本试验旨在研究香芹酚对肉兔生长性能、养分表观消化率、肠道形态结构、短链脂肪酸、肠道菌群结构和肠道菌群代谢通路的影响.选取160只35日龄健康伊拉肉兔,随机分为4组,每组40个重复,每个重复1只,对照组(CON组)饲喂基础饲粮,试验组(T1、T2、T3组)分别饲喂含有100、200和300 g·t-1香芹酚的试验饲粮.预试期5 d,正试期28 d.结果表明:1)与CON组相比,T1和T2组肉兔平均日增重和平均日采食量均显著提高(P<0.05),T1组的腹泻频率和死亡率显著降低(P<0.05),T1组的末重显著提高(P<0.05).2)T1、T2和T3组的粗蛋白质表观消化率显著高于CON组(P<0.05).3)T1、T2和T3组的回肠绒毛高度和黏膜厚度较CON组显著升高(P<0.05),且T1和T2组的回肠绒毛高度与隐窝深度的比值显著高于CON组(P<0.05).4)T1组盲肠中的丁酸含量显著高于CON组(P<0.05).5)T1、T2和T3组的盲肠中厚壁菌门和颤螺菌属的相对丰度较CON组显著升高(P<0.05),T1、T2和T3组的拟杆菌门相对丰度较CON组显著降低(P<0.05).6)与CON组相比,T1组盲肠菌群代谢通路的类固醇激素合成、糖胺聚糖的降解、次生胆汁酸合成、初级胆汁酸合成、泛素酮等萜类醌的生物合成、N-聚糖合成和酮体的合成与降解显著上调(P<0.05),鞘脂类代谢和脂多糖合成显著下调(P<0.05).综上说明,饲粮中添加香芹酚能够提高肉兔的生长性能和养分表观消化率,改善回肠形态结构,增加盲肠中丁酸的含量,改善盲肠菌群结构并对盲肠菌群的代谢通路有正向调节作用.在本试验条件下,综合香芹酚对肉兔的影响,推荐香芹酚添加量为100 g·t-1.

Carvacrol (CAR) is a plant extract that has been reported to enhance antioxidant activity in animals. However, the effect of CAR on the intestinal health of rabbits is poorly understood. Here, we investigated whether CAR exerts protective effects on the intestinal health of rabbits following lipopolysaccharide (LPS) challenge and whether these effects were mediated via the reduction of intestinal inflammation and the regulation of the intestinal flora. Intestinal damage was assessed in LPS-challenged rabbits treated or not with CAR. The serum levels of inflammatory factors were assessed by enzyme-linked immunosorbent assay. Histopathological changes in the ileum and cecum were examined using hematoxylin and eosin staining. The relative gene expression levels of inflammatory factors and tight junction proteins in the rabbit cecum were determined by qRT-PCR. High-throughput sequencing analysis of the microbial 16S rRNA gene was performed using the Illumina NovaSeq Platform. The results showed that CAR can prevent intestinal inflammation and damage as well as mitigate gut dysbiosis in rabbits following LPS challenge. Our study provides a theoretical reference for the application of dietary CAR in rabbit production.

Lycium barbarums are traditionally used as a homology of medicinal plants in China with a potent role in metabolism and immunomodulation. The current study was performed to explore the attenuation effect and microbiota regulation of Lycium barbarum polysaccharide (BLBP) on lipopolysaccharide (LPS)-induced intestine damage in mice. A total of 70 mice were randomly divided into five groups; negative control (GA), LPS (GB), both treated with an equal volume of normal saline, and BLBP treatment groups GC (100 mg/kg), GD (200 mg/kg), and GE (400 mg/kg) via gavage for 19 days. On Day 19, mice in groups GB, GC, GD, and GE were treated with 10 mg/kg LPS for 24 h and euthanized to collect intestine samples for pathological examination and microbiota sequencing. The results showed a non-significant difference in body weight gain among the five mouse groups; however, mice in the GC and GE groups showed decreased weight gain. An H&E examination revealed that the integrity of intestinal villi was destroyed by LPS, while BLBP supplement alleviated intestinal damage with an increase in villus height and a decrease in crypt depth. A total of over 59,000, 40,000, 50,000, 45,000, and 55,000 raw sequences were found in groups GA, GB, GC, GD, and GE, respectively. LPS challenge decreased alpha diversity indexes significantly ( p < 0.05), while a non-significant difference was found between different BLBP treatment groups and the GA group. A total of 8 phyla and 13 genera were found among five mouse groups, and BLBP partly restored the bacterial abundance in mice. LPS changed 282 metabolic pathways in KEGG L2, 77 metabolic pathways in KEGG L3, and 205 metabolic pathways in MetaCyc, respectively. The BLBP-supplemented groups, especially GE, showed reverse effects on those metabolic pathways. The current study revealed that BLBP can effectively decrease intestinal damage through the regulation of intestinal microbiota, which may provide new insights for the prevention of intestinal disease using food and medicine homologous of Lycium ruthenicum .