Oligosaccharides Released from Milk Glycoproteins Are Selective Growth Substrates for Infant-Associated Bifidobacteria
Oligosaccharides Released from Milk Glycoproteins Are Selective Growth Substrates for Infant-Associated Bifidobacteria
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DOI：
10.1128/aem.00547-16
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发表时间：
2016-06-01
影响因子：
4.4
通讯作者：
Mills, David A.
中科院分区：
文献类型：
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作者：
Karav, Sercan;Le Parc, Annabelle;Mills, David A.
牛奶除了滋养新生儿外，还提供一系列复杂的聚糖，其结构确保了哺乳期婴儿肠道微生物群关键成员的特定富集，该群落被称为以牛奶为导向的微生物组。乳糖蛋白被认为具有类似的功能，作为母乳喂养的婴儿肠道中常见的双歧杆菌的特定生长底物。最近，在各种婴儿传播的双歧杆菌中发现的细胞壁相关内切-β-N-乙酰氨基葡萄糖苷酶 (EndoBI-1) 被证明可以去除一系列完整的 N 连接聚糖。我们假设这些释放的寡糖结构可以作为双歧杆菌选择性生长的唯一来源。我们在中试规模证明了 EndoBI-1 从浓缩牛初乳中释放 N-聚糖。 EndoBI-1 释放的 N-聚糖支持长双歧杆菌亚种的快速生长。婴儿双歧杆菌（B.fantis），一种在人乳寡糖上生长良好的物种，但不支持动物双歧杆菌亚种的生长。乳酸菌（B.lactis），一种不具有这种特性的物种。相反，婴儿双歧杆菌 ATCC 15697 不在去糖基化的乳蛋白部分上生长，这清楚地表明乳糖蛋白的聚糖部分提供了生长的关键底物。基于质谱的分析显示，婴儿双歧杆菌消耗了 73% 的中性 N-聚糖和 92% 的唾液酸化 N-聚糖，而乳酸双歧杆菌仅降解了 11% 的中性 N-聚糖，几乎没有降解（
Milk, in addition to nourishing the neonate, provides a range of complex glycans whose construction ensures a specific enrichment of key members of the gut microbiota in the nursing infant, a consortium known as the milk-oriented microbiome. Milk glycoproteins are thought to function similarly, as specific growth substrates for bifidobacteria common to the breast-fed infant gut. Recently, a cell wall-associated endo-beta-N-acetylglucosaminidase (EndoBI-1) found in various infant-borne bifidobacteria was shown to remove a range of intact N-linked glycans. We hypothesized that these released oligosaccharide structures can serve as a sole source for the selective growth of bifidobacteria. We demonstrated that EndoBI-1 released N-glycans from concentrated bovine colostrum at the pilot scale. EndoBI-1-released N-glycans supported the rapid growth of Bifidobacterium longum subsp. infantis (B. infantis), a species that grows well on human milk oligosaccharides, but did not support growth of Bifidobacterium animalis subsp. lactis (B. lactis), a species which does not. Conversely, B. infantis ATCC 15697 did not grow on the deglycosylated milk protein fraction, clearly demonstrating that the glycan portion of milk glycoproteins provided the key substrate for growth. Mass spectrometry-based profiling revealed that B. infantis consumed 73% of neutral and 92% of sialylated N-glycans, while B. lactis degraded only 11% of neutral and virtually no (