Comparison between polymerase chain reaction-based and checkerboard DNA hybridization techniques for microbial assessment of subgingival plaque samples Periodontal diseases are infections caused primarily by bacteria living in

Abstract Aim: To compare polymerase chain reaction (PCR) with subsequent reverse hybridization (micro-IDent test) and checkerboard DNA-DNA hybridization for the identification of 13 bacterial species in subgingival plaque samples. Material and Methods: Subgingival plaque samples were taken using paper points and curettes from two sites each with pocket depth o4, 4-6 and 46 mm at baseline and 3 months in 25 periodontitis subjects and two sites in 25 periodontally healthy subjects. Samples were analysed for their content of 13 bacterial species using both assays. Similarities for each species between techniques were determined using regression analysis. Differences between health and periodontitis were determined using the Mann-Whitney test. Results: Three hundred and fifty samples were evaluated using both techniques. Regression analysis indicated that 10/13 test species showed significant positive correlations between the counts determined by checkerboard analysis and levels determined by the PCR-based test after adjusting for 13 comparisons. The highest rank correlations of 0.58, 0.49 and 0.46 were seen for Treponema denticola, Fusobacterium nucleatum and Eubacterium nodatum, respectively (po0.0001). Both tests could distinguish samples from healthy and periodontitis subjects. Conclusion: Detection patterns of 10/13 test species in subgingival plaque samples from periodontitis and healthy subjects were similar using the two molecular techniques

Household, dietary, and clinical characteristics of childhood caries and overweight progression : a prospective cohort study

Background: Childhood caries and obesity are complex chronic diseases with negative health outcomes. Aim: This study sought a risk profile for childhood caries and overweight. Design: Children were recruited into a longitudinal prospective cohort study. Caries and overweight characteristics were obtained at baseline, 6, 12, and 18 months. Sequential data modeling steps determined a disease risk profile. Results: At baseline, 50% of the children (n = 194, 3.0 to 6.9 years) had caries; 24% were overweight, of whom 50% had caries. Correlation analysis separated child characteristics from household circumstances. Principal component modeling separated child snacking from meal-eating patterns, and household smoking from parent education variables. Baseline caries and overweight were not associated, but they grouped together in the modeling of composite features. Forty-five percent of children showed caries progression, 29% overweight progression, and 10% progression of both diseases. The strongest predictors of progression were disease presence, household-based characteristics, and sugary drinks. Children with caries and overweight progression shared multiple child- and household-based features. Conclusion: Individually, caries and overweight were not associated. Children with progression of both conditions shared a profile and multiple risk characteristics suggesting these findings could be useful in assessing the risk for the most extreme cases of caries and overweight

Unhealthy Phenotype as Indicated by Salivary Biomarkers: Glucose, Insulin, VEGF-A, and IL-12p70 in Obese Kuwaiti Adolescents

Objective. Here, we investigated the relationships between obesity and the salivary concentrations of insulin, glucose, and 20 metabolic biomarkers in Kuwaiti adolescents. Previously, we have shown that certain salivary metabolic markers can act as surrogates for blood concentrations. Methods. Salivary samples of whole saliva were collected from 8,317 adolescents. Salivary glucose concentration was measured by a high-sensitivity glucose oxidase method implemented on a robotic chemical analyzer. The concentration of salivary insulin and 20 other metabolic biomarkers was assayed in 744 randomly selected saliva samples by multiplexed bead-based immunoassay. Results. Obesity was seen in 26.5% of the adolescents. Salivary insulin predicting hyperinsulinemia occurred in 4.3% of normal-weight adolescents, 8.3% of overweight adolescents, and 25.7% of obese adolescents (p<0.0001). Salivary glucose predicting hyperglycemia was found in only 3% of obese children and was not predictive (p=0.89). Elevated salivary glucose and insulin occurring together was associated with elevated vascular endothelial growth factor and reduced salivary interleukin-12. Conclusion. Considering the surrogate nature of salivary insulin and glucose, this study suggests that elevated insulin may be a dominant sign of metabolic disease in adolescent populations. It also appears that a proangiogenic environment may accompany elevated glucose in obese adolescents

