Stimulated Saliva Samples Research Articles

Does interindividual variability of saliva affect the release and metabolization of aroma compounds ex vivo? The particular case of elderly suffering or not from hyposalivation.

The aim of this work was to study the effects of interindividual variability of human elderly saliva on aroma release and metabolization by ex vivo approaches. Thirty individuals suffering or not from hyposalivation were selected from a panel formed by 110 elderly people (aged >65 years old) that were matched by age and sex. Then, their stimulated saliva samples were independently incubated in presence of three aroma compounds (ethyl hexanoate, octanal, 2-nonanone) to perform headspace-gas chromatography and liquid/liquid extraction-gas chromatography mass spectrometry analyses. These assays revealed that the extent of saliva effect on the release and metabolization of aroma compounds was highly dependent on the chemical family of the compounds (octanal>ethyl hexanoate>2-nonanone). Moreover, salivas from the hyposalivator (HPS) group exerted a significant lower release and/or higher metabolization than those of the control group for the three assayed compounds. Regarding the biochemical characterization of the saliva samples, no significant differences were found in the total protein content between the two groups. This does not preclude the involvement of specific proteins on the observed results that need to be clarified in further experiments. Saliva from the HPS group presented a significantly higher total antioxidant capacity than that of the control group, which suggests that this parameter could be related to the metabolization of aroma compounds by saliva. Such effects might alter aroma perception in individuals suffering from hyposalivation. PRACTICAL APPLICATIONS: The world population is getting older so fast that most countries are not prepared to handle this demographic challenge, characterized by an increasing prevalence of noncommunicable chronic diseases (e.g., diabetes, gastrointestinal disorders) associated to inadequate eating patterns. Thus, supporting a balanced diet is one of the most cost-effective strategies to maintain a good quality of life. A suitable diet needs to take into account both, specific sensory and nutritional individual needs. However, aging is often accompanied by deterioration in oral health (e.g., low salivary secretions), which could alter the capacities to taste and smell. Results from this work contribute to a better understanding of the role of human saliva in aroma release and metabolization, a first step to comprehend retronasal aroma release and perception. This knowledge will help to propose innovative solutions for the reformulation of food products better adapted to the elderly's needs, thus allowing delayed onset of dependency.

Modulation of salivary cytokines in response to alcohol, tobacco and caffeine consumption: a pilot study

It has been shown that long-term stimulant consumption alters the biological and microbiological status of the oral cavity. We present a pilot study describing stimulant-specific oral immunomodulation in the oral cavity. Changes in salivary cytokine levels in response to long-term alcohol, tobacco and caffeine were identified. Volunteers were recruited from amongst the patients visiting University Dental Clinic of CEU Cardenal Herrera University (Alfara del Patriarca, Spain). Participants were grouped according to their self-reported levels of consumption of either caffeine, alcohol or tobacco (control group volunteers were non-consumers of all three). Informed consent was provided and stimulated saliva samples were obtained and assayed for interleukin-1α IL-1α), Tumor Necrosis Factor α (TNF-α) and Interferon γ IFN-γ). Long-term, high-level consumers of alcohol or tobacco exhibited elevated salivary concentrations of the three inflammatory cytokines with respect to control values. Specifically, IL-1α was found to be elevated in alcohol users whilst IFN-γ concentration higher in tobacco users versus controls. Long-term caffeine consumers displayed elevated levels of IFN-γ and TNF-α, whereas IL-1α levels were reduced with respect to control volunteers. This pilot study demonstrates that salivary cytokines can be modulated in response to quantity and duration of alcohol, caffeine or tobacco consumption.

Switching to normal diet reverses kwashiorkor-induced salivary impairments via increased nitric oxide level and expression of aquaporin 5 in the submandibular glands of male Wistar rats.

