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5,082 result(s) for "Mouth - microbiology"
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The Influence of Ethanolic Extract of Brazilian Green Propolis Gel on Hygiene and Oral Microbiota in Patients after Mandible Fractures
Maintenance of proper oral hygiene by dental plaque elimination is one of the most important factors affecting the healing process in postoperative oral wounds. Propolis is a substance produced by bees. Ethanolic extract of propolis has bactericidal, fungicidal, anti-inflammatory, and antioxidative properties. Moreover, it can scavenge free radicals. The purpose of this paper is to demonstrate the efficacy of a gel containing 3% of ethanolic extract of Brazilian green propolis (EEP-B) when used for maintaining oral hygiene in patients with postoperative oral mucosal wounds. The hygiene was assessed using API, OHI, and SBI followed by microbiological examinations. The patients were divided into two groups. Group 1 consisted of those who used a gel containing EEP-B for oral hygiene, and group 2 consisted of those who used a gel without EEP-B. Although improved oral hygiene was noted in both groups, the improvement was markedly greater in the group using gel containing EEP-B. Summing up the results of microbiological examinations, EEP-B has beneficial effect on mouth microflora in postoperative period. Propolis preparations used for oral hygiene allow eliminating microorganisms of pathogenic character and physiological flora microorganisms considered as being opportunistic, with no harmful influence on physiological microflora in oral ecosystem.
Bacterial Topography of the Healthy Human Lower Respiratory Tract
Although culture-independent techniques have refuted lung sterility in health, controversy about contamination during bronchoscope passage through the upper respiratory tract (URT) has impeded research progress. We sought to establish whether bronchoscopic sampling accurately reflects the lung microbiome in health and to distinguish between two proposed routes of authentic microbial immigration, (i) dispersion along contiguous respiratory mucosa and (ii) subclinical microaspiration. During bronchoscopy of eight adult volunteers without lung disease, we performed seven protected specimen brushings (PSB) and bilateral bronchoalveolar lavages (BALs) per subject. We amplified, sequenced, and analyzed the bacterial 16S rRNA gene V4 regions by using the Illumina MiSeq platform. Rigorous attention was paid to eliminate potential sources of error or contamination, including a randomized processing order and the inclusion and analysis of exhaustive procedural and sequencing control specimens. Indices of mouth-lung immigration (mouth-lung community similarity, bacterial burden, and community richness) were all significantly greater in airway and alveolar specimens than in bronchoscope contamination control specimens, indicating minimal evidence of pharyngeal contamination. Ecological indices of mouth-lung immigration peaked at or near the carina, as predicted for a primary immigration route of microaspiration. Bacterial burden, diversity, and mouth-lung similarity were greater in BAL than PSB samples, reflecting differences in the sampled surface areas. (This study has been registered at ClinicalTrials.gov under registration no. NCT02392182.) IMPORTANCE This study defines the bacterial topography of the healthy human respiratory tract and provides ecological evidence that bacteria enter the lungs in health primarily by microaspiration, with potential contribution in some subjects by direct dispersal along contiguous mucosa. By demonstrating that contamination contributes negligibly to microbial communities in bronchoscopically acquired specimens, we validate the use of bronchoscopy to investigate the lung microbiome. This study defines the bacterial topography of the healthy human respiratory tract and provides ecological evidence that bacteria enter the lungs in health primarily by microaspiration, with potential contribution in some subjects by direct dispersal along contiguous mucosa. By demonstrating that contamination contributes negligibly to microbial communities in bronchoscopically acquired specimens, we validate the use of bronchoscopy to investigate the lung microbiome.
A Catalog of Reference Genomes from the Human Microbiome
The human microbiome refers to the community of microorganisms, including prokaryotes, viruses, and microbial eukaryotes, that populate the human body. The National Institutes of Health launched an initiative that focuses on describing the diversity of microbial species that are associated with health and disease. The first phase of this initiative includes the sequencing of hundreds of microbial reference genomes, coupled to metagenomic sequencing from multiple body sites. Here we present results from an initial reference genome sequencing of 178 microbial genomes. From 547,968 predicted polypeptides that correspond to the gene complement of these strains, previously unidentified (\"novel\") polypeptides that had both unmasked sequence length greater than 100 amino acids and no BLASTP match to any nonreference entry in the nonredundant subset were defined. This analysis resulted in a set of 30,867 polypeptides, of which 29,987 (̃97%) were unique. In addition, this set of microbial genomes allows for ̃40% of random sequences from the microbiome of the gastrointestinal tract to be associated with organisms based on the match criteria used. Insights into pan-genome analysis suggest that we are still far from saturating microbial species genetic data sets. In addition, the associated metrics and standards used by our group for quality assurance are presented.
