Proteomics-Based Identification of Salivary Changes in Patients with Burning Mouth Syndrome

A pilot study of the relationship between salivary microbial characteristics and endocrine and immune function in patients with burning mouth syndrome

OBJECTIVES

To explore the potential role of oral bacteria in the pathogenesis of burning mouth syndrome (BMS).

MATERIALS AND METHODS

Fifteen patients with BMS and 15 healthy controls were enrolled in this study. The relative abundance and diversity of salivary bacterial strains were analyzed using metagenomic DNA sequencing. The functionality of non-redundant genes was obtained by comparing the mmseqs2 with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. BMS relating salivary protein markers were detected using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Partial least-squares discriminant analysis (PLS-DA) revealed that the salivary bacterial profiles of the BMS group (mean age: 38.9 ± 2.2 years) differed significantly from those of the control group (mean age: 34.1 ± 2.3 years) in terms of the abundance of dominant phyla, classes, orders, families, genera and species. Functional analysis revealed distinct endocrine and immune functions in the BMS group. The salivary cortisol and α-amylase levels were significantly higher, and salivary interleukn-6 levels were significantly lower in the BMS group than in the control group. Species contribution analysis of endocrine and immune functions revealed that Streptococcus mitis was an important contributor to endocrine and immune functions in the BMS group.

CONCLUSIONS

Salivary dysbiosis related to endocrine and immune functions may be a possible cause of BMS.

CLINICAL RELEVANCE

These findings could assist in the diagnosis and therapy of BMS.

CLINICAL TRIAL NUMBER

Not applicable.

Comparative salivary proteomics analysis of children with and without early childhood caries using the DIA approach: A pilot study

OBJECTIVE

To screen differentially expressed proteins (DEPs) in the saliva of Early childhood caries (ECC) with different degrees of severity.

METHODS

The proteomic profiles of salivary of children with ECC of varying severity by data independent acquisition data independent acquisition (DIA) technique. A total of 12 preschool children aged 3-5 years were included in this study.

RESULTS

In this study, a total of 15,083 peptides and 1944 proteins were quantified; The results of DEPs screening showed that 34 DEPs were identified between the group H and the group LC, including 18 up-regulated proteins and 16 down-regulated proteins; 34 DEPs were screened between the group H and the group HC, including 17 up-regulated proteins and 17 down-regulated proteins; 42 DEPs were screened between the group LC and the group HC, including 18 up-regulated proteins and 24 down-regulated proteins. Among these DEPs, we screened several key proteins that may play a role in ECC, such as MK, histone H4, TGFβ3, ZG16B, MUC20, and SMR-3B.

CONCLUSION

Salivary proteins, as important host factors of caries, are differentially expressed between the saliva of ECC children and healthy children. Specific DEPs are expected to become potential biomarkers for the diagnosis of ECC.

Bacterial infection-biased abundance of proteins in the skin mucus of obscure puffer (Takifugu Obscurus)

The skin mucus of fish is equipped with immunological and antimicrobial peptides that confer protection against invading pathogens. The skin mucus has been studied in fish however information regarding its immunological roles in bacterial infection is rare. This study highlighted the proteins and peptides in the skin mucus of Obscure puffer Takifugu obscurus that quantitatively altered against Aeromonas hydrophila infection. We infected the fish through bath immersion, intraperitonially, and treated with PBS (control) then compared the level of proteins in the skin mucus among the groups using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The Tandem Mass Tag (TMT) based quantification showed that 4896 proteins were Deferentially Quantified Proteins (DQPs), based on 19,751 unique peptides. Of which 170 were depleted (decreased in abundance) and 69 were abundant in comparison of Bath Treated (BT) vs Control (C) groups. Similarly, 76 DQPs were depleted and 70 were abundant in comparison of Treated (T) vs BT groups. Further, 126 DQPs were depleted, and 34 were abundant in comparison to T vs C groups. The DQPs we report were mostly immunological and were involved in unique biological functions and pathways. The interesting protein we report, where some of the proteins are for the first time in fish, shows the protein-rich structure of the mucus of fish, which may act as a biomarker to be targeted for bacterial disease therapy in fish and ultimately hint to the way of making resistance in fish against bacterial pathogens.

