Perioperative gum-chewing training prevents a decrease in tongue pressure after esophagectomy in thoracic esophageal cancer patients: a nonrandomized trial.

Tongue pressure (TP) decreases significantly after esophagectomy in esophageal cancer patients (ECPs). Meanwhile, 2 weeks of gum-chewing training (GCT) significantly increased TP in healthy university students. We examined whether perioperative GCT would decrease the proportion of patients exhibiting a decline in TP at 2 weeks postoperatively, and prevent postoperative complications, in thoracic ECPs (TECPs). This was a single-center interventional study, and nonrandomized study with a historical control group (HCG). TECPs who underwent first-stage radical esophagectomy were recruited. Thirty-two patients of 40 in the gum-chewing group (GCG) were completed perioperative GCT in 3 times daily. Propensity score matching was performed with covariates related to TP including preoperative age, sex, body mass index, and the repetitive saliva swallowing test result, and yielded a matched cohort of 25 case pairs. Eleven GCG patients [44.0%] exhibited significantly lower TP at 2 weeks postoperatively than before esophagectomy was significantly fewer than that of 19 patients [76.0%] in the HCG. The median number of fever days (> 38 °C) in the 2 weeks after esophagectomy in the GCG was significantly fewer than those in the HCG. Perioperative GCT may prevent postoperative TP decline and postoperative dysphagia-related complications after esophagectomy.

Association between oral condition and subjective psychological well-being among older adults attending a university hospital dental clinic: A cross-sectional study.

Positive psychological well-being has a favorable impact on survival rates in both healthy and unhealthy populations. Oral health is also associated with psychological well-being, is multidimensional in nature, and includes physical, psychological, emotional, and social domains that are integral to overall health and well-being. This study aimed to identify the associations between individual and environmental characteristics, oral condition and nutritional status in relation to subjective well-being among older adults using the Wilson and Cleary conceptual model. The participants were older adults (age ≥ 60 years) attending a university hospital. Subjective well-being was assessed using the World Health Organization-5 Well-Being Index, oral condition was assessed based on the number of bacteria in the tongue coating, oral wettability, tongue pressure, occlusal force, oral diadochokinesis, and masticatory ability, and subjective swallowing function was assessed using the Eating Assessment Tool, number of remaining teeth, and number of functional teeth. In addition, factors related to well-being, including social networks, life-space mobility, nutritional status, smoking history, drinking history, and medical history were assessed. In the analysis, structural equation modeling was used to investigate the association between oral condition and subjective well-being. Confirmatory factor analysis revealed oral condition as a latent variable, including tongue pressure, oral diadochokinesis /pa/, /ta/, /ka/, occlusal force, masticatory ability, subjective swallowing function, and number of functional teeth. Structural Equation Modeling revealed that oral condition was positively correlated with nutritional status, and nutritional status was positively correlated with the World Health Organization-5 Well-Being Index. These findings suggest that oral condition may influence subjective well-being via nutritional status or social environmental factors.

Patients scheduled to undergo esophageal surgery should have the highest priority for perioperative oral management triage: a cross-sectional study.

OBJECTIVES: An increasing number of patients visiting the dental office have a growing need for perioperative oral management (POM) to prevent postoperative complications. Therefore, it is necessary to determine which patients should receive preferential POM. This study investigated the dental status of patients scheduled to undergo surgery and addressed the priority for POM. METHODS: This retrospective study included a total of 150 patients who were scheduled to undergo surgery at the Department of Respiratory Surgery (DRS), Department of Neurological Surgery (DNS), Department of Gynecological Surgery (DGS), Department of Breast and Endocrine Surgery (DBES), and Department of Esophageal Surgery (DES) managed by the Perioperative Management Center of Okayama University Hospital. We compared the general and dental status of patients among the five groups. RESULTS: The DES group had significantly fewer teeth than the DBES group (p = 0.012), more severe periodontitis than both the DBES (p = 0.005) and DNS groups (p = 0.020), and poorer molar occlusal support status than both the DBES (p = 0.002) and DGS groups (p = 0.041). The DES group exhibited a significantly higher median age (p = 0.002), a higher ratio of males (p < 0.001), a higher prevalence of malignant tumors (p < 0.001), and higher proportions of smokers (p < 0.001) and drinkers (p < 0.001) than the other groups. CONCLUSION: Patients who underwent surgery at the DES had more dental problems than other surgery patients. Accordingly, these patients should be given the highest priority for POM triage.

