Award Holder: Corinne Feuillatre
University: University of Bradford
Title of Research: Bringing up Baby: in search of novel biomarkers of nutrition using stable isotope ratios in incremental tissues in mother/infant pairs.
Nutrition during the first 1000 days of life from conception is crucial for the optimal health and development and eventually survival of babies. Poor nutrition during these early days is also linked to increased ill-health as adults. Given those important implications, studying infant feeding practices is a key area of research in archaeology and stable carbon and nitrogen isotope analysis (δ13C and δ15N) is central to help reconstruct how children were fed in ancient populations. Having a reliable tool to measure not only what children consume but also their nutritional status and how well they are growing would also be beneficial to further understand this key life period. The effect of nutritional stress on isotope values is well-established in adults. Yet, while the influence of metabolic factors is likely to be especially important in growing children, little research on the effect of growth and (mal)nutrition in babies has been done in humans. This project is part of doctoral research which examines the potential of δ15N and δ13C as biomarkers of nutrition in children. The project aims to provide preliminary data to explore the interaction between diet and metabolism on the isotope composition of breastfed babies by measuring δ15N and δ13C in the nails and/or hair from modern babies for whom diet, health, growth and development is known.
The planned methodology was straightforward and consisted in:-
1) collecting retrospective feeding, health and growth information from breastfed babies for whom nails and/or hair were already available,
2) measuring δ15N and δ13C in the babies’ nails/hair throughout the period of breastfeeding, and in the breastmilk consumed by the child when available, or in the hair of the nursing mother as a proxy to establish a dietary isotopic baseline.
The fieldwork consisted mostly of laboratory work at the University of Bradford isotope laboratory. The work took longer than initially planned for a variety of reasons. The start of the work was delayed by several months and further interruptions experienced due to issues with the mass spectrometer. It was also quickly identified that because different tissues were available for the different mother/infant dyads (i.e. mostly nails for babies, but either hair and milk, hair and nails or milk only for the dietary baseline), additional work was needed to ensure that results from the different tissues could be compared directly. The presence of non-protein nitrogen and carbon in the milk also meant that a protocol to extract milk protein needed to be developed. Finally locating tissue samples which had been collected several years earlier or collecting life information several years after the event also presented its own challenges. However preliminary results are promising. Increased δ15N offset between mother and baby is seen with slower growth and δ13C reductions from fat mobilization are observed with increased energy demand from lactation in mothers or increased physical activity when babies started walking.
The project provides invaluable insights and evidence for the metabolic effect on the isotope composition of babies, laying the groundwork to develop isotope analysis as a tool to identify poor nutrition during this crucial developmental period in both contemporary and ancient populations, but also contributing to improved isotopic interpretation when reconstructing infant feeding practices.