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    Pakiaka Tupuora Parenting From the Start : evaluating a preventative intervention to improve attachment and health outcomes for mothers and their babies : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Te Kungenga ki Pūrehuroa Massey University, Manawatū, New Zealand
    (Massey University, 2024-12-06) Morrimire, Leith
    Background: Parenting interventions can improve individual and societal outcomes but few are brief, preventative, or consistent with Indigenous knowledge. This is the first based on the latest multidisciplinary theory – the evolved developmental niche (EDN). Objective: To evaluate the one-day (8hr) preventative antenatal Parenting From the Start workshop in terms of infant attachment and other medium-term outcomes. Methods: Randomised controlled trial with two parallel arms open to pregnant residents of the Manawatū/Horowhenua regions of Aotearoa New Zealand. 57 English-speaking women aged 24 to 44 years were randomly assigned to intervention (n = 27) or wait-list control (n = 30) groups alongside standard free maternity care and parental leave. Retention rates were 81% at the home visit (n = 22 intervention; n = 24 control), and 74% at the clinic assessment (n = 20 intervention; n = 20 control). Primary analyses were based on maternal sensitive responsiveness as measured by the Ainsworth Sensitivity Scales, Mini-Maternal Behavior Q- Sort, and Observational Measure of Sensitivity and Responsiveness (11 to 24 months post birth) and infant attachment on the Strange Situation Procedure (11-22 months post birth). Secondary outcomes included a range of self-reported parenting intentions and strategies. Findings: Intervention group infants had higher rates of secure attachment (90%) than the control group (64%). This effect was significant at the level of 3-way attachment security (p = .011, Cramer’s V = 0.448), and attachment subcategory (p = .047, Cramer’s V = 0.552), but not 2-way attachment security (p = .059, Cramer’s V = 0.342). Maternal sensitive responsiveness did not differ across study conditions (p = .097, RBC = 0.288). Parenting intentions relating to breastfeeding, proximal care, room sharing, and elimination communication were significantly increased in the intervention group, as were responsive parenting beliefs, and frequency of positive care reported over the infants’ first year. Interpretation: The intervention significantly increased responsive parenting intentions and beliefs, positive care over the first year, and rates of secure attachment. Parenting From the Start warrants further study as a brief, preventative, bicultural intervention. Trial registration ACTRN12617000321347, universal trial number U111111840331. Trial information can be found at: http://www.ANZCTR.org.au/ACTRN12617000321347.aspx
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    Dietary intake, household food insecurity, and their associations with anthropometric status and sociodemographic factors amongst young New Zealand children : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science, Massey University, Auckland, New Zealand
    (Massey University, 2024-04-08) Jupiterwala, Rosario Pillar Monzales
    Background: Household food insecurity is a serious public health concern that may impact young children's dietary intake. In New Zealand (NZ), there are limited studies on young children’s dietary intake. However, comprehensive dietary data is crucial to ensure that young NZ children obtain adequate energy and nutrient intakes to support their optimal growth and development. Certain sociodemographic groups are disproportionately affected by household food insecurity, which may have been reflected by the high proportion of obesity in NZ compared to other high-income countries and poor dietary consumption indicative of suboptimal nutrition. Aim: Therefore, this thesis aims to describe the energy and nutrient intakes, food group consumption, and household food security status of young NZ children, their relationship, and associated correlates such as anthropometric status, ethnicity, socioeconomic status, sex, age, caregiver characteristics, and household size and structure. Methods: Two 24-hour food recalls from 289 children aged 1-3 years participating in the Young Foods NZ (YFNZ) study were analysed to obtain energy, nutrient, and food group intake data. YFNZ is an observational cross-sectional study of children living in Auckland, Wellington, and Dunedin, NZ. Household food security status was measured using the NZ food security scale, a NZ-specific and validated questionnaire. NZ Index of Deprivation was utilised as a proxy measure of socioeconomic status. Anthropometric status was measured using the Body Mass Index (BMI) z-score. Data on other sociodemographic characteristics such as ethnicity, sex, age, caregiver characteristics, household size and structure were collected through online and interviewer-assisted questionnaires. Results: Overall, most nutrient intake recommendations were met except for fibre, iron, calcium, and vitamin C, with a proportion of inadequacy at 54.0%, 15.2%, 3.8%, and 4.8% respectively. Additionally, high protein and saturated fat intakes were observed. Māori, Pacific, Asian, and children living in areas of high deprivation were more at risk of lower fibre intakes than their counterparts, whilst children living in areas of high deprivation had a higher fat intake than those living in low-deprived neighbourhoods. Grains and pasta (n=276 participants), fruits (n=266), and biscuits, crackers, cakes, and desserts (n=242) were most commonly consumed. Formulae (i.e., infant and follow-on formula mixes) and mixed dishes primarily contributed to the intake of energy and most nutrients. Children who were more likely to consume dairy products and dairy-alternative products were children with healthy weight compared to those who were overweight (p=0.036), NZ European compared to Māori, Asian and Pacific children (p=0.005), and children living in areas of low deprivation compared to those who live in highly deprived areas (p=0.014). Food insecure children were more likely to consume pies and pasties (p=0.013), potatoes, kūmara and taro (p=0.040), and beverages (i.e., all fluids except for milk and water) (p=0.011) but less likely