Oral Microbiota Composition and Antimicrobial Antibody Response in Patients with Recurrent Aphthous Stomatitis

Oral Mycobiome Alterations in Postmenopausal Women: Links to Inflammation, Xerostomia, and Systemic Health

The oral mycobiome plays a critical role in maintaining oral and systemic health, with its composition and function influenced by various physiological and environmental factors. This descriptive review explores the changes in the oral mycobiome among postmenopausal women, examining how aging and associated inflammatory processes contribute to these alterations. These changes are linked to an increased prevalence of xerostomia, oral dysbiosis, and inflammation, which can negatively impact both oral and systemic health. We discuss the impact of hormonal fluctuations and immune senescence on fungal diversity and abundance, highlighting key species implicated in oral and systemic diseases. The review also examines the role of systemic conditions and medications, which are common in postmenopausal women, in further exacerbating oral mycobiome alterations. Lastly, it highlights the need for future research to better understand these interactions and develop targeted therapeutic strategies. The current literature indicates a significant association between menopausal status, age-related mycobiome shifts, and increased inflammatory responses, suggesting potential pathways for intervention.

The underestimated role of major skin commensal Malassezia furfur in the development of neonatal invasive fungal infections

In recent years, some new evidence on the role of Malassezia in late-onset sepsis in immunocompromised patients have been published, but there are still very few studies with special focus on newborns. The prevalence of Malassezia-associated conditions in 3519 newborn patients of general and surgical neonatal intensive care units (NICU) was assessed. All patients underwent pharyngeal and rectal swab screening for Malassezia spp. Identification of Malassezia spp. was carried out with the use of an adapted nutrient media, microscopic assessment of yeast cell morphology, and real-time PCR analysis. Malassezia furfur-induced invasive mycoses (IM) were developed 2.5 times more often in very low birth weight (VLBW) M. furfur-positive newborns, than in neonates with birth weight ≥1500 g, and affecting 15.8 % of VLBW infants. Funguria occurred 16 times more often in VLBW babies, but fungemia incidence was similar for both weight categories. Gastrointestinal (GI) colonization was found in 94.6 % of Malassezia-positive population, and in 8 % of all studied neonates. Among IM patients, death rate was 6.5 %. The specific pathogen was highly detectable by a combination of real-time PCR and an adapted nutrient media. Colonization with M. furfur in newborns was associated with low gestational age, VLBW, and long stay in NICU. The findings emphasize the need to monitor colonization and infection with M. furfur in neonates, staying in ICU for more than two weeks and to improve current diagnostic approaches by using real-time PCR and an adapted nutrient media for M. furfur isolation.

Aphthous stomatitis - computational biology suggests external biotic stimulus and immunogenic cell death involved

BACKGROUND

The exact cause of recurrent aphthous stomatitis is still unknown, making it a challenge to develop effective treatments. This study employs computational biology to investigate the molecular basis of recurrent aphthous stomatitis, aiming to identify the nature of the stimuli triggering these ulcers and the type of cell death involved.

METHODS

To understand the molecular underpinnings of recurrent aphthous stomatitis, we used the Génie tool for gene identification, targeting those associated with cell death in recurrent aphthous stomatitis. The ToppGene Suite was employed for functional enrichment analysis. We also used Reactome and InteractiVenn for protein integration and prioritization against a PANoptosis gene list, enabling the construction of a protein-protein interaction network to pinpoint key proteins in recurrent aphthous stomatitis pathogenesis.

RESULTS

The study's computational approach identified 1,375 protein-coding genes linked to recurrent aphthous stomatitis. Critical among these were proteins responsive to bacterial stimuli, especially high mobility group protein B1 (HMGB1), toll-like receptor 2 (TLR2), and toll-like receptor 4 (TLR4). The enrichment analysis suggested an external biotic factor, likely bacterial, as a triggering agent in recurrent aphthous stomatitis. The protein interaction network highlighted the roles of tumor necrosis factor (TNF), NF-kappa-B essential modulator (IKBKG), and tumor necrosis factor receptor superfamily member 1A (TNFRSF1A), indicating an immunogenic cell death mechanism, potentially PANoptosis, in recurrent aphthous stomatitis.

CONCLUSION

The findings propose that bacterial stimuli could trigger recurrent aphthous stomatitis through a PANoptosis-related cell death pathway. This new understanding of recurrent aphthous stomatitis pathogenesis underscores the significance of oral microbiota in the condition. Future experimental validation and therapeutic strategy development based on these findings are necessary.

Bacteremia due to Lachnoanaerobaculum umeaense in a patient with acute myeloid leukemia during chemotherapy: A case report, and a review of the literature

The present case reports a bacteremia due to Lachnoanaerobaculum umeaense (a Gram-positive, filamentous, rod-shaped, anaerobic, spore-forming bacillus present in the human oral microbiota) in a patient treated for acute myeloid leukemia. After failed identification by MALDI-TOF, identification was done by sequencing of 16s rRNA. The patient was successfully treated with Amoxicillin-clavulanic acid and ciprofloxacin for seven days. Comparison of V1-V3 regions of the bacterial 16S rRNA gene gene with published sequences failed to classify the strain as pathogenic or non-pathogenic based on this phylogenetic classification alone. Although Lachnoanaerobaculum gingivalis are known to be associated with bacteremia in patients with acute myeloid leukemia, this clinical case of infection by L. umeaense argues for further studies that will lead to more efficient classification of the infection by these microorganisms.

