Modulation of pectin on intestinal barrier function via changes in microbial functional potential and metabolism in the post-weaned piglet

Weaning is one of the major factors that cause stress and intestinal infection in piglets due to an immature intestine and not fully developed immune functions. There are well-known roles of dietary pectin in intestinal epithelial signaling and function via modulation of the microbial community and has attracted considerable attention recently in the field of piglet nutrition. Here, we showed that 5% pectin supplementation improved intestinal mucosal barrier function of post-weaned pigs. Specifically, dietary pectin supplementation increased the number of crypt PAS/AB-positive goblet cells in the ileum (P=0.0118), as well as elevated the mRNA expressions of MUC2 (P<0.0001) and tight junction proteins including ZO-1 (P<0.0001) and Occludin (P<0.0001). And piglets supplemented with pectin showed decreased both D-lactate (P=0.0183) and APK activity (P=0.0079) in the serum. Moreover, dietary pectin supplementation increased ileal total bile acid concentration (P=0.0074), mainly in GCA (P=0.0374), CDCA (P=0.0478), as well as HCA species including HCA (P=0.0072), HDCA (P=0.0168), and THDCA (P=0.0256). And correlation analyses were used to further reveal dietary pectin supplementation may have beneficial effects through stimulation of the crosstalk between gut microbes and bile acid synthesis within the enterohepatic circulation. Thus, dietary pectin exhibited a further positive effect on the growth of post-weaned piglets. These findings suggest a moderate pectin supplementation as the prebiotic is beneficial for gut health and improvement of weaned stress via regulating microbiota and bile acid metabolism.