Effects of microencapsulation on the gastrointestinal transit and tissue distribution of a bioactive mixture of fish oil tributyrin and resveratrol

Bioactive formulations containing fish oil, tributryin and resveratrol, containing either radiolabeled [14C]-trilinolenin or [14C]-tributyrin and [3H]-resveratrol, were administered as free components or encapsulated mixtures within an oil-in-water emulsion stabilized by a heated mixture of a milk protein, glucose and a modified resistant starch. The distribution of the radioactive labels throughout the digestive system, blood and selected tissues following oral administration to rats was investigated. The time-course of transit and the relative distribution along the rat digestive system were not markedly altered by microencapsulation. As a percentage of the relative distribution along the GI tract tissue walls, the majority of the radioactivity from the bioactives was associated with the walls of the small intestine. Microencapsulation increased the levels of the radioactivity from the bioactives in the blood and liver, consistent with an increase in the bioavailability of agents. The potential of using microencapsulation to effectively deliver a mixture of bioactives within a single formulation was demonstrated.