Department of Poultry Science, University of Arkansas , Fayetteville, AR , USA.
Department of Animal Sciences, The Ohio State University , Columbus, OH , USA.
Front Vet Sci. 2016 Feb 15;3:10. doi: 10.3389/fvets.2016.00010. eCollection 2016.
Previous studies conducted in our laboratory have demonstrated that intestinal barrier function can be adversely affected by diet ingredients or feed restriction, resulting in increased intestinal inflammation-associated permeability. Two experiments were conducted in broilers to evaluate the effect of three concentrations of Aflatoxin B1 (AFB1; 2, 1.5, or 1 ppm) on gastrointestinal leakage and liver bacterial translocation (BT). In experiment 1, 240 day-of-hatch male broilers were allocated in two groups, each group had six replicates of 20 chickens (n = 120/group): Control feed or feed + 2 ppm AFB1. In experiment 2, 240 day-of-hatch male broilers were allocated in three groups, each group had five replicates of 16 chickens (n = 80/group): Control feed; feed + 1 ppm AFB1; or feed + 1.5 ppm AFB1. In both experiments, chickens were fed starter (days 1-7) and grower diets (days 8-21) ad libitum and performance parameters were evaluated every week. At day 21, all chicks received an oral gavage dose of FITC-d (4.16 mg/kg) 2.5 h before collecting blood samples to evaluate gastrointestinal leakage of FITC-d. In experiment 2, a hematologic analysis was also performed. Liver sections were aseptically collected and cultured using TSA plates to determine BT. Cecal contents were collected to determine total colony-forming units per gram of Gram-negative bacteria, lactic acid bacteria (LAB), or anaerobes by plating on selective media. In experiment 2, liver, spleen, and bursa of Fabricius were removed to determine organ weight ratio, and also intestinal samples were obtained for morphometric analysis. Performance parameters, organ weight ratio, and morphometric measurements were significantly different between Control and AFB1 groups in both experiments. Gut leakage of FITC-d was not affected by the three concentrations of AFB1 evaluated (P > 0.05). Interestingly, a significant reduction in BT was observed in chickens that received 2 and 1 ppm AFB1. An increase (P < 0.05) in total aerobic bacteria, total Gram negatives, and total LAB were observed in chickens fed with 2 and 1.5 ppm of AFB1 when compared with Control and 1 ppm chickens. The integrity of gut epithelial barrier was not compromised after exposure to the mycotoxin.
先前在本实验室进行的研究表明，饮食成分或饲料限制会对肠道屏障功能产生不利影响，导致肠道炎症相关通透性增加。本研究在肉鸡中进行了两项实验，以评估三种浓度的黄曲霉毒素 B1（AFB1；2、1.5 或 1ppm）对胃肠道渗漏和肝脏细菌易位（BT）的影响。在实验 1 中，将 240 日龄雄性肉鸡分配到两组，每组有六个 20 只鸡的重复（n=120/组）：对照饲料或饲料+2ppm AFB1。在实验 2 中，将 240 日龄雄性肉鸡分配到三组，每组有五个 16 只鸡的重复（n=80/组）：对照饲料；饲料+1ppm AFB1；或饲料+1.5ppm AFB1。在这两项实验中，肉鸡自由采食育雏期（1-7 天）和生长期（8-21 天）饲料，并每周评估性能参数。在第 21 天，所有小鸡在采集血液样本前 2.5 小时接受 FITC-d（4.16mg/kg）口服灌胃，以评估 FITC-d 的胃肠道渗漏情况。在实验 2 中，还进行了血液学分析。无菌收集肝脏切片，并用 TSA 平板进行培养，以确定 BT。收集盲肠内容物，在选择性培养基上平板计数每克革兰氏阴性菌、乳酸菌（LAB）或厌氧菌的总菌落形成单位。在实验 2 中，还切除肝脏、脾脏和法氏囊以确定器官重量比，并获得肠道样本进行形态计量分析。在这两项实验中，对照和 AFB1 组之间的性能参数、器官重量比和形态计量测量值均有显著差异。FITC-d 的肠道渗漏未受评估的三种 AFB1 浓度（P>0.05）的影响。有趣的是，接受 2ppm 和 1ppm AFB1 的鸡的 BT 显著减少。与对照和 1ppm 鸡相比，饲喂 2ppm 和 1.5ppm AFB1 的鸡的总需氧菌、总革兰氏阴性菌和总 LAB 均增加（P<0.05）。在接触真菌毒素后，肠道上皮屏障的完整性未受到损害。