to consume biscuits, crackers, cakes and desserts (p=0.001), vegetables (p=0.005), and nuts and seeds (p=0.004). Energy-dense and nutrient-poor foods such as sausages and processed meats; sugar, confectionery, sweet spreads; and pies and pasties were the primary contributors to Pacific children's energy intake and those living in areas of higher deprivation and food insecure households. Over a third of young children experienced food insecurity in the past year. Being overweight, Māori or Pacific, living in areas of high deprivation; having a caregiver who was younger, not in paid employment, or had low educational attainment; living with at least two other children in the household, and living in a sole parent household were associated with household food insecurity. Compared to food-secure children, moderately food-insecure children had higher fat and saturated fat intakes, consuming 3.0 (0.2, 5.8) g/day more fat, and 2.0 (0.6, 3.5) g/day more saturated fat (p<0.05). Moderately and severely food insecure children had lower fibre intake, consuming 1.6 (2.8, 0.3) g/day and 2.6 (4.0, 1.2) g/day less fibre, respectively, compared to food secure children. Severely food-insecure children had three times the prevalence of inadequate calcium intakes and over three times the prevalence of inadequate vitamin C intakes compared to food-secure children. Conclusion: Young NZ children consume a diet that is mostly adequate in terms of most nutrients with the exception of fibre, iron, calcium, and vitamin C. High intakes of nutrients of concern (i.e., saturated fat and protein) were detected and reported to be commonly sourced from low-cost, energy-dense, and nutrient-poor foods. The consumption of these foods mirrors the high prevalence of household food insecurity and obesity amongst young NZ children. Other sociodemographic factors closely related to poverty or low income were associated with food insecurity. Therefore, targeted policies and programmes are imperative, particularly for the most vulnerable groups, to ensure young children's optimal growth and development and attain more equitable health outcomes in NZ.
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    Complementary feeding practices, nutrient intake, and iron status of Māori, Pasifika, and other infants in Aotearoa New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science, Massey University, Albany, Aotearoa New Zealand
    (Massey University, 2023-09-09) Casale, Maria
    Background: The period of transition from a solely milk-based diet to sharing family foods at around 12 months of age is a critical time for infants. Complementary feeding practices, from the age of introduction to complementary foods, method of feeding (baby-led weaning vs. traditional spoon-feeding), use of the novel baby food pouches, use of traditional cultural foods and practices, and the characteristics and nutrient density of first foods offered support the healthy growth and development of the infant, as well as shape long term dietary patters and food preferences. Additionally, iron status is crucial for healthy infant growth and development, and while this is impacted by myriad maternal, genetic, and environmental factors, complementary feeding practices and the characteristics of foods offered are key modifiable practices that influence infant iron status. Aims and objectives: The overall aim of this study was to investigate and describe early infant feeding practices, key nutrient intake and density, and the iron status of Māori, Pasifika and other infants living in Aotearoa New Zealand, using an observational cross-sectional study design. The primary objective was to conduct an intra-ethnic analysis of infant complementary feeding practices, nutrient intake and density from complementary foods, and iron status between Māori, Pasifika, and ‘other’ infants. ‘Other’ refers to any infants who were not self-identified by the adult respondent as Māori or Pasifika. Methods: Infants aged 7.0–10.0 months along with their primary caregiver participated in an observational cross-sectional study, with 625 infant–caregiver dyads recruited from Auckland and Dunedin, New Zealand. Participants were recruited from a range of ethnic groups and deprivation statuses. Infants were stratified by ethnicity using total response for Māori and Pasifika, with all non-Māori, non-Pasifika infants categorised into a single ‘others’ group. Demographic and feeding practices data were collected via questionnaire. Nutrient intake from complementary food was measured using the multiple-source method from two multiple-pass 24-hour diet recalls. Nutrient density of complementary food was calculated as the concentration of selected nutrients per 418 kJ (100 kcal) of energy. For iron status, haemoglobin, plasma ferritin, soluble transferrin receptor, C-Reactive protein, and alpha-glycoprotein were obtained from a venous blood sample. Inflammation was adjusted for using the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anaemia (BRINDA) method. Body iron concentration (mg/kg body weight) was calculated using the ratio of sTfR and ferritin. Results: A total of 1424 infant-caregiver dyads were assessed for eligibility, and 625 eligible dyads were enrolled in the study, all of whom provided written consent. Data for complementary feeding practices and nutrient intake were analysed for all 625 infants, with blood samples obtained from 365 of these infants for the assessment of iron status. Within the cohort 131 infants were identified by their caregiver as Māori, and 82 as Pasifika. The remaining infants are allocated into a single ‘others’ group as the primary focus of this manuscript is Māori and Pasifika infants. The mean (SD) infant age was 8.4 (0.8) months for Māori, 8.5 (0.9) months for Pasifika, and 8.4 (0.8) months for ‘other’ infants. Over half of all ethnicities introduced CF at around six months of age (56.5% of Māori, 62.2% of Pasifika, and 80.9% of ‘others’). BLW prevalence increased from 11.5% of Māori, 3.7% of Pasifika, and 12.4% of ‘other’ infants at the time of introducing CF to 29.2% of Māori, 17.1% of Pasifika, and 27.3% of ‘others’ currently. Baby food pouches were used at least once by 89.3% of Māori, 85.4% of Pasifika, and 75.6% of ‘other’ infants. Of those who always or frequently were fed