Kwashiorkor, a form of malnutrition, has been shown to cause impaired salivary secretion. However, there is dearth of information on the mechanism that underlies this complication. Also, whether returning to normal diet after kwashiorkor will reverse these complications or not is yet to be discerned. Thus, this study aimed at assessing the mechanisms that underlie kwashiorkor-induced salivary impairments and to evaluate the effects of switching back to normal-diet on kwashiorkor-induced salivary impairments. Weaning rats were randomly divided into 3 groups (control group, kwashiorkor group (KG), re-fed kwashiorkor group (RKG)) of 7 rats each. The control group had standard rat chow while the KG and RKG were fed 2% protein diet for 6 weeks to induce kwashiorkor. The RKG had their diet changed to standard rat-chow for another 6 weeks. Blood and stimulated saliva samples were collected for the analysis of total protein, electrolytes, amylase, immunoglobulin A (IgA) secretion rate, leptin, and ghrelin. Tissue total protein, nitric oxide level, expressions of Na+/K+-ATPase, muscarinic (M3) receptor, and aquaporin 5 in the submandibular glands were also determined. Data were presented as means ± SEM and compared using ANOVA with Tukey's post hoc test. RKG showed improved salivary function evidenced by reduced salivary lag-time and potassium and increased flow rate, sodium, amylase, IgA secretion rate, leptin, submandibular nitric oxide level, and aquaporin 5 expression compared with KG. This study for the first time demonstrated that kwashiorkor caused significant reduction in salivary secretion through reduction of nitric oxide level and aquaporin 5 expression in submandibular salivary glands. Normal-diet re-feeding after kwashiorkor returned salivary secretion to normal.

Re-establishing normal diet following high fat-diet-induced obesity reverses the altered salivary composition in Wistar rats.

Background Obesity has been implicated in impaired salivary secretion. This study aimed at evaluating the influence of diet-induced obesity on salivary secretion and how re-feeding with normal diet would affect changes in salivary secretion associated with diet-induced obesity. Methods Weaning rats weighing 55-65 g were randomly divided into three groups (control, diet-induced obese, re-fed obese) of seven rats each. The diet-induced obese group was fed a high-fat diet for 15 weeks, whereas the re-fed obese group received normal diet for another 15 weeks following the 15 weeks of high-fat diet. After treatment, blood and stimulated saliva samples were collected for the analyses of total protein, electrolytes, amylase, Immunoglobulin A (IgA), leptin and ghrelin. Tissue total protein, nitric oxide level, expressions of Na+/K+-ATPase, muscarinic (M3) receptor and aquaporin 5 in the submandibular glands were determined. Data were presented as mean±SEM and compared using independent student t-test and ANOVA with Tukey's post-hoc test. Results Results indicated increases in the levels of salivary calcium, phosphate, bicarbonate and leptin, whereas the levels of salivary amylase and ghrelin showed reduction in the obese group compared with the control. Most of these changes were reversed in the re-fed obese group. There were no significant differences in salivary lag time, flow rate, levels of tissue total protein, nitric oxide and the relative expressions of M3 receptor, Na++/K+-ATPase and aquaporin 5 in the submandibular glands between the obese and control groups. Conclusions Diet-induced obesity lead to some changes in salivary factors which were reversed by returning to normal diet.

Stimulated and unstimulated saliva samples have significantly different bacterial profiles.

Epidemiological studies use saliva on a regular basis as a non-invasive and easy-to-take sample, which is assumed to be a microbial representative of the oral cavity ecosystem. However, comparative studies between different kinds of saliva samples normally used in microbial studies are scarce. The aim of the current study was to compare oral microbiota composition between two different saliva samples collected simultaneously: non-stimulated saliva with paper points and stimulated saliva collected after chewing paraffin gum. DNA was extracted from saliva samples of ten individuals, then analyzed by 16S rRNA pyrosequencing to describe bacterial diversity. The results demonstrate significant differences between the microbiota of these two kinds of saliva. Stimulated saliva was found to contain an estimated number of species over three times higher than unstimulated saliva. In addition, bacterial composition at the class and genus level was radically different between both types of samples. When compared to other oral niches, both types of saliva showed some similarity to tongue and buccal mucosa, but they do not correlate at all with the bacterial composition described in supra- or sub-gingival dental plaque, questioning their use in etiological and epidemiological studies of oral diseases of microbial origin.

Influence of periodontal treatment on subgingival and salivary microbiotas.

