Doctoral Degrees (Human Nutrition)

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    The effect of β-glucan prebiotic fibre (oats) on the gut microbiome of chronic kidney disease patients (Stage IV and V) and impact on kidney function
    (Stellenbosch : Stellenbosch University, 2022-04) Ebrahim, Zarina; Blaauw, Renée; Moosa, M. Rafique; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Human Nutrition.
    ENGLISH SUMMARY: Background: Chronic kidney disease (CKD) is increasing in global prevalence and has many nutritional complications. Increasing evidence suggests that gut dysbiosis is involved in CKD progression through various mechanisms including intestinally derived uraemic toxins, dietary, and immune-mediated factors. Therefore, modulating the gut microbiome may improve outcomes in CKD. The aim of this research project was to investigate the effect of a ß-glucan prebiotic supplement on kidney outcomes, uraemic toxins and the gut microbiome in predialysis CKD participants. Methods: This study was a randomised controlled intervention study over 18 weeks, performed at Tygerberg Hospital predialysis clinic in Cape Town, South Africa. There was a pre-randomisation period of four weeks where participants were counselled on a CKD diet before being randomised. At randomisation, the intervention group received the ß-glucan supplement and continued the diet, while the control group continued with the diet only. There were follow-ups at weeks 4, 8 and 14 after randomisation. The objectives were to assess nutritional status, kidney function, plasma levels of uraemic toxins and gut microbiota using 16S rRNA sequencing at pre-randomisation. Additionally, differences in these outcomes were measured at randomisation baseline (week 0), week 8 and week 14 between the intervention and the control groups. Anthropometrical measurements were done which included weight, height, waist circumference, mid-upper arm circumference and triceps. Clinical investigations included investigating for oedema as well as gastrointestinal symptom measurement. Stool consistency was described using the Bristol Stool Score (BSS). Dietary intake was measured using a quantified food frequency questionnaire (QFFQ) and a dietary adherence score sheet. Although most of the investigations was done locally, the uraemic toxins analysis was performed at the nephrology laboratories at the University of Ghent in Belgium, while the gut microbiome analysis was performed at VIB laboratories (Leuven, Belgium). Statistical analysis was performed using IBM®SPSS®version 26/27 and R Statistical Software. Results: Seventy participants were enrolled in the study at the pre-randomisation visit. The mean age of the participants was 41.7 ± 11.8 years, with a slight predominance of females (53%). Most participants were unemployed, earning less than US$126 per month. Hypertension was the main cause of kidney failure and most participants were in stage 5 CKD. A very high prevalence of overweight (30%) and obesity (36%) was found at pre-randomisation, with a low prevalence of undernutrition (3%). Abdominal obesity was found in 60% of participants. Dietary assessment showed an unhealthy dietary pattern. After four weeks, 59 participants were randomised. The diet intervention resulted in significant nutritional changes in participants after four weeks, while uraemic toxins remained unchanged. There was a significant reduction in body mass index (P < 0.006) and waist circumference (P < 0.001). Almost all dietary intake variables were significantly reduced and there was a high dietary adherence. Serum total cholesterol (P < 0.045) and triglyceride levels (P < 0.017) were also reduced. After randomisation to either the ß-glucan prebiotic or the diet, kidney function did not significantly change. However, there was a significant reduction in uraemic toxins in free IxS at week 8 (P = 0.003) and week 14 (P < 0.001), total and free pCG (P < 0.001, P < 0.001, respectively) and free pCS (P = 0.006) at week 14. There were no significant changes in dietary intake, clinical symptoms or anthropometry during the trial. The gut microbiome revealed that two enterotypes were prevalent, namely the Bacteroides2 and Prevotella enterotypes. The inter-individual Bray–Curtis distance (ß-diversity) was significantly higher in the control group than the intervention group at baseline (P < 0.0001), week 8 (P < 0.0001) and week 14 (P = 0.02). There were no differences in relative abundance of genera between groups. The redundancy analysis showed a few factors significantly affected the gut microbiome: these included triglyceride levels (P < 0.001), cause of kidney failure (P < 0.001), gender (P < 0.001), body mass index (P = 0.002), high- density lipoprotein (P < 0.001) and the prebiotic intervention (P = 0.002). Conclusion:While four weeks of the diet resulted in some nutritional changes in participants before randomisation, it did not affect other outcomes of the study. Once randomised, the prebiotic did not significantly affect kidney function, while it significantly reduced uraemic toxins and the gut microbiome, according to the RDA analysis. The ß-glucan prebiotic therefore had some beneficial effects on outcomes in CKD participants.