Oral microbiota in human systematic diseases
Oral bacteria directly affect the disease status of dental caries and periodontal diseases. The dynamic oral microbiota cooperates with the host to reflect the information and status of immunity and metabolism through two-way communication along the oral cavity and the systemic organs. The oral cavity is one of the most important interaction windows between the human body and the environment. The microenvironment at different sites in the oral cavity has different microbial compositions and is regulated by complex signaling, hosts, and external environmental factors. These processes may affect or reflect human health because certain health states seem to be related to the composition of oral bacteria, and the destruction of the microbial community is related to systemic diseases. In this review, we discussed emerging and exciting evidence of complex and important connections between the oral microbes and multiple human systemic diseases, and the possible contribution of the oral microorganisms to systemic diseases. This review aims to enhance the interest to oral microbes on the whole human body, and also improve clinician’s understanding of the role of oral microbes in systemic diseases. Microbial research in dentistry potentially enhances our knowledge of the pathogenic mechanisms of oral diseases, and at the same time, continuous advances in this frontier field may lead to a tangible impact on human health.
The oral microbiota change in oral cancer – a preliminary study
The relationship between oral bacteria and oral squamous cell carcinoma (OSCC) is not yet fully understood. This study aimed to profile the microbiota composition at tumour sites versus adjacent normal tissues in the oral mucosa of 10 OSCC patients using a qPCR Array. We recruited 10 OSCC patients (8 men and 2 women, aged 40 to 89 years) from the Department of Oral Surgery at the Medical University of Lublin. The diagnosis of OSCC was confirmed through clinical presentation and histopathology. Bilateral swabs were taken for further examination. The study identified 93 microorganisms using the Oral Disease Microbial DNA qPCR Array. From the 20 samples analyzed, we retrieved 868 species/genes across 37 genera, representing 90 different microbial species. The relative abundance of Fusobacterium nucleatum was significantly higher in OSCC samples (P < 0.05). Receiver operating characteristic (ROC) curve analysis identified F. nucleatum as a potential OSCC biomarker (p = 0.007). Correlation analysis revealed distinct ecological relationships within the bacterial communities of OSCC samples, consistent with the observed bacterial diversity. Notably, associations centred around Fusobacterium spp. were prominent in cancer samples, further suggesting a potential role for this genus in OSCC development. The differences in oral bacterial profiles between tumour and non-tumour tissues may serve as diagnostic markers.
Bifidobacterium animalis subsp. lactis BB-12 administration in early childhood: a randomized clinical trial of effects on oral colonization by mutans streptococci and the probiotic
A randomized clinical trial studied the effects of early administration of Bifidobacterium animalis subsp. lactis BB-12 (BB-12) on oral colonization of (1) mutans streptococci (MS), and (2) BB-12. In this double-blind, placebo-controlled study, infants (n = 106) received probiotic bacteria (BB-12 group), xylitol (X group), or sorbitol (S group). Test tablets were administered twice a day (from the age of 1-2 months) with a novel slow-release pacifier or a spoon (daily dose of BB-12 10(10) CFU, polyol 200-600 mg). Samples were collected from mucosa/teeth at the age of 8 months and 2 years for BB- 12 determination (qPCR) and plate culturing of MS (MSB, TYCSB), lactobacilli (Rogosa) and yeasts (Sabouraud). The MS levels of the mothers were determined (Dentocult SM Strip Mutans). The baseline characteristics of the three groups were similar. Mean duration of tablet delivery was 14.9 ± 6.7 months. In all groups, >90% of the mothers showed high MS counts (log CFU ≥5). MS colonization percentages of the children at the age of 2 years were rather low (BB-12 group: 6%; X group: 31%; S group: 10%; p < 0.05). The levels of lactobacilli and yeasts did not differ between the groups. BB-12 cell counts barely exceeding the detection limit were found in three of the oral samples of the 8-month-old children; however, the 2-year samples did not contain BB-12. The early administration of BB-12 did not result in permanent oral colonization of this probiotic or significantly affect MS colonization in the children.
