Study of Mothers' and Infants' Life Events Affecting Oral Health (SMILE) birth cohort study: cohort profile

Development and internal validation of the SMILE-FSS: a Free Sugars Screener for Australian children aged 2 and 5 years

OBJECTIVE

To develop and internally validate a Free Sugars Screener (FSS) for Australian children aged 2 and 5 years.

DESIGN

Using data collected from a ninety-nine-item (2-year-olds) and ninety-eight-item (5-year-olds) FFQ in the Study of Mothers' and Infants' Life Events affecting oral health (SMILE-FFQ), a regression-based prediction modelling approach was employed to identify a subset of items that accurately estimate total free sugars intake (FSI). The predictors were grams of free sugars (FSg) for individual items in the SMILE-FFQ and child's age and sex. The outcome variable was total FSI per person. To internally validate the SMILE-FSS items, the estimated FSg was converted to percent energy from free sugars (%EFS) for comparison to the WHO free sugars guideline categories (< 5 %, 5-< 10 % and ≥ 10 %EFS) using cross-classification analysis.

SETTING

Australia.

PARTICIPANTS

858 and 652 2- and 5-year-old children, respectively, with complete dietary (< 5 % missing) and sociodemographic data.

RESULTS

Twenty-two and twenty-six items were important in predicting FSI at 2 and 5 years, respectively. Items were similar between ages with more discretionary beverage items (e.g. sugar-sweetened beverages) at 5 years. %EFS was overestimated by 4·4 % and 2·6 %. Most children (75 % and 82 %) were categorised into the same WHO free sugars category with most (87 % and 95 %) correctly identified as having < 10 %EFS in line with the WHO recommendation.

CONCLUSIONS

The SMILE-FSS has good internal validity and can be used in research and practice to estimate young Australian children's FSI and compare to the WHO free sugars guidelines to identify those 'at risk'.

Pairwise approach for analysis and reporting of child's free sugars intake from a birth cohort study

OBJECTIVES

The prospective cohort design is an important research design, but a common challenge is missing data. The purpose of this study is to compare three approaches to managing missing data, the pairwise (n = 1386 children), the partial or modified pairwise (n = 1019) and the listwise (n = 546), to characterize the trajectories of children's free sugars intake (FSI) across early childhood.

METHODS

By applying the Group-based Trajectory Model Technique to three waves of data collected from a prospective cohort study of South Australian children, this study examined the three approaches in managing missing data to validate and discuss children's FSI trajectories.

RESULTS

Each approach identified three distinct trajectories of child's FSI from 1 to 5 years of age: (1) 'low and fast increasing', (2) 'moderate and increasing' and (3) 'high and increasing'. The trajectory memberships were consistent across the three approaches, and were for the pairwise scenario (1) 15.1%, (2) 68.3% and (3) 16.6%; the partial or modified pairwise (1) 15.9%, (2) 64.1% and (3) 20.0%; and the listwise (1) 14.9%, (2) 64.9% and (3) 20.2% of children.

CONCLUSIONS

Given the comparability of the findings across the analytical approaches and the samples' characteristics between baseline and across different data collection waves, it is recommended that the pairwise approach be used in future analyses to optimize the sample size and statistical power when examining the relationship between FSI in the first years of life and health outcome such as dental caries.

Parental recall bias in observational studies: Child dental service use

BACKGROUND

Parents are frequently used to recall events of exposure and disease as a proxy for their children in observational health research.

AIM

To assess the validity of parental recall of children's utilisation of dental services.

DESIGN

Parents in the Longitudinal Study of Australian Children (LSAC) were asked to recall their children's overall dental service use in the previous year and whether the study child had received fillings or extractions due to decay in the previous 2 years. True positives were identified through parents who correctly recalled child dental service utilisation with actual dental treatment received in a linked dataset.

