DIETARY INTERVENTION OF VITAMIN A-ENRICHED FOODS COULD POTENTIALLY CONTRIBUTE TO AN ANTI-INFLAMMATORY GUT MICROBIOME PROFILE AND REDUCE COLONIC AND SYSTEMIC INFLAMMATION IN HUMANS THROUGH UNCLEAR MECHANISMS. ATLANTIC MACKEREL FISH IS A LOW-COST, COMMONLY AVAILABLE SEAFOOD CONTAINING HIGH VITAMIN A LEVELS, PREDOMINANTLY RETINOL, IN THE FISH FILLETS. THERE REMAINS A SUBSTANTIAL KNOWLEDGE GAP REGARDING HOW ATLANTIC MACKEREL AND ITS BIOACTIVE COMPONENT RETINOL ALTER GUT MICROBIOME AND INFLAMMATION. THUS, WE PROPOSE A PRE-CLINICAL APPROACH USING YOUNG-ADULT SPRAGUE DAWLEY RATS AS MODELS TO PURSUE THE FOLLOWING TWO SPECIFIC OBJECTIVES: 1) EVALUATE THE ANTI-INFLAMMATORY PROPERTIES OF ATLANTIC MACKEREL FISH FILLETS VIA REBALANCING OF GUT MICROBIOME IN DSS-INDUCED INTESTINAL INFLAMMATION AND TEST THE ROLE OF DIET-INDUCED GUT MICROBIOME ALTERATION ON INFLAMMATION IN GERM-FREE MICE, AND 2) DETERMINE THE UNDERLYING METABOLIC MECHANISM BY WHICH RETINOL, AS ONE OF THE ATLANTIC MACKEREL BIOACTIVE COMPOUNDS, EXERTS THE ANTI-INFLAMMATORY ROLE THROUGH REGULATING CERTAIN ASPECTS OF GUT MICROBIOME GROWTH, METABOLISM, AND FUNCTION IN VITAMIN A DEFICIENT DSS RAT MODELS. THE RESULTS FROM THIS RESEARCH ARE EXPECTED TO HAVE A SIGNIFICANT IMPACT ON PUBLIC HEALTH BY PROVIDING NEW INSIGHTS INTO ATLANTIC MACKEREL AS A HEALTHY DIETARY OPTION THAT COULD REDUCE LOCAL AND SYSTEMATIC INFLAMMATION THROUGH DIFFERENTIAL EXPRESSION OF THE GUT MICROBIOME.