Chemotherapy-induced oral mucositis is associated with detrimental bacterial dysbiosis
Background Gastrointestinal mucosal injury (mucositis), commonly affecting the oral cavity, is a clinically significant yet incompletely understood complication of cancer chemotherapy. Although antineoplastic cytotoxicity constitutes the primary injury trigger, the interaction of oral microbial commensals with mucosal tissues could modify the response. It is not clear, however, whether chemotherapy and its associated treatments affect oral microbial communities disrupting the homeostatic balance between resident microorganisms and the adjacent mucosa and if such alterations are associated with mucositis. To gain knowledge on the pathophysiology of oral mucositis, 49 subjects receiving 5-fluorouracil (5-FU) or doxorubicin-based chemotherapy were evaluated longitudinally during one cycle, assessing clinical outcomes, bacterial and fungal oral microbiome changes, and epithelial transcriptome responses. As a control for microbiome stability, 30 non-cancer subjects were longitudinally assessed. Through complementary in vitro assays, we also evaluated the antibacterial potential of 5-FU on oral microorganisms and the interaction of commensals with oral epithelial tissues. Results Oral mucositis severity was associated with 5-FU, increased salivary flow, and higher oral granulocyte counts. The oral bacteriome was disrupted during chemotherapy and while antibiotic and acid inhibitor intake contributed to these changes, bacteriome disruptions were also correlated with antineoplastics and independently and strongly associated with oral mucositis severity. Mucositis-associated bacteriome shifts included depletion of common health-associated commensals from the genera Streptococcus , Actinomyces , Gemella , Granulicatella , and Veillonella and enrichment of Gram-negative bacteria such as Fusobacterium nucleatum and Prevotella oris . Shifts could not be explained by a direct antibacterial effect of 5-FU, but rather resembled the inflammation-associated dysbiotic shifts seen in other oral conditions. Epithelial transcriptional responses during chemotherapy included upregulation of genes involved in innate immunity and apoptosis. Using a multilayer epithelial construct, we show mucositis-associated dysbiotic shifts may contribute to aggravate mucosal damage since the mucositis-depleted Streptococcus salivarius was tolerated as a commensal, while the mucositis-enriched F. nucleatum displayed pro-inflammatory and pro-apoptotic capacity. Conclusions Altogether, our work reveals that chemotherapy-induced oral mucositis is associated with bacterial dysbiosis and demonstrates the potential for dysbiotic shifts to aggravate antineoplastic-induced epithelial injury. These findings suggest that control of oral bacterial dysbiosis could represent a novel preventive approach to ameliorate oral mucositis.
Hyposalivation, oral health, and Candida colonization in independent dentate elders
Hyposalivation is an important problem in elders and could interfere with several oral functions and microbial ecology. While the number of independent elders who retain more natural teeth increases worldwide, few studies examined hyposalivation in this population. Thus, this study aims to examine relationships between hyposalivation, oral health conditions and oral Candida colonization in independent dentate elders and evaluate factors associated with salivary flow and Candida carriage. We conducted a cross-sectional study in fifty-three dentate elders (≥65 years old with at least 4 pairs of posterior occlusal contacts) with no, or well-controlled, systemic conditions. Participants were interviewed for medical history, subjective dry mouth symptoms, oral hygiene practices and denture information. Unstimulated and stimulated salivary flow rates, objective dry mouth signs, gingival, tongue-coating, and root-caries indices were recorded. Stimulated saliva was cultured on Sabouraud-dextrose agar for Candida counts. Candida species were identified using chromogenic Candida agar and polymerase chain reaction. Statistical significance level was set at p<0 . 05 . The results showed that hyposalivation was associated with higher gingival and tongue-coating indices ( p = 0 . 003 and 0 . 015 , respectively), but not root-caries index. Hyposalivation was also associated with higher prevalence of oral Candida colonization ( p = 0 . 010; adjusted OR = 4.36, 95% confidence interval = 1.29–14.72). These two indices and Candida load were negatively correlated with unstimulated and stimulated salivary flow rates. Interestingly, non- albicans Candida species were more prevalent in denture wearers ( p = 0 . 017 ). Hence, hyposalivation is a risk factor for poorer oral health and oral Candida colonization in independent dentate elders. Because of its potential adverse effects on oral and systemic health, hyposalivation should be carefully monitored in elders.
Oral microbiomes: more and more importance in oral cavity and whole body
Microbes appear in every corner of human life, and microbes affect every aspect of human life. The human oral cavity contains a number of different habitats. Synergy and interaction of variable oral microorganisms help human body against invasion of undesirable stimulation outside. However, imbalance of microbial flora contributes to oral diseases and systemic diseases. Oral microbiomes play an important role in the human microbial community and human health. The use of recently developed molecular methods has greatly expanded our knowledge of the composition and function of the oral microbiome in health and disease. Studies in oral microbiomes and their interactions with microbiomes in variable body sites and variable health condition are critical in our cognition of our body and how to make effect on human health improvement.
Lactobacillus brevis CD2 for Prevention of Oral Mucositis in Patients With Head and Neck Tumors: A Multicentric Randomized Study
Oropharyngeal mucositis occurs in virtually all patients with head and neck cancer receiving radiochemotherapy. The manipulation of the oral cavity microbiota represents an intriguing and challenging target. A total of 75 patients were enrolled to receive Lactobacillus brevis CD2 lozenges or oral care regimen with sodium bicarbonate mouthwashes. The primary endpoint was the incidence of grade 3 or 4 oropharyngeal mucositis during radiotherapy treatment. There was no statistical difference in the incidence of grade 3-4 oropharyngeal mucositis between the intervention and control groups (40.6% vs. 41.6% respectively, p=0.974). The incidence of pain, dysphagia, body weight loss and quality of life were not different between the experimental and standard arm. Our study was not able to demonstrate the efficacy of L. brevis CD2 lozenges in preventing radiation-induced mucositis in patients with head and neck cancer. Although modulating homeostasis of the salivary microbiota in the oral cavity seems attractive, it clearly needs further study.