Acta Veterinaria et Zootechnica Sinica ›› 2022, Vol. 53 ›› Issue (3): 913-924.doi: 10.11843/j.issn.0366-6964.2022.03.024

• CLINICAL VETERINARY MEDICINE • Previous Articles     Next Articles

Effects of Total Polysaccharides from Zhukuqin on Intestinal Flora and Immune Function in Piglets with Dampness-heat Diarrhea

TAO Weilai1, LIU Jia1, LIU Qiongdan1, HAO Yongfeng1, HU Yu1, ZHU Zhaorong1, LIU Juan1,2,3*   

  1. 1. College of Veterinary Medicine, Southwest University, Chongqing 402460, China;
    2. Chinese Veterinary Herbal Drugs Innovation Research Laboratory, University Veterinary Science Engineering Research Center in Chongqing, Chongqing 402460, China;
    3. Immunology Research Center, Southwest University Medical Research Institute, Chongqing 402460, China
  • Received:2021-06-20 Online:2022-03-23 Published:2022-03-31

Abstract: This study was carried out to investigate the effect of polysaccharides from ZhuKuQin (ZKQPs) on the intestinal flora and immune function of piglets with dampness-heat diarrhea. We analyzed the monosaccharide composition of ZKQPs by HPLC, and studied the direct effects of ZKQPs on common intestinal pathogens in vitro antibacterial experiments. At the same time, we establish a piglet diarrhea model, and treated with Pulsatilla powder and three doses of ZKQPs (25, 50 and 75 mg·kg-1). After the treatment, the small intestine tissues and the contents of the cecum were collected. The cecal colony was identified and counted; the changes of intestinal flora were analyzed by 16S rDNA high-throughput sequencing, and the mRNA expression of small intestinal immune-related cytokines was determined. The results showed that the primary structure of ZKQPs is mainly composed of rhamnose, glucose, galactose and xylose. In vitro tests, E. coli, Salmonella, and Clostridium wischii were sensitive to ZKQPs and showed a concentration dependence within a certain range. In animal experiments, ZKQPs effectively promoted the growth of intestinal Lactobacilli in piglets with diarrhea, and had a strong inhibitory effect on the growth of pathogenic E. coli. Among them, 50 mg·kg-1ZKQPs had the most significant effect. The results of 16S rDNA high-throughput sequencing showed that ZKQPs regulate the Alpha diversity of diarrhea piglets, and had a significant impact on the intestinal flora at the class and genera level. The relative abundance of Bacillus and Lactobacillus decreased significantly and the relative abundance of bacteria increased significantly in diarrhea piglets; after ZKQPs treatment, the relative abundances of Bacillus and Lactobacillus increased significantly and were higher than normal, and the relative abundance of Clostridia significantly decreased, which significantly improved the intestinal flora structure of diarrhea piglets. In piglets with diarrhea, the level of Th1 cytokine IL-2 mRNA in each segment of the small intestine increased (P<0.01), while the Th2 cytokine IL-4 and IL-5 mRNA levels decreased; after treatment with ZKQPs, the levels of IL-2 mRNA in the small intestine decreased, the levels of IL-4 and IL-5 mRNA generally increased, and the mRNA levels of different cytokines vary in different locations in the small intestine. ZKQPs 50 and 75 mg·kg-1 have the most significant effects on them, comprehensive analysis ZKQPs 50 mg·kg-1 treatment of diarrhea piglets has the greatest impact on the level of cytokine mRNA. This study shows that ZKQPs have a good inhibitory effect on the growth of intestinal pathogens in vitro, can change the abundance and diversity of the intestinal microbiota of diarrhea piglets, increase the relative abundance of Lactobacillus and improve the structure of the flora. At the same time, ZKQPs regulate the intestinal immune response and effectively enhance the anti-diarrhea ability of piglets.

Key words: polysaccharides from Zhukuqin, diarrhea piglets, intestinal flora, immune

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