Project 455086

Malnutrition is an underlying cause of millions of maternal and infant deaths, especially in resource-limited settings where food may be inadequate in quantity and/or quality. As breastmilk is considered optimal for infant growth and development in the first six months of life, exclusive breastfeeding is recommended by the World Health Organization. Traditionally, breastmilk composition has been considered relatively consistent irrespective of maternal nutrition, although emerging evidence suggests that the nutrient makeup may vary. This includes breastmilk micronutrients (vitamins and minerals) and macronutrient (fat, protein, and carbohydrates). Identifying the effect of multiple micronutrient supplementation (MMS) and multiple measures of maternal nutritional status (e.g., dietary intake, body composition) on breastmilk composition in diverse populations, and ultimately on infant growth, will be important to informing this knowledge gap. We will analyze breastmilk samples and growth data collected from mother-infant pairs at 3 months after birth from existing trials conducted in Pakistan and Canada to (1) determine the effect of consuming a daily MMS on breastmilk micronutrient concentration compared to the standard of care; (2) identify pathways between maternal nutritional status, breastmilk composition, and infant growth using structural equation modelling; and (3) establish the extent to which maternal body composition is related to breastmilk macronutrient concentration. Nutritional interventions have traditionally focused on supplementing the child to improve growth, thus our understanding of the role of maternal nutritional status is limited. Furthermore, the existing international infant feeding guidelines have been based largely on studies conducted in the global north. This limited scope warrants the further evaluation of diverse populations with differing burdens of malnutrition.