Oral Microbiota Linking Associations of Dietary Factors with Recurrent Oral Ulcer

Recurrent oral ulcer (ROU) is a prevalent and painful oral disorder with implications beyond physical symptoms, impacting quality of life and necessitating comprehensive management. Understanding the interplays between dietary factors, oral microbiota, and ROU is crucial for developing targeted interventions to improve oral and systemic health. Dietary behaviors and plant-based diet indices including the healthful plant-based diet index (hPDI) were measured based on a validated food frequency questionnaire. Saliva microbial features were profiled using 16S rRNA gene amplicon sequencing. In this cross-sectional study of 579 community-based participants (aged 22-74 years, 66.5% females), 337 participants had ROU. Participants in the highest tertile of hPDI exhibited a 43% lower prevalence of ROU (odds ratio [OR] = 0.57, 95%CI: 0.34-0.94), compared to the lowest tertile, independent of demographics, lifestyle, and major chronic diseases. Participants with ROU tended to have lower oral bacterial richness (Observed ASVs, p < 0.05) and distinct bacterial structure compared to those without ROU (PERMANOVA, p = 0.02). The relative abundances of 16 bacterial genera were associated with ROU (p-FDR < 0.20). Of these, Olsenella, TM7x, and unclassified Muribaculaceae were identified as potential mediators in the association between hPDI and ROU (all p-mediations < 0.05). This study provides evidence of the intricate interplays among dietary factors, oral microbiota, and ROU, offering insights that may inform preventive and therapeutic strategies targeting diets and oral microbiomes.

Ascomycetes yeasts: The hidden part of human microbiome

The fungal component of the microbiota, the mycobiota, has been neglected for a long time due to its poor richness compared to bacteria. Limitations in fungal detection and taxonomic identification arise from using metagenomic approaches, often borrowed from bacteriome analyses. However, the relatively recent discoveries of the ability of fungi to modulate the host immune response and their involvement in human diseases have made mycobiota a fundamental component of the microbial communities inhabiting the human host, deserving some consideration in host-microbe interaction studies and in metagenomics. Here, we reviewed recent data on the identification of yeasts of the Ascomycota phylum across human body districts, focusing on the most representative genera, that is, Saccharomyces and Candida. Then, we explored the key factors involved in shaping the human mycobiota across the lifespan, ranging from host genetics to environment, diet, and lifestyle habits. Finally, we discussed the strengths and weaknesses of culture-dependent and independent methods for mycobiota characterization. Overall, there is still room for some improvements, especially regarding fungal-specific methodological approaches and bioinformatics challenges, which are still critical steps in mycobiota analysis, and to advance our knowledge on the role of the gut mycobiota in human health and disease. This article is categorized under: Immune System Diseases > Genetics/Genomics/Epigenetics Immune System Diseases > Environmental Factors Infectious Diseases > Environmental Factors.

Armillariella tabescens polysaccharide treated rats with oral ulcers through modulation of oral microbiota and activation of the Nrf2/HO-1 pathway

We identified Armillariella tabescens polysaccharide (PAT-W), a compound isolated from a Chinese medicinal mushroom, as a potential novel oral ulcer (OU) drug. In treating OU rats with PAT-W, especially in the high-dose group, oral mucous tissue TNF-α, IL-1β, and IL-6 levels were markedly reduced, and pathological morphology and oxidative stress were effectively improved. Western blot analysis showed that the PAT-W channel ameliorated OU mucous tissue damage, which depends on the activation of the Nrf2/HO-1 antioxidant signaling pathway. Furthermore, high-throughput sequencing results showed that PAT-W regulated the maladjustment of the oral microbiota caused by OU. Therefore, based on the new viewpoint of activating the Nrf2/HO-1 pathway and regulating oral microbiota, PAT-W is expected to become a new natural drug for treating oral ulcers and improving patients' quality of life.

[Recurrent aphthous stomatitis]

Recurrent aphthous stomatitis (RAS) is the most common clinical disease of the oral mucosa. Its prevalence in the general population varies between 5 and 25%, with its peak appearance in the second decade of life. So far, the etiopathogenesis is not clear. In genetically predisposed patients, the effect of certain triggering factors would initiate the proinflammatory cytokine cascade directed against certain regions of the oral mucosa. Ulcers are round or oval with well-defined erythematous margins and a shallow ulcerated center covered with a gray or yellowish fibrinous pseudomembrane. The ulcers may reappear at intervals of a few days and months. Given the appearance of periodic thrush in the oral mucosa, the first thing to do is to make a correct differential diagnosis, rule out associated systemic diseases and assess treatable causes before reaching the diagnosis of RAS. At present, there is no curative treatment.

Oral microbiota in active and passive states of recurrent aphthous stomatitis: An analysis of case-control studies

OBJECTIVE

This study was presented to reveal the most distinct microbial prevalence in recurrent aphthous stomatitis (RAS) lesions compared to healthy controls.

DESIGN

The case-control studies were selected in electronic databases until Nov 2022 with key search terms, and the eligible publications were screened and analyzed by independent authors.