Association between Self-Reported Chewing Status and Glycemic Control in Japanese Adults.

This cross-sectional study investigated the relationship between self-reported chewing status and glycemic control in 30,938 Japanese adults who participated in health checkups. Chewing status was evaluated using a self-reported questionnaire. We defined high hemoglobin A1c (HbA1c) levels as a HbA1c level ≥6.5%; 692 (2.2%) respondents met this criterion. After adjusting for gender, age, smoking status, exercise habits, body mass index and eating speed, high HbA1c levels was found to be associated with male gender (odds ratio (OR), 1.568; 95% confidence interval (CI), 1.310 to 1.878; p < 0.001), older age (OR, 1.077; 95% CI, 1.068 to 1.087; p < 0.001), higher body mass index (OR, 1.246; 95% CI, 1.225 to 1.268; p < 0.001), current smoker status (OR, 1.566; 95% CI, 1.303 to 1.882; p < 0.001) and chewing difficulty (OR, 1.302; 95% CI, 1.065 to 1.591; p < 0.05). In conclusion, self-reported chewing difficulty was associated with high HbA1c levels in Japanese adults.

Association of dental occlusal support with the Prognostic Nutritional Index in patients with esophageal cancer who underwent esophagectomy.

BACKGROUND: The Prognostic Nutritional Index is useful for predicting surgical risk and overall survival based on preoperative immunological and nutritional status in patients undergoing digestive organ cancer surgery. The purpose of this study was to examine the association between the Prognostic Nutritional Index and dental status in patients with esophageal cancer who underwent esophagectomy. METHODS: This retrospective case-control study included 73 patients who underwent resection of esophageal cancer (69 males, 4 females; age 36-83). General and dental status were evaluated. The Prognostic Nutritional Index was calculated based on the serum albumin concentration and the total lymphocyte count, and subjects were divided into two groups based on index scores: a higher group, characterized by scores ≥ 45 (n = 54); and a lower group, characterized by scores < 45 (n = 19). Univariate analysis and multiple logistic regression analyses were used to compare between groups. RESULTS: Total protein, C-reactive protein, the number of sound and total decayed, missing and filled teeth, and the rate of patients with poor dental occlusal support showed significant differences between the lower and higher Prognostic Nutritional Index groups (p < 0.05). Stepwise logistic regression analysis by backward selection approach showed that low total protein, few sound teeth, and poor status of dental occlusal support were significantly associated with the lower Prognostic Nutritional Index (p = 0.007, 0.042, and 0.009, respectively). CONCLUSION: Dental status, especially dental occlusal support and the number of sound teeth, showed a positive relationship with the Prognostic Nutritional Index in esophageal cancer patients who underwent esophagectomy.

A multicenter prospective cohort study on the effect of smoking cessation on periodontal therapies in Japan.

Few prospective studies have reported the effects of periodontal therapy on patients who attempted to quit smoking. This study aimed to assess how smoking cessation affects periodontal therapy. Twenty-five smokers with periodontitis were investigated by dividing them into two groups, a smoking cessation support group and a continued smoking group. Those in the support group received counseling and nicotine replacement therapy, followed by periodontal treatment conducted by dentists who had completed an e-learning course on smoking cessation. Clinical parameters were measured at baseline, 3, and 6 months. Most clinical parameters improved for those in the smoking cessation support group. There were no significant improvements in bleeding on probing (BOP) or the number of severe periodontal disease sites in the continued smoking group. Probing pocket depth (PPD) and clinical attachment levels (CAL) at sites that received scaling and root planing (SRP) significantly improved in all subjects. BOP did not improve at reevaluation in the smoking relapse subgroup. Patients in the smoking cessation support program led by dental professionals showed more improvement in BOP than those in the continued smoking group.