pouches, 27.1% of Māori, 25% of Pasifika, and 12% of ‘other’ infants always or mostly sucked directly from the nozzle. Vegetables and ‘pureed’ were the most common first food and texture offered, respectively, for all ethnic groups. At six months red meat was consumed by 54.6% of Māori infants, 63.4% of Pasifika infants, and 61.8% of ‘other’ infants, and approximately half had iron-fortified baby rice (Māori 57.3%, Pasifika 56.1%, ‘other’ 48.7%). Age-inappropriate drinks were currently given to 17.6% of Māori, 20.7% of Pasifika, and 3.8% of ‘other’ infants. In total, 9.1% of Māori and 20.7% of Pasifika respondents reported offering traditional cultural foods to their infants. Energy intake increased with age for all ethnic groups and was higher for boys than girls. Protein as a percentage of energy intake from CF was significantly lower for Māori compared to ‘others’. Fat as a percentage of energy intake from CF was significantly lower for both Māori and Pasifika than ‘others’, whereas carbohydrate as a percentage of energy intake from CF was significantly higher. Sugar intake in grams from CF was significantly higher for Pasifika when compared to ‘others’, and sugar as a percentage of energy intake from CF was significantly higher for Māori than ‘others’. Iron, zinc, and calcium density of the complementary diet was inadequate for all groups: Māori and ‘others’ had an iron density of 0.8 mg/418 kJ, and Pasifika 0.9 mg/418 kJ. Zinc density was 0.5 mg/418 kJ for all groups. Calcium density was 37 mg/418 kJ for Māori, 40 mg/418 kJ for Pasifika, and 38 mg/418 kJ for ‘others’. In total, 96.4% of Pasifika infants were iron sufficient, compared to 82.5% of Māori and 76% of ‘other’ infants. ‘Other’ infants had the highest prevalence of iron deficiency overall, with 3% categorised with iron-deficiency anaemia, 12% with early functional iron deficiency, and 9% with iron depletion. For Māori infants, 4.7% had iron-deficiency anaemia and early functional iron deficiency, respectively, and 8% were iron depleted. One (3.6%) Pasifika infant was iron depleted, and the remainder were iron sufficient. Mediation analysis suggested that the difference in body iron concentration between Pasifika and ‘others’ was partially explained by the frequency of their higher consumption of baby food pouches. Conclusions: The high prevalence of Māori and Pasifika infants feeding directly from baby food pouch nozzles is concerning in light of the increasing popularity and prevalence of this novel feeding device, with concerns for both the safety and impact on development of this way of feeding. The low density of iron, zinc, and calcium in the complementary diet warrants further investigation into feeding and fortification strategies, due to the key role these nutrients play in the growth and development of infants. The rate of iron deficiency was very low for Pasifika infants despite little iron intake from complementary food, indicating non-dietary factors as the likely cause for this group.
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    Feeding and dietary practices of New Zealand infants : an observational study : a thesis presented in the partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Albany, New Zealand
    (Massey University, 2023) Brown, Kimberley Jane
    Background: Nutrition and early-life feeding practices have short and long-term impacts on the quality and longevity of life. The importance of optimal nutrition during infancy is recognised worldwide and evidence-based infant feeding recommendations have been developed to promote infant health, growth, development, and the establishment of healthy eating behaviours. Currently, there is limited evidence on infant nutrition and feeding practices in New Zealand (NZ), with gaps in our knowledge about what infants are being fed, adherence to the Ministry of Health (MoH) ‘Healthy Eating Guidelines for New Zealand Babies and Toddlers (0–2 years old)’, and the prevalence of concerning feeding behaviours (CFB). Aim: To 1) investigate the contributions that key foods and food groups make to the dietary intake of NZ infants, 2) investigate infant adherence to key dietary indicators as recommended by the MoH’s ‘Healthy Eating Guidelines for New Zealand Babies and Toddlers (0–2 years old)’, and 3) determine the prevalence of parent-reported concerning infant feeding behaviours and associated demographic characteristics and feeding practices of NZ infants between 7.0 and 10.0 months of age. Methods: The observational First Foods NZ (FFNZ) study recruited 625 ethnically diverse infants (aged 7.0 to 10.0 months) living in Auckland and Dunedin between July 2020 and February 2022. Caregivers who were 16 years or older, spoke English, and had not recently participated in a nutritional intervention that may have influenced their infant’s diet were invited to attend two study visits. Appointments were conducted in the participant’s home, available research centre, or via Zoom (during Covid19 restrictions for second appointment only) and included two 24-hour diet recalls and demographic and feeding questionnaires. Diet recall data were analysed through FoodWorks (Version 10, Xyris Software, Australia) using the NZ Food Composition Database FOODfiles™ 2018 Version 01, and foods were allocated food and food group codes using the FFNZ coding system. Counts of foods and food groups consumed were analysed for at least one and both diet recall days, where available. Key indicators from the MoH’s ‘Healthy Eating Guidelines for New Zealand Babies and Toddlers (0–2 years old)’ that were measurable from FFNZ data and applied to those aged 7.0 to 10.0 months were extracted from questionnaire data, or where stated from 24-hour recalls. Recommendations analysed included exclusive breastfeeding to ‘around’ six months of age (defined as ‘5 months’ or ‘6 months’, being the age when something other than breast milk, i.e. either another drink, or solid foods, was first introduced); current breastfeeding; the introduction of solid foods ‘around’ six months of age” (defined as ‘5 months’ or ‘6 months’ when the first solid food was introduced); the introduction of puréed foods and spoon-feeding when starting solid foods; offering of iron-rich foods (meat, poultry, fish, seafood, and iron fortified infant cereals), vegetables, and