Effects of ornithine α-ketoglutarate on growth performance and gut microbiota of chronic oxidative stress model pig induced by D-galactose
The aim of this study was to evaluate the protective effects and underlying mechanisms of ornithine α-ketoglutarate (OKG) on D-galactose (D-gal)-induced chronic oxidative stress in a pig model. A total of 40 castrated young pigs were randomly separated into 5 groups, including a control group, a model group treated with 5mg/kg body weight (BW) D-gal, and three D-gal+OKG groups in which pigs received 0.5%, 1%, and 2% OKG (n=8). The experiment lasted for 28 days. Growth performance, serum oxidative stress index and intestine relative gene expressions, gut microbiota, and serum amino acid pool were determined. The results demonstrated that administration of D-gal significantly caused growth performance and SOD and GSH-Px levels including these relative mRNA expression suppression, MDA levels enhancement, gut microbiota dysfunction, and serum amino acid alteration in pigs. 0.5% OKG treatment markedly ameliorated the reduction in growth performance evidenced by the reversed final body weight, average feed intake, and average body weight. Also, 0.5%OKG enhanced SOD and GSH-Px levels including these relative mRNA expression in the intestine and inhibits lipid oxidation subsequent with MDA generation. Intestinal abundances of Firmicutes was increased and Proteobacteria, Fusobacteria, Bacteriodetes, and Euryarchaeota were decreased in 0.5% OKG-supplemented pigs. Meanwhile, 0.5% OKG increased Glu, Pro, Asp, Thr, Val, Ile and Leu levels in the serum. Collectively, these results indicated that the D-gal induced chronic oxidative stress and also proved the positive effects of 0.5%OKG on altering pig gut microbe, restoring serum amino acid and alleviating growth-suppression induced by D-gal chronic oxidative stress.