Association between Household Exposure to Secondhand Smoke and Dental Caries among Japanese Young Adults: A Cross-Sectional Study.

The long-term effects of secondhand smoke (SHS) on dental caries among Japanese young adults remain unclear. The purpose of this cross-sectional study was to evaluate whether household exposure to SHS is associated with dental caries in permanent dentition among Japanese young adults. The study sample included 1905 first-year university students (age range: 18-19 years) who answered a questionnaire and participated in oral examinations. The degree of household exposure to SHS was categorized into four levels according to the SHS duration: no experience (-), past, current SHS < 10 years, and current SHS ≥ 10 years. Dental caries are expressed as the total number of decayed, missing, and filled teeth (DMFT) score. The relationships between SHS and dental caries were determined by logistic regression analysis. DMFT scores (median (25th percentile, 75th percentile)) were significantly higher in the current SHS ≥ 10 years (median: 1.0 (0.0, 3.0)) than in the SHS-(median: 0.0 (0.0, 2.0)); p = 0.001). DMFT ≥ 1 was significantly associated with SHS ≥ 10 years (adjusted odds ratio: 1.50, 95% confidence interval: 1.20-1.87, p < 0.001). Long-term exposure to SHS (≥10 years) was associated with dental caries in permanent dentition among Japanese young adults.

Relationship of Salivary Microbiome with the Worsening of the Periodontal Health Status in Young Adults: A 3-Year Cohort Study.

The purpose of this prospective cohort study was to investigate the influence of the salivary microbiome on the worsening of the periodontal health status among Japanese young adults. We assessed the data of systemically healthy and non-smoking young (18-22 years) university students (n = 457) from Okayama University at baseline (2013) and follow-up (2016). The worsening group was defined based on an increase in the percentage of bleeding on probing (%BOP) or an increase in probing pocket depth (PPD) from <4 mm to ≥4 mm. Unstimulated saliva samples were randomly collected from 69 students for microbiome analysis at follow-up. The salivary microbiome was assessed through 16S rRNA metagenomic sequencing. The type of community in the salivary microbiome clustered by statistical analysis and diversity was not significantly associated with the worsening of the periodontal health status in cases of increasing %BOP and PPD (p > 0.05). The prevalence of some species was significantly higher in the worsening group than in the non-worsening group (p < 0.05) in both cases. The worsening of the periodontal health status was associated with some species, but not the type of community and diversity in the salivary microbiome among Japanese young adults.

Associations between sleep bruxism, sleep quality, and exposure to secondhand smoke in Japanese young adults: a cross-sectional study.

OBJECTIVE: Sleep bruxism, a major sleep disorder that causes serious harm to oral health, is considered a multifactorial disease. Sleep bruxism can be induced by smoking, which also adversely affects sleep quality. The objective of present study was to clarify the associations between sleep bruxism, sleep quality, and exposure to secondhand smoke (SHS). METHODS: To assess the prevalence of sleep bruxism, sleep quality, and SHS exposure, we conducted oral examinations and self-report questionnaires on university students in Japan. Sleep bruxism and quality were screened using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) and the third edition of the International Classification of Sleep Disorders (ICSD-3). The inclusion criteria were adults aged between 18 and 19 years, non-smokers and non-alcohol drinkers. The exclusion criteria was failing to complete the questionnaire in full. RESULTS: We analyzed a total of 1781 Japanese young adults. Young adult females who had been exposed to SHS had worse sleep quality (p = 0.019) than those who had not. Young adult female with worse sleep quality showed a higher prevalence of sleep bruxism (p = 0.034) than those with better sleep quality. Using structural equation modeling, direct associations were identified between SHS exposure and poor sleep quality (standardized coefficients, 0.153; p = 0.008) and between sleep bruxism and poor sleep quality (standardized coefficients, 0.187; p = 0.022) in young adult females. However, no association was found among young adult males. CONCLUSION: SHS exposure is indirectly associated with sleep bruxism through poor sleep quality in Japanese young adult females.