RESULTS

Of the 10 090 participants from the LSAC, 1290 study children had linked dental treatment data eligible for inclusion in this study. The absolute true-positive rate for parental recall of dental service use in the previous year was 82% (n = 1263). Overall true-positive percentages were lower for recall of fillings (40%) and extractions (7%) in the previous 2 years. Increasing number of recall days was associated with the rate of true-positive recall adjusted for other factors in all three models.

CONCLUSION

Accuracy of parental recall for tooth fillings and extractions was low. The use of parental recall for specific dental treatment over a time span of 2 years in further research is not recommended.

Trajectories of child free sugars intake and dental caries - a population-based birth cohort study

OBJECTIVES

To investigate the association between trajectories of free sugars intake during the first five years of life and dental caries experience at five years.

METHODS

Data from the SMILE population-based prospective birth cohort study, collected at one, two and five years old, were used. A 3-days dietary diary and food frequency questionnaire were used to estimate free sugars intake (FSI) in grams. The primary outcomes were dental caries prevalence and experience (dmfs). The Group-Based Trajectory Modelling method was used to characterize three FSI trajectories ('Low and increasing'; 'Moderate and increasing'; and 'High and increasing'), which were the main exposures. Multivariable regression models were generated to compute adjusted prevalence ratios (APR) and rate ratios (ARR) for the exposure, controlling for socioeconomic factors.

RESULTS

The prevalence of caries was 23.3%, with a mean dmfs of 1.4, and a median of 3.0 among those who had caries. There were clear gradients of caries prevalence and experience by the FSI trajectories. The 'High and increasing' had an APR of 2.13 (95%CI 1.23-3.70) and ARR of 2.77 (95%CI 1.45-5.32) against the 'Low and increasing'. The 'Moderate and increasing' group had intermediate estimates. A quarter of the caries cases could have been prevented if the whole study sample had been in the 'Low and increasing' FSI trajectory.

CONCLUSION

A sustained, high trajectory of FSI from a young age was positively associated with child dental caries. Measures to minimise consumption of free sugars must commence early in life.

CLINICAL SIGNIFICANCE

The study has provided high level evidence to inform clinicians' decisions in promoting a healthy dietary pattern for young children.

Microbiome and Human Health: Current Understanding, Engineering, and Enabling Technologies

The human microbiome is composed of a collection of dynamic microbial communities that inhabit various anatomical locations in the body. Accordingly, the coevolution of the microbiome with the host has resulted in these communities playing a profound role in promoting human health. Consequently, perturbations in the human microbiome can cause or exacerbate several diseases. In this Review, we present our current understanding of the relationship between human health and disease development, focusing on the microbiomes found across the digestive, respiratory, urinary, and reproductive systems as well as the skin. We further discuss various strategies by which the composition and function of the human microbiome can be modulated to exert a therapeutic effect on the host. Finally, we examine technologies such as multiomics approaches and cellular reprogramming of microbes that can enable significant advancements in microbiome research and engineering.

The Oral-Microbiome-Brain Axis and Neuropsychiatric Disorders: An Anthropological Perspective

In the 21st century, neuropsychiatric disorders (NPDs) are on the rise, yet the causal mechanisms behind this global epidemic remain poorly understood. A key to these unknowns may lie within the vast communities of bacteria, fungi, and viruses in the body (microbiota), which are intimately linked with health and disease. NPDs were recently shown to be connected to gut microbiota, which can communicate with and influence the brain through the Gut-Brain-Axis (GBA). Parallel studies examining oral microbiota and their connections to the brain also suggest that microbes in the mouth can similarly influence NPD outcomes. However, the mechanisms and pathways that illuminate how oral microbiota and brain communicate in NPDs remain unknown. Here, we review identified mechanisms and pathways that oral microbiota use to engage the brain, and we lay the theoretical foundation for an oral-microbiota-brain axis (OMBA). Specifically, we examine established neuroinflammatory and immune system activation responses that underpin interactions between the oral microbiota and the central nervous system (CNS), detailing four specific mechanisms: (1) microbial and metabolite escape, (2) neuroinflammation, (3) CNS signaling, and (4) response to neurohormones. We then scrutinize why including the OMBA, in addition to the GBA, is critically needed to elucidate specific causal relationships between microbial dysbiosis and observed NPD development and progression. Furthermore, we argue for comprehensive, interdisciplinary approaches that integrate lab-based microbiome research and population-level studies that examine the OMBA to improve NPDs. We specifically identify key anthropological perspectives that integrate sociocultural, epidemiological, genetic, and environmental factors that shape the oral microbiome and its interactions with NPDs. Together, future studies of the OMBA in conjunction with interdisciplinary approaches can be used to identify NPD risks and improve outcomes, as well as develop novel intervention and treatment strategies.

