Effects on Varying Intravenous Lipid Emulsions on the Small Bowel Epithelium in a Mouse Model of Parenteral Nutrition

Abstract

Injectable fat emulsions (FEs) are a clinically dependable source of essential fatty acids (FA). ω-6 FA is associated with an inflammatory response. Medium-chain triglycerides (MCT, ω-3 FA), fish oil, and olive oil are reported to decrease the inflammatory response. However, the effect of these lipids on the gastrointestinal tract has not been well studied. To address this, we used a mouse model of parenteral nutrition (PN) and hypothesized that a decrease in intestinal inflammation would be seen when either fish oil and MCT or olive oil were added. Three FEs were studied in adult C57BL/6 mice via intravenous cannulation: standard soybean-based FE (SBFE), 80% olive oil -supplemented FE (OOFE), or a combination of a soybean oil, MCT, olive oil, and fish oil emulsion (SMOF). PN was given for 7 days, small bowel mucosa-derived cytokines, animal survival rate, epithelial cell (EC) proliferation and apoptosis rates, intestinal barrier function and mucosal FA composition were analyzed. Compared to the SBFE and SMOF groups, the best survival, highest EC proliferation and lowest EC apoptosis rates were observed in the OOFE group; and associated with the lowest levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β expression. Jejunal FA content showed higher levels of eicosapentaenoic and docosapentaenoic acid in the SMOF group and the highest arachidonic acid in the OOFE group. The study showed that PN containing OOFE had beneficial effects to small bowel health and animal survival. Further investigation may help to enhance bowel integrity in patients restricted to PN.