Caries and background factors in Swedish 4-year-old children with special reference to immigrant status.

OBJECTIVE: This study assesses the prevalence of caries and some background factors in 4-year-old children in the city of Umeå, northern Sweden, and compares this with data from earlier studies to reveal changes over time. MATERIALS AND METHODS: Children from the catchment areas of three Public Dental Health Service clinics in Umeå (n = 224) born during the third quarter of 2008 were invited to undergo a clinical dental examination. Decayed surfaces (including both dentine and enamel, except for enamel lesions on buccal and lingual surfaces), missing and filled surfaces (dmfs) were recorded using the same methods and criteria as in a series of earlier studies performed between 1980-2007. Background data were collected in a case-history and a questionnaire. Results. The proportion of children with caries significantly decreased from 2007 (38%) to 2012 (22%) (p < 0.05). In addition, the distribution of dmfs differed significantly between these years (p < 0.05). More immigrant children had caries (42%) than non-immigrant children (15%) (p < 0.05). For children with caries, there were no significant changes in the distribution of dmfs between 1980-2012 (p > 0.05). An immigrant background was associated with a lower frequency of tooth brushing and a higher intake of ice cream, sweets and chocolate drinks (p < 0.05). CONCLUSION: Although the proportion of children with caries declined between 2007-2012, this decline was limited to non-immigrant children. Since 1980 the distribution of dmfs remained unchanged among children with caries. More research on interventions for changing oral health behaviours is needed, specifically for immigrant children.

Genetic Preference for Sweet Taste in Mothers Associates with Mother-Child Preference and Intake.

Taste perception is a well-documented driving force in food selection, with variations in, e.g., taste receptor encoding and glucose transporter genes conferring differences in taste sensitivity and food intake. We explored the impact of maternal innate driving forces on sweet taste preference and intake and assessed whether their children differed in their intake of sweet foods or traits related to sweet intake. A total of 133 single nucleotide polymorphisms (SNPs) in genes reported to associate with eating preferences were sequenced from saliva-DNA from 187 mother-and-child pairs. Preference and intake of sweet-, bitter-, sour-, and umami-tasting foods were estimated from questionnaires. A total of 32 SNP variants associated with a preference for sweet taste or intake at a p-value < 0.05 in additive, dominant major, or dominant minor allele models, with two passing corrections for multiple testing (q < 0.05). These were rs7513755 in the TAS1R2 gene and rs34162196 in the OR10G3 gene. Having the T allele of rs34162196 was associated with higher sweet intake in mothers and their children, along with a higher BMI in mothers. Having the G allele of rs7513755 was associated with a higher preference for sweets in the mothers. The rs34162196 might be a candidate for a genetic score for sweet intake to complement self-reported intakes.

Co-aggregation and growth inhibition of probiotic lactobacilli and clinical isolates of mutans streptococci: an in vitro study.

OBJECTIVE: Co-aggregation and growth inhibition abilities of probiotic bacteria may play a key role in their interference with the oral biofilm. The aim was to investigate the in vitro ability of selected commercial probiotic lactobacilli to co-aggregate and inhibit growth of oral mutans steptococci isolated from adults with contrasting levels of caries. MATERIALS AND METHODS: Mutans streptococci (MS) strains were isolated from caries-free (n = 3) and caries-susceptible (n = 5) young adults and processed with eight commercial probiotic lactobacilli strains. One laboratory reference strain (S. mutans Ingbritt) was selected as control. Co-aggregation was determined spectrophotometrically and growth inhibition was assessed with the agar overlay technique. RESULTS: All probiotic lactobacilli showed an ability to co-aggregate with the isolated MS strains. Statistically significant differences (p < 0.05) were found between strains from different individuals when compared with the reference strain. The selected lactobacilli inhibited MS growth, but the ability varied between the strains and was clearly related to pH. No differences were observed between the different MS strains from caries-free and caries-susceptible individuals. CONCLUSIONS: The selected lactobacilli displayed co-aggregation activity and inhibited growth of clinical mutans streptococci. The growth inhibition was strain-specific and dependent on pH and cell concentration. The findings indicate that the outcome of lactobacilli-derived probiotic therapy might vary between individuals and depend on the specific strain used.

Using Oral Microbiota Data to Design a Short Sucrose Intake Index.

Excessive sucrose consumption is associated with numerous health problems, including dental caries, and is considered to play a critical role in shaping the human microbiota. Here, we aimed to confirm the association between sucrose exposure and oral microbiota profile, develop a short food-based index capturing variation among sucrose consumers and validate it against oral microbiota and dental caries in a derivation cohort with 16- to 79-year-old participants (n = 427). Intake and food preferences were recorded by questionnaires and saliva microbiota by 16S rDNA sequencing. Taxonomic similarities clustered participants into five clusters, where one stood out with highest sucrose intake and predicted sugar related metabolic pathways but lowest species diversity in the microbiota. Multivariate modelling of food intake and preferences revealed foods suitable for a sucrose index. This, similarly to sucrose intake, was related to bacterial pattern and caries status. The validity of the sucrose index was replicated in the population-based Gene-Lifestyle Interactions in Dental Endpoints (GLIDE, n = 105,520 Swedish adults) cohort. This suggested that the index captured clinically relevant variation in sucrose intake and that FFQ derived information may be suitable for screening of sucrose intake in the clinic and epidemiological studies, although adjustments to local consumption habits are needed.

