Applications of Nutritional Biomarkers in Global Health Settings

In global health settings, there are three generic areas that require reliable biomarkers of nutritional status and function. Population surveillance needs to identify key nutrient deficiencies (or excesses) to monitor progress towards elimination of nutritional imbalances and to stratify populations into groups especially 'at risk' to whom public health resources can be focused. Clinical interventions need biomarkers to help identify disease pathways, to assist in targeting nutrient prescriptions, and to avoid potential harm (e.g. in the case of iron). Discovery science requires biomarkers in many domains, but especially in the study of nutrient-gene interactions and regarding the effects of nutritional status on the epigenome. Each of these applications imposes different constraints on the methodology though in all cases the optimum biomarker would have high sensitivity and specificity, would capture variation of functional significance, and would be cheap and easy to apply. These attributes are hard to achieve, and recent progress towards next-generation biomarkers, though holding much promise, has not yet delivered significant breakthroughs in the global health setting. Recent efforts to overcome these problems by two initiatives (BOND and INSPIRE) are highlighted as exemplars of a route map to progress.