** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** CAROTENOIDS ARE NATURALLY OCCURRING RED, ORANGE, AND YELLOW PIGMENTS FOUND MAINLY IN PLANTS. THEY MAY FUNCTION AS VITAMIN A PRECURSORS, HAVE IMPORTANT ANTIOXIDANT, IMMUNOLOGICAL, OR MEDIATE METABOLIC FUNCTIONS. ABSORPTION OF CAROTENOIDS TAKES PLACE IN THE SMALL INTESTINE, BUT THE OVERALL ABSORPTION EFFICIENCY FROM WHOLE FOODS IS LOW (~5-20%) AT THE LEVEL OF THE SMALL INTESTINE, AND THE REMAINING UNABSORBED CAROTENOIDS MOVE INTO THE COLON. HERE, CAROTENOIDS CAN BE FURTHER RELEASED AND METABOLIZED WITHIN THE COLON OR WITHIN COLON EPITHELIAL CELLS. THE OVERALL OBJECTIVE OF THIS PROPOSAL IS TO DETERMINE THE IMPACT OF CAROTENOIDS ON OBESITY-ASSOCIATED GUT DYSFUNCTION AND GUT MICROBIOTA. OUR CENTRAL HYPOTHESIS IS THAT CAROTENOIDS ESCAPING THE ABSORPTION IN THE SMALL INTESTINE CAN BE TRANSFORMED BY THE GUT MICROBIOTA IN THE COLON, AND THESE UNDIGESTED CAROTENOIDS ARE AVAILABLE TO THE GUT EPITHELIUM AND PROTECT AGAINST OBESITY-ASSOCIATED GUT DYSFUNCTION. WE WILL ELUCIDATE THE MOLECULAR MECHANISMS OF ACTION OF MAJOR DIETARY CAROTENOIDS ON INFLAMMATORY TRANSCRIPTION FACTORS AND GUT BARRIER INTEGRITY IN COLONIC EPITHELIAL CELLS IN AIM 1. WE WILL DETERMINE THE IMPACT OF CAROTENOIDS ON OBESITY-ASSOCIATED GUT DYSFUNCTIONIN A DIET-INDUCED OBESITY ANIMAL MODEL IN AIM 2. WE WILL CHARACTERIZE DIET-INDUCED CHANGES IN THE GUT MICROBIOTA RESULTING FROM A CAROTENOID-RICH DIET, UTILIZING SYSTEMS BIOLOGY APPROACHESIN AIM 3. WE BELIEVE THAT THE RESULTS OF THIS STUDY WILL INCREASE THE DEMAND FOR CAROTENOID-RICH PLANTS. FINALLY, THE FINDINGS OF THIS PROPOSAL WILL BE TRANSLATED TO THE COMMERCIAL USE OF PLANTS RICH IN CAROTENOIDS.