent advances in viral metagenomics have enabled the rapid discovery of its remarkable role in COPD. In this study, deep metagenomics sequencing of fecal virus-like particles and bacterial 16S rRNA sequencing was performed on 92 subjects from China to characterize alterations of the gut virome in COPD. Lower richness and diversity of the gut virome were observed in the COPD subjects compared with the healthy individuals. Sixty-four viral species, including Clostridium phage, Myoviridae sp., and Synechococcus phage, showed positive relationships with pulmonary ventilation functions and had markedly declined population in COPD subjects. Multiple viral functions, mainly involved in bacterial susceptibility and the interaction between bacteriophages and bacterial hosts, were significantly declined in COPD. In addition, COPD was characterized by weakened viral-bacterial interactions compared with those in the healthy cohort. The gut virome showed diagnostic performance with an area under the curve (AUC) of 88.7%, which indicates the potential diagnostic value of the gut virome for COPD. These results suggest that gut virome may play an important role in the development of COPD. The information can provide a reference for the future investigation of diagnosis, treatment, and in-depth mechanism research of COPD.

IMPORTANCE

Previous studies showed that the bacteriome plays an important role in the progression of chronic obstructive pulmonary disease (COPD). However, little is known about the involvement of the gut virome in COPD. Our study explored the disease-specific virome signatures of patients with COPD. We found the diversity and compositions altered of the gut virome in COPD subjects compared with healthy individuals, especially those viral species positively correlated with pulmonary ventilation functions. Additionally, the declined bacterial susceptibility, the interaction between bacteriophages and bacterial hosts, and the weakened viral-bacterial interactions in COPD were observed. The findings also suggested the potential diagnostic value of the gut virome for COPD. The results highlight the significance of gut virome in COPD. The novel strategies for gut virome rectifications may help to restore the balance of gut microecology and represent promising therapeutics for COPD.

Effects of Laurus nobilis Leaf Extract (LAURESH®) on Oral and Gut Microbiota Diversity in Mice

BACKGROUND/AIM

The leaves of Laurus nobilis have been used for culinary purposes for many years and have recently been shown to have beneficial effects on human health by altering microbiota composition. However, the effects of L. nobilis on the diversity of microbiomes in the oral cavity and gut remain unknown. Therefore, in this study, we examined the effects of an extract of L. nobilis on the diversity of microbiomes in the oral cavity and gut in mice.

MATERIALS AND METHODS

C57BL/6J mice were randomly divided into two groups and fed a standard diet (SD) and a standard diet containing 5% LAURESH®, a laurel extract (SDL). After 10 weeks, oral swabs and fecal samples were collected. The bacterial DNA extracted from the oral swabs and feces was used for microbiota analysis using 16S rRNA sequencing. The sequencing data were analyzed using the Quantitative Insights into Microbial Ecology 2 in the DADA2 pipeline and 16S rRNA database.

RESULTS

The α-diversity of the oral microbiome was significantly greater in the SDL group than in the SD group. The β-diversity of the oral microbiome was also significantly different between the groups. Moreover, the taxonomic abundance analysis showed that five bacteria in the gut were significantly different among the groups. Furthermore, the SDL diet increased the abundance of beneficial gut bacteria, such as Akkermansia sp.

CONCLUSION

Increased diversity of the oral microbiome and proportion of Akkermansia sp. in the gut microbiome induced by L. nobilis consumption may benefit oral and gut health.

Bioactives of the essential oil from the leaves of Eugenia pyriformis Cambess (Myrtaceae) on the effects of tobacco

Introduction

Lung cancer is the most commonly diagnosed and the main cause of cancer death, usually related to cigarette smoking. Furthermore, the microbiota of people exposed to cigarette smoke can be modified, making it difficult to eliminate opportunistic microorganisms. The leaves of Eugenia pyriformis are a by-product of fruit production and, to date, there have been no studies addressing the antiproliferative, anti-inflammatory, and antimicrobial activities.

