Effects Of Grape Seed Procyanidins On Colon Morphology,Cell Apoptosis And Microorganisms In Growing Pigs

The effects of grape seed proanthocyanidins（GSPs）on colon morphology,cell apoptosis and intestinal microorganisms in growing pigs were studied.A total of 48 Duroc × Landrace × Yorkshine at 25.17 kg of body weight were randomly assigned to four treatment groups with 3 replicate pens per group.The treatments fed a basal maize-soybean meal diet,or basal diet supplemented with 100,150 or 200 mg/kg GSPs respectively.The trial lasted 28 days.Fasting weight was weighed at the beginning and end of the morning,feed intake was recorded,and growth performance was calculated.The colonic mucosal thickness was detected by HE staining and the colonic morphology was observed by electron microscopy.Total antioxidant capacity（T-AOC）,glutathione peroxidase（GSH-Px）,total superoxide dismutase（T-SOD）,catalase（CAT）and malondialdehyde（MDA）were used to evaluate the antioxidant capacity of colon.The apoptotic rate of colon cells,apoptosis-related genes and proteins were determined by TUNEL assay,q PCR and Western blotting.Colonic microbial composition was determined by 16 S r DNA sequencing and short chain fatty acids（SCFAs）in colonic chyme were detected by gas chromatography.The results showed that dietary supplementation with GSPs had no significant effect on the average daily gain,average daily feed intake and feed/gain ratio of growing pigs（P>0.05）.Dietary supplementation with GSPs at 200 mg/kg could significantly increase the thickness of colonic mucosa and the surface microvilli（P<0.05）.GSPS significantly decreased the content of MDA in colon（P<0.05）,increased the activities of T-AOC,GSH-Px,T-SOD and CAT in colon（P<0.05）.Dietary supplementation with GSPs significantly decreased the apoptosis rate of colon cells（P<0.05）,the relative expression levels of Caspase-9,Fox O1,Fas L and Bimel genes（P<0.05）,and GSPs supplementation at concentrations of 150 or 200 mg/kg significantly decreased the relative expression levels of p-Akt（P<0.05）.Dietary supplementation with GSPs could significantly decrease OTUs（P<0.05）,but had no significant effect on Total tags（P>0.05）.At the genus level,with the increase of GSPs,the Prevotellaceae_NK3B31_group increased first and then decreased（P<0.05）,while the Christensenellaceae_R-7_group and Ruminococcaceae_UCG-002 showed significant increase（P<0.05）.The Treponema₂ and Bacteroides in the group receiving 200 mg/kg GSPs increased significantly（P<0.05）,and Lactobacillus（Lactobacillus）was inhibited by dietary supplementation with GSPs（P<0.05）.GSPs significantly decreased acetic acid concentration（P<0.05）,and 200mg/kg GSPs significantly decreased propionic acid concentration（P<0.05）,and no butyric acid value was detected.In conclusion,dietary supplementation of 200 mg/kg GSPS can significantly improve colon morphology,improve colon antioxidant capacity,reduce cell apoptosis rate,change the composition of intestinal microorganism,and reduce SCFAs of growing pigs.