乳糖

全解奶粉是对奶粉中的蛋白质进行水解，相当于替代了人体的消化系统的一部分工作，可以避免和减少宝宝出现过敏和不耐受的情况，无乳糖奶粉则是去除了奶粉中的乳糖（乳糖是奶粉中的主要碳水化合物），适合有乳糖不耐受的宝宝。

Senescence-associated beta-galactosidase (SA-β-gal or SABG) is a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides only in senescent cells.Its existence was proposed in 1995 by Dimri et al.following the observation that when beta-galactosidase assays were carried out at pH 6.0, only cells in senescence state develop staining. They proposed a cytochemical assay based on production of a blue-dyed precipitate that results from the cleavage of the chromogenic substrate X-Gal. Since then, even more specific quantitative assays were developed for its detection at pH 6.0.Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidasespecifically in senescent cells. Its expression is not required for senescence. However, it remains as the most widely used biomarker for senescent and aging cells, because it is easy to detect and reliable both in situ and in vitro.More in http://en.wikipedia.org/wiki/Senescence-associated_beta-galactosidaseb-半乳糖苷酶会在衰老的细胞中活化，它是在溶酶体内的水解酶，ph4的时候才有活性，但在衰老细胞中一样可以活化，而且不断积累细胞衰老的两个表型就是 b-半乳糖苷酶积累 和 细胞生长停滞，分裂停止。

Senescence-associated beta-galactosidase (SA-β-gal or SABG) is a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides only in senescent cells.Its existence was proposed in 1995 by Dimri et al. following the observation that when beta-galactosidase assays were carried out at pH 6.0, only cells in senescence state develop staining. They proposed a cytochemical assay based on production of a blue-dyed precipitate that results from the cleavage of the chromogenic substrate X-Gal. Since then, even more specific quantitative assays were developed for its detection at pH 6.0.Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidasespecifically in senescent cells. Its expression is not required for senescence. However, it remains as the most widely used biomarker for senescent and aging cells, because it is easy to detect and reliable both in situ and in vitro.http://en.wikipedia.org/wiki/Senescence-associated_beta-galactosidase书上写的是b-半乳糖苷酶会在衰老的细胞中活化，它是在溶酶体内的水解酶，ph4的时候才有活性，但在衰老细胞中一样可以活化细胞衰老的两个表型就是 b-半乳糖苷酶积累 和 细胞生长停滞，分裂停止。

乳糖是一种从哺乳动物乳汁中所提取出来的一种糖类属于双糖，是一种大分子的糖类，是由一分子的半乳糖和一分子的葡萄糖经过缩合后而得。

乳糖酶一般都是针对乳糖不耐受患者的，也是当前非常实用的用来缓解婴幼儿、儿童或者成人食用母乳、奶粉、牛奶后出现腹泻腹胀情况的一类产品，但是乳糖酶的作用受许多因素影响，如乳糖的剂量、酶的含量、酶在消化道能维持的活性时间、食物对胃肠蠕动的刺激、胃内pH值、胆汁酸盐浓度等均影响乳糖酶的效果，而且成本较高，国内专业做乳糖酶的很少很少。。另外像益生菌，双歧杆菌、乳酸杆菌、链球菌，以及其他如肠球菌、拟杆菌中的某些菌株，也可以促进肠道微生物平衡，改善乳糖不耐受。。