PROJECT SUMMARY Biomarker determination for both nutritional status and inflammation has classically relied on blood-based biomarkers. Blood sampling has associated challenges including being partially invasive, requiring specially trained personnel and equipment for collection and processing, and having resistance to blood collection in some communities. Our long-term goal is to evaluate salivary biomarkers as an option to address issues common with blood sampling. Our overall objectives in this application are to determine salivary and serum biomarkers of iron and inflammation status in a population with expected burden of malnutrition and inflammation. We hypothesize that salivary biomarkers will demonstrate sufficient diagnostic performance for determining the degree of inflammation and iron status relative to serum biomarkers. We will test our hypothesis with the following specific aims: 1) In a resource-limited setting with heterogeneity in iron status, compare salivary versus serum biomarkers accounting for inflammation, 2) Evaluate the utility of saliva for determination of the ratio-based body iron index, and 3) Measure changes in salivary biomarkers and the body iron index in response to an iron intervention. Our approach includes domestic pilot work and leveraging a cohort of mothers and their young children in India participating in a feeding trial including biofortified high iron pearl millet. We also have paired serum-saliva samples from a survey of women of reproductive age participating in a CDC-supported periconceptional surveillance program at the same site in India as a potential back up. In our opinion, this research is innovative because the development of salivary biomarkers of inflammatory and nutritional status, including the ratio-based body iron index, would facilitate easier, cheaper, and more acceptable sampling and assessment of an individual’s or population’s status. These contributions are significant because they could dramatically improve biological sampling and assessment for nutritional and inflammatory assessment, which remain significant public health burdens globally and have challenges with assessment of high-risk individuals. Such developments would open up future avenues of research and development in salivary biomarkers and diagnostics.