Department of Animal Science, University of Manitoba, Winnipeg R3T 2N2, Canada.
J Anim Sci. 2012 Jul;90(7):2246-54. doi: 10.2527/jas.2011-4184. Epub 2012 Jan 13.
The combined effects of probiotics (Lactobacillus acidophilus, Lactobacillus casei, Streptococcus faecium, and Saccharomyces cerevisiae) and organic acids (sorbic and citric acid) on intestinal morphology and expression of immune-related genes were investigated. One-day-old chicks were randomly assigned to 1 of 3 groups: birds not receiving probiotic or organic acids (control; T1), or birds receiving an oral combination (1 g/L in water) of 10(8) CFU/g of each of the aforementioned probiotics and organic acids (1% sorbic acid and 0.2% citric acid) for 7 (T2) or 14 d (T3). Each group was divided into 5 replicate pens of 20 birds each, and 5 birds from each group (1 from each pen) were killed on d 11 and 22. Intestinal sections were collected for histological assessment, and reverse transcriptase-PCR analysis was used to assess defensin and cathelicidins expression. Quantitative real-time PCR was used to assess toll-like receptors (TLR) and cytokine expression. Duodenal villus height was greater in T2 and T3 at d 11 (P ≤ 0.036) and 22 (P ≤ 0.015) compared with T1. At d 11, duodenal goblet cell/unit area was less in T3, whereas it was greater in T2 compared with T1 in the jejunum (P = 0.009). Ileal goblet cell/unit area was greater in T3 at d 22 compared with T1 (P < 0.001). Avian beta-defensin-3 was expressed in all tissues except the bursa of T3 birds at d 11, and TLR-2 was down regulated in the cecal tonsil of birds in T2 and T3 at d 11 compared with T1 (P = 0.020 and 0.003, respectively). Expression of IL-12p35 in the ileum at d 11 was down regulated in T2 and T3 compared with T1 (P = 0.030 and 0.012, respectively). Reduced expression of INF-γ was observed in the ileum in T3 compared with T1 at d 11 (P = 0.047). Ileal IL-6 and IL-10 and cecal tonsil interferon-gamma (INF-γ) expressions were greater T2 at d 22 (P ≤ 0.047) than T1. In conclusion, supplementation of combined probiotics and organic acids resulted in inconsistent gut morphology associated responses, and avian beta-defensins and cathelicidins expression were not associated with combined probiotics and organic acids supplementation. Birds supplemented with combined probiotics and organic acids for 7 d showing similar responses in TLR-2, IL-12p35, and IFN-γ compared with those supplemented for 14 d indicates that shorter periods of supplementation might be enough to elicit beneficial responses.
本研究旨在探讨益生菌（嗜酸乳杆菌、干酪乳杆菌、粪肠球菌和酿酒酵母）和有机酸（山梨酸和柠檬酸）联合使用对肠道形态和免疫相关基因表达的影响。将 1 日龄雏鸡随机分为 3 组：未接受益生菌或有机酸处理的对照组（T1）、口服上述益生菌和有机酸混合物（1 g/L 水中含有 10(8) CFU/g 的每种益生菌和 1%山梨酸和 0.2%柠檬酸）7（T2）或 14（T3）d 的组。每组分为 5 个重复栏，每个栏 20 只鸡，每组（每个栏 1 只）在第 11 天和第 22 天各宰杀 5 只鸡。收集肠道切片进行组织学评估，采用逆转录聚合酶链反应（RT-PCR）分析防御素和抗菌肽的表达。采用实时定量 PCR 分析 Toll 样受体（TLR）和细胞因子的表达。与 T1 相比，T2 和 T3 在第 11 天（P≤0.036）和第 22 天（P≤0.015）十二指肠绒毛高度更高。在第 11 天，T3 空肠的杯状细胞/单位面积较小，而 T2 则较大，与 T1 相比（P=0.009）。在第 22 天，T3 回肠的杯状细胞/单位面积大于 T1（P<0.001）。在第 11 天，T3 组的除法氏囊外的所有组织均表达禽β-防御素-3，与 T1 相比，T2 和 T3 组的回肠 TLR-2 在第 11 天的回肠中下调（P=0.020 和 0.003）。在第 11 天，T2 和 T3 组的回肠中 IL-12p35 的表达均低于 T1（P=0.030 和 0.012）。与 T1 相比，T3 组的回肠中 IFN-γ的表达在第 11 天降低（P=0.047）。第 22 天，T2 组回肠中 IL-6 和 IL-10 以及盲肠扁桃体干扰素-γ（INF-γ）的表达高于 T1（P≤0.047）。综上所述，联合使用益生菌和有机酸会导致肠道形态的不一致反应，而禽β-防御素和抗菌肽的表达与联合使用益生菌和有机酸无关。与补充 14 d 相比，补充 7 d 联合益生菌和有机酸的雏鸡 TLR-2、IL-12p35 和 IFN-γ的反应相似，这表明较短的补充时间可能足以产生有益的反应。