Comprehensive analysis of the oral microbiota and metabolome change in patients of burning mouth syndrome with psychiatric symptoms

Background

Burning mouth syndrome (BMS) is a chronic idiopathic facial pain with intraoral burning or dysesthesia. BMS patients regularly suffer from anxiety/depression, and the association of psychiatric symptoms with BMS has received considerable attention in recent years. The aims of this study were to investigate the potential interplay between psychiatric symptoms and BMS.

Methods

Using 16S rRNA sequencing and liquid chromatography-mass spectrometry (LC/MS) to evaluate the oral microbiota and saliva metabolism of 40 BMS patients [including 29 BMS patients with depression or anxiety symptoms (DBMS)] and 40 age matched healthy control (HC).

Results

The oral microbiota composition in BMS exhibited no significant differences from HC, although DBMS manifested decreased α-diversity relative to HC. Noteworthy was the discernible elevation in the abundance of proinflammatory microorganisms within the oral microbiome of individuals with DBMS. Parallel findings in LC/MS analyses revealed discernible disparities in metabolites between DBMS and HC groups. Principal differential metabolites were notably enriched in amino acid metabolism and lipid metabolism, exhibiting associations with infectious and immunological diseases. Furthermore, the integrated analysis underscores a definitive association between the oral microbiome and metabolism in DBMS.

Conclusions

This study suggests possible future modalities for better understanding the pathogenesis and personalized treatment plans of BMS.

Prevalence of Xerostomia and Hyposalivation Among Individuals Attending Oral Cancer Screening in Thailand: A Cross-Sectional Study

Aim

It has been speculated that the prevalence of xerostomia and hyposalivation might be higher among individuals attending oral cancer screening than among members of the general population. Therefore, this study investigated the prevalence of these conditions and their associated factors among individuals taking part in oral cancer screening and residing in the northeastern provinces of Thailand.

Materials and Methods

This cross-sectional study recruited convenient individuals aged ≥40 years with at least one oral cancer risk factor. In total, 561 participants were included. Demographic characteristics and relevant oral cancer risk factors were recorded. A questionnaire comprising five items was used to assess xerostomia. Participants were then categorized into two groups based on the absence or presence of xerostomia. Subsequently, the stimulated salivary flow rate was assessed using the spitting technique to identify hyposalivation. Participants were then separated into two groups depending on the absence or presence of hyposalivation. Univariate and multivariate logistic regression analyses were then performed to identify factors associated with xerostomia or hyposalivation.

Results

The mean age of participants was 65.62 ± 9.70 years, and approximately 60% of participants were post-menopausal women. The prevalence of xerostomia was 43.85%, and the prevalence of hyposalivation was 61.50%. It was revealed that age ≥65 years (odds ratio [OR] = 1.57, P = 0.02) and burning sensation in the mouth (OR = 5.36, P < 0.001) were strongly associated with xerostomia. Female participants were more likely to exhibit hyposalivation (OR = 2.38, P = 0.001). Oral cancer risk factors were not associated with xerostomia or hyposalivation.

Conclusions

In this study, age ≥65 years and burning sensation were identified as risk factors for xerostomia, whereas female sex was a risk factor for hyposalivation. Dentists should be aware of both conditions. Various interventions to alleviate dry mouth symptoms might be useful for individuals with these risk factors.

Is burning mouth syndrome associated with stress? A meta-analysis

BACKGROUND

Some studies have shown burning mouth syndrome (BMS) as comorbid psychosocial and psychiatric disorders, and as well, pointed at stress as a major risk factor.

OBJECTIVE

The aim of this meta-analysis was to answer the following question: 'Is there an association between BMS and stress, compared to healthy controls?'

METHODS

Two reviewers searched for the effect of stress in BMS and published on five main databases and three from the grey literature. Various questionnaires and biomarkers were analysed. Of the 2489 selected articles, 30 met the inclusion criteria. Studies englobed questionnaires, such as Perceived Stress Questionnaire, Lipp Stress Symptoms Inventory, Holmes-Rahe scale, Depression, Anxiety, and Stress Scale (DASS-21), Recent Experience Test; and various biomarkers, such as cortisol, opiorphin, IgA, α-amylase and interleukins.