Objective

Investigate the antimicrobial, Nitric Oxide (NO)-production inhibition, and antiproliferative activities of the essential oil from E. pyriformis leaves and its possible effect on the treatment and prevention of damage caused by tobacco.

Methods

The essential oil (EO) was obtained by hydrodistillation (3 h). Its chemical composition was investigated by GC-MS. It was proposed to investigate antiproliferative activity against human tumor cell lines, namely, breast adenocarcinoma (MCF-7), lung (NCI-H460), cervical (HeLa), and hepatocellular (HepG2) carcinomas. A non-tumor primary culture from pig liver (PLP2) was also tested. The EO capacity to inhibit nitric oxide (NO) production was evaluated by a lipopolysaccharide stimulated murine macrophage cell line. Antibacterial and antifungal activities against opportunistic pathogens were investigated against seven strains of bacteria and eight fungi.

Results

The results indicated the presence of 23 compounds in the essential oil, the majority were spathulenol (45.63%) and β-caryophyllene oxide (12.72%). Leaf EO provided 50% inhibition of nitric oxide production at a concentration of 92.04 µg mL-1. The EO also demonstrated antiproliferative activity against all human tumor cell lines studied, with GI50 values comprised between 270.86 and 337.25 µg mL-1. The essential oil showed antimicrobial potential against the bacteria Listeria monocytogenes (Murray et al.) Pirie (NCTC 7973) and Salmonella Typhimurium ATCC 13311 (MIC 1870 µg mL-1) and fungi Aspergillus versicolor ATCC 11730, Aspergillus ochraceus ATCC 12066, Penicillium ochrochloron ATCC 90288, Penicillium verrucosum var. cyclopium (Westling) Samson, Stolk & Hadlok (food isolate) (MIC 1870 µg mL-1) and Trichoderma viride Pers. IAM 5061 (1,400 µg mL-1).

Conclusion

The demonstrated anti-inflammatory, antiproliferative, and antimicrobial activities in the leaves of E. pyriformis can add value to the production chain of this plant, being a possible option for preventing and combating cancer, including lung cancer.

Lung microbiome: new insights into bronchiectasis' outcome

The present treatments for bronchiectasis, which is defined by pathological dilatation of the airways, are confined to symptom relief and minimizing exacerbations. The condition is becoming more common worldwide. Since the disease's pathophysiology is not entirely well understood, developing novel treatments is critically important. The interplay of chronic infection, inflammation, and compromised mucociliary clearance, which results in structural alterations and the emergence of new infection, is most likely responsible for the progression of bronchiectasis. Other than treating bronchiectasis caused by cystic fibrosis, there are no approved treatments. Understanding the involvement of the microbiome in this disease is crucial, the microbiome is defined as the collective genetic material of all bacteria in an environment. In clinical practice, bacteria in the lungs have been studied using cultures; however, in recent years, researchers use next-generation sequencing methods, such as 16S rRNA sequencing. Although the microbiome in bronchiectasis has not been entirely investigated, what is known about it suggests that Haemophilus, Pseudomonas and Streptococcus dominate the lung bacterial ecosystems, they present significant intraindividual stability and interindividual heterogeneity. Pseudomonas and Haemophilus-dominated microbiomes have been linked to more severe diseases and frequent exacerbations, however additional research is required to fully comprehend the role of microbiome in the evolution of bronchiectasis. This review discusses recent findings on the lung microbiota and its association with bronchiectasis.

Does Exposure to Burning and Heated Tobacco Affect the Abundance of Perio-Pathogenic Species in the Subgingival Biofilm?

