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Journal of Clinical Medicine Aug 2020Halitosis is a common ailment concerning 15% to 60% of the human population. Halitosis can be divided into extra-oral halitosis (EOH) and intra-oral halitosis (IOH). The... (Review)
Review
Halitosis is a common ailment concerning 15% to 60% of the human population. Halitosis can be divided into extra-oral halitosis (EOH) and intra-oral halitosis (IOH). The IOH is formed by volatile compounds, which are produced mainly by anaerobic bacteria. To these odorous substances belong volatile sulfur compounds (VSCs), aromatic compounds, amines, short-chain fatty or organic acids, alcohols, aliphatic compounds, aldehydes, and ketones. The most important VSCs are hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, and methyl mercaptan. VSCs can be toxic for human cells even at low concentrations. The oral bacteria most related to halitosis are spp., spp., spp., spp., spp., spp., spp., spp., spp., spp., spp., , and spp. Most bacteria that cause halitosis are responsible for periodontitis, but they can also affect the development of oral and digestive tract cancers. Malodorous agents responsible for carcinogenesis are hydrogen sulfide and acetaldehyde.
PubMed: 32748883
DOI: 10.3390/jcm9082484 -
Microbiome Nov 2023Oral squamous cell carcinoma (SCC) is associated with oral microbial dysbiosis. In this unique study, we compared pre- to post-treatment salivary microbiome in patients...
BACKGROUND
Oral squamous cell carcinoma (SCC) is associated with oral microbial dysbiosis. In this unique study, we compared pre- to post-treatment salivary microbiome in patients with SCC by 16S rRNA gene sequencing and examined how microbiome changes correlated with the expression of an anti-microbial protein.
RESULTS
Treatment of SCC was associated with a reduction in overall bacterial richness and diversity. There were significant changes in the microbial community structure, including a decrease in the abundance of Porphyromonaceae and Prevotellaceae and an increase in Lactobacillaceae. There were also significant changes in the microbial community structure before and after treatment with chemoradiotherapy, but not with surgery alone. In patients treated with chemoradiotherapy alone, several bacterial populations were differentially abundant between responders and non-responders before and after therapy. Microbiome changes were associated with a change in the expression of DMBT1, an anti-microbial protein in human saliva. Additionally, we found that salivary DMBT1, which increases after treatment, could serve as a post-treatment salivary biomarker that links to microbial changes. Specifically, post-treatment increases in human salivary DMBT1 correlated with increased abundance of Gemella spp., Pasteurellaceae spp., Lactobacillus spp., and Oribacterium spp. This is the first longitudinal study to investigate treatment-associated changes (chemoradiotherapy and surgery) in the oral microbiome in patients with SCC along with changes in expression of an anti-microbial protein in saliva.
CONCLUSIONS
The composition of the oral microbiota may predict treatment responses; salivary DMBT1 may have a role in modulating the oral microbiome in patients with SCC. After completion of treatment, 6 months after diagnosis, patients had a less diverse and less rich oral microbiome. Leptotrichia was a highly prevalent bacteria genus associated with disease. Expression of DMBT1 was higher after treatment and associated with microbiome changes, the most prominent genus being Gemella Video Abstract.
Topics: Humans; Mouth Neoplasms; Longitudinal Studies; Carcinoma, Squamous Cell; RNA, Ribosomal, 16S; Microbiota; Saliva; Bacteria; Calcium-Binding Proteins; DNA-Binding Proteins; Tumor Suppressor Proteins
PubMed: 38037123
DOI: 10.1186/s40168-023-01677-w -
Oral Health & Preventive Dentistry Apr 2023Antibiotics play an important role in treating periodontal diseases. Due to the effectiveness of antibiotic therapies, their usage in dentistry has significantly...
PURPOSE
Antibiotics play an important role in treating periodontal diseases. Due to the effectiveness of antibiotic therapies, their usage in dentistry has significantly increased. The aim of this study focused on the in-vitro susceptibility of different gram-negative oral bacteria species - which are associated with periodontal diseases (Fusobacterium spp., Capnocytophaga spp. and Leptotrichia buccalis) and have different geographical origins (Asia and Europe) - against antimicrobials that are clinically relevant in dental therapy.