RESULTS

In all studies with questionnaires, stress was significantly increased in the BMS group vs. control. Patients with BMS presented 25.73% higher cortisol levels, 28.17% higher IgA levels and 40.62% higher α-amylase levels than controls. Meta-analysis found that BMS subjects presented 3.01 nmoL/L [0.53; 5.50] higher cortisol levels, 84.35 kU/L [15.00; 153.71] higher α-amylase levels, 29.25 mg/mL [9.86; 48.64] higher IgA levels and 258.59 pg/mL [59.24; 457.94] higher IL-8 levels than control. No differences were found for opiorphin concentration in ng/mL [-0.96; 2.53]. For interleukins, no differences were founded for IL-1 β, IL-2, IL-4, IL-6, IL-8, IL-10 and TNF-α.

CONCLUSION

Based on the available evidence, this meta-analysis suggests more stress factors in questionnaire-based studies, and higher levels of cortisol, α-amylase, IgA and IL-8 biomarkers in BMS subjects than controls.

Salivary biomarkers in burning mouth syndrome: A systematic review and meta-analysis

The objective of this systematic review was to evaluate which salivary biomarkers are altered in patients with burning mouth syndrome (BMS) compared to a control group (CG). A comprehensive literature search was conducted in four databases. Case-control studies evaluating salivary biomarkers in BMS patients were included. Risk of bias was assessed using the Newcastle-Ottawa tool. RevMan was used for meta-analysis. Seventeen studies were selected. The included studies collected 54 different biomarkers. Of these biomarkers, only three (cortisol, α-amylase, and dehydroepiandrosterone) were analyzed in three or more studies. Dehydroepiandrosterone obtained contradictory results among the studies. However, cortisol and α-amylase levels were found to be higher in BMS patients. Cortisol was the only biomarker which could be included for meta-analysis. Cortisol levels were significantly higher in the BMS group compared to the CG (Mean Difference = 0.39; 95% CI [0.14-0.65]; p = 0.003). In conclusion, different studies investigated salivary biomarkers in patients with BMS compared to a CG, with controversial results. Meta-analysis, confirmed by trial-sequential analysis, showed how cortisol levels were significantly higher in BMS. Cortisol emerges as an interesting salivary biomarker in BMS, but future properly designed studies are needed to evaluate its role in diagnosis and/or response to treatment.

The Influence of (Poly)phenol Intake in Saliva Proteome: Short- and Medium-Term Effects of Apple

The relationship between salivary proteome and dietary habits was studied in previous works, where a relationship between salivary proteins like cystatins and polyphenol/tannin levels in diet was observed. However, it remains to be elucidated if this association results from an effect of polyphenol-rich food ingestion on saliva composition. The aim of this work was to test the effects of apple intake on the saliva proteome, both in the short and medium term (after 4 days of continuous intake). By incubating saliva samples with apple phenolic-rich extract, protein bands containing α-amylase, S-type cystatins, and proline-rich proteins (PRPs) appeared in the fraction that precipitated, showing the potential of these (poly)phenols to precipitate salivary proteins. Among these, it was salivary cystatins that presented changes in their levels both in the saliva samples collected immediately after apple intake and in the ones collected after 4 days of intake of an extra amount of apple. These results support the thought that intake is reflected in the salivary proteome. The effect of a polyphenol-rich food, like the apple, on salivary cystatin levels is in line with results observed in animal models and, due to the involvement of these proteins in oral food perception, it would be interesting to explore in future studies the effect of these changes on sensory perception and acceptance of polyphenol-rich food.