fruit as first foods; the daily offering of MoH food groups (24-hour recall data; vegetables, fruit, grain foods, milk and milk products, and meat and protein-rich foods); no salt and sugar added to meals (specific 24-hour recall question); avoidance of inappropriate drinks (specific 24-hour recall question; beverages other than breast milk, formula, or water such as cow’s milk as a drink, other milk, juice, soft drinks, tea, and alcohol); and use of self-feeding when developmentally appropriate. Logistic regression was then used to estimate odds ratios, 95% confidence intervals, and p-values for associated sociodemographic characteristics and key indicators. After their second appointment, caregivers were emailed a final questionnaire, which included the Paediatric Eating Assessment Tool (PediEAT). Feeding behaviours were categorised according to the total PediEAT and subscale scores (physiologic symptoms, problematic mealtime behaviours, selective/restrictive eating, and oral processing). Scores were categorised as ‘concern’ and ‘no concern’ using the PediEAT scoring system. Unpaired t-tests and the chi-squared tests determined associations between PediEAT scores and infant and caregiver sociodemographic characteristics. Logistic regression, adjusted by infant age and deprivation, determined associations between PediEAT scores and food groups consumed during both diet recalls. Data were analysed using Stata software (StataCorp, Texas) and Microsoft Excel (version 16.66). Results: Written consent was obtained from 625 caregivers. Data from the demographic and feeding questionnaire were available from all infants (n=625). All caregivers completed at least one diet recall. A second diet recall was available from 614 infants. PediEAT results were available for 554 term infants. Most infants consumed vegetables (96.2% of infants), fruit (91.8%), grain foods (90.4%), milk and milk products (64.0%), and meat and protein-rich foods (84.3%) at least once during the two 24-hour diet recall days. Commercial infant foods (CIF) were consumed by 78.1% and discretionary foods by 56.3% of infants at least once. The proportion of infants who consumed vegetables (63.2%), fruit (53.9%), grain foods (49.5%), milk and milk products (38.6%), meat and protein-rich foods (31.8%), CIF (41.8%), and discretionary foods (16.1%) on both diet recall days was lower. Overall, only 6.5% of infants met guidelines for the daily consumption of the MoH food groups. The ten most common foods consumed were carrot, banana, bread, brassicas, kumara, extruded commercial infant snacks, pumpkin, apple, potato, and commercial infant pouches. Breastfeeding was initiated by 97.2% of mothers, and 37.8% of infants were exclusively breastfed to around six months. At the time of participation, 66.2% of infants were breastfed. Most infants met guidelines for introducing solid foods, including the age of introduction (75.4%), offering iron-rich foods as first foods (88.3%), providing puréed textures (80.3%) and spoon-feeding (74.1%). Self-feeding at the time of participation was common (86.9%). Most met guidelines for avoiding inappropriate beverages (93.9%) and adding salt (76.5%) and sugar (90.6%) to foods. Typically, infants with caregivers who were younger, higher educated, not currently working, primiparous, and living in low deprivation were more likely to meet the guidelines. Feeding behaviour scores were higher than PediEAT norm-reference values and 17.3% of infants were categorised with ‘concern’ feeding behaviours. ‘Concern’ scores were highest for selective/restrictive eating (29.2%), problematic mealtime behaviours (21.5%), and physiologic symptoms (13.7%) subscales. Mothers who were primiparous and highly educated caregivers were more likely to report ‘concern’ total PediEAT scores. Primiparous mothers and caregivers with higher education, that did not use early child education centres, and had infants of NZ Asian infant ethnicity were more likely to report problematic mealtime behaviours. Infants characterised as of ‘concern’ had significantly lower odds of consuming ‘vegetables’ and ‘meat and protein-rich foods’ and were more likely to consume ‘CIF’. Infants with problematic mealtime behaviours had a lower odds of consuming ‘discretionary foods’ and were more likely to be still breastfeeding. Conclusion: This research provides evidence on infant food and food group intake, adherence to key MoH infant feeding guidelines, and the prevalence of parent-reported infant feeding behaviours and associated demographic characteristics and feeding practices from an ethnically diverse group of NZ infants from Auckland and Dunedin. Infants were shown to consume a range of foods within the MoH food groups at least once during the study. However, only 6.5% of infants consumed all five food groups during both recalls. Grain foods, milk and milk products, and meat and protein-rich foods were the least commonly consumed food groups when investigating those consumed on both recall days, increasing the risk of nutritional deficiencies. Most infants met guidelines for introducing solid foods and avoiding inappropriate beverages and adding salt and sugar to meals, although the prevalence of exclusive breastfeeding to ‘around’ six months, however, continues to be low, particularly for first-time mothers. As seen previously, sociodemographic characteristics were also associated with adherence, identifying key groups (primiparous mothers, lower educated caregivers, those living with multiple children, and those living in areas of high deprivation) that require additional support. Finally, CFB were prevalent in our study, with higher scores reported by primiparous mothers and caregivers who were highly educated. Infants with CFB were less likely to meet recommendations for ‘vegetables’ and ‘meat and protein-rich foods’ and were more likely to consume ‘CIF’. Further investigation is required to understand parental perceptions of feeding behaviours and the nutritional implications of CFB. Further research will determine the nutritional implications of not meeting the MoH food group guidelines during complementary feeding, investigate what support parents need in NZ to improve adherence to the MoH breastfeeding and food group recommendations, and the impact of CFB on nutrient intake.
