LAUSR

Intestinal barrier function in vitro is quantified by the transepithelial electrical resistance (TEER) across epithelial cell monolayers due to polarization and expression of tight junction proteins. The objective of the current study was to measure the TEER of porcine intestinal epithelial cells (IPEC-J2) treated with butyric acid, sodium butyrate, monobutyrin and tributyrin. MTT assays were performed for each compound to determine cell viability and appropriate treatment doses. Butyric acid and tributyrin treatments were: 0, 0.5, 1, 2, and 4 mM. Monobutyrin and sodium butyrate doses were: 0, 1, 2, 4, 8 mM. Cells were seeded at 5 × 105 cells/mL into 12-well plates on Corning transwell inserts. Cells were cultured for 4 to 5 days (until all wells had TEER close to 1000 Ωcm2) and were then treated with organic acids. Each compound was tested in a randomized complete block design with 10 replicates. TEER was measured in Ωcm2 using a Millicell ERS-2 voltohmmeter at 0 h (before treatment) and at 24, 48, and 72 h post-treatment. All data were analyzed by PROC MIXED of SAS. Butyric acid linearly enhanced (P < 0.001) TEER of IPEC-J2 dose-dependently, with the highest TEER observed at doses of 1 and 2 mM at each time point. Sodium butyrate did not impact TEER at h 24, but linearly increased (P < 0.05) TEER at h 48 and 72. Treatment of monobutyrin linearly improved (P < 0.001) TEER at h 24, 48, and 72, with the highest TEER observed at the dose of 8 mM. Tributyrin had the tendency to improve (P < 0.10) TEER at h 48 and 72 when the highest dose was applied. Results of the current in vitro study indicate that butyric acid and its derivatives may improve intestinal barrier function of pigs, which requires verification in vivo.