RESULTS

A total of 14 studies were identified, which included 531 cases of active states of RAS (AS-RAS), 92 cases of passive states of RAS (PS-RAS) and 372 healthy controls. The most sample pattern was the mucosa swab performed in 8 of 14 studies, biopsies in 3 studies, followed by micro-brush, and saliva. A variety of bacteria in higher or lower abundance were observed in RAS lesions.

CONCLUSIONS

The etiopathogenesis of RAS may not be ascribed to a single pathogen. A possible explanation is that microbial interactions modify immune response or destroy the epithelial integrity, thus contributing to the development of the condition.

Oral microbiota dysbiosis accelerates the development and onset of mucositis and oral ulcers

With the rapid development of metagenomic high-throughput sequencing technology, more and more oral mucosal diseases have been proven to be associated with oral microbiota shifts or dysbiosis. The commensal oral microbiota can greatly influence the colonization and resistance of pathogenic microorganisms and induce primary immunity. Once dysbiosis occurs, it can lead to damage to oral mucosal epithelial defense, thus accelerating the pathological process. As common oral mucosal diseases, oral mucositis and ulcers seriously affect patients' prognosis and quality of life. However, from the microbiota perspective, the etiologies, specific alterations of oral flora, pathogenic changes, and therapy for microbiota are still lacking in a comprehensive overview. This review makes a retrospective summary of the above problems, dialectically based on oral microecology, to provide a new perspective on oral mucosal lesions management and aims at improving patients' quality of life.

Skin microbiota signature distinguishes IBD patients and reflects skin adverse events during anti-TNF therapy

Crohn's disease (CD) and ulcerative colitis (UC) are two forms of inflammatory bowel disease (IBD), where the role of gut but not skin dysbiosis is well recognized. Inhibitors of TNF have been successful in IBD treatment, but up to a quarter of patients suffer from unpredictable skin adverse events (SkAE). For this purpose, we analyzed temporal dynamics of skin microbiota and serum markers of inflammation and epithelial barrier integrity during anti-TNF therapy and SkAE manifestation in IBD patients. We observed that the skin microbiota signature of IBD patients differs markedly from healthy subjects. In particular, the skin microbiota of CD patients differs significantly from that of UC patients and healthy subjects, mainly in the retroauricular crease. In addition, we showed that anti-TNF-related SkAE are associated with specific shifts in skin microbiota profile and with a decrease in serum levels of L-FABP and I-FABP in IBD patients. For the first time, we showed that shifts in microbial composition in IBD patients are not limited to the gut and that skin microbiota and serum markers of the epithelium barrier may be suitable markers of SkAE during anti-TNF therapy.

Association between ustekinumab therapy and changes in specific anti-microbial response, serum biomarkers, and microbiota composition in patients with IBD: A pilot study

BACKGROUND

Ustekinumab, is a new therapy for patients with IBD, especially for patients suffering from Crohn's disease (CD) who did not respond to anti-TNF treatment. To shed light on the longitudinal effect of ustekinumab on the immune system, we investigated the effect on skin and gut microbiota composition, specific immune response to commensals, and various serum biomarkers.

METHODOLOGY/PRINCIPAL FINDINGS

We recruited 11 patients with IBD who were monitored over 40 weeks of ustekinumab therapy and 39 healthy controls (HC). We found differences in the concentrations of serum levels of osteoprotegerin, TGF-β1, IL-33, and serum IgM antibodies against Lactobacillus plantarum between patients with IBD and HC. The levels of these biomarkers did not change in response to ustekinumab treatment or with disease improvement during the 40 weeks of observation. Additionally, we identified differences in stool abundance of uncultured Subdoligranulum, Faecalibacterium, and Bacteroides between patients with IBD and HC.

CONCLUSION/SIGNIFICANCE

In this preliminary study, we provide a unique overview of the longitudinal monitoring of fecal and skin microbial profiles as well as various serum biomarkers and humoral and cellular response to gut commensals in a small cohort of patients with IBD on ustekinumab therapy.

Functional biomes beyond the bacteriome in the oral ecosystem

Selective constraint and pressures upon the host tissues often signifies a beneficial microbiome in any species. In the context of oral microbiome this displays a healthy microbial cosmos resisting the colonization and helps in rendering protection. This review highlights the endeavors of the oral microbiome beyond the bacteriome encompassing virome, mycobiome, protozoa and archaeomes in maintaining the oral homeostasis in health and disease. Scientific data based on the peer-reviewed publications on the microbial communities of the oral microbiome were selected and collated from the scientific database collection sites of web of science (WOS), pubmed central, Inspec etc., from 2010 to 2021 using the search key words like oral microbiome, oral microbiota, oral virome, oral bacteriome, oral mycobiome and oral archaeome. Data excluded were from conference proceedings, abstracts and book chapters. The oral homeostasis in both the health and disease conditions, mostly is balanced by the unrevealed virome, mycobiome, oral protozoa and archaeome. The review documents the need to comprehend the diversity that prevails among the kingdoms in order to determine the specific role played by each domain. Oral microbiome is also a novel research arena to develop drug and targeted therapies to treat various oro-dental infections.

