Feeding Medium-Chain Fatty Acid Rich Formula Causes Liver Steatosis and Alters Hepatic Metabolism in Neonatal Pigs.

Medium (MCFA) and long (LCFA) chain fatty acids are often added to enhance the caloric value of infant formulas. Evidence suggests that MCFA promote growth, and are preferred over LCFA due to greater digestibility and ease of absorption. Our hypothesis was that MCFA supplementation would enhance neonatal pig growth to a greater extent than LCFA. Neonatal pigs (n=4) were fed a low energy control (CONT), or two isocaloric high energy formulas containing fat either from LCFA, or MCFA for 20 d. Pigs fed the LCFA had greater body weight compared to CONT and MCFA fed pigs (P < 0.05). In addition, pigs fed the LCFA and MCFA had more body fat than those in the CONT group. Liver and kidney weights as a percentage of body weight were greater (P ≤ 0.05) for pigs fed the MCFA than those fed the CONT formula with those fed LCFA intermediate (P ≤ 0.05). Pigs in the CONT and LCFA groups had less liver fat (12%) compared with those in the MCFA (26%) group (P ≤ 0.05). Isolated hepatocytes from these pigs where incubated in media containing [C]tracers of alanine, glucose, glutamate and propionate. Our data suggest alanine contribution to pyruvate is less in hepatocytes from LCFA and MCFA pigs than those in the CONT group (P < 0.05). These data suggest that a formula rich in MCFA caused steatosis compared with an isocaloric LCFA formula. In addition, MCFA feeding can alter hepatocyte metabolism and increase total body fat without increasing lean deposition.