Influence of Occupational Stress and Coping Style on Periodontitis among Japanese Workers: A Cross-Sectional Study.

The aim of this cross-sectional study was to evaluate the association between the influence of occupational stress and coping style on periodontitis among Japanese workers. The study sample included 738 workers (age range: 19-65 years) at a manufacturing company in Kagawa Prefecture, Japan. To analyze occupational stress and coping style, all participants answered a self-report questionnaire composed of items on their work environment and oral health behavior. Oral examinations were performed by calibrated dentists. Among all workers, 492 (66.7%) workers were diagnosed with periodontitis, and 50 (6.8%) were diagnosed with a high stress-low coping condition. Significant differences (p < 0.05) were observed between the periodontitis and non-periodontitis groups in terms of age, gender, body mass index, smoking status, daily alcohol drinking, monthly overtime work, worker type, and stress-coping style. Logistic regression analysis showed that a high stress-low coping condition was associated with an increased risk of periodontitis (odds ratio: 2.79, 95% confidence interval: 1.05-7.43, p = 0.039). These findings suggest that a high stress-low coping condition is associated with periodontitis among the 19-65 years of age group of Japanese workers.

Relationship between acetaldehyde concentration in mouth air and characteristics of microbiota of tongue dorsum in Japanese healthy adults: a cross-sectional study.

OBJECTIVE: Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum. The aim of this study was to investigate the relationship between acetaldehyde concentration in mouth air and bacterial characteristics on the tongue dorsum. METHODOLOGY: Thirty-nine healthy volunteers participated in the study. Acetaldehyde concentrations in mouth air were evaluated by a high-sensitivity semiconductor gas sensor. A 16S rRNA gene sequencing technique was used to compare microbiomes between two groups, focusing on the six samples with the highest acetaldehyde concentrations (HG) and the six samples with lowest acetaldehyde concentrations (LG). RESULTS: Acetaldehyde concentration increased in correlation with the increase in bacterial count (p=0.048). The number of species observed in the oral microbiome of the HG was higher than that in the oral microbiome of the LG (p=0.011). The relative abundances of Gemella sanguinis, Veillonella parvula and Neisseria flavescens in the oral microbiome of the HG were higher than those in the oral microbiome of the LG (p<0.05). CONCLUSION: Acetaldehyde concentration in mouth air was associated with bacterial count, diversity of microbiome, and relative abundance of G. sanguinis, V. parvula, and N. flavescens.

Smoking and periodontal microorganisms.

Resolution of dysbiosis following treatment for periodontal disease and tobacco dependence has been reported in longitudinal intervention studies. In the present report, we evaluated the biological findings regarding the effect of smoking on the periodontal microbiome. A standardized electronic search was conducted using MEDLINE; overall, 1099 papers were extracted. Studies that addressed the relationship between tobacco and periodontal pathogens were included. Finally, 42 papers were deemed appropriate for the present review. Functional changes in periodontal pathogens exposed to nicotine and cigarette smoke extract support the clinical findings regarding dysbiosis of the subgingival microbiome. Dysbiosis of the periodontal microbiome was presented in smokers regardless of their periodontal condition (healthy, gingivitis, or periodontitis) and remained significant only in smokers even after the resolution of experimentally-induced gingivitis and following reduction of clinical signs of periodontitis with non-surgical periodontal treatment and over 3 months post-therapy. Based on these findings, smoking cessation in periodontitis patients is beneficial for promoting a health-compatible subgingival microbial community. To maximize the benefits of these interventions in dental settings, further studies on periodontal microbiome are needed to elucidate the impact of tobacco intervention on preventing recurrence of periodontal destruction in the susceptible subjects.