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    Impact of a "vegetables first" approach to complementary feeding on later intake and liking of vegetables in infants: a study protocol for a randomised controlled trial
    (BioMed Central Ltd, 2021-12) Rapson JP; von Hurst PR; Hetherington MM; Conlon CA
    BACKGROUND: Vegetables as first complementary foods for infants may programme taste preferences that lead to improved vegetable intake in children. Yet few studies have investigated the impact of a "vegetables first" approach to complementary feeding, especially in New Zealand. The purpose of this randomised control trial is to investigate the effect of starting complementary feeding with vegetables only on infants' later intake and liking of vegetables, compared to those starting with fruit and vegetables. METHODS/DESIGN: One-hundred and twenty mother-infant pairs living in Auckland, New Zealand, will be randomised to receive either vegetables only (intervention) or fruit and vegetables (control) for 28 days, starting from the first day of complementary feeding at around 4-6 months of age. Infants will be presented with a brassica (broccoli), followed by a green leafy vegetable (spinach) and sweet fruit (pear) at 9 months of age. The primary outcome measures of intake of each food will be assessed using a weighed food diary. Secondary outcome measures of overall intake, liking and wanting of vegetables will be assessed using a food frequency questionnaire, liking tool and video coding tool, respectively, at 9, 12, and 24 months of age. Infant growth and iron status will be assessed as part of health screening and monitoring at baseline, post intervention and 9 months of age. Other biological samples to be collected include infant stool samples, vitamin D (mother and infant), iron status (mother), and mothers' diet. DISCUSSION: This randomised, controlled trial will be the first to our knowledge to investigate a "vegetables first" approach to complementary feeding on infants' liking and intake of vegetables in New Zealand. Comparison against standard practice (fruit and vegetables as first foods) should complement other trials underway, such as the Baby's First Bites and Nordic OTIS trial. Results may contribute to the evidence supporting complementary feeding guidelines in New Zealand and worldwide. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registry ACTRN12619000737134 . Registered on 16 May 2019.
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    Ruminants' milk in early postnatal brain development in a pig model of the human infant : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand
    (Massey University, 2023) Jena, Ankita
    Given the rapid brain development in the early postnatal period and its sensitivity towards changes in the external environment like nutrition, this period is of utmost importance for determining later life health and well-being. Emerging evidence suggests a link between the triad of early life nutrition, the gut and brain axis and its potential for optimising or retrograding early postnatal brain development. In this context, human breast milk has been most studied. However, whether the development of the brain is responsive towards milk from ruminant species used to make milk formula via modulating gut-derived molecules has not been well understood. The aim, therefore, of the thesis was to evaluate the effects of milk from bovine, caprine and ovine species on circulatory blood plasma metabolites, brain tissue metabolites and brain tissue gene expression in piglets and establish associations between changes in plasma metabolite profile with neurochemical and molecular features of the brain. The hypothesis was that metabolites in the peripheral circulation would differ between different ruminant milk consumption, influencing brain metabolite and gene expression. Liquid chromatography-mass spectrometry-based metabolomics was used to profile the plasma, hippocampal, prefrontal cortex, and striatal tissue metabolite relative abundances. NanoString technology was used to evaluate the expression of genes associated with neuro- and cognitive development in the hippocampus, prefrontal cortex, and striatum tissue samples. Multi-omics data integration was used to explore the correlation between plasma and brain lipid profiles. The results showed that the relative intensity of plasma metabolites differed between bovine, caprine and ovine milk treatments, and lipid metabolites were the predominant features. The bovine group had a higher relative intensity of plasma lipids (e.g., saturated triglycerides, phosphatidylcholine, sphingomyelin) than the ovine and caprine milk groups, except for unsaturated triglycerides, which had a higher intensity in the ovine milk group. Metabolite profiling of brain regions indicated that the relative intensity of lipid metabolites, mainly phospholipids, changed in response to different milk treatments. Further analysis showed that in the striatum and hippocampus, the relative intensity of phospholipids in the bovine milk group was higher than in the ovine and caprine milk groups. In contrast, the relative intensity of phospholipids in the prefrontal cortex was higher in the ovine milk group than in the other milk groups. Gene expression profiling showed that the expression of genes in the striatum and hippocampus associated with neurotransmission differed between milk treatments. Both increased and decreased gene expressions were observed in response to ovine milk treatment, whereas a similar gene expression pattern was observed between the caprine and ovine milk treatments. No effect of milk treatments was observed on the prefrontal cortex gene expressions. Striatal and hippocampal lipid relative intensities showed a positive association with that of plasma lipids and the prefrontal cortex showed negative associations. Thus, this PhD research findings suggest that consuming different ruminant milk can impact early postnatal brain development by influencing the peripheral circulatory metabolites in piglets as a model of human infants
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    Complementary feeding to nourish the infant gut microbiome : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Palmerston North, New Zealand
    (Massey University, 2022) McKeen, Starin