This study investigated the impact of tobacco exposure, specifically through heating and burning, on periodontopathogens in the subgingival microbiome among clinically healthy individuals and those diagnosed with periodontitis. The sample comprised 66 subjects (26–56 years, median 38 yrs; 64% females) classified as non-smokers, classic cigarette smokers, and tobacco heating system (THS) smokers (each N = 22). Full-mouth periodontal examination was performed, and 330 paper-point samples from periodontal pockets were collected. Next-generation sequencing of 16S rRNA genes was conducted to identify the composition of subgingival microbiome. Periodontitis prevalence among the groups was ranked as THS (41%) < non-smokers (44%) < cigarette smokers (68%), without statistically significant differences between the groups. The number of perio-pathogenic species was higher in subjects with periodontitis compared to those without (median 7 vs. 6 species; p = 0.005) but without significant differences between exposure groups: non-smokers (6) = smokers (6) < THS (6.5). When combining exposure and periodontal status, each smoker group had more perio-pathogenic species than non-smokers: non-smokers without periodontitis (5) < smokers without periodontitis (5.5) < THS without periodontitis (6); non-smokers with periodontitis (6.5) < THS with periodontitis (7) = smokers with periodontitis (7). Multiple linear regression indicated periodontitis as the sole predictor of perio-pathogenic species quantity, irrespective of the type of tobacco consumption, sex, age, or oral hygiene (R2 = 0.163; p = 0.005). In conclusion, the quantity of perio-pathogenic species in the subgingival microbiome was more influenced by periodontitis than by exposure to tobacco smoke, regardless of whether it was heated or burned.

Environmental exposures, the oral-lung axis and respiratory health: The airway microbiome goes on stage for the personalized management of human lung function

The human respiratory system is constantly exposed to environmental stimuli, sometimes including toxicants, which can trigger dysregulated lung immune responses that lead to respiratory symptoms, impaired lung function and airway diseases. Evidence supports that the microbiome in the lungs has an indispensable role in respiratory health and disease, acting as a local gatekeeper that mediates the interaction between the environmental cues and respiratory health. Moreover, the microbiome in the lungs is intimately intertwined with the oral microbiome through the oral-lung axis. Here, we discuss the intricate three-way relationship between (i) cigarette smoking, which has strong effects on the microbial community structure of the lung; (ii) microbiome dysbiosis and disease in the oral cavity; and (iii) microbiome dysbiosis in the lung and its causal role in patients suffering chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide. We highlight exciting outcomes arising from recently established interactions in the airway between environmental exposures, microbiome, metabolites-functional attributes and the host, as well as how these associations have the potential to predict the respiratory health status of the host through an airway microbiome health index. For completion, we argue that incorporating (synthetic) microbial community ecology in our contemporary understanding of lung disease presents challenges and also rises novel opportunities to exploit the oral-lung axis and its microbiome towards innovative airway disease diagnostics, prognostics, patient stratification and microbiota-targeted clinical interventions in the context of current therapies.

Two cosmoses, one universe: a narrative review exploring the gut microbiome's role in the effect of urban risk factors on vascular ageing

In the face of rising global urbanisation, understanding how the associated environment and lifestyle impact public health is a cornerstone for prevention, research, and clinical practice. Cardiovascular disease is the leading cause of morbidity and mortality worldwide, with urban risk factors contributing greatly to its burden. The current narrative review adopts an exposome approach to explore the effect of urban-associated physical-chemical factors (such as air pollution) and lifestyle on cardiovascular health and ageing. In addition, we provide new insights into how these urban-related factors alter the gut microbiome, which has been associated with an increased risk of cardiovascular disease. We focus on vascular ageing, before disease onset, to promote preventative research and practice. We also discuss how urban ecosystems and social factors may interact with these pathways and provide suggestions for future research, precision prevention and management of vascular ageing. Most importantly, future research and decision-making would benefit from adopting an exposome approach and acknowledging the diverse and boundless universe of the microbiome.