Change in tongue pressure and the related factors after esophagectomy: a short-term, longitudinal study.

BACKGROUND: Dysphagia is a prominent symptom after esophagectomy and may cause aspiration pneumonia. Swallowing evaluation after esophagectomy can predict and help control the incidence of postoperative pneumonia. The aim of this study was to clarify whether the change in tongue pressure was associated with any related factor and postoperative dysphagia/pneumonia in patients with esophageal cancer after esophagectomy. METHODS: Fifty-nine inpatients (41 males and 18 females; 33-77 years old) who underwent esophagectomy participated in this study. Measurement of tongue pressure and the repetitive saliva swallowing test (RSST) was performed before esophagectomy (baseline) and at 2 weeks postoperatively. The general data were collected from patients' medical records, including sex, age, type of cancer, cancer stage, location of cancer, operative approach, history of previous chemotherapy, surgical duration, amount of bleeding during surgery, incidences of postoperative complications, intubation period, period between surgery and initiation of oral alimentation, and intensive care unit (ICU) stay, blood chemical analysis, and lifestyle. RESULTS: Tongue pressure decreased significantly after esophagectomy (p = 0.011). The decrease of tongue pressure was significantly associated with length of ICU stay and preoperative tongue pressure on multiple regression analysis (p < 0.05). The decrease of tongue pressure in the RSST < 3 or postoperative pneumonia (+) group was significantly greater than in the RSST ≥ 3 (p = 0.003) or pneumonia (-) group (p = 0.021). CONCLUSIONS: The decrease in tongue pressure was significantly associated with the length of ICU stay, preoperative tongue pressure, and the incidence of dysphagia and pneumonia among inpatient after esophagectomy.

Efficacy of Oral Care Provided by Interprofessional Collaboration for a Patient with Esophageal Cancer Associated with Post-polio Syndrome during Neoadjuvant Chemotherapy.

Preoperative oral care is helpful to prevent postoperative complications in patients who are undergoing esophagectomy. Here, we report the case of an 81-year-old Japanese man with an upper limb disability caused by post-polio syndrome who was receiving neoadjuvant chemotherapy for esophageal cancer. He had poor oral health status and developed oral complications as a side effect of chemotherapy. He could not brush his teeth by himself. However, infection control by oral care provided by an interprofessional collaboration successfully improved his oral hygiene, and his follow-up involved no severe complications. Interprofessional collaboration is useful especially for patients with upper limb disability.

Relationship Between Renal Dysfunction and Oral Mucositis in Patients Undergoing Concurrent Chemoradiotherapy for Pharyngeal Cancer: A Retrospective Cohort Study.

BACKGROUND/AIM: The aim of this retrospective cohort study was to investigate the association between renal dysfunction (RD) and the development of oral mucositis (OM) in patients undergoing concurrent chemoradiotherapy (CCRT) for pharyngeal cancer including radiation to the oral cavity. PATIENTS AND METHODS: Of 130 patients diagnosed as having pharyngeal cancer who received CCRT at the Okayama University Hospital Head and Neck Cancer Center, 44 were finally selected. RESULTS: During the observation period, 24 (54.5%) patients experienced severe OM (grade 3). The Cox proportional hazards regression model demonstrated that RD (hazard ratio(HR)=2.45, 95% confidence interval(CI)=1.067-6.116, p=0.035) and nasopharynx/oropharynx as center of the irradiated area (HR=2.56, 95% CI=1.072-5.604, p=0.034) were significantly associated with the incidence of severe OM (grade 3). CONCLUSION: In patients with pharyngeal cancer treated with CCRT including radiation to the oral cavity, RD at baseline can be a risk factor for developing severe OM.