MATERIALS AND METHODS
A total of 45 strains were tested (29 Fusobacterium spp., 13 Capnocytophaga spp. and 3 L. buccalis) that were either isolated from Chinese patients or were obtained from different strain collections. Their antimicrobial susceptibility to the antimicrobial agents benzylpenicillin, amoxicillin, amoxicillin-clavulanic acid, ciprofloxacin, moxifloxacin, clindamycin, doxycycline, tetracycline and metronidazole was tested using the E-Test. Strains with particular resistance to penicillin, clindamycin and metronidazole were further analysed for resistance genes.
RESULTS
All tested bacterial isolates were sensitive to amoxicillin, amoxicillin-clavulanic acid, doxycycline and tetracycline, but showed variable sensitivity towards other antibiotics such as benzylpenicillin, ciprofloxacin, moxifloxacin, clindamycin and metronidazole.
CONCLUSION
The results of the present study suggest that certain periodontal disease-related bacterial strains can be resistant towards antimicrobial agents commonly used in adjuvant periodontal therapy.
Topics: Humans; Clindamycin; Metronidazole; Capnocytophaga; Doxycycline; Fusobacterium; Amoxicillin-Potassium Clavulanate Combination; Moxifloxacin; Leptothrix; Leptotrichia; Drug Resistance, Bacterial; Microbial Sensitivity Tests; Anti-Bacterial Agents; Amoxicillin; Anti-Infective Agents; Ciprofloxacin; Periodontal Diseases
PubMed: 37014213
DOI: 10.3290/j.ohpd.b4009553 -
Danish Medical Journal Apr 2014Bacterial vaginosis (BV) is an imbalance of the vaginal bacterial microbiota and its aetiology is still unknown. Our aims were to investigate the diagnostic potential of... (Review)
Review
BACKGROUND
Bacterial vaginosis (BV) is an imbalance of the vaginal bacterial microbiota and its aetiology is still unknown. Our aims were to investigate the diagnostic potential of species/genus specific quantitative PCR (qPCR) for bacteria present in swabs and first-void urine (FVU) samples using Nugent's and Claeys' criteria and 454 sequencing of the vaginal microbiome as reference.
METHODS
Self-collected swabs, vaginal smears and FVU were obtained from 177 women from Greenland (Study I and III) and physician-collected vaginal swabs and smears were obtained from 163 Swedish women (Study II). BV was diagnosed by Nugent's criteria in Study I and III and by Amsel's criteria in Study II. The vaginal swabs and FVU samples were analysed by qPCR for selected vaginal bacteria in all three studies and for four sexually transmitted infections (STIs) in Study I.
RESULTS
Study I: STIs were common in women from Greenland and BV was found in 45% of these women but was not associated with individual STIs. In multivariate logistic analysis, Atopobium vaginae and Prevotella spp. were both independently associated with BV in swabs. BV could be subdivided into clusters dominated by a single or a few species together. Seven vaginal bacteria (A. vaginae, Prevotella spp. Gardnerella vaginalis, Bacterial vaginosis associated bacterium (BVAB) 2, Eggerthella-like bacterium, Leptotrichia amnionii and Megasphaera type 1) had areas under the receiver operating characteristic (ROC) curve > 85% in swabs, suggesting that they were good predictors of BV according to Nugent. Study II: For the majority of species/genera, the kappa values indicated fair to good agreement when their presence was determined by 454 pyrosequencing versus real-time PCR. The same seven vaginal bacteria as found in Study I, had areas under the ROC-curve > 85% in swabs from Swedish women, demonstrating a good diagnostic accuracy for BV according to Amsel. Study III: In a multivariate model, Megasphaera type 1 and Prevotella spp. remained significantly associated with BV in FVU samples. A linear regression analysis showed good agreement between bacterial load from swabs and FVU, but Prevotella spp. could be detected in high numbers in a few FVU samples without being present in swabs. After applying ROC curve analysis, the same seven vaginal bacteria as previously mentioned showed good prediction for BV according to Nugent in FVU. BV could be detected with comparable sensitivity in FVU and vaginal swabs.
