Effect of Clostridium butyricum on Plasma Immune Function, Antioxidant Activity and Metabolomics of Weaned Piglets

After weaning, piglets suffer from various stresses, and their immune function declines, causing diarrhoea and death. In recent years, the intestinal health of piglets has been a hot topic in the field of swine nutrition and feedstuff research. The present work aimed to investigate the effects of Clostridium butyricum (C. butyricum) on plasma immune function, antioxidant activity and plasma metabolomics of weaned piglets. A total of 90 weaning piglets of average weight (6.22 +/- 0.24 kg BW) and 28 +/- 2 days old were randomly divided into three groups: control diet, control diet + 0.1 g/kg antibiotic (colistin sulphate), and control diet + 5 x 10(8) CFU/kg C. butyricum. The pigs were divided into 6 pens per group with 5 piglets per pen for 21 days. Our results showed that the diet supplemented with 5 x 10(8) CFU/kg C. butyricum significantly reduced the levels of plasma glucose, total protein, high-density lipoprotein, phosphorus, IL-6, TNF-alpha, MDA and increased the levels of albumin, triglyceride, low-density lipoprotein, IgG, C3, SOD activity, T-AOC in the plasma (P<0.05). There were se-venteen kinds of differential metabolites were obtained by qualitative comparison of mass spectrometry (P 0.05). we conjectured that C. butyricum's role in immunity of weaned piglets may be mainly realized through the taurine and hypotaurine metabolism pathways (P=0.07). Based on the Spearman's rho correlation analysis, there were eleven differential metabolites (|rho|>= 0.60, P <= 0.05) among significant plasma biochemical indexes, immune indexes, antioxidant enzyme activity and plasma metabolites. They were UMP, melanin, L-valine, thiamine(1+) diphosphate chloride, vanillylmandelic acid, L-methionine, bis(2-ethylhexyl) phthalate, Phosphatidylethanolamine lyso 18:0, (R)-octopamine, 3-amino-2-naphthoic acid and galactitol, respectively. To sum up, C. butyricum can improve the immune performance and antioxidant enzyme activity of weaned piglets and can be considered as a potential substitute for antibiotics.