Utilization of galactooligosaccharides by Bifidobacterium longum subsp infantis isolates
Utilization of galactooligosaccharides by Bifidobacterium longum subsp infantis isolates
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DOI：
10.1016/j.fm.2012.10.003
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发表时间：
2013-04-01
影响因子：
5.3
通讯作者：
Mills, David A.
中科院分区：
文献类型：
--
作者：
Garrido, Daniel;Ruiz-Moyano, Santiago;Mills, David A.
益生元是一种不可消化的底物，可以刺激肠道中有益微生物种群的生长，特别是双歧杆菌。其中，果寡糖和半乳低聚糖在食品工业中普遍使用，特别是作为婴儿配方奶粉的补充剂。这些益生元丰富双歧杆菌的机理细节对于理解这些饮食干预的效果很重要。本研究研究了22株长双歧杆菌对低聚半乳糖的消耗。婴幼儿是婴幼儿肠道微生物区系中最具代表性的物种之一。总体而言，所有菌株都显示出对这些低聚糖的旺盛生长，但对较大的低聚半乳糖的消耗是不同的。婴儿双歧杆菌ATCC 15697有5个基因编码β-半乳糖苷酶，其中3个基因是在商品低聚半乳糖上细菌生长时诱导的。婴儿芽孢杆菌ATCC 15697的重组β-半乳糖苷酶对4‘和6’-半乳二糖等β-半乳糖苷酶表现出不同的选择性，该菌株的4种β-半乳糖苷酶从低聚半乳糖中释放单糖。最后，我们测定了菌株ATCC 15697在不同益生元上生长后所产生的短链脂肪酸的量。我们观察到，乳糖和低聚半乳糖的生物量和产物产量都较高，但在人乳低聚糖上生长后，单位细胞的产酸量较大。这些结果为婴儿半乳低聚糖的消耗提供了分子基础，也为益生元代谢的生理差异提供了证据，这些差异可能对宿主产生不同的影响。(C)2012爱思唯尔有限公司。保留所有权利。
Prebiotics are non-digestible substrates that stimulate the growth of beneficial microbial populations in the intestine, especially Bifidobacterium species. Among them, fructo- and galacto-oligosaccharides are commonly used in the food industry, especially as a supplement for infant formulas. Mechanistic details on the enrichment of bifidobacteria by these prebiotics are important to understand the effects of these dietary interventions. In this study the consumption of galactooligosaccharides was studied for 22 isolates of Bifidobacterium longum subsp. infantis, one of the most representative species in the infant gut microbiota. In general all isolates showed a vigorous growth on these oligosaccharides, but consumption of larger galactooligosaccharides was variable. Bifidobacterium infantis ATCC 15697 has five genes encoding beta-galactosidases, and three of them were induced during bacterial growth on commercial galactooligosaccharides. Recombinant beta-galactosidases from B. infantis ATCC 15697 displayed different preferences for beta-galactosidases such as 4' and 6'-galactobiose, and four beta-galactosidases in this strain released monosaccharides from galactooligosaccharides. Finally, we determined the amounts of short chain fatty acids produced by strain ATCC 15697 after growth on different prebiotics. We observed that biomass and product yields of substrate were higher for lactose and galactooligosaccharides, but the amount of acids produced per cell was larger after growth on human milk oligosaccharides. These results provide a molecular basis for galactooligosaccharide consumption in B. infantis, and also represent evidence for physiological differences in the metabolism of prebiotics that might have a differential impact on the host. (C) 2012 Elsevier Ltd. All rights reserved.