Procyanidins regulate colonic metabolome, inflammatory response and antioxidant capacity in lambs fed a high-concentrate diet.

This study explored the mechanism by which grape seed procyanidins (GSPs) alleviate colon inflammatory injury induced by a high-concentrate diet in lambs. Forty-eight 1/2 Dorper (♂) × 1/2 Small thin-tailed (♀) crossed male lambs were randomly assigned into four groups: the control group (CON), fed with a high-concentrate diet (concentrate:forage = 7:3) and three GSPs groups fed a high-concentrate diet + 10 (LGSP), 20 (MGSP) and 40 (HGSP) mg/kg body weight (BW) GSPs per day, respectively. The results showed that the levels of interleukin (IL)-1β and tumour necrosis factor (TNF)-α in plasma of lambs of the MGSP (0.155 and 38.52 pg/ml) and HGSP (0.165 and 39.60 pg/ml) groups were significantly lower than those in the CON (0.248 and 48.74 pg/ml) and LGSP (0.245 and 50.52 pg/ml) group (p < 0.05), and levels of IL-1β in colon tissue in the MGSP (28.49 ng/g) and HGSP (26.67 ng/g) groups were also lower (p < 0.05) than that in CON (40.55 ng/g). Metabonomics analysis of colon tissue showed that differentially expressed metabolites were mainly enriched in the arachidonic acid metabolism, citric acid cycle, glycine, serine and threonine metabolism, and peroxisome proliferator-activated receptor signalling pathway (p < 0.05). In conclusion, GSPs alleviate the colonic epithelium inflammatory response induced by a high-concentrate diet by increasing energy metabolism, amino acid metabolism, antioxidant metabolism and inhibiting arachidonic acid metabolism.