The purpose of this study was to characterize and compare subgingival and salivary microbiotas before and after periodontal treatment to learn if any changes of the subgingival microbiota were reflected in saliva. We tested the hypothesis that salivary levels of specific periopathogens correlate with corresponding subgingival levels before and after periodontal treatment. Twenty-five patients with generalized chronic periodontitis completed the study. Stimulated saliva samples and subgingival plaque samples were collected at baseline and 2, 6, and 12weeks after nonsurgical periodontal therapy. Subgingival and salivary microbiotas were processed by means of the Human Oral Microbe Next Generation Sequencing (HOMINGS) technique and characterized based on relative abundance. Spearman signed rank test was used to test correlation of periopathogens in subgingival and saliva samples. Periodontal treatment resulted in significantly higher relative abundance of Streptococcus, Rothia and Actinomyces in combination with a significant decrease in Porphyromonas and Treponema in subgingival plaque samples. Relative abundance of the overall predominant genera in saliva was not influenced by periodontal treatment. However, there was a positive correlation between samples of subgingival plaque and saliva before and after periodontal treatment (p<0.0001) with respect to relative abundance of specific periopathogens, such as Porphyromonas gingivalis (r=0.68), Prevotella intermedia (r=0.72), Filifactor alocis (r=0.58), Treponema denticola (r=0.51), Tannerella forsythia (r=0.45) and Parvimonas micra (r=0.45). Subgingival and salivary abundance of periodontal pathogens correlated before and after treatment. Thus, data from this study suggest that periopathogens identified in saliva may be spill-over from the subgingival microbiota.

Comparison of Salivary Cotinine Concentrations in Male Smokers and Smokeless Tobacco Users

Objective:Smoking cigarettes and smokeless tobacco are one of the causes of oral cancer. This study compared the salivary level of cotinine in male smokeless tobacco users and smokers.Methods:In this cross-sectional (descriptive-analytical) study, stimulated saliva samples from 30 male smokers and 30 male smokeless tobacco consumers were collected and their cotinine contents were measured using the competitive ELISA method according the standard curve. The data was analyzed with independent t-test and linear regression using SPSS-19, and P<0.05 was considered significant.Result:Among the 60 subjects with the mean age of 21.27±2.6 years, the average level of cotinine in smokers (12.32±7.5 ng/ml) had no significant difference with that of smokeless tobacco consumers (11.23±4.4 ng/ml) (p=0.49).Conclusion:Salivary levels of cotinine were not significantly different in smokeless tobacco users and cigarette smokers. In addition, increases in the number of cigarettes smoked and in pack of smokeless tobacco used, were associated with increased salivary levels of cotinine. The increase was higher in smokeless tobacco consumers.

Evidence of variable bacterial colonization on coloured elastomeric ligatures during orthodontic treatment: An intermodular comparative study.

BackgroundBesides, other factors, the choice of materials used as orthodontic ligatures could be one of the many tools to counter the effects of microbial adhesion, that culminates into dental ailments. Therefore, we assessed bacterial adhesion on elastomeric ligatures with special reference to coloured elastomeric rings during orthodontic treatment.Material and MethodsA split mouth study, involving 240 samples of different elastomeric ligatures from forty orthodontic patients possessing good oral hygiene was carried out. The archwire was ligated to the brackets on both arches with elastomeric rings (superslick, clear transparent , blue and pink) at predetermined quadrants. After six weeks, ligatures from second premolars were removed and processed for bacterial enumeration using standard techniques. Bacterial counts were also determined for stimulated saliva samples taken at 0 and 6 weeks.ResultsA statistically significant difference in bacterial counts was obtained amongst different elastomeric modules used. Maximum bacterial counts were found on conventional pigmented elastomeric modules, followed by Superslick module and clear module. More number of bacteria associated with the conventional pink as compared to the conventional blue pigmented modules, however it was not statistically significant. The three bacterial genera Streptococcus Staphylococcus and Aerobic Lactobacilli adhered to elastomeric modules in following predominant pattern i.e. Conventional pink>Conventional Blue>Superslick>Clear.ConclusionsThe studies evidenced colour and material dependent bacterial colonization on orthodontic modules and could be an indicator of bacterial biofilm forming potential based on surface chemistries and a clinically efficacious tool to redesign conventional and modified elastomeric rings as orthodontic ligation accessories. Key words:Bacterial colonization, biofilm, coloured elastomers, orthodontic ligatures.

Effects of xylitol-containing chewing gum on the oral microbiota.