The Oral Microbiota: Community Composition, Influencing Factors, Pathogenesis, and Interventions

The human oral cavity provides a habitat for oral microbial communities. The complexity of its anatomical structure, its connectivity to the outside, and its moist environment contribute to the complexity and ecological site specificity of the microbiome colonized therein. Complex endogenous and exogenous factors affect the occurrence and development of the oral microbiota, and maintain it in a dynamic balance. The dysbiotic state, in which the microbial composition is altered and the microecological balance between host and microorganisms is disturbed, can lead to oral and even systemic diseases. In this review, we discuss the current research on the composition of the oral microbiota, the factors influencing it, and its relationships with common oral diseases. We focus on the specificity of the microbiota at different niches in the oral cavity, the communities of the oral microbiome, the mycobiome, and the virome within oral biofilms, and interventions targeting oral pathogens associated with disease. With these data, we aim to extend our understanding of oral microorganisms and provide new ideas for the clinical management of infectious oral diseases.

Comparative Evaluation of the Salivary and Buccal Mucosal Microbiota by 16S rRNA Sequencing for Forensic Investigations

The human microbiome has emerged as a new potential biomarker for forensic investigations with the development of high-throughput sequencing and bioinformatic analysis during the last decade. The oral cavity has many different microbial habitats, with each habit colonized by specific and individualized microbiota. As saliva and buccal mucosa are common biological evidence in forensic science, understanding the differences of microbial communities between the two is important for forensic original identification. Moreover, the oral microbiota is individualized, whereas there are few studies on the application of forensic personal identification that need to be supplemented. In this study, Streptococcus was the most abundant genus, with an average relative abundance of 49.61% in the buccal mucosa, while in the saliva, Streptococcus, Veillonella, and Neisseria had similar proportions (20%, 15%, 16%) and were the dominant genera. The α and β diversity displayed a significant distinctness between the saliva and buccal mucosal groups. The community assembly mechanism stated that the deterministic process played a more significant effect in shaping the salivary bacterial community assembly than buccal mucosa, which explained the microbial differences. Of the test samples, 93.3% can be correctly classified with the random forest model based on the microbial differences. Targeting the low-abundance bacteria at the species level, 52% of experimental participants could be discriminated by using the observed unique bacterial species. In conclusion, the salivary bacterial community composition differed from that of the buccal mucosa and showed high richness and diversity. With the random forest model, the microbiota of saliva and buccal mucosa can be classified, which can be used in identifying the source of oral biological trace. Furthermore, each individual has a unique bacterial community pattern, and the presence or absence of unique bacteria and differences in the composition of the core oral microbiota are the key points for forensic personal discrimination that supplement the study of oral microbial application to forensic personal discrimination. Whether for original identification or personal discrimination, the oral microbiome has great potential for application.

Influence of cigarette smoking on oral microbiota in patients with recurrent aphthous stomatitis

Recurrent aphthous stomatitis (RAS) is a common recurrent ulcerative disease of the oral mucosa which is closely related to oral microbial composition. However, the specific effect and the mechanism of smoking in RAS are unclear. In this study, 16S rRNA sequencing technology was used to compare the differences in saliva microbial community between 28 non-smoking healthy controls (NSctrl), 31 non-smoking RAS patients (NSras), and 19 smoking RAS patients (Sras). The results showed that the bacterial community diversity in patients with RAS (NSras and Sras) was lower than that of NSctrl. The microbial community in smoking-associated RAS is less diverse and distinct from that of non-smokers. The RAS groups have higher abundance of Veillonella, Rothia, and Sneathia and lower abundance of Bacteroidales, Bacteroides, Wolinella, Moryella, Pyramidobacter, and Christensenellaceae at the genera level. A significantly different abundance of Anaerovorax, Candidatus Endomicrobium, Lactococcus, Sneathia, Veillonella, and Cloacibacterium was observed between the Sras and the NSras group. Notably, there was a significant difference in many species from the genus Prevotella and Treponema between the NSras and the Sras group. Further, the relative abundance of several taxa is correlated with smoking age or frequency, including Megasphaera, Haemophilus, Leptotrichia, and Rothia at the genera level, and Prevotella melaninogenica, Prevotella salivae, Megasphaera micronuciformis, Haemophilus parainfluenzae, Alloprevotella tannerae, Actinomyces naeslundii, Lautropia mirabilis, and Capnocytophaga sputigena at the species level. Among patients with RAS, smoking aggravated the pathways of respiration and human pathogens. Our results suggest that smoking is closely related to changes in the oral microbiota, which may contribute an opposite effect to the pathogenesis of RAS. This study provides new insight and theoretical basis for the cause and pathogenesis of RAS and better prevention and treatment.

The efficacy of herbal medicine in the treatment of recurrent aphthous stomatitis: A systematic review of randomized clinical trials

This systematic review was undertaken with the main aim of assessing the therapeutic effects of herbal medicines in recurrent aphthous stomatitis (RAS). A comprehensive search was performed in PubMed, Scopus, ISI Web of Science, and Google Scholar up to July 2021 to identify randomized clinical trials investigated the effects of herbal medicines on RAS. Thirty-three papers comprising 2,113 patients met the eligibility criteria, of which 30 studies had a high quality based on the Jadad scale. Totally, 22 out of 30 studies which assessed the pain showed that herbal agents significantly decreased the pain compared with the control group or placebo. In 17 out of 25 studies that evaluated ulcer size, herbal agents significantly reduced the size of ulcers compared with the control or placebo groups. In 15 out of 18 studies that assessed the healing time, herbal agents significantly reduced healing time in the intervention groups compared with the placebo or control groups. Few adverse events were reported only in four studies. Findings of the current review indicated medicinal plants and phytochemicals as effective and safe agents that for the treatment of RAS.

