Rhubarb Supplementation Promotes Intestinal Mucosal Innate Immune Homeostasis through Modulating Intestinal Epithelial Microbiota in Goat Kids

The abuse and misuse of antibiotics in livestock production pose a potential health risk globally. Rhubarb can serve as a potential alternative to antibiotics, and several studies have looked into its anticancer, antitumor, and anti-inflammatory properties. The aim of this study was to test the effects of rhubarb supplementation to the diet of young ruminants on innate immune function and epithelial microbiota in the small intestine. Goat kids were fed with a control diet supplemented with or without rhubarb (1.25% DM) and were slaughtered at days 50 and 60 of age. Results showed that the supplementation of rhubarb increased ileal villus height (<i>P</i> = 0.036), increased jejujal and ileal anti-inflammatory <i>IL-10</i> production (<i>P</i> < 0.05), increased jejunal and ileal <i>Claudin-1</i> expression at both mRNA and protein levels (<i>P</i> < 0.05), and decreased ileal pro-inflammatory <i>IL-1β</i> production (<i>P</i> < 0.05). These changes in innate immune function were accompanied by shifts in ileal epithelial bacterial ecosystem in favor of <i>Blautia</i>, <i>Clostridium</i>, <i>Lactobacillus</i>, and <i>Pseudomonas</i>, and with a decline in the relative abundance of <i>Staphylococcus</i> (<i>P</i> < 0.001) when rhubarb was supplemented. Additionally, age also affected (<i>P</i> < 0.05) crypt depth, cytokine production, <i>Claudin-1</i> expression and relative abundances of specific genera in epithelial bacteria. Collectively, the supplementation of rhubarb could enhance host mucosal innate immune homeostasis by modulating intestinal epithelial microbiota during the early stages of animal development