Curcumin and Resveratrol Regulate Intestinal Bacteria and Alleviate Intestinal Inflammation in Weaned Piglets

Abstract

Human infants or piglets are vulnerable to intestinal microbe-caused disorders and inflammation due to their rapidly changing gut microbiota and immaturity of their immune systems at weaning. Resveratrol and curcumin have significant anti-inflammatory, bacteria-regulating and immune-promoting effects. The purpose of this study was to investigate whether dietary supplementation with resveratrol and curcumin can change the intestinal microbiota and alleviate intestinal inflammation induced by weaning in piglets. One hundred eighty piglets weaned at 21 ± 2 d were fed a control diet (CON group) or supplemented diet (300 mg/kg of antibiotics, ANT group; 300 mg/kg of resveratrol and curcumin, respectively, HRC group; 100 mg/kg of resveratrol and curcumin, respectively, LRC group; 300 mg/kg of resveratrol, RES group; 300 mg/kg of curcumin, CUR group) for 28 days. The results showed that compared with the CON group, curcumin alone and antibiotics decreased the copy numbers of Escherichia coli. Both curcumin and resveratrol down-regulated the level of Toll-like-receptor 4 mRNA and protein expression in the intestine to inhibit the release of critical inflammation molecules (interleukin-1β, tumor necrosis factor-α), and increase the secretion of immunoglobulin. Our results suggested that curcumin and resveratrol can regulate weaned piglet gut microbiota, down-regulate the TLR4 signaling pathway, alleviate intestinal inflammation, and ultimately increase intestinal immune function.

Keywords: curcumin; intestinal bacteria; intestinal inflammatory; resveratrol; toll-like-receptor 4; weaned piglets.

Figure 1

Effects of curcumin and resveratrol supplementation on relative mRNA expression in jejunum (a) and ileum epithelium (b) of weaned piglets. The column and its bar represented the means value and SEM, n = 6/group. Different letters on the shoulder mark indicate significant difference (p < 0.05), the same letter or no letter indicates that the difference is not significant (p ≥ 0.05). IL-1β, Interleukin-1β; IL-10, Interleukin-10; TNF-α, Tumor necrosis factor α; TLR4, Toll like receptor 4; TLR2, Toll like receptor 2. ANT, control diet + antibiotics (300 mg/kg); CON, control diet; HRC, control diet + curcumin and resveratrol (300 mg/kg); LRC, control diet + curcumin and resveratrol (100 mg/kg); RES, control diet + resveratrol (300 mg/kg); CUR, control diet + curcumin (300 mg/kg).

Figure 2

Effects of dietary resveratrol and curcumin supplementation on TLR4 protein in the jejunum (a) and ileum (b) of weaned piglets. a, ANT group. b, CON group. c, HRC group. d, LRC group. e, RES group. f, CUR group. TLR4, Toll like receptor 4. ANT, control diet + 300 mg/kg antibiotics; CON, control diet; HRC, control diet + curcumin and resveratrol (300 mg/kg); LRC, control diet + curcumin and resveratrol (100 mg/kg); RES, control diet + 300 mg/kg resveratrol; CUR, control diet + 300 mg/kg curcumin.

Figure 3

DGGE profiles of V6-V8 regions of 16S rDNA of jejunal digesta (a) and ileum digesta (b) from weaned piglets. ANT, control diet + 300 mg/kg antibiotics; CON, control diet; HRC, control diet + curcumin and resveratrol (300 mg/kg); LRC, control diet + curcumin and resveratrol (100 mg/kg); RES, control diet + 300 mg/kg resveratrol; CUR, control diet + 300 mg/kg curcumin.

Figure 4

Effects of curcumin and resveratrol supplementation on intestinal bacteria copy number in the (a) jejunal and (b) ileal. The column and its bar represented the means value and SEM, n = 6/group. Different letters on the shoulder mark indicate significant difference (p < 0.05), the same letter or no letter indicates that the difference is not significant (p ≥ 0.05). ANT, control diet + 300 mg/kg antibiotics; CON, control diet; HRC, control diet + curcumin and resveratrol (300 mg/kg); LRC, control diet + curcumin and resveratrol (100 mg/kg); RES, control diet + 300 mg/kg resveratrol; CUR, control diet + 300 mg/kg curcumin.