Growth inhibition of oral mutans streptococci and candida by commercial probiotic lactobacilli--an in vitro study.

BACKGROUND: Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and C. albicans in vitro. METHODS: Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of Candida albicans with an agar overlay method. RESULTS: At concentrations ranging from 109 to 105 CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of L. acidophilus La5 that executed only a slight inhibition of some strains at concentrations corresponding to 107 and 105 CFU/ml. At the lowest cell concentration (103 CFU/ml), only L. plantarum 299v and L. plantarum 931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by L. rhamnosus LB21, L. paracasei F19, L. reuteri PTA 5289 and L. reuteri ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two L. plantarum strains and L. reuteri ATCC 55730 displayed the strongest inhibition on Candida albicans. No significant differences were observed between the reference strains and the clinical isolates. CONCLUSION: The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and Candida albicans in vitro.

Chapter 10: Probiotic Bacteria and Dental Caries.

The World Health Organization has defined probiotics as "Live microorganisms which, when administered in adequate amounts, confer a health benefit to the host." Traditionally, probiotic microorganisms (mainly Lactobacillus ssp. and Bifidobacterium ssp.) have been used to prevent or treat diseases in the gastrointestinal tract. In the past 20 years, there has been an increased interest in possible oral health effects of probiotics. In vitro studies have shown promising results with growth inhibition of mutans streptococci (MS) and Candida albicans. There are only a few clinical studies with caries development as the primary outcome while more studies have been focusing on control of caries risk factors or so-called surrogate outcomes. Several studies have evaluated the effects of probiotic bacteria on MS in saliva and/or plaque, and a number of probiotic strains show ability to reduce the number of MS. Probiotic bacteria have not been shown to permanently colonize the oral cavity; in early-in-life interventions or in subjects with a mature microbiota. To date investigated strains are transiently present in saliva during and shortly after an intervention. There are eight randomized controlled clinical trials with dental caries as outcome and probiotic strains, administration, duration of the intervention, and target group varied. In a majority of the studies (75%), the interventions resulted in caries reduction in the treatment groups. Although a majority of these studies suggest a caries-preventive effect of probiotic bacteria, more long-term clinical studies are needed in this field before probiotics could be recommended for preventing or treating dental caries.

Oral Microbiota Profile Associates with Sugar Intake and Taste Preference Genes.

Oral microbiota ecology is influenced by environmental and host conditions, but few studies have evaluated associations between untargeted measures of the entire oral microbiome and potentially relevant environmental and host factors. This study aimed to identify salivary microbiota cluster groups using hierarchical cluster analyses (Wards method) based on 16S rRNA gene amplicon sequencing, and identify lifestyle and host factors which were associated with these groups. Group members (n = 175) were distinctly separated by microbiota profiles and differed in reported sucrose intake and allelic variation in the taste-preference-associated genes TAS1R1 (rs731024) and GNAT3 (rs2074673). Groups with higher sucrose intake were either characterized by a wide panel of species or phylotypes with fewer aciduric species, or by a narrower profile that included documented aciduric- and caries-associated species. The inferred functional profiles of the latter type were dominated by metabolic pathways associated with the carbohydrate metabolism with enrichment of glycosidase functions. In conclusion, this study supported in vivo associations between sugar intake and oral microbiota ecology, but it also found evidence for a variable microbiota response to sugar, highlighting the importance of modifying host factors and microbes beyond the commonly targeted acidogenic and acid-tolerant species. The results should be confirmed under controlled settings with comprehensive phenotypic and genotypic data.

Caries prevalence in children with cleft lip and palate--a systematic review of case-control studies.

AIM: To conduct a systematic review of literature in order to examine the evidence of an increased prevalence of dental caries in children with cleft lip and palate (CLP). METHODS: A search of the PubMed database was conducted through May 2006. Sex- and age-matched case-control studies with noncavitated and manifest caries lesions as endpoint were targeted (n = 6). The studies were assessed independently by two reviewers and scored A-C according to predetermined criteria for methodology and performance. RESULTS: Significantly more caries in CLP children were reported in two of the four studies in the permanent dentition and in three out of four publications dealing with primary teeth. None of the articles were, however, assessed with the highest grade 'A' and the level of evidence was therefore based on three papers graded 'B'. There was a tendency towards higher caries scores in preschool children, but as conflicting results were revealed, the evidence that children with CLP exhibit more caries than noncleft controls was inconclusive. CONCLUSION: This systematic review of literature was unable to find firm evidence for the assumption that CLP children have an increased prevalence of dental caries.