Effects of dietary L-methionine supplementation on intestinal integrity and oxidative status in intrauterine growth-retarded weanling piglets

Purpose The present study investigated whether dietary methionine supplementation might protect against intrauterine growth retardation (IUGR)-induced damage in the intestine of piglets. Methods Thirty normal birth weight (NBW) female piglets and sixty same-sex IUGR piglets were weaned at 21 days of postnatal age and fed the control diet (4.0g methionine per kg of feed, NBW-CON, and IUGR-CON groups) or the methionine-supplemented diet (5.2g methionine per kg of feed, IUGR-MET group) for 28 days (n = 6). Results Piglets in the IUGR-CON group showed decreased average daily feed intake and average daily gain and an increased feed conversion ratio than those in the NBW-CON group. Compared with NBW-CON piglets, IUGR-CON piglets had decreased villus height (VH) and villus height-to-crypt depth ratio in both the jejunum and ileum. In addition, in comparison with the NBW-CON piglets, IUGR increased the concentration of malondialdehyde (MDA) and the index of apoptosis, while it decreased the concentrations of methionine and reduced glutathione (GSH), the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG), and the protein expression of occludin (OCLN) in both the jejunum and ileum. Dietary methionine supplementation decreased the MDA and protein carbonyl concentrations and the apoptotic index, while it increased the VH level, methionine and GSH concentrations, GSH/GSSG ratio, and the OCLN protein expression in the jejunum of IUGR-MET piglets. Conclusions Methionine may have beneficial effects in improving intestinal integrity and oxidative status in IUGR weanling piglets.