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    Development of contextualised food-based strategy to improve the dietary diversity and nutritional status of children aged 12 to 36 months in rural farming households in central Uganda
    (Stellenbosch : Stellenbosch University, 2020-12) Nabuuma, Deborah; Mbhenyane, Xikombiso; Ekesa, Beatrice; Faber, Mieke; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Human Nutrition.
    ENGLISH SUMMARY: Food insecurity, low dietary diversity, and malnutrition remain prevalent in sub-Saharan Africa. Food-based strategies have a high potential of improving diet quality in agriculture-dependent communities and their development and effectiveness can be enhanced by systematic approaches. This study aimed to develop a food-based strategy to improve the dietary diversity of children aged 12 to 36 months from rural smallholder farming households in Central Uganda. An embedded-sequential, mixed-methods research design was used: i) quantitative situation analysis using household and market surveys, ii) qualitative assessment of community perspectives using focus group discussions, iii) design of the food-based strategy using intervention mapping, and iv) qualitative validation using key informant interviews and focus group discussions. The results showed household food production and food consumption were mainly based on cereals and grains, roots, tubers, cooking bananas and legumes. There was low dietary diversity; 78% of six- to 23-month-old children did not meet the minimum dietary diversity and 71% of children ≥ 24 months were consuming less than three food groups. The most accessed markets had limited diversity of food groups (six out of 11 (55%)) compared to other markets in the community. Food production and consumption focused on priority crops that alleviated hunger and contributed to income – mainly maize, cooking bananas, sweet potatoes, cassava and beans. Food production was influenced by access to land, production costs, income potential, climate and farmer knowledge. The cost of food and market availability influenced the type and quantity of food bought and consumed. Poor perception towards meetings/training and inadequate nutrition information and skills were noted. These findings, relevant theory and literature were applied using intervention mapping to systematically identify determinants, outcomes, objectives, and pathways to improve dietary diversity. The resulting contextualised food-based strategy (CFBS) aims to improve dietary diversity of children in smallholder farming households through improved household production, income utilisation, and food consumption practices by: i) increasing diversity of foods produced, particularly fruits and vegetables, ii) increasing access to diverse foods through appropriate income and market, including an increase in diversity of foods in consumer markets and financial literacy, and iii) improving the quality of diets consumed, especially diversity, frequency, nutrient quality and safety through nutrition education. Actors included policy makers, development organisations, extension workers, community-level groups, community champions and smallholder farmers. Validation results rated the factors and actors in the CFBS as important for improving productivity, food availability, dietary diversity, livelihoods of smallholder farmers, thereby verifying the strategy and design process used. To improve dietary diversity among rural smallholder farmers, their food security and production challenges need to be addressed. This increases the relevance and motivation to participate and implement recommended practices. Markets have the potential to significantly contribute to dietary diversity. However, this requires adequate supply and demand of diverse foods in rural consumer food markets, as well as income and financial literacy to facilitate financial decisions that promote dietary diversity. The CFBS empowers smallholder farmers to decide on a course of action that achieves dietary diversity, having been equipped with information and skills on agriculture, nutrition and finances.
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    Support for exclusive breastfeeding in the workplace : development of a practice model for designated workplaces in the Breede Valley sub-district, Western Cape Province, South Africa
    (Stellenbosch : Stellenbosch University, 2020-03) Daniels, Lynette Carmen; Mbhenyane, Xikombiso; du Plessis, Lisanne Monica; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Human Nutrition.
