Dietary antibiotic growth promoters enhance the bioavailability of α-tocopheryl acetate in broilers by altering lipid absorption
Dietary antibiotic growth promoters enhance the bioavailability of α-tocopheryl acetate in broilers by altering lipid absorption
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DOI：
10.1093/jn/134.6.1487
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发表时间：
2004-06-01
影响因子：
4.2
通讯作者：
Jensen, SK
中科院分区：
文献类型：
--
作者：
Knarreborg, A;Lauridsen, C;Jensen, SK
在Ross 208肉鸡试验中研究了肠道微生物胆盐去结合对脂肪酸和α-和γ-生育酚吸收的影响。将鸡（n = 1600）分配至4种饮食处理：不补充或补充抗生素（盐霉素，40 mg/kg饲料和阿维拉霉素，10 mg/kg饲料），以及在饮食中包括动物脂肪（10 g/100 g饲料）或大豆油（10 g/100 g饲料）。在7，14，21，和35日龄，肠的胆盐水解酶活性细菌产气荚膜梭菌的数量，共轭和非共轭胆盐的浓度，回肠吸收的脂肪酸和生育酚，和生育酚的血浆浓度进行了测量。所有变量都受到鸟龄的显著影响。C.在饲喂大豆油的鸟类中，产气荚膜杆菌计数较低，胆盐浓度较高。抗生素的补充降低了C.小肠中的产气荚膜杆菌并降低未结合的胆汁盐的浓度。脂肪酸和α-生育酚的回肠吸收以及α-生育酚的血浆浓度在饲喂抗生素的禽类中更高。γ-生育酚的吸收和血药浓度不受抗生素的影响。与仅以游离醇形式存在的γ-生育酚不同，膳食α-生育酚的主要部分以α-生育酚乙酸酯形式存在，其在吸收前需要胆盐依赖性酶水解。总之，脂溶性化合物的适当消化高度依赖于小肠中足够浓度的胆汁盐，以提供适当的脂质乳化和脂解酶的活化。
The influence of intestinal microbial bile salt deconjugation on absorption of fatty acids and alpha- and gamma-tocopherol was investigated in a trial with Ross 208 broilers. Birds (n = 1600) were assigned to 4 dietary treatments: no supplementation or supplementation of antibiotics (salinomycin, 40 mg/kg feed and avilamycin, 10 mg/kg feed), and inclusion of either animal fat (10 g/100 g feed) or soybean oil (10 g/100 g feed) in the diet. At d 7, 14, 21, and 35 of age, the intestinal number of the bile salt hydrolase-active bacteria Clostridium perfringens, the concentration of conjugated and unconjugated bile salts, the ileal absorption of fatty acids and tocopherols, and the blood plasma concentrations of tocopherols were measured. All variables were significantly influenced by bird age. C. perfringens counts were lower and bile salt concentrations were greater in birds fed soybean oil. The supplementation of antibiotics reduced the numbers of C. perfringens in the small intestine and reduced the concentration of unconjugated bile salts. The ileal absorption of fatty acids and a-tocopherol, as well as the plasma concentration of a-tocopherol, was greater in birds fed antibiotics. The absorption and plasma concentration of gamma-tocopherol were not influenced by antibiotics. Unlike gamma-tocopherol, which is present solely as the free alcohol, the major proportion of dietary a-tocopherol is present as a-tocopheryl acetate, which requires a bile salt-dependent enzymatic hydrolysis before absorption. In conclusion, proper digestion of lipid-soluble compounds is highly dependent on an adequate concentration of bile salts in the small intestine to provide proper lipid emulsification and activation of lipolytic enzymes.