POSTMENOPAUSAL BONE LOSS IS A PRIMARY CONTRIBUTOR TO OSTEOPOROSIS AND OSTEOPOROTIC FRACTURES IN ADULT WOMEN. THE OVERALL GOAL OF THIS PROJECT IS TO EVALUATE THE EFFECTS OF BC SUPPLEMENTATION ON CHANGES IN GUT MICROBIOME AND BONE MASS IN ADULT WOMEN. FOR THIS PURPOSE, WE WILL CONDUCT A PILOT RANDOMIZED PLACEBO-CONTROLLED CLINICAL TRIAL WITH BLACKCURRANT SUPPLEMENTATION FOR 6 MONTHS IN PERI- AND EARLY POSTMENOPAUSAL WOMEN AGED 45-60 YEARS. THE PRIMARY ENDPOINT WILL BE LUMBAR SPINE BMD; SECONDARY ENDPOINTS WILL BE GUT MICROBIAL FIRMICUTES/BACTEROIDETES (F/B) RATIO. TO DELINEATE THE UNDERLYING MECHANISMS OF THE ACTION, CHANGES IN BIOMARKERS FOR BONE METABOLISM, BONE-RELATED IMMUNE AND ENDOCRINE SYSTEMIC BIOMARKERS BY BC SUPPLEMENTATION WILL BE MEASURED IN PLASMA AND PERIPHERAL BLOOD DERIVED MONONUCLEAR CELLS. THE SPECIFIC OBJECTIVES OF THE STUDY ARE TO INVESTIGATE THE EFFECTS OF BLACKCURRANT EXTRACT ON: 1) BONE MASS AND BONE REMODELING MARKERS; 2) CHANGES IN THE GUT MICROBIOTA ABUNDANCEAND COMPOSITION, IMMUNE AND ENDOCRINE BIOMARKERS AND THEIR RELATIONSHIPS WITH CHANGES IN BONE MASS. THE PROPOSED STUDY WILL PROVIDE NOVEL INSIGHT INTO WHETHER AND HOW BLACKCURRANT CONSUMPTION REDUCES THE RISK OF POSTMENOPAUSAL BONE LOSS IN ADULT WOMEN AND WILL IMPROVE UNDERSTANDING OF THE CLINICAL ROLES OF GUT MICROBIOME IN POSTMENOPAUSAL BONE LOSS. FINDINGS FROM THIS STUDY WILL HELP INCREASE AWARENESS OF THE BONE HEALTH PROMOTING EFFECT OF BC AND MOTIVATE INCREASED PRODUCTION OF BC AND BERRY PRODUCTS IN RESPONSE TO THE INCREASING CONSUMER DEMAND. THUS, THIS STUDY IS CONSISTENT WITH THE USDA NIFA PROGRAM AREA PRIORITY OF FOOD AND HUMAN HEALTH (A1343).