In this interventional study, a randomized controlled trial was used to evaluate the short-term effects of xylitol-containing chewing gum on the salivary microbiota. In total, 70 healthy adult men recruited from the Japan Ground Self Defense Force participated in the study during a 2-day training at Yamaguchi camp, Yamaguchi Prefecture, Japan. The men were randomly divided into two groups: one group chewed two pieces of xylitol-containing chewing gum 7 times/day for 2 days (n = 34) and the other did not (n = 36). Baseline and follow-up stimulated saliva samples were collected and the salivary microbial composition was assessed using the 16S rRNA gene next-generation sequencing analysis. The total salivary bacterial count was quantified using a quantitative real-time PCR system. No statistically significant difference was found between the two groups regarding any parameter analyzed in the baseline samples; however, the follow-up samples of the test group showed significantly lower total salivary bacterial count than those of the control group. Conversely, no significant difference was observed in the overall composition of the salivary microbiota between the baseline and follow-up samples of the two groups. These results indicate that xylitol-containing chewing gum inhibits the increase in total salivary bacteria over a short time during which the salivary microbial composition is not affected.

Metagenomic and metatranscriptomic analysis of saliva reveals disease-associated microbiota in patients with periodontitis and dental caries

The taxonomic composition of the salivary microbiota has been reported to differentiate between oral health and disease. However, information on bacterial activity and gene expression of the salivary microbiota is limited. The purpose of this study was to perform metagenomic and metatranscriptomic characterization of the salivary microbiota and test the hypothesis that salivary microbial presence and activity could be an indicator of the oral health status. Stimulated saliva samples were collected from 30 individuals (periodontitis: n = 10, dental caries: n = 10, oral health: n = 10). Salivary microbiota was characterized using metagenomics and metatranscriptomics in order to compare community composition and the gene expression between the three groups. Streptococcus was the predominant bacterial genus constituting approx. 25 and 50% of all DNA and RNA reads, respectively. A significant disease-associated higher relative abundance of traditional periodontal pathogens such as Porphyromonas gingivalis and Filifactor alocis and salivary microbial activity of F. alocis was associated with periodontitis. Significantly higher relative abundance of caries-associated bacteria such as Streptococcus mutans and Lactobacillus fermentum was identified in saliva from patients with dental caries. Multiple genes involved in carbohydrate metabolism were significantly more expressed in healthy controls compared to periodontitis patients. Using metagenomics and metatranscriptomics we show that relative abundance of specific oral bacterial species and bacterial gene expression in saliva associates with periodontitis and dental caries. Further longitudinal studies are warranted to evaluate if screening of salivary microbial activity of specific oral bacterial species and metabolic gene expression can identify periodontitis and dental caries at preclinical stages.

Cross-reactive saliva IgA antibodies to oxidized LDL and periodontal pathogens in humans.

Oxidized low-density lipoproteins (oxLDL) are formed as a result of lipid peroxidation and are highly immunogenic and proatherogenic. In this study, saliva antibodies binding to oxLDL, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) were characterized and their cross-reactivity was evaluated. Resting and stimulated saliva samples were collected from 36 healthy adults (mean age 26years). Saliva IgA, IgG and IgM autoantibody levels to copper oxidized LDL (CuOx-LDL) and malondialdehyde acetaldehyde-modified LDL (MAA-LDL) were determined with chemiluminescence immunoassay. Saliva IgA and IgG antibodies binding to MAA-LDL and CuOx-LDL were detected in all samples and they were associated with the saliva levels of IgA and IgG to P.gingivalis and A.actinomycetemcomitans. Competitive immunoassay showed that saliva antibodies to MAA-LDL cross-reacted specifically with P.gingivalis. The autoantibody levels to oxLDL in saliva were not associated with the autoantibody levels to oxLDL in plasma or with saliva apolipoprotein B 100 levels. Saliva contains IgA and IgG binding to oxLDL, which showed cross-reactive properties with the periodontal pathogens Porphyromonas gingivalis (P.g). The data suggest that secretory IgA to P.g may participate in immune reactions involved in LDL oxidation through molecular mimicry.

