Rowan A M, Moughan P J, Wilson M N, Maher K, Tasman-Jones C
Department of Chemistry and Biochemistry, Massey University, Palmerston North, New Zealand.
Br J Nutr. 1994 Jan;71(1):29-42. doi: 10.1079/bjn19940108.
The aim of the study was to determine if there is a difference between ileal and faecal assays for determining amino acid and N digestibilities in adult human subjects. Comparison of true ileal amino acid and N digestibilities was also made between adult human subjects and growing pigs to establish the usefulness of the pig as a model animal. Five subjects with established ileostomies and six subjects with intact large bowels consumed a constant diet consisting of meat, vegetables, fruit, bread and dairy products for 7 d with collection of ileostomy contents or faeces respectively over the last 4 d. The study was repeated using 25 kg body weight ileostomized and intact pigs. Apparent amino acid and N digestibility coefficients were determined. For human subjects the faecal digestibility values were significantly higher (P < 0.05) than the ileal values for Arg, Asp, Gly, Phe, Pro, Ser, Thr and Trp. The faecal digestibility of Met was significantly lower than the ileal value. Determination of DNA, diaminopimelic acid (DAPA) and the digestibilities of pectin, hemicellulose and cellulose in human subjects indicated that some microbial colonization had occurred at the terminal ileum after formation of an ileostomy; however, this was not as extensive as in the large intestine. True ileum amino acid and N digestibilities were calculated after correcting for the endogenous contribution of amino acids at the terminal ileum determined using a protein-free diet. There were no significant differences between adult human subjects and pigs for true ileal dietary amino acid digestibility except for Thr, Phe, Cys and Met. There were no significant differences between adult humans and pigs for the ileal digestibility of dry matter and the faecal digestibility of gross energy.
本研究的目的是确定在成年人体受试者中，回肠检测法和粪便检测法在测定氨基酸和氮消化率方面是否存在差异。还对成年人体受试者和生长猪的回肠氨基酸和氮的真消化率进行了比较，以确定猪作为模型动物的实用性。五名有回肠造口术的受试者和六名大肠完整的受试者连续7天食用由肉类、蔬菜、水果、面包和乳制品组成的固定饮食，分别在最后4天收集回肠造口术内容物或粪便。使用体重25 kg的回肠造口猪和完整猪重复该研究。测定了表观氨基酸和氮消化率系数。对于人体受试者，粪便中精氨酸、天冬氨酸、甘氨酸、苯丙氨酸、脯氨酸、丝氨酸、苏氨酸和色氨酸的消化率值显著高于回肠值（P < 0.05）。蛋氨酸的粪便消化率显著低于回肠值。对人体受试者的DNA、二氨基庚二酸（DAPA）以及果胶、半纤维素和纤维素的消化率进行测定，结果表明回肠造口术后末端回肠发生了一些微生物定植；然而，其程度不如大肠广泛。使用无蛋白饮食确定末端回肠氨基酸的内源性贡献后，计算了回肠氨基酸和氮的真消化率。除苏氨酸、苯丙氨酸、半胱氨酸和蛋氨酸外，成年人体受试者和猪的回肠膳食氨基酸真消化率没有显著差异。成年人体受试者和猪在干物质的回肠消化率和总能的粪便消化率方面没有显著差异。