Relationship between acetaldehyde concentration in mouth air and characteristics of microbiota of tongue dorsum in Japanese healthy adults: a cross-sectional study

Abstract Acetaldehyde, associated with consumption of alcoholic beverages, is known to be a carcinogen and to be related to the tongue dorsum. Objective The aim of this study was to investigate the relationship between acetaldehyde concentration in mouth air and bacterial characteristics on the tongue dorsum. Methodology Thirty-nine healthy volunteers participated in the study. Acetaldehyde concentrations in mouth air were evaluated by a high-sensitivity semiconductor gas sensor. A 16S rRNA gene sequencing technique was used to compare microbiomes between two groups, focusing on the six samples with the highest acetaldehyde concentrations (HG) and the six samples with lowest acetaldehyde concentrations (LG). Results Acetaldehyde concentration increased in correlation with the increase in bacterial count (p=0.048). The number of species observed in the oral microbiome of the HG was higher than that in the oral microbiome of the LG (p=0.011). The relative abundances of Gemella sanguinis, Veillonella parvula and Neisseria flavescens in the oral microbiome of the HG were higher than those in the oral microbiome of the LG (p<0.05). Conclusion Acetaldehyde concentration in mouth air was associated with bacterial count, diversity of microbiome, and relative abundance of G. sanguinis, V. parvula, and N. flavescens.

New oral hygiene care regimen reduces postoperative oral bacteria count and number of days with elevated fever in ICU patients with esophageal cancer.

Using a controlled pre/post study design, we investigated the effects of professional mechanical cleaning of the oral cavity with benzethonium chloride, interdental brushes, and hydrogen peroxide on the number of oral bacteria and postoperative complications among esophageal cancer patients in an intensive care unit. Before surgery, 44 patients with esophageal cancer were recruited at Okayama Hospital from January through August 2015. The control group (n = 23) received routine oral hygiene care in the intensive care unit. The intervention group (n = 21) received intensive interdental cleaning with benzethonium chloride solution and tongue cleaning with hydrogen peroxide. The number of oral bacteria on the tongue surface and plaque index were significantly lower in the intervention group than in the control group on postoperative days 1 and 2 (P < 0.05). Additionally, the number of days with elevated fever during a 1-week period was significantly lower in the intervention group than in the control group (P = 0.037). As compared with routine oral hygiene, a new oral hygiene regimen comprising benzethonium chloride, interdental brushes, and hydrogen peroxide significantly reduced the number of oral bacteria and days with elevated fever in patients with esophageal cancer.

Commensal Microbiota Enhance Both Osteoclast and Osteoblast Activities.

Recent studies suggest that the commensal microbiota affects not only host energy metabolism and development of immunity but also bone remodeling by positive regulation of osteoclast activity. However, the mechanism of regulation of bone cells by the commensal microbiota has not been elucidated. In this study, 8-week-old specific pathogen-free (SPF) and germ-free (GF) mice were compared in terms of alveolar bones and primary osteoblasts isolated from calvarias. Micro-CT analysis showed that SPF mice had larger body size associated with lower bone mineral density and bone volume fraction in alveolar bones compared with GF mice. Greater numbers of osteoclasts in alveolar bone and higher serum levels of tartrate-resistant acid phosphatase 5b were observed in SPF mice. Tissue extracts from SPF alveolar bone showed higher levels of cathepsin K, indicating higher osteoclast activity. SPF alveolar extracts also showed elevated levels of γ-carboxylated glutamic acid⁻osteocalcin as a marker of mature osteoblasts compared with GF mice. Polymerase chain reaction (PCR) array analysis of RNA directly isolated from alveolar bone showed that in SPF mice, expression of mRNA of osteocalcin, which also acts as an inhibitor of bone mineralization, was strongly enhanced compared with GF mice. Cultured calvarial osteoblasts from SPF mice showed reduced mineralization but significantly enhanced expression of mRNAs of osteocalcin, alkaline phosphatase, insulin-like growth factor-I/II, and decreased ratio of osteoprotegerin/receptor activator of nuclear factor-kappa B ligand compared with GF mice. Furthermore, PCR array analyses of transcription factors in cultured calvarial osteoblasts showed strongly upregulated expression of Forkhead box g1. In contrast, Gata-binding protein 3 was strongly downregulated in SPF osteoblasts. These results suggest that the commensal microbiota prevents excessive mineralization possibly by stimulating osteocalcin expression in osteoblasts, and enhances both osteoblast and osteoclast activity by regulating specific transcription factors.

