关键词: 白术多糖；肠炎沙门氏菌；雏鸡；肠道损伤

Abstract: To investigate the alleviating effect and mechanism of Polysaccharide from Atractylodes macrocephala Koidz（PAMK）on intestinal injury induced by Salmonella enteritis in Lingnan Yellow chickens，a total of 60 one?day? old Lingnan Yellow chicks were randomly divided into four groups：Control group，PAMK??treated group（PAMK）， Salmonella enteritidis-challenged group（SE），and PAMK plus Salmonella enteritidis group （PAMK+SE）. Each group consists of three replicateswith five chicks per replicate. The Control and the SE groups were fed a basal diet， while the PAMK and PAMK+SE groups received the basal diet supplemented with 200 mg/kg PAMK. At 21 days of age，the SE and the PAMK+SE groups were orally administered 1 mL of S. enteritidis suspension at a concentration of 1×109 cfu/mL，whereas the Control and PAMK groups received an equal volume of sterile saline. At 60 h post- challenge，duodenal and jejunal tissue samples were collected for histological examination and analysis of tight junction protein and inflammatory cytokine expression. Fecal observation showed that the incidence of diarrhea in the PAMK+SE group was lower than that in the SE group throughout the experimental period. Histological examination revealed that in the SE group，the duodenal villi were disorganized，the villus height?to?crypt depth（V/C）ratio was significantly decreased，and the crypt depth was significantly increased（P<0.05）. In contrast，PAMK treatment effectively alleviated these intestinal morphological alterations. Quantitative real ? time PCR analysis further demonstrated that PAMK significantly attenuated the SE-induced downregulation of ZO?1，Claudin?1 and Occludin mRNA expression，as well as the upregulation of IL ? 1β and TGF ? β mRNA expression. In conclusion，dietary supplementation with PAMK alleviates S. enteritidis - induced intestinal injury in Lingnan Yellow chicks，likely through the suppression of intestinal inflammation and preservation of the intestinal epithelial barrier.

Key words: Polysaccharide of Atractylodes macrocephala Koidz；Salmonella enteritidis；chicks；Intestinal injury