Oral microbiota in aging and diseases

Human microbiomes are microbial populations that form a symbiotic relationship with humans. There are up to 1000 species on the surface of human skin and mucosal system, among which gut microbiota attracts the most interest. As the beginning of the digestive tract, oral cavity is also an important microbial habitat in the human body which is the first line of defense against pathogens entering the body. Many studies have revealed that oral microbial dysbiosis could not only contribute to oral diseases but also whole-body systemic diseases and health status. Oral microorganisms can enter the gastrointestinal tract with saliva and food, or enter the blood circulation through mouth breakage, thus causing systemic inflammation and aging-related diseases including some causal links to Alzheimer's disease. A series of changes take place in oral microbial composition during development, with different age stages marked by different dominant microbial species. Despite a lack of comprehensive studies on aging oral microbiota, through systemic inflammation, oral pathogenic microbes are likely to contribute inflammatory aging. As inflammaging is a key signature and one of the causes for accelerated aging, improving the structure of oral microbiome may be not only a new strategy for disease prevention and treatment, but also for aging intervention.

Evolution and the critical role of the microbiota in the reduced mental and physical health associated with low socioeconomic status (SES)

The evolution of the gut-microbiota-brain axis in animals reveals that microbial inputs influence metabolism, the regulation of inflammation and the development of organs, including the brain. Inflammatory, neurodegenerative and psychiatric disorders are more prevalent in people of low socioeconomic status (SES). Many aspects of low SES reduce exposure to the microbial inputs on which we are in a state of evolved dependence, whereas the lifestyle of wealthy citizens maintains these exposures. This partially explains the health deficit of low SES, so focussing on our evolutionary history and on environmental and lifestyle factors that distort microbial exposures might help to mitigate that deficit. But the human microbiota is complex and we have poor understanding of its functions at the microbial and mechanistic levels, and in the brain. Perhaps its composition is more flexible than the microbiota of animals that have restricted habitats and less diverse diets? These uncertainties are discussed in relation to the encouraging but frustrating results of attempts to treat psychiatric disorders by modulating the microbiota.

Microbial Communities and Functional Genes in Periodontitis and Healthy Controls

BACKGROUND

Periodontitis is a chronic progressive disease and the leading cause of tooth loss in adults. Recent studies have shown the impact of oral microbial communities on systemic health and diseases such as cancer, atherosclerosis, rheumatoid arthritis, inflammatory bowel disease, diabetes, hypertension, and Alzheimer's disease. In previous case control studies investigatin the relationship between periodontal disease and the oral microbiota, little attention has been paid to the intersections of these domains.

METHODS

Here, we used high-throughput 16S rRNA sequencing to analyse the differences in the microbial composition in saliva between a group of patients with chronic periodontitis (C; n = 51) and a healthy control group (H; n = 61) and predicted the functional gene composition by Phylogenetic Investigation of Communities by Reconstruction of Unobserved States.

RESULTS

We found significant alterations in oral microbial diversity between C and H (P = 0.002). Sixteen genera were significantly different between C and H, and 15 of them were enriched in C linear discriminant analysis (LDA > 2). Fifty functional genes were significantly different between C and H, and 34 of them were enriched in C (P < .025).

CONCLUSIONS

Periodontitis is associated with significant changes in the oral microbial community.

The effect of cigarette smoking on the oral microbiota in a South African population using subgingival plaque samples

Disturbances in the oral microbiota may be due to several mechanisms and factors, such as smoking. An imbalance in oral bacteria may result in changes to the innate immune system and the development of periodontal disease. This study aimed to investigate the distribution of oral microbiota in smokers and non-smokers in a South African population using subgingival plaque samples. From the 128 recruited participants, 57 were identified as smokers (serum cotinine: >15 ng/ml). Analysis of 16S rRNA gene sequencing demonstrated significant differences between the two groups with a reduced abundance of Actinobacteria in smokers. Fusobacterium and Campylobacter were found in higher abundance, while a lower abundance of Leptotrichia, Actinomyces, Corynebacterium, and Lautropia were observed. This study highlighted significant differences in the oral microbiota of smokers, indicating an abundance of anaerobic gram-negative bacteria. These findings suggest that smoking allows certain oral microorganisms to gain dominance, thereby predisposing individuals to periodontal disease development and progression.