Fecal Microbiome Changes and Specific Anti-Bacterial Response in Patients with IBD during Anti-TNF Therapy

Inflammatory bowel diseases (IBD) are chronic disorders of the gastrointestinal tract that have been linked to microbiome dysbiosis and immune system dysregulation. We investigated the longitudinal effect of anti-TNF therapy on gut microbiota composition and specific immune response to commensals in IBD patients. The study included 52 patients tracked over 38 weeks of therapy and 37 healthy controls (HC). To characterize the diversity and composition of the gut microbiota, we used amplicon sequencing of the V3V4 region of 16S rRNA for the bacterial community and of the ITS1 region for the fungal community. We measured total antibody levels as well as specific antibodies against assorted gut commensals by ELISA. We found diversity differences between HC, Crohn's disease, and ulcerative colitis patients. The bacterial community of patients with IBD was more similar to HC at the study endpoint, suggesting a beneficial shift in the microbiome in response to treatment. We identified factors such as disease severity, localization, and surgical intervention that significantly contribute to the observed changes in the gut bacteriome. Furthermore, we revealed increased IgM levels against specific gut commensals after anti-TNF treatment. In summary, this study, with its longitudinal design, brings insights into the course of anti-TNF therapy in patients with IBD and correlates the bacterial diversity with disease severity in patients with ulcerative colitis (UC).

Crosstalk between the oral microbiota, mucosal immunity, and the epithelial barrier regulates oral mucosal disease pathogenesis

Oral mucosal disease (OMD), which is also called soft tissue oral disease, is described as a series of disorders or conditions affecting the mucosa and soft tissue in the oral cavity. Its etiology is unclear, but emerging evidence has implicated the influence of the composition of the oral mucosa and saliva-resident microbiota. In turn, this dysbiosis effects the immune response balance and epithelial barrier function, followed by the occurrence and progression of OMD. In addition, oral microbial dysbiosis is diverse in different types of diseases and different disease progressions, suggesting that key causal pathogens may exist in various oral pathologies. This narrative literature review primarily discusses the most recent findings focusing on how microbial dysbiosis communicates with mucosal adaptive immune cells and the epithelial barrier in the context of five representative OMDs, including oral candidiasis (OC), oral lichen planus (OLP), recurrent aphthous ulcer (RAU), oral leukoplakia (OLK), and oral squamous cell carcinoma (OSCC), to provide new insight into the pathogenetic mechanisms of OMDs.

The effects of removing dead bacteria by propidium monoazide on the profile of salivary microbiome

Background

Oral microbiome played an important role in maintaining healthy state and might exhibit certain changes under circumstances of diseases. However, current microbiological research using sequencing techniques did not regard dead bacteria as a separate part, causing findings based on subsequent analyses on dynamic equilibrium and functional pathways of microbes somewhat questionable. Since treatment by propidium monoazide (PMA) was able to remove dead bacteria effectively, it would be worth studying how the sequencing results after PMA treatment differed from those focusing on the whole microbiota.

Methods

Unstimulated whole saliva samples were obtained from 18 healthy people from 3 age groups (children, adults, and the elderly). After removal of dead bacteria by propidium monoazide (PMA), changes in the profile of salivary microbiome were detected using 16S rRNA sequencing technology, and differences among age groups were compared subsequently.

Results

Dead bacteria accounted for nearly a half of the whole bacteria flora in saliva, while freezing had little effect on the proportion of deaths. After treatment with PMA, the numbers of OTUs reduced by 4.4–14.2%, while the Shannon diversity indices decreased significantly (P < 0.01). Only 35.2% of positive and 6.1% of negative correlations were found to be shared by the whole microbiota and that with dead bacteria removed. Differences in significantly changed OTUs and functional pathways among different age groups were also observed between the group of PMA and the control.

Conclusions

It was necessary to take the influence of living state of bacteria into account in analytic studies of salivary microbiome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01832-5.

Clinical Characteristics and Outcomes of Oral Mucositis Associated With Immune Checkpoint Inhibitors in Patients With Cancer

BACKGROUND

Immune checkpoint inhibitor (ICI) therapy predisposes patients to immune-related adverse events (irAEs). Data are limited regarding the incidence, management, and outcomes of one such irAE: mucositis. In this study, we evaluated the clinical characteristics, disease course, treatment, and outcomes of ICI-mediated mucositis.

METHODS

This was a retrospective, single-center study of patients who received ICI therapy and developed oral mucositis at The University of Texas MD Anderson Cancer Center from January 2009 to September 2019. Inclusion criteria included age ≥18 years, a diagnosis of oral mucositis and/or stomatitis based on ICD-9 and ICD-10 codes, and therapy using CTLA-4 or PD-1/L1 inhibitors alone or combined with other agents.