    The transition from milk-feeding to consuming a range of solid foods during the first 1000 days of life constitutes the most dramatic dietary shift in the human lifespan. This period coincides with the development of host-microbial processes. This PhD dissertation aimed to identify relationships between complementary feeding and characteristics of the developing microbiome of the infant using faecal samples as a proxy of the large intestine. The composition and gene abundances of the microbiome and the metabolites of dietary, host, and/or microbial origins were detected and analysed. The Nourish to Flourish pilot clinical study was conducted to inform subsequent study designs and develop sampling and processing protocols for research in weaning infants. The faecal samples were analysed to characterise the microbiome and metabolome at 4, 9, and 12 months of age. These data revealed greater shifts during the introduction of solid foods between 4 and 9 months of age than during the continued diversification of solid foods in the diet between 9 and 12 months of age. The changes occurring in the microbiome and metabolome in faecal samples were then interpreted in the context of milk-feeding behaviours and associated dietary diversification. The associations between the faecal microbiome and metabolome and dietary nutrient composition estimates were identified and evaluated. The patterns of association that emerged were varied and showed low prediction values but supported published evidence about relationships between specific nutrients, microbial taxa, and predicted functional pathways based on microbial gene abundance. Correlation networks between dietary food groups and relative abundance of microbes, KEGG pathway abundance, and metabolites revealed patterns that implicate the food matrix by protein-rich foods compared to the relatively weak effect of starchy foods on the luminal environment. This research demonstrates the window of opportunity for the greatest influence of solid foods on the infant gastrointestinal environment is prior to 9 months of age. However, the impact of continued milk feeding behaviours is likely to be relatively greater than solid foods later in the complementary feeding window. This research provides a basis for selecting food products that can benefit the infant's development by modulating the microbiome and metabolome in the gastrointestinal tract.
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    The effect of weaning food substrate on segmented filamentous bacteria in infant small intestinal immune barrier maturation : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutrition at Massey University, Palmerston North, New Zealand (School of Food and Advanced Technology)
    (Massey University, 2021) Oemcke, Linda
    Appropriate and complete maturation of the gastrointestinal tract (GIT) barriers is crucial as it contributes to overall health and wellness. Maturation of the small intestinal immunological barrier has gained interest due to GIT-associated disorders such as inflammatory bowel disease thought to be caused by improper maturation. The transition from milk-based feeding to complementary feeding in healthy infants at weaning introduces new antigens and microbes into the GIT. These changes induce immune cell production and is thought to be the final stages in the maturation process of the immunological barrier. It is during this maturation process at weaning that segmented filamentous bacteria (SFB) are thought to play a role. These Gram-positive, obligate anaerobic, spore-forming commensals have been observed in the faeces of 6–25-month-old infants and the terminal ileum of weanling rodents. The abundance of ileal and faecal SFB increases at weaning, peaks then decreases post-weaning and remains at that lower plateau throughout life. The transient abundance change of SFB has also been correlated with immune markers, immunoglobulin A (IgA) concentration in faeces and interleukin 17 (IL-17) concentration in blood plasma. The reported correlation between SFB, IgA and IL-17, and the timing at which the abundance of SFB changes at weaning, suggests that weaning foods might have an influence on changes in SFB abundance and hence on the immunological barrier. The published SFB genome identified carbohydrate metabolic and transport genes and a published study also reported an influence of complex substrates from the diet on SFB abundance. These findings suggested that a diet supplemented with complex carbohydrates may enhance the ileal SFB abundance, which had not been investigated at weaning previously. The aim therefore of this thesis was to investigate whether the complex carbohydrate inulin would influence the ileal and faecal abundances of SFB at weaning and would modulate the concentration of the GIT immune markers, IgA in faeces, and IL-17 in plasma. The hypothesis was that a weaning diet enriched with inulin would increase the peak abundance of SFB in the terminal ileum which would then enhance GIT immune barrier maturation. Initial method development showed that the temporal profile of SFB colonisation in the ileal tissue and contents of weanling rats was similar to those published for mice and infants of corresponding weaning age. Additionally, and for the first time, whole tissue homogenisation was favoured over ileal mucosal scraping as the ideal collection technique due to lower variability in whole ileal tissue data. These methods were implemented in a final study where inulin was selected because it is commonly found in weaning foods such as fruit and vegetables and is also routinely added to bovine-based milk formulas to supplement the deficit of oligosaccharides (compared to human milk). Results revealed that inulin did not influence the peak abundance of SFB, regardless of inulin dosing (0%, 2.5%, 5%, 10%) or sample type (ileal tissue, ileal contents, faeces), three days post-weaning in 24-day-old Sprague-Dawley rats. There were no differences of inulin dosing on ileal and faecal SFB abundances, blood plasma IL-17 and faecal IgA concentrations, nor between male and female rats. This outcome from the inulin intervention suggests that SFB may not utilise inulin directly or a longer period of adaptation to the inulin-supplemented diet might be required to assess if there is a long-term effect on ileal SFB abundance. The findings do not rule out other complex carbohydrates with potential influence on ileal SFB abundance. Further investigation would entail determining any interactive effects among inulin-supplemented diet, SFB abundance, and immune markers at broader time-points beyond the expected peak of SFB abundance post-weaning. In addition, analysis could be carried out to determine the abundance of other microbes relative to the predicted pre- and post-weaning SFB abundance changes. Further investigations will advance our understanding on the ability of specific food substrates to manipulate SFB and important members of the GIT microbiota and in turn support the development of high-value foods for overall health benefits in infants.