Investigating the Impact of Gut Microbiota on Gout Through Mendelian Randomization

Background

The relationship between gout and gut microbiota has attracted significant attention in current research. However, due to the diverse range of gut microbiota, the specific causal effect on gout remains unclear. This study utilizes Mendelian randomization (MR) to investigate the causal relationship between gut microbiota and gout, aiming to elucidate the underlying mechanism of microbiome-mediated gout and provide valuable guidance for clinical prevention and treatment.

Materials and Methods

The largest genome-wide association study meta-analysis conducted by the MiBioGen Consortium (n=18,340) was utilized to perform a two-sample Mendelian randomization investigation on aggregate statistics of intestinal microbiota. Summary statistics for gout were utilized from the data released by EBI. Various methods, including inverse variance weighted, weighted median, weighted model, MR-Egger, and Simple-mode, were employed to assess the causal relationship between gut microbiota and gout. Reverse Mendelian randomization analysis revealed a causal association between bacteria and gout in forward Mendelian randomization analysis. Cochran's Q statistic was used to quantify instrumental variable heterogeneity.

Results

The inverse variance weighted estimation revealed that Rikenellaceae exhibited a slight protective effect on gout, while the presence of Ruminococcaceae UCG_011 is associated with a marginal increase in the risk of gout. According to the reverse Mendelian Randomization results, no significant causal relationship between gout and gut microbiota was observed. No significant heterogeneity of instrumental variables or level pleiotropy was detected.

Conclusion

Our MR analysis revealed a potential causal relationship between the development of gout and specific gut microbiota; however, the causal effect was not robust, and further research is warranted to elucidate its underlying mechanism in gout development. Considering the significant association between diet, gut microbiota, and gout, these findings undoubtedly shed light on the mechanisms of microbiota-mediated gout and provide new insights for translational research on managing and standardizing treatment for this condition.

Cigarette smoke-induced dysbiosis: comparative analysis of lung and intestinal microbiomes in COPD mice and patients

BACKGROUND

The impact of cigarette smoke (CS) on lung diseases and the role of microbiome dysbiosis in chronic obstructive pulmonary disease (COPD) have been previously reported; however, the relationships remain unclear.

METHODS

Our research examined the effects of 20-week cigarette smoke (CS) exposure on the lung and intestinal microbiomes in C57BL/6JNarl mice, alongside a comparison with COPD patients' intestinal microbiome data from a public dataset.

RESULTS

The study found that CS exposure significantly decreased forced vital capacity (FVC), thickened airway walls, and induced emphysema. Increased lung damage was observed along with higher lung keratinocyte chemoattractant (KC) levels by CS exposure. Lung microbiome analysis revealed a rise in Actinobacteriota, while intestinal microbiome showed significant diversity changes, indicating dysbiosis. Principal coordinate analysis highlighted distinct intestinal microbiome compositions between control and CS-exposed groups. In the intestinal microbiome, notable decreases in Patescibacteria, Campilobacterota, Defferibacterota, Actinobacteriota, and Desulfobacterota were observed. We also identified correlations between lung function and dysbiosis in both lung and intestinal microbiomes. Lung interleukins, interferon-ɣ, KC, and 8-isoprostane levels were linked to lung microbiome dysbiosis. Notably, dysbiosis patterns in CS-exposed mice were similar to those in COPD patients, particularly of Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 4 patients. This suggests a systemic impact of CS exposure.

CONCLUSION

In summary, CS exposure induces significant dysbiosis in lung and intestinal microbiomes, correlating with lung function decline and injury. These results align with changes in COPD patients, underscoring the important role of microbiome in smoke-related lung diseases.

