Saliva sampling method influences oral microbiome composition and taxa distribution associated with oral diseases.

Saliva is a readily accessible and inexpensive biological specimen that enables investigation of the oral microbiome, which can serve as a biomarker of oral and systemic health. There are two routine approaches to collect saliva, stimulated and unstimulated; however, there is no consensus on how sampling method influences oral microbiome metrics. In this study, we analyzed paired saliva samples (unstimulated and stimulated) from 88 individuals, aged 7-18 years. Using 16S rRNA gene sequencing, we investigated the differences in bacterial microbiome composition between sample types and determined how sampling method affects the distribution of taxa associated with untreated dental caries and gingivitis. Our analyses indicated significant differences in microbiome composition between the sample types. Both sampling methods were able to detect significant differences in microbiome composition between healthy subjects and subjects with untreated caries. However, only stimulated saliva revealed a significant association between microbiome diversity and composition in individuals with diagnosed gingivitis. Furthermore, taxa previously associated with dental caries and gingivitis were preferentially enriched in individuals with each respective disease only in stimulated saliva. Our study suggests that stimulated saliva provides a more nuanced readout of microbiome composition and taxa distribution associated with untreated dental caries and gingivitis compared to unstimulated saliva.

Periodontitis Risk Factors in Adults with Cystic Fibrosis: A pilot study.

Purpose Individuals with cystic fibrosis (CF) present with multiple condition-specific risk factors for periodontitis including CF-related diabetes, chronic inhaled treatments that induce xerostomia, and increased systemic inflammation because of frequent lung infections. General factors like age, oral hygiene, and diet may also contribute to the risk of periodontitis. However the relative importance of these specific risk factors and periodontitis in individuals with CF has not yet been evaluated. The purpose of this pilot study was to assess the associations between CF condition-specific and general risk factors and the prevalence of periodontitis in adults with CF.Methods This cross-sectional pilot study was designed to assess a multifactorial model of periodontitis risk factors in a population in adults with CF who were recruited from the University of Washington Adult CF center. Periodontitis was defined using the Centers for Disease Control and Prevention and the American Academy of Periodontology (CDC/AAP) case definition. Risk factors included condition-specific and general factors. Differences between participants with moderate/severe periodontitis and those with no/mild periodontitis was assessed using the Mann-Whitney test, the Fisher's exact test, and the exact chi-square test (α=0.05).Results Thirty-two participants were enrolled. Twenty-eight percent of the participants had moderate periodontitis, 72% had no/mild periodontitis; none of the participants had severe periodontitis. There were no significant differences in condition-specific factors between between the two study groups. Participants with moderate periodontitis were older (p=0.028) and reported daily flossing in higher proportions than those with no/mild periodontitis (p=0.023).Conclusions The findings from this pilot study suggest that future research is needed to determine whether sociodemographic and other general risk factors are more important contributors to periodontitis risk than CF-specific factors.

Untreated dental disease and lung transplant waitlist evaluation time for individuals with cystic fibrosis.

AIMS: Dental clearance is typically part of the evaluation process prior to placement on the lung transplant waiting list. Individuals with cystic fibrosis (CF) are thought to be at low risk for dental disease. We hypothesized that individuals with CF in need of lung transplantation would have lower dental disease prevalence and shorter waitlist evaluation time than individuals with non-CF lung diseases. METHODS AND RESULTS: We conducted a retrospective study of individuals who received a lung transplant between 2011 and 2017 at the University of Washington (Seattle, WA, USA) (N = 280). Untreated dental disease was assessed by the individual's dentist. Waitlist evaluation time was defined as the time, in days, from the initial evaluation by a transplant pulmonologist to placement on the lung transplant waiting list. We used logistic and linear regression models for hypothesis testing. The prevalence of untreated dental disease did not differ by CF status (p = 0.99). There was no difference in waitlist evaluation time for transplant recipients by CF status (p = 0.78) or by dental disease status (p = 0.93). CONCLUSIONS: Our findings provide further evidence that individuals with CF are not at low risk for dental disease. Ensuring optimal oral health is important for all individuals with lung diseases.

Unstimulated Saliva-Related Caries Risk Factors in Individuals with Cystic Fibrosis: A Cross-Sectional Analysis of Unstimulated Salivary Flow, pH, and Buffering Capacity.

Salivary flow rate, pH, and buffering capacity are associated with dental caries, but studies from the cystic fibrosis (CF) literature are inconclusive regarding these salivary factors and caries. The aim of this study was to evaluate these factors and their associations with dental caries in individuals with CF. Unstimulated whole saliva was collected from individuals aged 6-20 years at Seattle Children's Hospital CF Clinic, USA (n = 83). Salivary flow rate was measured in milliliters per minute. Salivary pH was assessed using a laboratory pH meter. Buffering capacity was assessed by titration with HCl. The outcome measure was caries prevalence, defined as the number of decayed, missing, or filled primary and permanent tooth surfaces. Spearman's rank correlation coefficient and the t test were used to test for bivariate associations. Multiple variable linear regression models were used to (1) run confounder-adjusted analyses and (2) assess for potential interactions. There was no significant association between salivary flow rate or buffering capacity and caries prevalence. There was a significant negative association between salivary pH and caries prevalence, but this association was no longer significant after adjusting for age. There was no significant interaction between salivary flow rate and buffering capacity or between antibiotic use and the 3 salivary factors. Our results indicate that unstimulated salivary factors are not associated with dental caries prevalence in individuals with CF. Future studies should investigate other potential saliva-related caries risk factors in individuals with CF such as cariogenic bacteria levels, salivary host defense peptide levels, and medication use.