The Australian Feeding Infants and Toddlers Study (OzFITS) 2021: Study Design, Methods and Sample Description

(1) Background: Caregiver feeding practices during the first two years of a child's life influence nutrition, growth, and development, as well as long term taste preferences and dietary patterns. Suboptimal feeding practices lead to poorer health outcomes, such as obesity, that persist into adulthood. Although the importance of early life nutrition is well-established, there are no Australia-wide surveys of dietary intakes of children under two years of age. The 2021 Australian Feeding Infants and Toddlers Study (OzFITS) aims to fill this gap. This paper describes the methods and study sample of OzFITS 2021. (2) Methods: OzFITS 2021 is a cross-sectional study of children aged 0 to 23.9 months of age and their caregiver across Australia. Data were collected between April 2020 and April 2021. A telephone-based survey was completed with a caregiver to obtain information on child and caregiver characteristics and feeding practices. For exclusively breastfed infants, the number of breastfeeds in a 24 h period was reported. Dietary intakes for mixed fed children were estimated using a one-day food record, with 30% of caregivers completing a second food record on a non-consecutive day. (3) Results: We enrolled 1140 caregiver and child dyads. Of those eligible to complete a food record, 853 (87%) completed the food record. Compared to the Australian population, caregivers were more likely to be university-educated (>75%), married or in a de facto relationship (94%), and have a household income >$100,000/y (60%). (4) Conclusions: OzFITS 2021 is the first national study to examine food and nutrient intake in Australian children aged under 2 years. The study will provide information on breastfeeding rates and duration, use of breast milk substitutes, and timing of solid food introduction. Dietary intake data will allow the comparison of core food groups and discretionary food intake to Australian guidelines and estimate the prevalence of inadequate intake of key nutrients, like iron. Healthcare practitioners and policymakers can use the study findings as a source of evidence to inform the next iteration of infant feeding guidelines.

Sources and Determinants of Wholegrain Intake in a Cohort of Australian Children Aged 12-14 Months

In the first two years of life, exposure to wholegrain foods may help establish life‑long consumption patterns associated with reduced risk of chronic disease, yet intake data are lacking for this age group. This cross‑sectional analysis aimed to determine intakes and food sources of wholegrains in a cohort of 828 Australian children aged 12–14 months, and to identify determinants of wholegrain intake. Three non‑consecutive days of dietary intake data were collected using a 24‑h recall and 2‑day estimated food record. The multiple source method was used to estimate usual wholegrain intake, and the multivariable general linear model procedure used to identify associations between usual wholegrain intake and socio‑demographic determinants. The mean wholegrain intake was 19.5 (±14) g/day, and the major food sources were ready to eat breakfast cereals (40%) breads and bread rolls (26.6%), flours and other cereal grains (9.4%), and commercial infant foods (8.3%). Lower wholegrain intakes were observed for children whose mothers were born in China (p < 0.001) and other Asian countries (p < 0.001), with the exception of India (p = 0.193); those with mothers aged less than 25 years (p = 0.001) and those with two or more siblings (p = 0.013). This study adds to the weight of global evidence highlighting the need to increase children’s intake of foods high in wholegrain, including in the first few years of life.