Survival of probiotic lactobacilli in acidic environments is enhanced in the presence of metabolizable sugars
Survival of probiotic lactobacilli in acidic environments is enhanced in the presence of metabolizable sugars
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DOI：
10.1128/aem.71.6.3060-3067.2005
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发表时间：
2005-06-01
影响因子：
4.4
通讯作者：
Ross, RP
中科院分区：
文献类型：
--
作者：
Corcoran, BM;Stanton, C;Ross, RP
鼠李糖乳杆菌GG是一种工业上重要的益生菌菌株，具有公认的健康益处。本实验研究了葡萄糖对L.在pH2.0的模拟胃液中分析鼠李糖乳杆菌GG存活。研究发现，暴露90分钟后，19.4 mM葡萄糖的存在导致高达6-log（10）-增强的存活率。用稀盐酸进一步研究证实，葡萄糖是唯一负责的组分。与其他乳酸杆菌菌株的比较分析表明，增强的生存是明显的，在所有菌株，但在不同的pH值。葡萄糖浓度从1到19.4mM的存在增强了L.在模拟胃液中，鼠李糖乳杆菌GG的存活率为6.4 - 8 log（10）CFU ml（-1）。研究了葡萄糖保护作用背后的机制。向模拟胃液中加入N '，N'-二环己基碳二亚胺导致存活崩溃，这表明在F0F1-ATP酶的抑制中具有显著作用。对新霉素抗性突变体的进一步研究证实了这一点，这些突变体的F0F1-ATP酶活性为亲本的38%至48%，因为与野生型的存活率相比，这些突变体在葡萄糖存在下的存活率降低了3 × 10（6）倍（其存活率为8.02 log（10）CFU ml（-1））。L.鼠李糖乳杆菌GG在酸性条件下的存活仅发生在其可有效代谢的糖存在下。为了证实糖酵解参与葡萄糖效应，使用碘乙酸抑制甘油三酸酯3-磷酸脱氢酶（GAPDH）活性。在葡萄糖存在下，GAPDH活性的降低导致存活率降低8.30 log（10）CFU ml（-1）。数据表明，葡萄糖通过糖酵解向F0F1-ATP酶提供ATP，使质子排斥成为可能，从而提高胃转运期间的存活率。
Lactobacillus rhamnosus GG is an industrially significant probiotic strain with proven health benefits. In this study, the effect of glucose on L. rhamnosus GG survival was analyzed in simulated gastric juice at pH 2.0. It was found that the presence of 19.4 mM glucose resulted in up to 6-log(10)-enhanced survival following 90 min of exposure. Further work with dilute HCl confirmed that glucose was the sole component responsible. Comparative analysis with other Lactobacillus strains revealed that enhanced survival was apparent in all strains, but at different pH values. The presence of glucose at concentrations from I to 19.4 mM enhanced L. rhamnosus GG survival from 6.4 to 8 log(10) CFU ml(-1) in simulated gastric juice. The mechanisms behind the protective effect of glucose were investigated. Addition of N',N'-dicyclohexylcarbodiimide to simulated gastric juice caused survival to collapse, which was indicative of a prominent role in inhibition of F0F1-ATPase. Further work with neomycin-resistant mutants that exhibited 38% to 48% of the F0F1-ATPase activity of the parent confirmed this, as the survival in the presence of glucose of these mutants decreased 3 x 10(6)-fold compared with the survival of the wild type (which had a viability of 8.02 log(10) CFU ml(-1)). L. rhamnosus GG survival in acidic conditions occurred only in the presence of sugars that it could metabolize efficiently. To confirm the involvement of glycolysis in the glucose effect, iodoacetic acid was used to inhibit glyceraldehyde3-phosphate dehydrogenase (GAPDH) activity. The reduction in GAPDH activity caused survival to decrease by 8.30 log(10) CFU ml(-1) in the presence of glucose. The data indicate that glucose provides ATP to F0F1-ATPase via glycolysis, enabling proton exclusion and thereby enhancing survival during gastric transit.