CONCLUSION
BV can be diagnosed by molecular methods performed either on swabs or urine but it is important to apply thresholds in order to improve the accuracy of the diagnosis. Furthers it was possible to identify clusters of BV dominated by single or paired bacteria, and these clusters could classify BV into subgroups, providing a more detailed understanding of the condition. Seven vaginal bacteria were highly accurate for BV diagnosis both in swabs and FVU. Finally a good agreement between Nugent and Claeys was found.
Topics: Biofilms; DNA, Bacterial; Female; Gardnerella vaginalis; Humans; Immunity, Innate; Lactobacillus; Risk Factors; Vagina; Vaginal Smears; Vaginosis, Bacterial
PubMed: 24814599
DOI: No ID Found -
Scientific Reports Nov 2017The gastric microbiome has been proposed as an etiological factor in gastric carcinogenesis. We compared the gastric microbiota in subjects presenting with gastric...
The gastric microbiome has been proposed as an etiological factor in gastric carcinogenesis. We compared the gastric microbiota in subjects presenting with gastric cancer (GC, n = 12) and controls (functional dyspepsia (FD), n = 20) from a high GC risk population in Singapore and Malaysia. cDNA from 16S rRNA transcripts were amplified (515F-806R) and sequenced using Illumina MiSeq 2 × 250 bp chemistry. Increased richness and phylogenetic diversity but not Shannon's diversity was found in GC as compared to controls. nMDS clustered GC and FD subjects separately, with PERMANOVA confirming a significant difference between the groups. H. pylori serological status had a significant impact on gastric microbiome α-diversity and composition. Several bacterial taxa were enriched in GC, including Lactococcus, Veilonella, and Fusobacteriaceae (Fusobacterium and Leptotrichia). Prediction of bacterial metabolic contribution indicated that serological status had a significant impact on metabolic function, while carbohydrate digestion and pathways were enriched in GC. Our findings highlight three mechanisms of interest in GC, including enrichment of pro-inflammatory oral bacterial species, increased abundance of lactic acid producing bacteria, and enrichment of short chain fatty acid production pathways.
Topics: Biodiversity; Carcinogenesis; Dysbiosis; Gastrointestinal Microbiome; Helicobacter Infections; Helicobacter pylori; Humans; Phylogeny; Stomach Neoplasms
PubMed: 29162924
DOI: 10.1038/s41598-017-16289-2 -
Frontiers in Oncology 2023Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis... (Review)
Review
Head and neck cancer (HNC) is the sixth most common type of cancer, with more than half a million new cases annually. This review focuses on the role of oral dysbiosis and HPV infection in HNCs, presenting the involved taxons, molecular effectors and pathways, as well as the HPV-associated particularities of genetic and epigenetic changes and of the tumor microenvironment occurred in different stages of tumor development. Oral dysbiosis is associated with the evolution of HNCs, through multiple mechanisms such as inflammation, genotoxins release, modulation of the innate and acquired immune response, carcinogens and anticarcinogens production, generation of oxidative stress, induction of mutations. Thus, novel microbiome-derived biomarkers and interventions could significantly contribute to achieving the desideratum of personalized management of oncologic patients, regarding both early diagnosis and treatment. The results reported by different studies are not always congruent regarding the variations in the abundance of different taxons in HNCs. However, there is a consistent reporting of a higher abundance of Gram-negative species such as , which are probably responsible of chronic inflammation and modulation of tumor microenvironment. is the dominant fungi found in oral carcinoma being also associated with shorter survival rate. Specific microbial signatures (e.g., and ) have been associated with later stages and larger tumor, suggesting their potential to be used as biomarkers for tumor stratification and prognosis. On the other hand, increased abundance of is associated with a reduced risk of HNC. Microbiome could also provide biomarkers for differentiating between oropharyngeal and hypopharyngeal cancers as well as between HPV-positive and HPV-negative tumors. Ongoing clinical trials aim to validate non-invasive tests for microbiome-derived biomarkers detection in oral and throat cancers, especially within high-risk populations. Oro-pharyngeal dysbiosis could also impact the HNCs therapy and associated side-effects of radiotherapy, chemotherapy, and immunotherapy. HPV-positive tumors harbor fewer mutations, as well as different DNA methylation pattern and tumor microenvironment. Therefore, elucidation of the molecular mechanisms by which oral microbiota and HPV infection influence the HNC initiation and progression, screening for HPV infection and vaccination against HPV, adopting a good oral hygiene, and preventing oral dysbiosis are important tools for advancing in the battle with this public health global challenge.
