Abstract
This study aimed to determine the regulatory mechanism of dietary zinc lactate (ZL) supplementation on intestinal oxidative stress damage in a paraquat (PQ)-induced piglet model. Twenty-eight piglets (mean body weight 9.51 ± 0.23 kg) weaned at 28 d of age were randomly divided into control, ZL, PQ, and ZL + PQ groups (n = 7 in each group). The ZL-supplemented diet had little effect on growth performance under normal physiological conditions. However, under PQ challenge, ZL supplementation significantly improved average daily gain (P < 0.05) and reduced the frequency of diarrhea. ZL improved intestinal morphology and ultrastructure by significantly increasing the expression level of the jejunal tight junction protein, zonula occludens-1 (ZO-1) (P < 0.05), and intestinal zinc transport and absorption in PQ-induced piglets, which reduced intestinal permeability. ZL supplementation also enhanced the expression of antioxidant and anti-inflammatory factor-related genes and decreased inflammatory cytokine expression and secretion in PQ-induced piglets. Furthermore, ZL treatment significantly inhibited the activation of constitutive androstane receptor (CAR) signaling (P < 0.01) in PQ-induced piglets and altered the structure of the gut microbiota, especially by significantly increasing the abundance of beneficial gut microbes, including UCG_002, Ruminococcus, Rikenellaceae_RC9_gut_group, Christensenellaceae_R_7_group, Treponema, unclassified_Christensenellaceae, and unclassified_Erysipelotrichaceae (P < 0.05). These data reveal that pre-administration of ZL to piglets can suppress intestinal oxidative stress by improving antioxidant and anti-inflammatory capacity and regulating the crosstalk between CAR signaling and gut microbiota.