Spik G, Brunet B, Mazurier-Dehaine C, Fontaine G, Montreuil J
Acta Paediatr Scand. 1982 Nov;71(6):979-85. doi: 10.1111/j.1651-2227.1982.tb09560.x.
Human lactotransferrin was characterized in the faecal extracts from breastfed babies. Quantitative determination of human copro-lactotransferrin from birth for a period of up to 3 weeks showed that the daily elimination decreased from 35 to 5 mg. The amount of copro-lactotransferrin corresponding to the endogenous secretion was calculated to be from 0.5 to 1 mg per day. When a cow's milk diet supplemented by partially or completely iron-saturated human or bovine lactotransferrin was fed to the babies, the amounts of copro-lactotransferrin excreted depended on the origin and on the iron saturation of the lactoransferrin. In particular, the amount of bovine copro-lactotransferrin in the faeces averaged 200 mg per day. The human and bovine copro-lactotransferrins were isolated by ion-exchange chromatography or by affinity chromatography and were still able to bind iron. The fingerprints of native human and bovine lactotransferrins hydrolysed in vitro by infant's gastric or duodenal secretions showed that both proteins were not extensively digested. This demonstrates that these lactotransferrins ingested by babies are not completely destroyed and keep their ability to bind iron, and thus may supplement the bacteriostatic effects of the endogenous lactotransferrin in the intestinal tract.
对母乳喂养婴儿的粪便提取物中的人乳铁蛋白进行了表征。对出生后长达3周的人粪便乳铁蛋白进行定量测定表明，每日排泄量从35毫克降至5毫克。计算得出，与内源性分泌相对应的粪便乳铁蛋白量为每天0.5至1毫克。当给婴儿喂食添加了部分或完全铁饱和的人乳铁蛋白或牛乳铁蛋白的牛奶饮食时，粪便中排泄的粪便乳铁蛋白量取决于乳铁蛋白的来源和铁饱和度。特别是，粪便中的牛粪便乳铁蛋白量平均每天为200毫克。通过离子交换色谱法或亲和色谱法分离出人乳铁蛋白和牛乳铁蛋白，它们仍然能够结合铁。婴儿胃或十二指肠分泌物在体外水解的天然人乳铁蛋白和牛乳铁蛋白的指纹图谱表明，这两种蛋白质均未被广泛消化。这表明婴儿摄入的这些乳铁蛋白不会被完全破坏，并保持其结合铁的能力，因此可能补充肠道内源性乳铁蛋白的抑菌作用。