Oral microbiome dysbiosis among cigarette smokers and smokeless tobacco users compared to non-users

Tobacco use significantly influences the oral microbiome. However, less is known about how different tobacco products specifically impact the oral microbiome over time. To address this knowledge gap, we characterized the oral microbiome of cigarette users, smokeless tobacco users, and non-users over 4 months (four time points). Buccal swab and saliva samples (n = 611) were collected from 85 participants. DNA was extracted from all samples and sequencing was carried out on an Illumina MiSeq, targeting the V3-V4 region of the 16S rRNA gene. Cigarette and smokeless tobacco users had more diverse oral bacterial communities, including a higher relative abundance of Firmicutes and a lower relative abundance of Proteobacteria, when compared to non-users. Non-users had a higher relative abundance of Actinomyces, Granulicatella, Haemophilus, Neisseria, Oribacterium, Prevotella, Pseudomonas, Rothia, and Veillonella in buccal swab samples, compared to tobacco users. While the most abundant bacterial genera were relatively constant over time, some species demonstrated significant shifts in relative abundance between the first and last time points. In addition, some opportunistic pathogens were detected among tobacco users including Neisseria subflava, Bulleidia moorei and Porphyromonas endodontalis. Overall, our results provide a more holistic understanding of the structure of oral bacterial communities in tobacco users compared to non-users.

Factors associated with irritable bowel syndrome and Helicobacter pylori infection: public knowledge and awareness of signs and symptoms

OBJECTIVE

To investigate factors related to the risk of developing irritable bowel syndrome (IBS) or Helicobacter pylori infection.

METHODS

This cross-sectional, questionnaire-based study analysed the responses from participants that completed an online questionnaire, which asked about their knowledge of the causes and risk factors associated with IBS and H. pylori infection.

RESULTS

The study analysed responses from 230 participants: 181 females (of 227 participants; 79.7%) and 190 aged 18-40 years (of 228; 83.3%). Of the 230 participants, 40 (17.4%) had been diagnosed by a physician with IBS and 57 (24.8%) had been diagnosed with H. pylori infection. Of 226 participants, 93 (41.2%) had self-medicated with antibiotics in the past 6 months for various reasons. The overall mean ± SD knowledge score about IBS and H. pylori infection for the study cohort (n = 230) was 35.8 ± 19.2%. Wald χ2-test analysis demonstrated that chronic diseases, antibiotic use and having an endoscopy were significantly associated with developing IBS. Male sex and chronic diseases were significantly associated with H. pylori infection. Logistic regression analysis showed no relationship between IBS and H. Pylori infection.

CONCLUSION

Chronic diseases was the only risk factor common for IBS and H. pylori infection.

Acidovorax temperans skews neutrophil maturation and polarizes Th17 cells to promote lung adenocarcinoma development

Change within the intratumoral microbiome is a common feature in lung and other cancers and may influence inflammation and immunity in the tumor microenvironment, affecting growth and metastases. We previously characterized the lung cancer microbiome in patients and identified Acidovorax temperans as enriched in tumors. Here, we instilled A. temperans in an animal model driven by mutant K-ras and Tp53. This revealed A. temperans accelerates tumor development and burden through infiltration of proinflammatory cells. Neutrophils exposed to A. temperans displayed a mature, pro-tumorigenic phenotype with increased cytokine signaling, with a global shift away from IL-1β signaling. Neutrophil to monocyte and macrophage signaling upregulated MHC II to activate CD4+ T cells, polarizing them to an IL-17A+ phenotype detectable in CD4+ and γδ populations (T17). These T17 cells shared a common gene expression program predictive of poor survival in human LUAD. These data indicate bacterial exposure promotes tumor growth by modulating inflammation.

