PROJECT SUMMARY Breast milk provides numerous health benefits for infants including reduced illnesses such as otitis media, respiratory and gastrointestinal infections, asthma, sudden infant death syndrome, and a reduction in the likelihood of obesity and diabetes. It is the standard of care for NICU infants. The American Academy of Pediatrics (AAP), World Health Organization (WHO), and Center for Disease Control and Prevention (CDC) recommend exclusive breastfeeding the first 6 months and ideally until age 2. Breastmilk alone is not adequate to meet the needs of very low birth weight (VLBW) infants due to the high variability amongst mothers and higher needs of VLBW preterm neonates and infants. Therefore, human milk fed to preterm infants requires fortification (supplementation) with nutrients. Standard fortification involves adding a fixed amount of fortifier per 100ml of human milk and is the most utilized fortification method in the US. The fixed amount is determined by the manufacturer of the human milk fortifier and assumes that all human milk contains the same amount of protein and other macronutrients. These assumptions of the macronutrient composition of human milk have been shown to underestimate the amount of protein a neonate and infant in the NICU is receiving and can lead to poor neurocognitive outcomes. Therefore, a rapid point of care test for macronutrient and micronutrient concentrations in breast milk is imperative for improving infant nutrition and essential for targeted fortification. We present an easy-to-use device that includes a test strip coupled with our smartphone application to rapidly quantify macronutrients in human milk. These results will help a health care provider determine the fortification based on actual values and decrease conjectures for macronutrient composition of a milk sample, providing optimal targeted nutrition for the most vulnerable NICU patients. Further, the rapid point of care macronutrients test will change the workflow for failure to thrive and slow growth infants. Our device will allow for rapid and accurate diagnosis in the clinic and warrant more immediate referral to pediatric specialists e.g., if the caloric value of a sample is tested then there may be immediate confirmation of caloric intake for the work-up of failure to thrive infants. Successful completion of the proposed Phase I program will provide critical data to expand development of our one-of-a- kind technology in a Phase II program that will be geared towards validation in a large clinical study. This study will include further development of easy-to-use point of care tests in human milk and demonstrate the use of our test strip as an easy tool to integrate into NICU workflow enabling a custom electronic health record-friendly software to allow for our test strip results to be analyzed and facilitate targeted fortification and family integrated therapy.