A total of 128 Huanjiang mini-pigs were selected and randomly divided into four groups,including control,Lactobacillus delbrueckii (LD),xylo-oligosaccharides (XOS),and synbiotic (LD+ XOS) groups.Blood was collected to determine plasma biochemical parameters and oxidant-antioxidant indices.The results showed that,triglyceride and hydroxy radical levels in the LD,XOS,and synbiotics groups were increased;while glutathione peroxidase level was decreased on day 28 of the trial.On day 56 of the trial,total protein,albumin,urea nitrogen,glucose,triglyceride,cholesterol,low density lipoprotein-cholesterol,and hepaticlipase levels in the synbiotics group were increased;while lactate dehydrogenase and total glutathione levels in the XOS group,and malondialdehyde,aspartate aminotransferase,and lactate dehydrogenase levels in the synbiotics group were decreased.On day 84 of the trial,H₂O₂,aspartate aminotransferase,and lactate dehydrogenase levels in the LD,XOS,and synbiotics groups were decreased;while total protein and glutathione peroxidase levels in the synbiotics group were increased.Collectively,these findings suggested that dietary supplementation with LD and/or XOS could regulate the body′s nutritional metabolism and oxidant-antioxidant balance.