PubMed: 38179168
DOI: 10.3389/fonc.2023.1273516 -
International Journal of Molecular... Oct 2023The tumor microbiome, a relatively new research field, affects tumor progression through several mechanisms. The Cancer Microbiome Atlas (TCMA) database was recently...
The tumor microbiome, a relatively new research field, affects tumor progression through several mechanisms. The Cancer Microbiome Atlas (TCMA) database was recently published. In the present study, we used TCMA and The Cancer Genome Atlas and examined microbiome profiling in head and neck squamous cell carcinoma (HNSCC), the role of the intratumoral microbiota in the prognosis of HNSCC patients, and differentially expressed genes in tumor cells in relation to specific bacterial infections. We investigated 18 microbes at the genus level that differed between solid normal tissue ( = 22) and primary tumors ( = 154). The tissue microbiome profiles of , , and at the genus level differed between the solid normal tissue and primary tumors of HNSCC patients. When the prognosis of groups with rates over and under the median for each microbe at the genus level was examined, rates for which were over the median correlated with significantly higher overall survival rates. We then extracted 35 differentially expressed genes between the over- and under-the-median-for groups based on the criteria of >1.5 fold and < 0.05 in the Mann-Whitney U-test. A pathway analysis showed that these -related genes were associated with the pathways of Alzheimer disease, neurodegeneration-multiple diseases, prion disease, MAPK signaling, and PI3K-Akt signaling, while protein-protein interaction analysis revealed that these genes formed a dense network. In conclusion, probiotics and specific antimicrobial therapy targeting may have an impact on the prognosis of HNSCC.
Topics: Humans; Squamous Cell Carcinoma of Head and Neck; Phosphatidylinositol 3-Kinases; Head and Neck Neoplasms; Signal Transduction; Microbiota; Biomarkers, Tumor; Gene Expression Regulation, Neoplastic
PubMed: 37895136
DOI: 10.3390/ijms242015456 -
Frontiers in Cellular and Infection... 2021Autoimmune hepatitis (AIH) is a common cause of liver cirrhosis. To identify the characteristics of the oral microbiome in patients with AIH, we collected 204 saliva... (Randomized Controlled Trial)
Randomized Controlled Trial
Autoimmune hepatitis (AIH) is a common cause of liver cirrhosis. To identify the characteristics of the oral microbiome in patients with AIH, we collected 204 saliva samples including 68 AIH patients and 136 healthy controls and performed microbial MiSeq sequencing after screening. All samples were randomly divided into discovery cohorts (46 AIH and 92 HCs) and validation cohorts (22 AIH and 44 HCs). Moreover, we collected samples of 12 AIH patients from Hangzhou for cross-regional validation. We described the oral microbiome characteristics of AIH patients and established a diagnostic model. In the AIH group, the oral microbiome diversity was significantly increased. The microbial communities remarkably differed between the two groups. Seven genera, mainly and , were dominant in the HC group, while 51 genera, and , were enriched in the AIH group. Notably, we found 23 gene functions, including Membrane Transport, Carbohydrate Metabolism, and Glycerolipid metabolism that were dominant in AIH and 31 gene functions that prevailed in HCs. We further investigated the correlation between the oral microbiome and clinical parameters. The optimal 5 microbial markers were figured out through a random forest model, and the distinguishing potential achieved 99.88% between 46 AIH and 92 HCs in the discovery cohort and 100% in the validation cohort. Importantly, the distinguishing potential reached 95.55% in the cross-regional validation cohort. In conclusion, this study is the first to characterize the oral microbiome in AIH patients and to report the successful establishment of a diagnostic model and the cross-regional validation of microbial markers for AIH. Importantly, oral microbiota-targeted biomarkers may be able to serve as powerful and noninvasive diagnostic tools for AIH.
Topics: Cohort Studies; Hepatitis, Autoimmune; Humans; Microbiota; Saliva; Veillonella
PubMed: 34094998
DOI: 10.3389/fcimb.2021.656674 -
International Journal of Molecular... Nov 2016Dental caries (tooth decay) is an infectious disease. Its etiology is not fully understood from the microbiological perspective. This study characterizes the diversity...