RESULTS

We identified 152 patients with a mean age of 60 years, 51% of whom were men. Of the sample patients, 73% had stage IV cancer, with melanoma the most common (28%). Median time from ICI initiation to mucositis was 91 days. The most common clinical presentation of mucositis was odynophagia and/or oral pain (89%), 91% developed CTCAE grade 1-2 mucositis, and 78% received anti-PD-1/L1 monotherapy. Compared with anti-PD-1/L1-based therapy, anti-CTLA-4-based therapy was more frequently associated with earlier onset of mucositis (73 vs 96 days; P=.077) and a lower rate of symptom resolution (76% vs 92%; P=.029); 24% of patients required immunosuppressive therapy, which was associated with longer symptom duration (84 vs 34 days; P=.002) and higher mucositis recurrence rate (61% vs 32%; P=.006). ICI interruption was associated with worse survival (P=.037). Mucositis recurrence, immunosuppressant use, and presence of other irAEs did not affect survival.

CONCLUSIONS

For ICI-mediated mucositis, a diagnosis of exclusion has not been well recognized and is understudied. Although the clinical symptoms of mucositis are mostly mild, approximately 25% of patients require immunosuppression. Mucositis recurrence can occur in approximately 39% patients. Our results showed that ICI interruption compromises overall survival.

Salivary proteome of aphthous stomatitis reveals the participation of vitamin metabolism, nutrients, and bacteria

There are currently no preventative options for recurrent aphthous stomatitis, and the only available treatments are palliative. This is partly due to a poor understanding of its etiopathogenesis. In this case-control study, we characterized the salivary proteome of patients with recurrent aphthous stomatitis in the presence and absence of lesions. Through mass spectrometry-based proteomics and bioinformatics tools, we identified that the presence of oral ulcers is associated with several specific biological processes, including the metabolic pathways of vitamin B9, B12, nitrogen, selenium, and the bacterium Neisseria meningitidis. These changes occurred only in the presence of clinically visible lesions, and there were no relevant differences between patients in anatomical regions unaffected by ulcers. Additionally, using western blot and ELISA assays, we verified that carbonic anhydrase 1 (CA1) and hemoglobin subunit beta (HBB) proteins are highly expressed during the ulcerative and remission phases of recurrent aphthous stomatitis. Our results cumulatively support saliva as an indicator of the pathophysiological changes, which occur during the clinical course of lesions. From a clinical perspective, we suggest that recurrent aphthous stomatitis is a condition triggered by temporary biological changes in people with lesions.

Microbiome of Odontogenic Abscesses

Severe odontogenic abscesses are regularly caused by bacteria of the physiological oral microbiome. However, the culture of these bacteria is often prone to errors and sometimes does not result in any bacterial growth. Furthermore, various authors found completely different bacterial spectra in odontogenic abscesses. Experimental 16S rRNA gene next-generation sequencing analysis was used to identify the microbiome of the saliva and the pus in patients with a severe odontogenic infection. The microbiome of the saliva and the pus was determined for 50 patients with a severe odontogenic abscess. Perimandibular and submandibular abscesses were the most commonly observed diseases at 15 (30%) patients each. Polymicrobial infections were observed in 48 (96%) cases, while the picture of a mono-infection only occurred twice (4%). On average, 31.44 (±12.09) bacterial genera were detected in the pus and 41.32 (±9.00) in the saliva. In most cases, a predominantly anaerobic bacterial spectrum was found in the pus, while saliva showed a similar oral microbiome to healthy individuals. In the majority of cases, odontogenic infections are polymicrobial. Our results indicate that these are mainly caused by anaerobic bacterial strains and that aerobic and facultative anaerobe bacteria seem to play a more minor role than previously described by other authors. The 16S rRNA gene analysis detects significantly more bacteria than conventional methods and molecular methods should therefore become a part of routine diagnostics in medical microbiology.

Quantitative changes of Veillonella, Streptococcus, and Neisseria in the oral cavity of patients with recurrent aphthous stomatitis: A systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate that these bacteria counts in the oral cavity were modulated by the recurrent aphthous stomatitis (RAS) status according to age and ethnicity with a systematic review and meta-analysis.

DESIGN

The relevant case-control studies were searched in the literature database in English, Korean, and Chinese until June 2020 using keywords, and the literature was screened and collated for Review Manager analysis. Sensitivity analysis and quality check of the included literature were conducted.

RESULTS

From the selection process, oral bacteria counts were measured by polymerase chain reaction (PCR) in 8 studies and next-generation sequencing in 4 studies. Healthy control, ulcerative phases of RAS (UC-RAS), non-ulcerative phases of RAS (Non-UC-RAS) groups included 442, 473, and 386 participants in a total of 12 studies. For PCR detection, mean differences (95 % confidence intervals) of Veillonella and Streptococcus counts between the healthy-control and RAS groups were -1.91 (-2.41 ∼ -1.41) and -1.34 (-1.85 ∼ -0.83)(P < 0.0001). The bacteria count results by "Next-generation" sequencing (NGS) and PCR methods were similar. Significantly lower Veillonella and Streptococcus counts were observed in the UC-RAS group than in the non-UC-RAS group (P < 0.0001). Veillonella and Streptococcus count differences between RAS and controls aged ≥30 years were greater than those aged <30 years. At the species level, the prevalence of RAS had a negative relation with Veillonella dispar count.

