Host Microbe Interactomics Group, Wageningen University and Research, De Elst 1, 6708 WD, Wageningen, The Netherlands.
Laboratory of Food Chemistry, Wageningen University and Research, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands.
Sci Rep. 2020 Dec 10;10(1):21657. doi: 10.1038/s41598-020-78721-4.
Several Lactobacillus plantarum strains are marketed as probiotics for their potential health benefits. Prebiotics, e.g., galacto-oligosaccharides (GOS), have the potential to selectively stimulate the growth of L. plantarum probiotic strains based on their phenotypic diversity in carbohydrate utilization, and thereby enhance their health promoting effects in the host in a strain-specific manner. Previously, we have shown that GOS variably promotes the strain-specific growth of L. plantarum. In this study we investigated this variation by molecular analysis of GOS utilization by L. plantarum. HPAEC-PAD analysis revealed two distinct GOS utilization phenotypes in L. plantarum. Linking these phenotypes to the strain-specific genotypes led to the identification of a lac operon encoding a β-galactosidase (lacA), a permease (lacS), and a divergently oriented regulator (lacR), that are predicted to be involved in the utilization of higher degree of polymerization (DP) constituents present in GOS (specifically DP of 3-4). Mutation of lacA and lacS in L. plantarum NC8 resulted in reduced growth on GOS, and HPAEC analysis confirmed the role of these genes in the import and utilization of higher-DP GOS constituents. Overall, the results enable the design of highly-selective synbiotic combinations of L. plantarum strain-specific probiotics and specific GOS-prebiotic fractions.
几种植物乳杆菌菌株因其潜在的健康益处而被作为益生菌出售。益生元，例如半乳糖低聚糖（GOS），具有根据其碳水化合物利用表型多样性选择性刺激植物乳杆菌益生菌菌株生长的潜力，从而以菌株特异性方式增强其在宿主中的促进健康作用。以前，我们已经表明 GOS 可变化地促进植物乳杆菌的菌株特异性生长。在这项研究中，我们通过植物乳杆菌对 GOS 利用的分子分析研究了这种变化。HPAEC-PAD 分析显示植物乳杆菌中有两种不同的 GOS 利用表型。将这些表型与菌株特异性基因型联系起来，导致鉴定出一个编码β-半乳糖苷酶（lacA）、透酶（lacS）和一个反向调节因子（lacR）的 lac 操纵子，该操纵子预测参与利用 GOS 中存在的更高聚合度（DP）成分（特别是 DP 为 3-4）。植物乳杆菌 NC8 中 lacA 和 lacS 的突变导致在 GOS 上的生长减少，并且 HPAEC 分析证实了这些基因在导入和利用更高 DP GOS 成分中的作用。总的来说，这些结果使得能够设计高度选择性的植物乳杆菌菌株特异性益生菌和特定 GOS 益生元部分的共生组合。
