Effects of Lactococcus lactis on composition of intestinal microbiota:: Role of nisin
Effects of Lactococcus lactis on composition of intestinal microbiota:: Role of nisin
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DOI：
10.1128/aem.72.1.239-244.2006
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发表时间：
2006-01-01
影响因子：
4.4
通讯作者：
Norrung, B
中科院分区：
文献类型：
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作者：
Bernbom, N;Licht, TR;Norrung, B
本研究考察了（i）纯乳链菌肽、（ii）产乳链菌肽的乳酸乳球菌菌株CHCC 5826和（iii）不产乳链菌肽的乳酸乳球菌菌株的能力。乳酸菌菌株CHCH 2862影响人类菌群相关大鼠肠道微生物群的组成。乳酸链球菌素产生菌和非产生菌的存在。乳酸菌菌株显著增加了前8天粪便样品中双歧杆菌细胞的数量，但减少了十二指肠、回肠、盲肠和结肠样品中肠球菌/链球菌的数量，如通过选择性培养所检测的。在用乳链菌肽给药后未观察到大鼠粪便微生物群的显著变化。对粪便微生物群中存在的16 S rRNA基因的变性梯度凝胶电泳图谱进行皮尔逊聚类分析，结果显示，给予两种L.乳酸菌菌株不同于用盐水给药的对照动物。然而，来自给予乳链菌肽的动物的微生物群的概况与对照没有差异。通过竞争性酶联免疫吸附测定（ELISA）估计的乳酸链球菌素浓度比通过生物测定估计的相应浓度高出约10倍，在粪便中高出约200倍。这表明乳链菌肽在胃肠道中降解或失活，因为通过ELISA检测到该细菌素的片段，而需要完整的分子来保持生物活性。
This study examined the ability of (i) pure nisin, (ii) nisin-producing Lactococcus lactis strain CHCC5826, and (iii) the non-nisin-producing L. lactis strain CHCH2862 to affect the composition of the intestinal microbiota of human flora-associated rats. The presence of both the nisin-producing and the non-nisin-producing L. lactis strains significantly increased the number of Bifidobacterium cells in fecal samples during the first 8 days but decreased the number of enterococci/streptococci in duodenum, ileum, cecum, and colon samples as detected by selective cultivation. No significant changes in the rat fecal microbiota were observed after dosage with nisin. Pearson cluster analysis of denaturing gradient gel electrophoresis profiles of the 16S rRNA genes present in the fecal microbial population revealed that the microbiota of animals dosed with either of the two L. lactis strains were different from that of control animals dosed with saline. However, profiles of the microbiota from animals dosed with nisin did not differ from the controls. The concentrations of nisin estimated by competitive enzyme-linked immunosorbent assay (ELISA) were approximately 10-fold higher in the small intestine and 200-fold higher in feces than the corresponding concentrations estimated by a biological assay. This indicates that nisin was degraded or inactivated in the gastrointestinal tract, since fragments of this bacteriocin are detected by ELISA while an intact molecule is needed to retain biological activity.