​Background

The aim of this research is to explore the impact of complementary foods on infant health, focusing on immunity and a reduced number of infections in early life. During infancy, the introduction of solid foods (weaning) and the changes in milk consumption are accompanied by significant gastrointestinal tract (GI), immune and developmental adaptations [Backhed 2015]. It is especially in this period of weaning that there are opportunities for the recommendations for foods that aid in the maintenance of optimal health. Recent discoveries have highlighted how the infant immune system co-evolves with GI microbiota in a mutualistic relationship, a crucial event that impacts on the host’s immune system throughout life, and how aberrant GI microbiota during infancy is associated with disease conditions later in life [Sjogren 2009; Tamburini 2016].

Seeding Through Feeding (SUN) project

The present research programme will generate knowledge and methods to support evidence for dietary guidelines for infants and potentially future product development and validation by NZ companies. The first objective of the five-year plan was to design and conduct a Randomised Controlled Trial (RCT) of identified complementary foods in Infants in NZ. The RCT was based on the results and outcomes of a pilot clinical trial (Nourish to Flourish) [Lovell 2022] and in vitro work conducted in 2018-2019. Kūmara was identified through a novel in silico approach to determine the best sources of prebiotics to nourish the infant microbiome [Michelini 2018]. The pilot study (Nourish to Flourish) [Lovell 2022] and in vitro work identified that kūmara was a safe, acceptable and commercially feasible food for infants. The pilot study also demonstrated that the majority of challenges that arise through conducting clinical research among infants can be overcome.

The randomised control trial (RCT)

Nourishing the Infant Gut Microbiome to Support Immune Health (SUN RCT) incorporated learnings from the pilot study at the following levels: (i) design of experimental prebiotic weaning food prototypes; (ii) integration and interpretation of longitudinal, multidimensional clinical with molecular phenotyping data; and (iii) documenting associations and – if possible – causality between prebiotic feeding, growth of immune health-beneficial microbes in the infant gut and reduced number of infections and vaccine- specific antibody responses.

An additional secondary outcome has been incorporated into the trial. This follows on from the contestable research project “A Good Night’s Sleep” conducted in Tranche 1 of the High Value Nutrition Programme by the University of Otago [Heath 2020]. This project hypothesised that the increased production of propionate from the fermentation of plant-based polysaccharides leads to fewer night wakings in infants. We now aim to measure sleep duration and sleep behaviour in infants in the SUN RCT and the relationship of these sleep variables with the production of short chain fatty acids. This research is conducted in collaboration with the University of Otago.