Effect of solid and liquid diet on uptake of large particulates across intestinal epithelium in rats

The effect of diet composition on the uptake of particulates across the gastrointestinal epithelium has been examined in fasted male weanling Sprague-Dawley rats by estimating the systemic uptake of orally administered 2-microns latex polystyrene microspheres. Using a tissue solubilization assay, particle transfer in animals maintained on a fluid diet was determined. A larger number of particles was transferred from the gut lumen to the internal organs, including the mesenteric lymph node, spleen, bone marrow, liver, kidney, and heart of animals fed solid pelleted diet than those maintained on a fluid-diet 4 hr after oral administration of particles. The increase in particle number in rats fed the solid diet was only statistically significant (P < 0.05) for brain tissue in the analysis for trend. However, the number of particles retained in the proximal region of the gut at the end of this period was greater in animals fed the fluid diet. This work demonstrates that diet composition is important in gastrointestinal transepithelial translocation of microspheres.