Oral symptoms and salivary findings in oral lichen planus, oral lichenoid lesions and stomatitis

BackgroundTo examine if patients with oral lichen planus, oral lichenoid lesions and generalised stomatitis and concomitant contact allergy have more frequent and severe xerostomia, lower unstimulated and chewing-stimulated saliva and citric-acid-stimulated parotid saliva flow rates, and higher salivary concentration of total protein and sIgA than cases without contact allergy and healthy controls.MethodsForty-nine patients (42 women, aged 61.0 ± 10.3 years) and 29 healthy age- and gender-matched subjects underwent a standardised questionnaire on general and oral health, assessment of xerostomia, clinical examination, sialometry, mucosal biopsy and contact allergy testing.ResultsNineteen patients had oral lichen planus, 19 patients had oral lichenoid lesions and 11 patients had generalised stomatitis. 38.8% had contact allergy. Xerostomia was significantly more common and severe in patients (46.9%) than in healthy controls, whereas the saliva flow rates did not differ. The patients had higher sIgA levels in unstimulated and chewing-stimulated saliva than the healthy controls. The total protein concentration in saliva was lower in the unstimulated saliva samples whereas it was higher in the chewing stimulated saliva samples from patients when compared to healthy controls. The differences were not significant and they were irrespective of the presence of contact allergy.ConclusionXerostomia is prevalent in patients with oral lichen planus, lichenoid lesions and generalised stomatitis, but not associated with salivary gland hypofunction, numbers of systemic diseases or medications, contact allergy, age, or gender. Salivary sIgA levels were higher in patients than in healthy controls, but did not differ between patient groups. The total salivary protein concentration was lower in unstimulated saliva samples and higher in chewing-stimulated saliva samples in patients than in healthy controls, but did not differ between patient groups. Our findings do not aid in the discrimination between OLP and OLL and these conditions with or without contact allergic reactions.

Salivary Iron (Fe) Ion Levels, Serum Markers of Anemia and Caries Activity in Pregnant Women.

Introduction Anemia is a very frequent event among pregnant women. There are evidences of differences in the incidence of dental caries between pregnant and non-pregnant women, but the relationship between salivary iron (Fe) and serum markers of anemia and caries development has not been investigated. Objective To evaluate the correlation between salivary (Fe) and serum iron (Fe, ferritin and hemoglobin) parameters in pregnant women with the development of dental caries. Methods A prospective cohort was conducted with 59 women. The outcome of interest was represented by new dental caries lesions during pregnancy, using the Nyvad criteria. Pregnant women were evaluated at three clinical times: up to the 16th week of gestational age (GA) (T1), in the last trimester of pregnancy (T2), and postpartum (T3), at the Mother and Child Unit of University Hospital of the Universidade Federal do Maranhão. A stimulated saliva sample was collected for biochemical analysis of salivary Fe, and a blood sample was collected early in the morning. The correlation between salivary and serum Fe was evaluated through the Pearson correlation test. Analysis of variance (ANOVA) and Kruskal-Wallis were used to compare the means of anemia parameters at different times. The Student's t and Mann-Whitney tests were used to compare the anemia parameters between the groups of pregnant women (with and without new caries lesions). Results Serum Fe concentrations were higher in the first trimester of pregnancy and lower after delivery (p = 0.036). It was also observed that the ferritin concentrations were higher in the first trimester and lower at the end of gestation (p = 0.011). There was no association between the expositions of salivary iron and anemia, and the development of dental caries. There was a positive correlation between serum Fe in T1 and salivary Fe in T2 (p < 0.05). Conclusion The serum markers of anemia were more prevalent in the last trimester of pregnancy.

Salivary microbiota in individuals with different levels of caries experience

ABSTRACTThis study compared salivary bacterial profiles in two groups having a 10-fold difference in levels of caries experience, as it was hypothesized that the composition of the salivary microbiota might associate with the levels of caries experience.Bacterial profiles in stimulated saliva samples from 85 individuals with low levels of caries experience (healthy group) and 79 individuals with high levels of caries experience (caries group) were analyzed by means of the Human Oral Microbiome Identification Next Generation Sequencing (HOMINGS) technique. Subsequently, saliva samples from caries-free individuals in the healthy group (n = 57) and the caries group (n = 31) were compared.A significantly higher α-diversity (p < 0.0001) and a twofold higher relative abundance of Neisseria, Haemophilus, and Fusobacterium were recorded in saliva samples from the healthy group compared with the caries group. Differences observed were more pronounced when limiting the analyses to caries-free individuals in each group.Data from this cross-sectional analysis suggest that low levels of caries experience might associate with a characteristic salivary bacterial composition different from that in individuals with high caries experience. Consequently, longitudinal studies are required to determine if the composition of the salivary microbiota might be a predictive factor of caries risk at the individual level.