Clinical Utility of Quantitative Parameters of Salivary Gland Scintigraphy for Diagnosing Burning Mouth Syndrome

Burning mouth syndrome (BMS) is a chronic disorder characterized by a burning sensation in the oral cavity, often accompanied by xerostomia, with no relevant clinical or laboratory findings. This study aimed to investigate diagnostic values of quantitative parameters of salivary gland scintigraphy for BMS in patients with xerostomia. A total of 164 patients who underwent salivary gland scintigraphy for the workup of xerostomia were retrospectively reviewed. All patients were classified into patient groups with primary BMS, secondary BMS, and non-specific xerostomia. From salivary gland scintigraphy, 22 quantitative parameters were calculated and their diagnostic values were assessed based on the area under the receiver operating characteristic curve (AUC) values. Among salivary gland scintigraphy parameters, uptake speed in the left submandibular gland showed the highest AUC value (0.647) for detecting BMS and pre-stimulatory oral activity showed the highest AUC value (0.710) for detecting primary BMS. A salivary gland scintigraphy scoring system based on these two parameters further enhanced the diagnostic ability, demonstrating AUC values of 0.731 for BMS and 0.782 for primary BMS. These results suggest a potential diagnostic value of the quantitative parameters of salivary gland scintigraphy for detecting BMS in patients with xerostomia.

Saliva changes in composition associated to COVID-19: a preliminary study

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV 2), is usually associated with a wide variety of clinical presentations from asymptomatic to severe cases. The use of saliva as a diagnostic and monitoring fluid has gained importance since it can be used to investigate the immune response and to direct quantification of antibodies against COVID-19. Additionally, the use of proteomics in saliva has allowed to increase  our understanding of the underlying pathophysiology of diseases, bringing new perspectives on diagnostics, monitoring, and treatment. In this work, we compared the salivary proteome of 10 patients with COVID-19, (five patients with mild and five patients with severe COVID-19) and ten control healthy patients. Through the application of proteomics, we have identified 30 proteins whose abundance levels differed between the COVID-19 groups and the control group. Two of these proteins (TGM3 and carbonic anhydrase-CA6) were validated by the measurement of gGT and TEA respectively, in 98 additional saliva samples separated into two groups: (1) COVID-19 group, integrated by 66 patients who tested positive for COVID-19 (2) control group, composed of 32 healthy individuals who did not show any sign of disease for at least four weeks and were negative for COVID-19 in RT-PCR. In the proteomic study there were observed upregulations in CAZA1, ACTN4, and ANXA4, which are proteins related to the protective response against the virus disturbance, and the upregulation of TGM3, that is correlated to the oxidative damage in pulmonary tissue. We also showed the downregulation in cystatins and CA6 that can be involved in the sensory response to stimulus and possibly related to the presence of anosmia and dysgeusia during the COVID-19. Additionally, the presence of FGB in patients with severe COVID-19 but not in mild COVID-19 patients could indicate a higher viral aggregation and activation in these cases. In conclusion, the salivary proteome in patients with COVID-19 showed changes in proteins related to the protective response to viral infection, and the altered sensory taste perception that occur during the disease. Moreover, gGT and TEA could be potential biomarkers of respiratory complications that can occurs during COVID 19 although further larger studies should be made to corroborate this.

Burning mouth syndrome: a review of therapeutic approach

Burning mouth syndrome (BMS) is described by an intense burning sensation of the tongue or other oral areas without a clear etiopathology. The diagnosis of BMS is challenging due to variations of manifestations. The management of BMS is complicated due to the complex etiology of the disease. Many medications and treatment methods have been recommended for BMS management, but no one confirmed as the standard method. In this study, the therapeutic approaches of BMS were evaluated. The data of the article was obtained from PubMed/MEDLINE, Cochrane Library, and Web of Science. The following terms including "burning mouth syndrome", "therapy", and "treatment" were used for search in the databases. A wide range of articles about the therapeutic approach of BMS was searched and reviewed. Pharmacological and non-pharmacological approaches have been used for BMS management. Pharmacological treatments are including Capsaicin, Clonazepam, Low-dose aripiprazole, Alpha-lipoic acid, Duloxetine, Amitriptyline, Gabapentin, and Pregabalin, and ultra-micronized palmitoylethanolamide. Non-pharmacological therapies for BMS are cognitive therapy, Electroconvulsive therapy, Laser therapy, Acupuncture and auriculotherapy, Transcranial Magnetic Stimulation (rTMS), Salivary Mechanical Stimulation, and Botulinum Toxin. A detailed assessment of the etiology and pathophysiology of BMS, and having information about novel therapeutic interventions are essential for the management of BMS.