    ENGLISH SUMMARY: Globally, mothers have identified employment as one of the leading barriers to exclusive and continued breastfeeding. This study aimed to develop a practice model to support exclusive breastfeeding for working mothers. The study was conducted with participants from designated workplaces in the Breede Valley sub-district, Western Cape, South Africa. An explanatory, sequential, mixed methods research design was employed, comprising a quantitative, descriptive, cross-sectional study (phase one), followed by a qualitative, multiple case study (phase two), and the development and validation of a practice model (phase three). In phase one an online survey was conducted to assess current breastfeeding support practices. In phase two, data was collected at nine purposively selected workplaces, using focus group discussions (FGDs) and in-depth interviews. FGDs were also conducted with employed breastfeeding mothers from designated workplaces who exclusively or predominantly breastfed their children for any period up to six months. In phase three, the practice model was developed, drawing on the analysis of data from phases one and two and making use of programme theory approaches and logic models. The draft model was sent to 11 experts. After input from the two modified Delphi rounds had been received and amendments to the model had been made, it was presented for feedback to the nine participating workplaces during four FGDs and one in-depth interview. A response rate of 36.8% (14/38) was achieved for the online survey. The results revealed that arrangements surrounding breastfeeding in designated workplaces were limited and inadequate, with few support practices. Onsite or nearby crèche facilities (n=2, 14.3%), breastfeeding counsellors (n=1, 7.1%), promotion of the benefits of breastfeeding to employees (n=2, 14.3%) and provision of private space for expressing (n=2, 14.3%) were not common practice. Workplace breastfeeding policies (n=4, 28.6%) were not readily available, and were mostly found in the public sector. Forty-three percent of workplaces (n=6, 42.9%) did not allocate time for expressing breastmilk at work. Phase two revealed that employees viewed their workplaces as unsupportive in terms of providing breastfeeding time and designated spaces for expressing breastmilk. Returning to work was viewed as challenging, mainly because of the unsupportive attitudes of co–workers and supervisors and a lack of space and time to express breastmilk. The challenges reported by managers related to the absence of appropriate space and infrastructure, as well as the resources to finance what was needed. The majority of managers claimed that they valued a supportive workplace environment and a culture of caring focusing on staff wellness. They regarded themselves as flexible (including in respect of allowing employees personal time). This was in conflict with employees’ views. Employees felt that their employers were unsupportive, strict and un-accommodating with regard to the provision of time for expressing, mentioning that they mostly used their lunch and tea breaks. Participants were positive about the final practice model and viewed it as informative and well designed. They were positive that the model would be feasible and commended the tiered approach to implementation. The model was perceived as an ideal tool to use, if accompanied by some training. The study showed that legislated breastfeeding breaks are poorly implemented or mostly absent, mainly due to widespread ignorance of breastfeeding rights in the formal sector. There is an urgent need for advocacy around creating an enabling workplace environment for breastfeeding. The practice model has the potential to be locally applied and will be of particular use to workplaces that want to initiate and/or strengthen breastfeeding support.
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    Development of a roadmap for mainstreaming nutrition-sensitive interventions in Anambra and Kebbi States, Nigeria
    (Stellenbosch : Stellenbosch University, 2019-04) Ezekannagha, Oluchi; Mbhenyane, Xikombiso G.; Drimie, Scott; Von Fintel, Dieter; Maziya-Dixon, Busie; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Human Nutrition.