Antimicrobial potential and gustatory perception of chlorhexidine gluconate mouthwashes with or without alcohol after a single rinse - a randomized controlled crossover clinical trial.

The aim of this double-blind randomized clinical trial was to assess whether the presence of alcohol in chlorhexidine gluconate mouthwashes influences their antimicrobial potential against salivary bacteria in young adults. Additionally, the taste perception was assessed. In a randomized crossover design, 20 participants (17 women and three men; aged 18-38 years old) rinsed with the 0.12% chlorhexidine gluconate with (CHX+) or without alcohol (CHX-) for 1 min. Sterile flavoured-mint physiological saline was used as control solution. All participants rinsed with the assigned products only once with a period of at least 7 days of washout in between. For antimicrobial potential assay, stimulated saliva samples were collected from participants and had their total viable bacteria determined before and after each rinse. For taste perception assay, a visual analogue scale (VAS) was used to evaluate the taste perception after each rinse. Friedman followed by Wilcoxon tests and Bonferroni correction were performed. A P-value <0.017 was considered as statistically significant. The median per cent reduction in groups CHX+ and CHX- was 16.07 and 12.87, respectively. No statistically significant difference was found between these groups (P = 0.09). Regarding the gustatory perception, the VAS median values in groups CHX+ and CHX- were 3.50 and 5.50. No statistically significant difference was found in this outcome (P = 0.052). The presence of the alcohol on the formulation of gluconate chlorhexidine mouthwashes does not seem to interfere with their antimicrobial potential and with their taste perception.

Differential effects of total and partial sleep deprivation on salivary factors in Wistar rats

ObjectiveAim of this study was to investigate the effects of sleep deprivation on salivary factors in rats. DesignAnimals were randomly assigned into three groups of 6 animals each as control, total sleep deprivation (TSD) and partial sleep deprivation (PSD) groups. The multiple platform method was used to induce partial and total sleep deprivation for 7days. On the 8th day, stimulated saliva samples were collected for the analysis of salivary lag time, flow rate, salivary amylase activity, immunoglobulin A secretion rate and corticosterone levels using ELISA and standard kinetic enzyme assay. Data were analyzed using ANOVA with Dunnett T3 post hoc tests. ResultsSalivary flow rate reduced significantly in the TSD group compared with the PSD group as well as the control group (p=0.01). The secretion rate of salivary IgA was significantly reduced in the TSD group compared with the control group (p=0.04). Salivary amylase activity was significantly elevated in the TSD group compared with the PSD group as well as control group (p<0.001). However, there were no significant changes in the salivary lag time and levels of corticosterone among the groups. ConclusionsThese findings suggest that total sleep deprivation is associated with reduced salivary flow rate and secretion rate of IgA as well as elevated levels of salivary amylase activity in rats. However, sleep recovery of four hours in the PSD group produced ameliorative effects on the impaired functions of salivary glands.

Alcohol and tobacco consumption affect the oral carriage of Candida albicans and mutans streptococci.

This study sought to determine if there is a relationship between the consumption of alcohol and tobacco and oral colonization by mutans streptococci and Candida species. Subjects were recruited from the University Dental Clinic of CEU Cardenal Herrera University (Moncada, Valencia). Information on alcohol and tobacco consumption was obtained by questionnaire. Individual stimulated saliva samples from 105 patients were obtained and selective media was used to isolate and quantify mutans streptococci and Candida spp. colony forming units per millilitre of saliva (CFUml(-1) ). Samples were stratified by duration and quantity of alcohol and tobacco consumption. Alcohol consumption statistically significantly decreased oral carriage of mutans streptococci, whereas there was no effect on Candidaalbicans colonization levels. Tobacco users were found to harbour elevated levels of C.albicans; however, there was no observed effect on bacterial colonization by mutans streptococci. The carriage of other species investigated, such as Candidakrusei, Candidatropicalis and lactobacilli, do not show a response to the consumption of the stimulants analysed. Microbial colonization of the oral cavity changes in a species-specific manner in response to dietary and social habits such as drinking alcohol and smoking. In this paper, we evaluate the effect of alcohol and tobacco consumption on key species of the oral microflora. Our results show species-specific changes in two major opportunistic pathogens, such as Candida albicans and mutans streptococci, whereas other members of oral microflora are not affected by the consumption of the stimulants studied. We believe this original paper will contribute to raise awareness among the dental community towards a more personalized oral health assessment, taking in consideration alcohol and tobacco consumption in the prevention of specific oral and systemic pathologies.