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    Impact of a 'vegetables first' approach to complementary feeding on later intake and liking of vegetables in infants : a randomised controlled trial : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Albany, New Zealand
    (Massey University, 2021) Rapson, Jeanette
    Background: Most children worldwide do not meet vegetable intake recommendations, which has implications for health, including an increased risk of obesity and chronic diseases later in life. A ‘vegetables first’ approach to complementary feeding has emerged as a promising strategy to promote vegetable consumption in children. This approach prioritises vegetables as first foods, capitalising on young infants’ willingness to try new foods and establish food preferences that comprise healthy eating. While some authorities have started to encourage the introduction of vegetables first, more longitudinal randomised, controlled studies are needed to strengthen the evidence-base. In addition, there is a concern that a focus on vegetables as first foods may negatively impact infant iron status, which needs to be addressed. Aims and objectives: The overall aim of this study was to determine whether exposure to vegetables-only during the first four weeks of complementary feeding increases later vegetable intake and liking, compared to a control group which includes both fruit and vegetables. The primary objective was to examine whether providing vegetable-only first foods results in higher intake of vegetables at 9 months of age, compared to a control. Secondary objectives were to examine infants’ acceptance of vegetable-only first foods, to assess whether intervention effects are maintained at 12 months of age, and to describe the iron status of infants who had participated in the trial. Methods/Design: In this longitudinal randomised, controlled, parallel-group study, 117 Auckland mother-infant dyads, received either vegetables-only (veg-only, n = 61) or a combination of fruit and vegetables (control, n = 56) for a duration of four weeks, starting from the first day of complementary feeding at around 4–6 months of age. At 9 months of age all infants were offered target vegetables at home: broccoli (day 1), spinach (day 2) and pear (day 3). At 12 months of age, mothers completed infant feeding questionnaires only. The primary outcome measure was intake (grams) of vegetables at 9 months of age. Additional food acceptance variables were mother-rated liking (5-point Likert scale), frequency of positive/negative behaviours (%), rate of eating (grams/min), rate of acceptance (video coding) and daily intake/preferences of fruit and vegetables (food frequency/liking questionnaires). Infants’ iron status (n = 75) was assessed at baseline, post-intervention and 9 months of age via capillary blood samples. Independent t-tests and Mann-Whitney tests were performed for the primary analysis. Demographic data was collected at baseline via an online questionnaire, and written consent obtained from all participants. Results: Of those who completed the 4-week intervention, 108 (92 %) provided intake data needed for the primary analysis at 9 months of age (veg-only, n = 56; controls, n = 52). Most (> 90 %) mothers had a university qualification or higher and were European ethnicity with adequate access to food. Intake of the target vegetables at 9 months was significantly higher among veg-only infants than controls: median (25th, 75th percentile) for broccoli was 47.0 (27.0, 72.0) vs 30.0 (16.0, 62.0) grams, P = 0.024, respectively; spinach was 37.0 (19.0, 55.0) vs 24.0 (12.0, 41.0) grams, P = 0.028, respectively. Daily vegetable intake was also significantly higher: veg-only group, 86.3 (52.5, 146.3) grams vs controls 67.5 (37.5, 101.3) grams, P = 0.042. Veg-only infants consumed the target vegetables at a faster rate (broccoli, P < 0.001; spinach, P = 0.004) and showed greater acceptance than controls (all target vegetables P = 0.018). Fruit intake (target and daily) was similar, as were all other acceptance variables. At 12 months of age (n = 107), these effects were maintained as daily vegetable intake was 20 % higher in the veg-only group, than controls (P = 0.021); daily fruit intake and liking of vegetables and fruit remained similar. With respect to secondary outcomes, intake, rate of eating and liking of the study foods during the 4-week intervention were similar between groups and increased significantly between week one and four (all P < 0.001). Frequency of negative behaviours in response to study foods in both groups significantly decreased over time (both P < 0.001) while positive behaviours did not change (veg-only P = 0.07; control P = 0.147). In terms of iron status, most were iron sufficient at baseline (93 %) and at 9 months of age (92 %). Conclusion: Providing vegetables as first foods increased vegetable intake at 9 months of age, and may be an effective strategy for improving child vegetable consumption and developing a preference for vegetables in infancy. Meanwhile, vegetable-only first foods were well-accepted and iron status maintained, which may be of encouragement to parents. However, given limited generalisability, more research investigating ways to support families in feeding vegetables as first foods at a population level is warranted.
