摘要目的：探讨母乳及配方乳中糖巨肽对体外婴儿双歧杆菌增殖活性的影响以及量效关系。方法成熟乳取自2014年9月广州市妇女儿童医疗中心就诊的广州地区身体健康、无特殊饮食习惯、生活安定、奶量充足的30例产妇，从母乳中分离出酪蛋白，通过凝乳酶水解酪蛋白分离糖巨肽，再使用超滤和离子交换色谱法纯化人乳糖巨肽。将牛乳糖巨肽及人乳糖巨肽按一定浓度（0、250、500、1000、1500、2000和3000 mg/L）添加至婴儿双歧杆菌液体培养基，进行厌氧培养，通过比浊法（检测培养基OD600 nm值）确定婴儿双歧杆菌浓度，比较人乳和牛乳糖巨肽促进婴儿双歧杆菌增殖活性的差异。采用两独立样本t检验进行统计学分析。结果人乳纯化的糖巨肽浓度为1712.20 mg/L，纯度为80.3%。培养基中牛乳糖巨肽浓度在250~2000 mg/L的范围内增加其初始浓度，可以提高双歧杆菌的菌体浓度和增殖速率。培养36 h时，不同糖巨肽浓度下，双歧杆菌的生长均处于对数生长期，因此选取36 h作为双歧杆菌浓度的观察时间点。当培养36 h，培养基中糖巨肽浓度分别为1000、1500、2000和3000 mg/L时，人乳糖巨肽培养基中双歧杆菌浓度分别为2.255±0.036、2.583±0.088、2.877±0.080和3.219±0.081，均高于牛乳糖巨肽培养基中的浓度（分别为2.115±0.053、2.312±0.064、2.542±0.090和2.894±0.076），差异均有统计学意义（t值分别为4.867、5.569、6.192和6.516，P值均＜0.01）。结论牛乳糖巨肽及人乳糖巨肽在体外均具有促进婴儿双歧杆菌增殖的活性。在相同浓度时，人乳糖巨肽促双歧杆菌增殖活性高于牛乳糖巨肽。

abstractsObjectiveTo explore the effects of glycomacropeptide (GMP) in human milk and formula milk on proliferation ofbifidobacterium infantis and their dose-response relationship.Methods Casein was isolated from the milk of 30 healthy postpartum women from Guangzhou Women and Children's Medical Center in September 2014, and hydrolyzed by rennet to obtain GMP, which was then purified by ultrafiltration and ion exchange chromatography. Human milk GMP and cow milk GMP (0, 250, 500, 1 000, 1 500, 2 000 and 3 000 mg/L) were added tobifidobacterium infantis liquid medium, and cultured under anaerobic conditions. Concentration of bacteria was measured by turbidimetric microplate assay (detection of OD600 nmvalue of medium). Difference of proliferative activities ofbiifdobacterium infantis in human milk GMP and cow milk GMP was compared with independent samplest-test.ResultsPurified human milk GMP concentration was 1 712.20 mg/L, with a purity of 80.3%. Increasing the cow milk GMP initial concentration in&nbsp;the culture medium at 250-2 000 mg/L could increase the concentration and proliferation rate ofbiifdobacteria infantis. When cultured at 36 h with GMP of various concentrations, the proliferation ofbiifdobacteria infantis maintained at a logarithmic phase. Therefore, 36 h was chosen as the test time point to compare the proliferation ofbifidobacterium infantis. At 36 h, when GMP in the medium was 1 000, 1 500, 2 000 and 3 000 mg/L, concentrations ofbiifdobacteria infantis in human milk GMP were 2.255±0.036, 2.583±0.088, 2.877±0.080 and 3.219±0.081, respectively, which were significantly higher than those in cow milk GMP (2.115±0.053, 2.312±0.064, 2.542±0.090 and 2.894±0.076;t=4.867, 5.569, 6.192 and 6.516; allP<0.01).Conclusions Both human milk GMP and cow milk GMP can promote the proliferation ofbiifdobacterium infantisin vitro, and the proliferative activity in human milk is greater than in cow milk at the same concentration of GMP.