SURVIVAL OF MICROENCAPSULATED PROBIOTIC BACTERIA IN DYNAMIC GASTROINTESTINAL CONDITIONS AND THE EFFECT OF FOOD MATRICES

Microencapsulation of probiotics for improving human health has been extensively studied in the last decade. Most of the past studies focused on microencapsulation techniques and carrier materials. The cell release and survival studies and related mechanisms were mostly studied with the static digestion model. The information is limited about how the dynamic changes in pH and rheological conditions of GI media, as well as contraction forces, could modulate the transit and release properties of probiotic-embedded microcapsules (PEMs). The effect of the food matrices and wall materials on the transformation, transit, mucoadhesion, and release properties of PEMs in dynamic GI conditions remains mostly unknown.The overall goal of this project is to understand how dynamic GI conditions, food matrices, and wall materials affect transit, release, mucoadhesion, and cell survival of PEMs in the human GI tract using in vitro, ex vivo, and in vivo models.Specific objectives are 1) Investigate the impact of dynamic GI conditions (pH, viscosity, and contraction force) on release and viability of microencapsulated probiotics; 2)Study the protective effect of selected wall materials with different preparation methods on probiotics at realistic physiological conditions; 3)Determine the effect of food matrices and composition on the behavior of PEMs in the human GI tract; 4)Study the mucoadhesive property of PEMs as affected by wall materials and food matrices; 5) Assess the cell release and colonization in pigs and the effect on gut microbiota changes.The information obtained from this study will contribute to developing effective microencapsulation delivery systems for probiotic bacteria and other bioactive targeting improved health benefits.