Composition of the sputum bacterial microbiome of patients with different pathomorphological forms of non-small-cell lung cancer

Recent studies have shown that the bacterial microbiome of the respiratory tract influences the development of lung cancer. Changes in the composition of the microbiome are observed in patients with chronic inflammatory processes. Such microbiome changes may include the occurrence of bacteria that cause oxidative stress and that are capable of causing genome damage in the cells of the host organism directly and indirectly. To date, the composition of the respiratory microbiome in patients with various histological variants of lung cancer has not been studied. In the present study, we determined the taxonomic composition of the sputum microbiome of 52 patients with squamous cell carcinoma of the lung, 52 patients with lung adenocarcinoma and 52 healthy control donors, using next-generation sequencing (NGS) on the V3-V4 region of the bacterial gene encoding 16S rRNA. The sputum microbiomes of patients with different histological types of lung cancer and controls did not show significant differences in terms of the species richness index (Shannon); however, the patients differed from the controls in terms of evenness index (Pielou). The structures of bacterial communities (beta diversity) in the adenocarcinoma and squamous cell carcinoma groups were also similar; however, when analyzed according to the matrix constructed by the Bray-Curtis method, there were differences between patients with squamous cell carcinoma and healthy subjects, but not between those with adenocarcinoma and controls. Using the LEFse method it was possible to identify an increase in the content of Bacillota (Streptococcus and Bacillus) and Actinomycetota (Rothia) in the sputum of patients with squamous cell carcinoma when compared with samples from patients with adenocarcinoma. There were no differences in the content of bacteria between the samples of patients with adenocarcinoma and the control ones. The content of representatives of the genera Streptococcus, Bacillus, Peptostreptococcus (phylum Bacillota), Prevotella, Macellibacteroides (phylum Bacteroidota), Rothia (phylum Actinomycetota) and Actinobacillus (phylum Pseudomonadota) was increased in the microbiome of sputum samples from patients with squamous cell carcinoma, compared with the control. Thus, the sputum bacterial microbiome of patients with different histological types of non-small-cell lung cancer has significant differences. Further research should be devoted to the search for microbiome biomarkers of lung cancer at the level of bacterial species using whole-genome sequencing.

Characteristics of the oral and gastric microbiome in patients with early-stage intramucosal esophageal squamous cell carcinoma

BACKGROUND

Oral microbiome dysbacteriosis has been reported to be associated with the pathogenesis of advanced esophageal cancer. However, few studies investigated the potential role of oral and gastric microbiota in early-stage intramucosal esophageal squamous carcinoma (EIESC).

METHOD

A total of 104 samples were collected from 31 patients with EIESC and 21 healthy controls. The compositions of oral and gastric microbiota were analyzed using 16 S rRNA V3-V4 amplicon sequencing. Linear discriminant analysis effect size (LEfSe) analysis was performed to assess taxonomic differences between groups. The correlation between oral microbiota and clinicopathological factors was evaluated using Spearman correlation analysis. Additionally, co-occurrence networks were established and random forest models were utilized to identify significant microbial biomarkers for distinguishing between the EIESC and control groups.

RESULTS

A total of 292 oral genera and 223 species were identified in both EIESC and healthy controls. Six oral genera were remarkably enriched in EIESC groups, including the genera Porphyromonas, Shigella, Subdoligranulum, Leptotrichia, Paludibacter, and Odoribacter. LEfSe analysis identified genera Porphyromonas and Leptotrichia with LDA scores > 3. In the random forest model, Porphyromonas endodontalis ranked the top microbial biomarker to differentiate EIESC from controls. The elimination rate of Porphyromonas endodontalis from the oral cavity to the stomach was also dramatically decreased in the EIESC group than controls. In the microbial co-occurrence network, Porphyromonas endodontalis was positively correlated with Prevotella tannerae and Prevotella intermedia and was negatively correlated with Veillonella dispar.

CONCLUSION

Our study potentially indicates that the dysbacteriosis of both the oral and gastric microbiome was associated with EIESC. Larger scale studies and experimental animal models are urgently needed to confirm the possible role of microbial dysbacteriosis in the pathogenesis of EIESC. (Chinese Clinical Trial Registry Center, ChiCTR2200063464, Registered 07 September 2022, https://www.chictr.org.cn/showproj.html?proj=178563).