Temporal development of the oral microbiome and prediction of early childhood caries.

Human microbiomes are predicted to assemble in a reproducible and ordered manner yet there is limited knowledge on the development of the complex bacterial communities that constitute the oral microbiome. The oral microbiome plays major roles in many oral diseases including early childhood caries (ECC), which afflicts up to 70% of children in some countries. Saliva contains oral bacteria that are indicative of the whole oral microbiome and may have the ability to reflect the dysbiosis in supragingival plaque communities that initiates the clinical manifestations of ECC. The aim of this study was to determine the assembly of the oral microbiome during the first four years of life and compare it with the clinical development of ECC. The oral microbiomes of 134 children enrolled in a birth cohort study were determined at six ages between two months and four years-of-age and their mother's oral microbiome was determined at a single time point. We identified and quantified 356 operational taxonomic units (OTUs) of bacteria in saliva by sequencing the V4 region of the bacterial 16S RNA genes. Bacterial alpha diversity increased from a mean of 31 OTUs in the saliva of infants at 1.9 months-of-age to 84 OTUs at 39 months-of-age. The oral microbiome showed a distinct shift in composition as the children matured. The microbiome data were compared with the clinical development of ECC in the cohort at 39, 48, and 60 months-of-age as determined by ICDAS-II assessment. Streptococcus mutans was the most discriminatory oral bacterial species between health and current disease, with an increased abundance in disease. Overall our study demonstrates an ordered temporal development of the oral microbiome, describes a limited core oral microbiome and indicates that saliva testing of infants may help predict ECC risk.

Examiner calibration in caries detection for populations and settings where in vivo calibration is not practical.

AIM: to compare two methods of in vitro examiner calibration in populations and settings where clinical (in vivo) calibration is not practical. METHODS: Study design was cross-sectional and fully-crossed. The units of analysis were 880 tooth surfaces, from ten children ages 3 to 4 years. The study had three data components: (1) Examiner training and calibration using the International Caries Detection and Assessment System (ICDAS) e-Learning programme (2) In vivo community-based visual examination and (3) Intra-oral digital photographs of the same tooth surfaces from the in vivo visual examination. Kappa and weighted kappa scores were used to study reliability estimates. Systematic differences in caries assessments were determined using the Stuart Maxwell test. Data were analysed using STATA 13.1 and SAS 9.2. RESULTS: Weighted kappa scores for the in vivo component ranged from 0.50 to 0.66 and from 0.64-0.74, for inter- and intraexaminer reliability, respectively. Caries lesions detected in vivo were also detected on photographs, albeit with more false positives when using photographs. For example, of 46 tooth surfaces assessed as being sound in the in vivo examination, 22 (48%) of these were assessed as having caries when photographs were used as the diagnostic method. CONCLUSIONS: From this research it appears that good quality photographs alone may be used for training and calibration among challenging populations or settings without adversely affecting data quality.

Transition from milks to the introduction of solid foods across the first 2 years of life: findings from an Australian birth cohort study.

BACKGROUND: The current literature regarding the transition from milks to solid foods across the first 2 years of life is limited despite the important influence of early dietary intake on children's growth and development. The present study describes dietary intake from birth to 2 years across four developmental relevant time-points within an Australian birth cohort. METHODS: Dietary data from 466 infants was collected at four time-points in the first 2 years of life via parent-reported questionnaire, including a 45-item food and beverage frequency questionnaire. Subsample analyses of children who were aged 1-3, 6-8, 12-14 and 18-20 months at the time of data collection were conducted. RESULTS: Infant formula remained consistently consumed by over 75% of children from the 6-8- to 18-20 months old age groups. Mean (SD) age of introduction to solid foods was 5.2 (1.3) months. Almost 20% and 10% of children were introduced before 16 and after 32 weeks, respectively. The highest consumption of core foods, recommended for a healthy diet, daily was seen in the 12-14 months old age group with lower proportions in the 18-20 months old age group coinciding with an increased proportion of children eating discretionary choice foods, not recommended for a healthy diet. Discretionary choice foods/beverages presented in children's diets as early as in the 6-8 months old age group. By 18-20 months, at least 20% of children were consuming savoury biscuits, sweet biscuits, muesli bars and luncheon meats at least twice a week. CONCLUSIONS: The present study identified a number of findings outside the recommendations of the Australian Dietary and Infant Feeding Guidelines. Further work is warranted to explore these outcomes.