Impact of commensal flora on periodontal immune response to lipopolysaccharide.

BACKGROUND: Commensal flora are involved in the appropriate development of the mature immune system. However, it is unclear how commensal flora contribute to immune responses against periodontal pathogens, including the response to lipopolysaccharide (LPS). The purpose of this study was to evaluate the expression of immune responses after topical application of LPS in germ-free (GF) and specific-pathogen-free (SPF) mice. METHODS: GF and SPF mice at 8 weeks of age were randomly divided into four groups each: a baseline group (n = 4/group) and three experimental groups (n = 6/group). Experimental groups received topical application of Porphyromonas gingivalis LPS (10 µg/µL) into the palatal gingival sulcus. Sampling was performed before LPS application (baseline) and at 3, 24, or 72 hours after LPS application. The numbers of neutrophils, CD4+ , and CD8+ T cells in periodontal tissue were evaluated by immunohistochemistry. Expression of genes encoding cytokines, chemokines, and a transcription factor was determined by real-time PCR. RESULTS: SPF mice, but not GF mice, showed an increased number of CD4+ T cells in the periodontal tissue at 3 hours after LPS application, compared with the number at baseline (p < 0.05). Gene expressions of tumor necrosis factor-α (Tnf-α) and forkhead box protein p3 (Foxp3) was also significantly higher in the SPF mice than in the GF mice at 3 hours after LPS application (p < 0.05). The number of neutrophils peaked at 24 hours in both GF and SPF mice. CONCLUSIONS: LPS-exposed SPF mice exhibited increases in the number of CD4+ T cells and in Tnf-α and Foxp3 gene expression in periodontal tissue compared with LPS-exposed GF mice.

Unusual oral mucosal microbiota after hematopoietic cell transplantation with glycopeptide antibiotics: potential association with pathophysiology of oral mucositis.

Severe oral mucositis occurs frequently in patients receiving hematopoietic stem cell transplantation (HCT). Oral mucosal bacteria can be associated with progression of oral mucositis, and systemic infection may occur via ulcerative oral mucositis. However, little information is available regarding the oral microbiota after HCT. Here, PCR-denaturing gradient gel electrophoresis (DGGE) was performed to characterize the oral mucosal microbiota, which can be affected by antibiotics, before and after HCT. Sixty reduced-intensity HCT patients were enrolled. Three patients with the least antibiotic use (quinolone prophylaxis and/or ß-lactam monotherapy group) and three patients with the most antibiotic use (ß-lactam-glycopeptide combination therapy group) were selected. Bacterial DNA samples obtained from the oral mucosa before and after HCT were subjected to PCR-DGGE. The trajectory of oral mucositis was evaluated. The oral mucosal microbiota in the ß-lactam-glycopeptide combination therapy group was different from that in the quinolone prophylaxis and/or ß-lactam monotherapy group, and Staphylococcus spp. and Enterococcus spp. were identified. Lautropia mirabilis was dominant in one patient. Ulcerative oral mucositis was observed only in the ß-lactam-glycopeptide combination therapy group. In conclusion, especially with the use of strong antibiotics, such as glycopeptides, the oral mucosal microbiota differed completely from that under normal conditions and consisted of Staphylococcus spp., Enterococcus spp., and unexpectedly L. mirabilis. The normal oral microbiota consists not only of bacteria, but these unexpected bacteria could be involved in the pathophysiology as well as systemic infection via oral mucositis. Our results can be used as the basis for future studies in larger patient populations.