CONCLUSIONS

Counts of Veillonella and Streptococcus are strongly correlated with the recovery and progression of RAS, especially in middle-aged patients. Adjustment of oral microbiota should be considered in the treatment of RAS.

Association Between Serum Thyroid-Stimulating Hormone Levels and Salivary Microbiome Shifts

High serum thyroid-stimulating hormone (TSH) levels are linked to many metabolic disorders, but the effects of TSH levels on the oral microbiota are still largely unknown. This study aimed to explore the association between the salivary microbiome in adults and serum TSH levels. Saliva and fasting blood samples were obtained from a health census conducted in Southeast China. All participants were divided according to serum TSH levels. The microbial genetic profiles and changes were acquired by 16S rDNA sequencing and bioinformatics analysis. Relevant anthropometric and biochemical measurements such as insulin resistance, blood lipids, and body composition were evaluated with laboratory tests and physical examinations. The salivary microbiome in individuals with higher TSH level showed significantly higher taxa diversity. Principal coordinates analysis and partial least squares discriminant analysis showed distinct clustering in the Abnormal and Normal Groups (Adonis, P=0.0320). Granulicatella was identified as a discriminative genus for comparison of the two groups. Fasting serum insulin, Homeostatic Model Assessment for Insulin Resistance, and hemoglobin A1 were elevated in the Abnormal Group (P<0.05), showing the presence of insulin resistance in individuals with abnormal higher serum TSH levels. Distance-based redundancy analysis revealed the association of this distinctive difference with salivary microbiome. In conclusion, shifts in microbial profile were observed in the saliva of individuals with different serum TSH levels, and insulin resistance may play an important role in the biochemical and microbial alteration.

A Clinic Trial Evaluating the Effects of Aloe Vera Fermentation Gel on Recurrent Aphthous Stomatitis

Recurrent aphthous stomatitis (RAS) is the most common disorder in the oral mucosa that affects the daily quality of life of patients, and there is currently no specific treatment. In the present study, we developed aloe vera fermentation gel under the action of probiotics on aloe vera. In total, 35 patients with the history of aphthous stomatitis were enrolled to explore the potential benefits of aloe vera fermentation gel to treat RAS, and the healing-promotion effects were recorded and compared; microbial compositions in different groups were tested by high-throughput sequencing. Our results indicated that the duration of healing time of the aloe group showed potentially better effects because of the higher proportion of 4-6 day healing time (35% vs. 20%) and lower proportion of 7-10 day healing time (65% vs. 80%) compared with that of the chitosan group. Also, the use of aloe vera fermentation gel could return oral bacteria to normal levels and reduce the abundance of harmful oral bacteria including Actinomyces, Granulicatella, and Peptostreptococcus. These results suggest that aloe vera fermentation gel has the ability to treat patients with RAS and has positive prospects in clinical applications.

Throat Microbial Community Structure and Functional Changes in Postsurgery Laryngeal Carcinoma Patients

The microbial community structure in the throat and its shift after laryngectomy in laryngeal squamous cell carcinoma (LSCC) patients were investigated. Thirty swab samples taken prior to laryngectomy (SLC), 18 samples 1 week after laryngectomy (SLCA1w), and 30 samples 24 weeks after laryngectomy (SLCA24w) from 30 LSCC patients were examined. Microbial diversity was profiled through sequencing the V3-V4 variable region of the 16S rRNA gene. Quantitative real-time PCR (qPCR) was used to validate the 16S rRNA sequence data for the V3-V4 region. The community structure and function of throat microbiota were assessed by PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states) analysis. Both alpha and beta diversity results showed significant differences in the throat microbiota of LSCC patients before and after laryngectomy (P < 0.05). The drinking index of the SLC group was positively associated with the genus abundance of Prevotella (P < 0.05). The SLCA1w group had lower abundances of Fusobacterium, Leptotrichia, Lachnoanaerobaculum, and Veillonella than the SLC group (P < 0.05). The SLCA24w group had higher abundances of Streptococcus and Leptotrichia as well as lower abundances of Fusobacterium and Alloprevotella than the SLC group (P < 0.05). The throat microbiomes of the SLC group could be implicated in human cancer signaling pathways, as evidenced by PICRUSt analysis (P < 0.05). Our study clarifies alterations in throat microbial community structure and function in LSCC patients during the perioperative period and postoperative recovery period.IMPORTANCE Laryngeal squamous cell carcinoma greatly impacts patients' lives, and noninvasive means of prognostic assessment are valuable in determining the effectiveness of laryngectomy. We set out to study the microbial structure changes in the throat before and after laryngectomy and found the gene functions of several throat bacteria to be associated with human cancer signaling pathways. Our findings may offer insights into the disease management of patients with laryngeal squamous cell carcinoma. We hope to provide a means of using molecular mechanisms to improve the prognosis of laryngeal cancer treatment and to facilitate relevant research.

Efficacy and safety of acupuncture for recurrent aphthous stomatitis: a systematic review protocol

INTRODUCTION

Recurrent aphthous stomatitis (RAS) is a distressing symptom. There are many ways to treat RAS, such as pudilan anti-inflammatory oral liquid and doxycycline and laser therapy, but these take a long time to produce positive effects and compliance is low. Previous reviews of acupuncture treatment for RAS has been growing, but a systematic review is not available. To assess the efficacy and safety of acupuncture for the management of RAS.

