母乳成分 - 探索之旅

科学家不断探究发现母乳中的新成分及特性,而且研究之路还很漫长。在 2007 年,研究人员发现了母乳干细胞(Cregan 等人)。不久之后,2009 年,母乳蛋白质组谱图的综合性研究(Molinari 等人)就发现了以前从未确定过的 261 种蛋白质。随后在 2015 年,一篇文章(Alsaweed 等人)描述了 300 多种母乳miRNA 分子,这些成分对调控基因表达至关重要。

重大发现

What makes breast milk so amazing

母乳不仅只是营养来源,母乳中的多功能蛋白质,包括分泌型免疫球蛋白sIgA、乳铁蛋白、溶菌酶以及游离脂肪酸,可作为抗感染成分,助益婴儿健康。

这些抗感染物质共同作用,抑制、杀死或与某些微生物竞争性结合,防止微生物在粘膜表面的粘附。

母体活细胞可通过母乳传递给婴儿,包括血液白细胞、乳腺上皮细胞、干细胞和细胞碎片,可为婴儿提供免疫保护。

母乳还传递大量母乳寡聚糖给婴儿,据报道寡聚糖可作为益生元发挥重要的免疫作用,促进肠道共生菌的生长。寡聚糖还作为诱饵或受体类似物,抑制致病菌 – 包括轮状病毒 – 与肠道表面结合。

母乳中还含有共生菌,其可成为肠道菌群的一部分,发挥炎性反应和免疫调节作用。共生菌不仅抑制病原菌的过度生长,还帮助形成肠道酸性环境、促进乳糖发酵、分解脂质和蛋白质、促进维生素 K 和维生素 H的生成。

在此下载信息图表: “母乳有何独特之处?”

研究摘要
Identification of nestin-positive putative mammary stem cells in human breast milk(英语)

Stem cells in mammary tissue have been well characterised by using the mammary stem cell marker, cytokeratin (CK) 5 and the mature epithelial markers CK14, ...

Cregan MD, Fan Y, Appelbee A, Brown ML, Klopcic B, Koppen J, Mitoulas LR, Piper KM, Choolani MA, Chong YS, Hartmann PE (2007)

Cell Tissue Res 329, 129-136
Proteome mapping of human skim milk proteins in term and preterm milk(英语)

The abundant proteins in human milk have been well characterized and are known to provide nutritional, protective, and developmental advantages to both term and preterm ...

Molinari CE, Casadio YS, Hartmann BT, Livk A, Bringans S, Arthur PG, Hartmann PE (2012)

J Proteome Res 11, 1696-1714
参考文献

Alsaweed,M. et al. Human milk microRNA and total RNA differ depending on milk fractionation. Journal of Cellular Biochemistry doi:10.1002/jcb.25207, (2015)

Newburg,D.S. & Walker,W.A. Protection of the neonate by the innate immune system of developing gut and of human milk. Pediatr Res 61, 2-8 (2007)

Hassiotou,F. et al. Maternal and infant infections stimulate a rapid leukocyte response in breastmilk. Clin Transl Immunology 2, e3 (2013)

Hassiotou,F. et al. Breastmilk is a novel source of stem cells with multilineage differentiation potential. Stem Cells 30, 2164-2174 (2012)

Bode,L. Human milk oligosaccharides: Every baby needs a sugar mama. Glycobiology 22, 1147-1162 (2012)

Garrido,D., Kim,J.H., German,J.B., Raybould,H.E., & Mills,D.A. Oligosaccharide binding proteins from Bifidobacterium longum subsp. Infantis reveal a preference for host glycans. PLoS One 6, e17315 (2011)

Sela,D.A. et al. An infant-associated bacterial commensal utilizes breast milk sialyloligosaccharides. J Biol Chem 286, 11909-11918 (2011)

Wu,S., Grimm,R., German,J.B., & Lebrilla,C.B. Annotation and structural analysis of sialylated human milk oligosaccharides. J Proteome Res 10, 856-868 (2011)