COLORECTAL CANCER (CRC) REMAINS A MAJOR PUBLIC HEALTH PROBLEM IN THE US - WITH APPROXIMATELY 135,000 NEW CASES BEINGDIAGNOSED AND 50,000 DEATHS FROM THIS DISEASE EACH YEAR. ALTHOUGH SEVERAL AGENTS ARE REPORTED TO REDUCE CANCER FORMATION INLABORATORY RODENTS, ASPIRIN REMAINS THE ONLY AGENT WITH ROBUST EVIDENCE IN HUMAN POPULATIONS - HOWEVER ITS ADVERSE SIDE EFFECTSMAY OUTWEIGH ITS BENEFITS. THUS, THERE IS A CLEAR NEED TO IDENTIFY NEW, EFFECTIVE AND SAFE STRATEGIES TO PREVENT CRC.DIET IS A MAJOR DETERMINANT OF CRC RISK - RECENT ESTIMATES INDICATE THAT UP TO 38% OF ALL CRC CASES CAN BE ATTRIBUTED TO POORDIET. THE CONSENSUS OF SEVERAL HUMAN POPULATION STUDIES IS THAT CONSUMPTION OF A MEDITERRANEAN DIET (MD) IS ASSOCIATED WITH ASIGNIFICANTLY REDUCED RISK FOR CRC. THE MD IS CHARACTERIZED BY A HIGH INTAKE OF VEGETABLES, LEGUMES, FRUITS, NUTS, GRAINS, FISH,SEAFOOD, OLIVE OIL, AND MODERATE INTAKE OF RED WINE.CHANGES IN THE COMPOSITION OF THE GUT BACTERIA PLAY A ROLE IN CRC FORMATION. MOREOVER, THE COMPOSITION OF THE GUT BACTERIA ISALSO SENSITIVE TO DIET. THE GOAL OF OUR CURRENT STUDIES IS TO UNDERSTAND THE INVOLVEMENT OF GUT BACTERIA IN CRC PREVENTION BY MDAND WHETHER THE CRC PROTECTIVE EFFECT OF MD CAN BE ENHANCED BY GIVING SPECIFIC BACTERIA WITH KNOWN ANTI-CANCER PROPERTIESWE WILL ACHIEVE THIS GOAL BY CONDUCTING TWO EXPERIMENTS UTILIZING A MOUSE MODEL OF CRC. MICE WILL BE FED STANDARD DIET OR AMEDITERRANEAN AND UNDERGO VARIOUS BACTERIA TREATMENTS INCLUDING DEPLETION, DEPLETION WITH ADDING BACK INFLAMMATORY BACTERIACOMPONENTS AND SUPPLEMENTATION WITH PROTECTIVE BACTERIA.SUCCESSFUL COMPLETION OF THESE STUDIES WILL ENHANCE OUR UNDERSTANDING OF HOW MD PROTECTS AGAINST CRC AND MAY OUTLINE ANOVEL APPROACH TO FURTHER ENHANCE THE PROTECTIVE EFFECT OF MD.