Radiotherapy changes salivary properties and impacts quality of life of children with Hodgkin disease

ObjectiveWe aimed to perform a longitudinal investigation of the effects of radiotherapy on salivary flow rate, pH, buffering capacity, and protein composition of saliva and on the quality of life of children with Hodgkin disease. DesignTen children (6–16-year-old) with Hodgkin disease and 10 matched healthy children were investigated. Stimulated and non-stimulated saliva samples were collected at baseline, after 1080 and 2160cGy of radiation, and 1, 2, and 3 months post-radiotherapy. The salivary flow rate was expressed as mL/min. Buffer capacity was determined by titration. Amylase activity, immunoglobulin A, mucin, and lactoferrin concentrations were determined by ELISA. Quality of life was assessed by Quality of Life – Head and Neck module 35 questionnaire. ResultsWe found that radiotherapy caused hyposalivation at 1080cGy and 1 month after radiotherapy and reduced buffering capacity at 2160cGy. Mucin concentration and amylase activity in non-stimulated saliva increased 1 month after radiotherapy. Lactoferrin concentration increased during and after radiotherapy. Immunoglobulin A concentration increased at 1080cGy, 1 and 2 months, for non-stimulated saliva and at 2160cGy and 1 month for stimulated saliva. Children reported more pain after radiotherapy and more xerostomia during radiotherapy. ConclusionWe concluded that the radiotherapy protocol affected the children’s salivary properties and children’s quality of life.

Salivary antimicrobial defensins in pregnancy.

Susceptibility to and severity of gingival inflammation are enhanced during pregnancy; however, regulation of oral innate immune response, including antimicrobial peptides, during pregnancy is still unknown. We analysed salivary levels of human beta-defensin (hBD)-1, -2, -3, and human neutrophil peptide (HNP)-1 in pregnant women, and related those to their periodontal status. In this cohort study, 30 generally healthy, non-smoking Caucasian women without periodontitis were followed at three time points during pregnancy and twice post-partum. The non-pregnant group consisted of 24 women, who were examined three times at the following months. At each visit, periodontal status was recorded and stimulated saliva samples were collected. Salivary estradiol, progesterone, and defensin concentrations were measured by ELISA assays. After adjusting for visible plaque and gingival bleeding, reduced salivary concentrations of hBD-1, hBD-2, and HNP-1 were found especially during the third trimester, whereas hBD-3 concentrations did not change during pregnancy and post-partum visits. Weak associations were observed between salivary defensin and hormone concentrations and clinical parameters. There seems to be an independent regulation cascade for each antimicrobial defensin in the oral cavity during pregnancy, despite of the similarities between these antimicrobial peptides.

Sequencing of 16S rRNA reveals a distinct salivary microbiome signature in Behçet's disease

Behçet's disease (BD) is characterized by recurrent oro-genital ulcers, mucocutaneous lesions, and serious organ involvement. We investigated the salivary microbiome in BD using high-throughput sequencing of the 16S rRNA V4 region. Stimulated saliva samples were collected from 31 BD patients and 15 healthy controls, and in 9 BD patients, a second saliva sample was collected following dental and periodontal treatment. Sequence analysis identified a total of 908 operational taxonomic units (OTUs) present across all samples. Patients had a microbial community structure that is significantly less diverse than healthy controls. The most overabundant species in BD was Haemophilus parainfluenzae, while the most depleted included Alloprevotella rava and species in the genus Leptotrichia. Periodontal treatment improved oral health indices in BD but had no short-term effect on bacterial community structure. Neither the BD-associated genetic risk locus within the HLA-B/MICA region nor being on immunosuppressive medications explained the differences between patients and controls.