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    Maternal thyroid function, postnatal depression, the intake and status of iodine, selenium, and iron in postpartum women and their infants : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand
    (Massey University, 2021) Jin, Ying
    Background: Thyroid dysfunction is a common health issue in women, with a higher prevalence found in postpartum women. Postnatal depression (PND) is a maternal health issue which can exacerbate negative health effects on their newborns. Iodine, selenium, and iron are three essential nutrients for the synthesis of thyroid hormones. Historically, dietary insufficiency of iodine and selenium exist in New Zealand. To improve iodine status, the New Zealand government introduced mandatory fortification of bread with iodised salt (2009), and recommended iodine supplementation (150 µg/day) for all pregnant and breastfeeding women (2010). Mostly, the iron status of postpartum women in New Zealand is rarely medically examined, unless high levels of blood loss during childbirth are recorded. Objectives: The overall aim of this PhD thesis was to investigate maternal thyroid function, postnatal depression, and the intake and status of iodine, selenium and iron in mothers and infants during their first postpartum year. Method: This observational longitudinal cohort study was conducted in Palmerston North, New Zealand, from June 2016 to December 2017. Mother-infant pairs attended study visits at three, six and twelve months postpartum (3MPP, 6MPP, and 12MPP). Online questionnaires investigated maternal iodine knowledge, supplement use, mode of infant feeding, and sociodemographic characteristics. Weighed four-day dietary diary, with urine/blood/breastmilk samples, were taken to measure maternal iodine, selenium, and iron intake/status. Infant iodine and selenium concentrations were determined in spot urine samples. The Edinburgh Postnatal Depression Scale was used to screen for PND. At 6MPP, serum thyroid hormones [free triiodothyronine, free thyroxine, thyroid stimulating hormone (TSH), thyroglobulin (Tg) and anti-Tg and thyroid peroxidase antibodies] and thyroid volume were measured. Results: At 3MPP, 87 breastfeeding mother-infant pairs were recruited, followed up at 6MPP (n = 78) and 12MPP (n = 71). At 6MPP, 18% of women had thyroid dysfunction. Median total thyroid volume was 6.1 mL. Median (p25, p75) Tg was 11.4 (8.6, 18.6) µg/L, above 10 µg/L. Median maternal plasma selenium was 105.8 (95.6, 115.3) µg/L; 23% (17/74) being below 95 µg/L; with 4% of women experiencing iron deficiency without anaemia. Women with marginally lower plasma selenium were 1.14% times more likely to have abnormal TSH concentrations. Over the first postpartum year, maternal median urinary iodine concentration (MUIC) was 82 (46, 157) µg/L, 85 (43, 134) µg/L, and 95 (51, 169) µg/L, all below 100 µg/L; median BMIC was 69 (52, 119) µg/L, 59 (39, 108) µg/L, and 35 (26, 54) µg/L, all below the recommended 75 µg/L. Median maternal iodine intake was 151 (99, 285) µg/day, with 58% below the Estimated Average Requirement (EAR). At 3MPP, 46% of women took iodine-containing supplements, this reduced to 11% at 6MPP, and 6% at 12MPP. Women who used iodine-containing supplements had significantly higher MUIC (111 vs 68 µg/L) and BMIC (84 vs 62 µg/L) than non-users (P < 0.001). Infants fed by women using iodine-containing supplements had a higher MUIC (150 vs 86 µg/L, P = 0.036) than those of non-users. Infant MUIC at 3MPP [115 (69, 182) µg/L] and 6MPP [120 (60, 196) µg/L] were below 125 µg/L (suggested cut-point for iodine adequacy in infants). Median maternal selenium intake was 62 (51, 85) µg/day and 56% had intakes below the EAR. Median infant selenium intakes at 3MPP and 6MPP were 9 and 8 µg/day. Median maternal urinary selenium concentrations were 22, 22, and 26 µg/L across three time points, respectively. The highest prevalence of minor depression was observed in women with mean plasma selenium at 106 µg/L. Conclusions: A high prevalence of thyroid dysfunction was observed in a cohort of postpartum women who were iodine deficient, with suboptimal selenium intake, but having mostly adequate iron status. Women with low plasma selenium were likely to experience thyroid dysfunction. Iodine deficiency of lactating women remains, particularly for those who did not use iodine-containing supplements. The low use of iodine-containing supplements is concerning during later breastfeeding. Maternal selenium intake/status was suboptimal. Relation between selenium status and risk of PND was inconclusive. Iodine/selenium intake and status of infants were suboptimal.