VEGF-A, and IL-12p70 in Obese Kuwaiti Adolescents

Objective. Here, we investigated the relationships between obesity and the salivary concentrations of insulin, glucose, and 20 metabolic biomarkers in Kuwaiti adolescents. Previously, we have shown that certain salivary metabolic markers can act as surrogates for blood concentrations. Methods. Salivary samples of whole saliva were collected from 8,317 adolescents. Salivary glucose concentration was measured by a high-sensitivity glucose oxidase method implemented on a robotic chemical analyzer. The concentration of salivary insulin and 20 other metabolic biomarkers was assayed in 744 randomly selected saliva samples by multiplexed bead-based immunoassay. Results. Obesity was seen in 26.5% of the adolescents. Salivary insulin predicting hyperinsulinemia occurred in 4.3% of normal-weight adolescents, 8.3% of overweight adolescents, and 25.7% of obese adolescents ( &lt; 0.0001). Salivary glucose predicting hyperglycemia was found in only 3% of obese children and was not predictive ( = 0.89). Elevated salivary glucose and insulin occurring together was associated with elevated vascular endothelial growth factor and reduced salivary interleukin-12. Conclusion. Considering the surrogate nature of salivary insulin and glucose, this study suggests that elevated insulin may be a dominant sign of metabolic disease in adolescent populations. It also appears that a proangiogenic environment may accompany elevated glucose in obese adolescents

The salivary microbiome is altered in the presence of a high salivary glucose concentration

<div><p>Background</p><p>Type II diabetes (T2D) has been associated with changes in oral bacterial diversity and frequency. It is not known whether these changes are part of the etiology of T2D, or one of its effects.</p><p>Methods</p><p>We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years) using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG; glucose concentration ≥ 1.0 mg/d, n = 175) and those with low salivary glucose (LSG, glucose concentration < 0.1 mg/dL n = 2,537).</p><p>Results</p><p>HSG was associated with dental caries and gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83%) of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64%) were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness.</p><p>Conclusions</p><p>HSG was associated with a reduction in overall bacterial load and alterations to many relative bacterial frequencies in saliva when compared with LSG in samples from adolescents. We propose that hyperglycemia due to obesity and/or T2D results in HSG and subsequent acidification of the oral environment, leading to a generalized perturbation in the oral microbiome. This suggests a basis for the observation that hyperglycemia is associated with an increased risk of dental erosion, dental caries, and gingivitis. We conclude that HSG in adolescents may be predicted from salivary microbial diversity or frequency, and that the changes in the oral microbial composition seen in adolescents with developing metabolic disease may the consequence of hyperglycemia.</p></div

Proposed hypothesis for salivary microbial changes in response to high salivary glucose concentration.

<p>The central theme of this hypothesis is that hyperglycemia changes the oral microbial environment by salivary acidification. Numbers refer to points made in discussion. The bar graph represents data from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0170437#pone.0170437.t008" target="_blank">Table 8</a>.</p

Demographic and clinical variables for the total study population of 8,173 adolescents by sex.

<p>Demographic and clinical variables for the total study population of 8,173 adolescents by sex.</p

Median bacterial counts (number/mL x 10⁻⁵) in LSG and HSG conditions, sorted by univariate area under the curve (AUC).

<p>Percent difference was computed as [100 x (HSG-LSG)/LSG] between the HSG group and the LSG group. Negative values represent a reduction in bacterial count. The random forest ROC area under the curve was 0.935. Source data is listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0170437#pone.0170437.s001" target="_blank">S1 Table</a>.</p

Distribution of cmetS-Z and cmetS-PCA across WHO body weight categories in a cohort of 8,112 Kuwaiti children.

<p>The four body weight categories were defined according to WHO criteria. The numbers at the top of each graph were the mean ± SD of cmetS-Z and cmetS-PCA for each category, as also indicated by the bars at the corresponding locations of the distributions.</p