Department of Animal and Food Sciences, University of Delaware, Newark, DE, USA.
Vetagro S.p.A., 42124 Reggio Emilia, Italy.
Poult Sci. 2023 Mar;102(3):102460. doi: 10.1016/j.psj.2022.102460. Epub 2022 Dec 28.
With restricted usage of growth-promoting antibiotics, identifying alternative feed additives that both improve intestinal barrier function and reduce inflammation is the center to improve chickens' health. This study examined the effects of a microencapsulated feed additive containing citric acid, sorbic acids, thymol, and vanillin on intestinal barrier function and inflammation status. A total of 240 birds were assigned to either a commercial control diet or control diet supplemented with 500 g/MT of the microencapsulated additive product. Birds were raised by feeding a 2-phase diet (starter, d 1 to d 21; and grower, d 15 to d 42). Growth performance was recorded weekly. At d 21 and d 42, total gastrointestinal tract permeability was evaluated by FITC-dextran (FD4) oral gavage. Jejunum-specific barrier functions were evaluated by Ussing chamber. Intestinal gene expression of selected epithelial cell markers, tight junction (TJ) proteins, inflammatory cytokines, and endocannabinoid system (ECS) markers were determined by RT-PCR. Statistical analysis was performed using Student t test. Results showed significant improvement of feed efficiency in the birds supplemented with the blend of organic acids and botanicals. At d 21, both oral and jejunal FD4 permeability were lower in the supplemented group. Jejunal transepithelial resistance was higher in the supplemented birds. At d 21, expression of TJs mRNA (CLDN1 and ZO2) was both upregulated in the jejunum and ileum of supplemented birds, while CLDN2 was downregulated in cecum. Proliferating cell marker SOX9 was higher expressed in jejunum and ceca. Goblet cell marker (MUC2) was upregulated, while Paneth cell marker (LYZ) was downregulated in the ileum. Proinflammatory cytokine expressions of IL1B, TNFA, and IFNG were downregulated in jejunum, while anti-inflammatory IL10 expression was higher in jejunum, ileum, cecum, and cecal tonsil. The ECS markers expressions were upregulated in most intestinal regions. Together, these results demonstrated that the blend of organic acids and botanical supplementation reduced inflammation, improved the TJs expression and intestinal barrier function, and thus improved chicken feed efficiency. The activated ECS may play a role in reducing intestinal tissue inflammation.
在限制使用促生长抗生素的情况下，寻找既能改善肠道屏障功能又能减轻炎症的替代饲料添加剂是提高鸡只健康的关键。本研究探讨了一种含有柠檬酸、山梨酸、百里香酚和香草醛的微胶囊饲料添加剂对肠道屏障功能和炎症状态的影响。将 240 只鸡分为商业对照组或对照组，对照组饲料中添加 500 g/MT 的微胶囊添加剂产品。鸡只采用两段式饲养（育雏期，d 1 至 d 21；生长期，d 15 至 d 42）。每周记录生长性能。在 d 21 和 d 42，通过 FITC-葡聚糖（FD4）口服灌胃评估整个胃肠道通透性。通过 Ussing 室评估空肠特定的屏障功能。通过 RT-PCR 测定选定的上皮细胞标记物、紧密连接（TJ）蛋白、炎症细胞因子和内源性大麻素系统（ECS）标记物的肠道基因表达。使用学生 t 检验进行统计分析。结果表明，在添加有机酸和植物混合物的鸡群中，饲料效率显著提高。在 d 21，补充组的口服和空肠 FD4 通透性均较低。补充组的空肠跨上皮电阻较高。在 d 21，补充组的空肠和回肠 TJ mRNA（CLDN1 和 ZO2）表达均上调，而回肠 CLDN2 下调。增殖细胞标记物 SOX9 在空肠和盲肠中高表达。杯状细胞标记物（MUC2）在空肠和回肠中上调，而 Paneth 细胞标记物（LYZ）在回肠中下调。促炎细胞因子 IL1B、TNFA 和 IFNG 的表达在空肠中下调，而抗炎细胞因子 IL10 的表达在空肠、回肠、盲肠和盲肠扁桃体中上调。ECS 标记物的表达在大多数肠道区域上调。总之，这些结果表明，有机酸和植物混合物的添加减少了炎症，改善了 TJ 表达和肠道屏障功能，从而提高了鸡的饲料效率。激活的 ECS 可能在减轻肠道组织炎症中发挥作用。