Dental caries (tooth decay) is an infectious disease. Its etiology is not fully understood from the microbiological perspective. This study characterizes the diversity of microbial flora in the saliva of children with and without dental caries. Children (3-4 years old) with caries ( = 20) and without caries ( = 20) were recruited. Unstimulated saliva (2 mL) was collected from each child and the total microbial genomic DNA was extracted. DNA amplicons of the V3-V4 hypervariable region of the bacterial 16S rRNA gene were generated and subjected to Illumina Miseq sequencing. A total of 17 phyla, 26 classes, 40 orders, 80 families, 151 genera, and 310 bacterial species were represented in the saliva samples. There was no significant difference in the microbiome diversity between caries-affected and caries-free children ( > 0.05). The relative abundance of several species (, , sp. , , and ) was higher in the caries-affected group than in the caries-free group ( < 0.05). and sp. were more abundant in caries-free children than in caries-affected children ( < 0.05). The salivary microbiome profiles of caries-free and caries-affected children were similar. Salivary counts of certain bacteria such as and may be useful for screening/assessing children's risk of developing caries.
Topics: Actinomyces; Adolescent; Child; Child, Preschool; Dental Caries; Female; Humans; Infant; Male; Microbiota; Phylogeny; Prevotella; RNA, Ribosomal, 16S; Saliva; Streptococcus mutans; Veillonella
PubMed: 27898021
DOI: 10.3390/ijms17121978 -
Gut Microbes 2022Frequently, patients with functional gastrointestinal disorders (FGIDs) report intolerance of wheat products. We compared gastrointestinal symptoms, sensory function,...
The duodenal mucosa associated microbiome, visceral sensory function, immune activation and psychological comorbidities in functional gastrointestinal disorders with and without self-reported non-celiac wheat sensitivity.
Frequently, patients with functional gastrointestinal disorders (FGIDs) report intolerance of wheat products. We compared gastrointestinal symptoms, sensory function, psychiatric comorbidities, gut-homing immune cells, and duodenal mucosa-associated microbiome (d-MAM) in FGID patients and controls with and without self-reported wheat sensitivity (SR-NCWS). We recruited 40 FGID patients and 20 controls referred by GPs for treatment. Gastrointestinal/extraintestinal symptoms, visceral sensory function, psychological comorbidities, and SR-NCWS were assessed in a standardized approach. Peripheral gut homing T-cells (CD4α4β7CCR9/CD8α4β7CCR9) were quantified, and the d-MAM was assessed by DNA sequencing for 46 subjects. Factors of bacterial genera were extracted utilizing factor analysis with varimax rotation and factors univariately associated with FGID or SR-NCWS included in a subsequent multivariate analysis of variance to identify statistically independent discriminators. Anxiety scores (p < .05) and increased symptom responses to a nutrient challenge (p < .05) were univariately associated with FGID. Gut homing T-cells were increased in FGID patients with SR-NCWS compared to other groups (p all <0.05). MANOVA revealed that anxiety (p = .03), visceral sensory function (p = 0.007), and a d-MAM factor comprise members of the , and lineages were significantly (p = .001) associated with FGID, while gut homing CD4α4 β7CCR9 T-cells were associated (p = .002) with SR-NCWS. Compared to controls, patients with and without SR-NCWS show that there are shifts in the amplicon sequence variants within specific bacterial genera between the FGID subgroups (particularly and ) as well as distinct bacterial taxa discriminatory for the two different FGID subtypes. Compared to controls, both FGID patients with and without SR-NCWS have an increased symptom response to a standardized nutrient challenge and increased anxiety scores. The FGID patients with SR-NCWS - as compared to FGID without SR-NCWS (and controls without SR-NCWS) - have increased gut homing T-cells. The d-MAM profiles suggest species and strain-based variations between the two FGID subtypes and in comparison to controls.
Topics: Humans; Wheat Hypersensitivity; Self Report; Gastrointestinal Microbiome; Gastrointestinal Diseases; Intestinal Mucosa; Sensation
PubMed: 36303431
DOI: 10.1080/19490976.2022.2132078