    ENGLISH SUMMARY : Malnutrition, though on a slight decline, has continued to be a problem in developing countries. The role of nutrition-sensitivity sectors as a linkage between immediate causes and basic causes of malnutrition has been increasingly recognised in recent years as positively associated with malnutrition reduction. Considering the accumulating evidence pointing to a strong relationship between malnutrition reduction and nutrition-sensitive sectors, including agriculture, education, water, sanitation and hygiene (WASH), and social protection, mainstreaming nutrition into these sectors has been widely discussed, designed and implemented in programmes and policies. Large-scale government programmes in nutrition-sensitive sectors are important elements of delivering nutrition-sensitive malnutrition-preventive benefits to the population. Mainstreaming nutrition into these cross-cutting sectors becomes imperative in the fight for malnutrition reduction. The Mainstreaming Nutrition Initiative Assessment (MNIA) is a framework developed for the assessment of mainstreaming nutrition (Menon et al, 2011), which measures the domains of epidemiology, operational and political commitment. However, there has been little attempt to explore its application in mainstreaming nutrition. The aim of the study was to develop a roadmap for mainstreaming nutrition-sensitivity in Anambra and Kebbi States, Nigeria. The study used a four-phased convergent parallel mixed methods design. In Phase 1, small area estimation methodology was employed to estimate local government prevalence of stunting in Nigeria. Phase 2 was carried out in two stages, first, a nutrition-sensitivity and potential checklist were used to determine the current nutrition-sensitivity and possible potential of programme execution in the various sectors in both states. Subsequently, a theory-based process evaluation that employed key informant interviews, document reviews, and site observations were used to determine the operational factors influencing the implementation of the programmes. In Phase 3, a political commitment rapid assessment test was administered in a workshop to explore the political realities regarding nutrition and nutrition-sensitivity in the states. In Phase 4, the data and information from the previous phases were employed to develop a roadmap for mainstreaming nutrition-sensitivity in both states, which was also validated by the stakeholders. Data were analysed using qualitative thematic analysis and MAXQDA software. LGA stunting prevalence estimations varied across the states. Kebbi State had high state average accompanied by very high LGA stunting estimates. Stunting prevalence in Kebbi State ranged from 54 percent to 67 percent. While in Anambra State, the stunting prevalence ranged from 17 percent to 25 percent, both states were in WHO category of medium to high stunting prevalence. The programmes assessed were averagely nutrition-sensitive but most of them had excellent potential to be highly nutrition-sensitive. The agricultural programmes have the best implementation while programmes in the WASH sector were the weakest in terms of implementation. The process evaluation showed that the programmes’ theory was validly nutrition-sensitive. The programmes had varied implementation dimensions, while the Agricultural Transformation Agenda Programme had a very high dose, the programmes reach was minimal. Programmes such as the Environmental Sanitation and Early Childhood Development Education has wide reach but lower dose and implementation. With regards to political commitment, while Kebbi had high expressed commitment, this was supported with the poor institutional commitment, unlike Anambra where strong institutional commitment existed but lacked financial support. From these findings, a roadmap for mainstreaming nutrition-sensitivity was developed and most stakeholders agreed that the roadmap was implementable and feasible. Future investigation is needed to replicate the study in other states. In addition, following-up Anambra and Kebbi states with the implementation of the roadmap may shed more light on the dynamics and role of the various domains in nutrition-sensitive mainstreaming.
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    Design of an architectural framework for a health assessment information system for urban agriculture interventions in low-resource settings using a soft systems approach to information system design
    (Stellenbosch : Stellenbosch University, 2019-04) Idzerda, Leanne; McLachlan, Milla; Michalowski, Wojtek; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Human Nutrition.
    ENGLISH SUMMARY: Introduction: Urban agriculture interventions in low-resource settings have not demonstrated the expected improvements to nutrition outcomes. Urban agriculture interventions also pose a number of potential risks to population health. The purpose of this research is to design the architectural framework for a technology-supported information system that can support program managers in developing strategies that aim to improve nutrition outcomes and mitigate the risks to population health. This tool is called the Health Assessment Information System for Urban Agriculture Interventions in Low-Resource Settings (HAIS). Methods: The architectural framework was developed by identifying and capturing the technical and soft elements of the health impact assessment (HIA) approach. Soft systems methodology (SSM) was used in three phases of research to design the architectural framework of the HAIS. Each phase corresponds to a research question and determines (1) what activities need to be supported, (2) what information is required to support these activities, and (3) how to structure that information. Results: Five activities where program managers require support were identified, and the information required to support these activities was defined. The architectural framework of the HAIS, which consists of several components that function together, was developed around these activities. This architectural framework builds the theoretical foundation for the development of a future technology-supported information system that can be used to support program managers to develop their own strategies within a complex organizational context. Conclusion: The HAIS represents the first step towards developing a decision tool that can support program managers in complex low-resource organizational settings to develop strategies to improve nutrition outcomes and mitigate population health risks. This research represents the first attempt to use SSM to identify and capture the technical and soft elements of the HIA approach into an architectural framework for an information system that, when developed, may be used by non-experts to design urban agriculture interventions.