METHODS AND ANALYSIS

The following databases will be searched from their inception to 1 February 2020: PubMed, Embase, Cochrane Library, CINAHL, Chinese Biomedical Literature Database, VIP Database for Chinese Technical Periodicals, China National Knowledge Infrastructure and Wanfang. The randomised controlled trials in English or Chinese associated with acupuncture for patients with RAS will be included. Eligible study conference abstracts and reference lists of manuscripts will also be searched. Two reviewers will select the studies, extract data independently. The Cochrane risk of bias tool will be used to assess the risk of bias for the studies. According to heterogeneity testing, data will be synthesised using a random-effects model. A meta-analysis will be performed using Rev Man V.5.3.5 statistical software for each outcome. Subgroup analysis and sensitivity analysis are planned according to clinical evidence. Mean difference or standardised mean difference for continuous data and risk ratio for dichotomous data will be calculated.

ETHICS AND DISSEMINATION

No ethical approval is required. This protocol will not involve individual patient information and endangering participant rights. The results will be reported in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/QASUY.

Reflux and dental disorders in the pediatric population: A systematic review

OBJECTIVES

To investigate the role of laryngopharyngeal reflux (LPR) or gastroesophageal reflux disease (GERD) in the development of dental disorders in pediatric population.

METHODS

PubMed, Scopus Cochrane database were assessed for subject headings using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) recommendations. Relevant studies published between January 1990 and January 2020 describing the association between reflux and dental disorders in children were retrieved. Three authors reviewed the LPR diagnosis method; inclusion criteria and outcomes. The bias analysis was performed through the tools of the Oxford Centre for Evidence-Based Medicine evidence levels.

RESULTS

The electronic search identified 126 publications, of which 11 clinical studies and 2 basic science researches met our inclusion criteria. There is an important heterogeneity between studies about diagnostic method and clinical outcome evaluation. All studies based the reflux diagnosis on GERD criteria. No author considered hypopharyngeal nonacid reflux episodes through hypopharyngeal-esophageal intraluminal multichannel impedance pH monitoring (HEMII-pH). The results of studies support a higher prevalence of dental erosion in children with GERD compared with healthy individuals. Controversial findings were found about the potential association between reflux and caries, and the modification of both saliva composition and production in reflux children.

CONCLUSION

The association between reflux and dental disorder is still uncertain. Future studies considering pharyngeal acid and nonacid reflux episodes through HEMII-pH are needed to confirm this hypothesis. The pepsin detection in saliva would be an additional way for detecting LPR in children with dental disorders.

Evaluation of the effect of probiotic lozenges in the treatment of recurrent aphthous stomatitis: a randomized, controlled clinical trial

OBJECTIVES

The study aimed to explore the effectiveness of probiotics in the treatment of minor recurrent aphthous stomatitis (RAS).

MATERIALS AND METHODS

We performed a randomized, controlled clinical study. Sixty adult (group A) and 60 children patients (group B) with diagnosis of minor RAS were included. Both groups were divided into two subgroups; AI and BI (test subgroups) and AII and BII (control subgroups). For test subgroups, probiotic lozenges were consecutively administered twice daily, for 5 days. The size and pain level of ulcers were recorded on treatment days 0, 3, and 5. The outbreak frequency of RAS within 6 months was investigated for all subgroups.

RESULTS

Compared with baseline, an improvement was evident for all subgroups. However, for effectiveness in pain reduction, a statistically significant difference in favor of AI was observed for all evaluation periods when compared with control subgroup. Regarding effectiveness in ulcer size reduction, a statistically significant difference in favor of BI was observed at day 5 when compared with control subgroup. No significant difference was observed in the effectiveness index between subgroups AI and BI (test subgroups) except in effectiveness in pain reduction at day 3. The outbreak frequency decreased significantly in subgroup BI.

CONCLUSIONS

Topical application of probiotics decreased pain intensity and accelerates RAS healing. The effectiveness in pain reduction is more evident in adult patients while acceleration of healing is more evident in children.

CLINICAL RELEVANCE

Probiotics could be a well-tolerated, topical therapeutic agent in the treatment of minor RAS.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04383236.

Gene mapping and functional annotation of GWAS of oral ulcers using FUMA software

Oral ulcers not only influence the physical health of patients, but they also interfere with their quality of life. However, the exact etiology of oral ulcers is not clear. To explore the roles of genetic factors in oral ulcers, a genome-wide association study of the condition in European individuals was re-evaluated by the FUMA v1.3.5e online tool. A total of 380 independent significant single nucleotide polymorphisms (SNPs) and 89 lead SNPs were identified in 34 genomic risk loci. Out of these identified genomic risk loci, 280 possible causal genes were pinpointed by positional mapping and expression quantitative trait locus mapping. Among these genes, 216 novel genes were identified. Furthermore, some genomic loci were mapped to a single gene. Functional annotation of these prioritized genes revealed that the immune response pathway was implicated in the onset of oral ulcers. Overall, our findings revealed novel possible causal genes and demonstrated that the immune response has a crucial role in the occurrence of oral ulcers.