背景:益生菌菌株对宿主健康的影响是众所周知的。关于细菌与宿主相互作用的现有研究主要集中在细菌在宿主中诱导的变化上。确定细菌细胞中发生的变化的研究很少。在这篇论文中,我们确定了所选择的青春期双歧杆菌和长双歧杆菌ssp会发生什么。在具有肠上皮层的实验环境中长。为此,我们测试了细菌细胞的生存能力,氧化还原活性,不同环境下的膜电位和酶活性,包括CaCo-2/HT-29共培养,细胞培养基,炎症感应器(TNF-α)和氧气的存在。
结果:我们指出外部环境影响细菌的活力和活力。青春期双歧杆菌减少了含有和不含TNF-α的细胞培养基中活群的大小(分别为p<0.001和p<0.01)。相比之下,长双歧杆菌。longum与真核细胞和细胞培养基接触后显着增加了生存能力(p<0.001)。青春期双歧杆菌显示膜电位显著变化,在真核细胞存在下下降(p<0.01),真核细胞处于炎症状态(p<0.01),细胞培养基(p<0.01)和含TNF-α的细胞培养基(p<0.05)。相比之下,长双歧杆菌。longum不调节膜电位。相反,细菌显着降低氧化还原活性,以响应环境,如真核细胞的存在,发炎的真核细胞以及培养基(p<0.001)。细胞培养基中的氧化还原活性与真核细胞的存在显著不同(p<0.001)。所选菌株产生β-半乳糖苷酶的能力不同:长双歧杆菌ssp。longum显示91.5%的阳性细胞,而青少年双歧杆菌仅占4.34%。两种菌株均显着降低了与真核环境接触的酶产量,但在细胞培养基中却没有。
结论:环境诱导的变化可能会影响细菌菌株的益生菌特性。似乎了解细菌对外部环境的敏感性可能有助于选择最有前途的益生菌菌株,降低研究成本,并有助于获得的益生菌效应的更大再现性。
BACKGROUND: The impact of probiotic strains on host health is widely known. The available studies on the interaction between bacteria and the host are focused on the changes induced by bacteria in the host mainly. The studies determining the changes that occurred in the bacteria cells are in the minority. Within this paper, we determined what happens to the selected Bifidobacterium adolescentis and Bifidobacterium longum ssp. longum in an experimental environment with the intestinal epithelial layer. For this purpose, we tested the bacteria cells\' viability, redox activity, membrane potential and enzymatic activity in different environments, including CaCo-2/HT-29 co-culture, cell culture medium, presence of inflammatory inductor (TNF-α) and oxygen.
RESULTS: We indicated that the external milieu impacts the viability and vitality of bacteria. Bifidobacterium adolescentis decrease the size of the live population in the cell culture medium with and without TNF-α (p < 0.001 and p < 0.01 respectively). In contrast, Bifidobacterium longum ssp. longum significantly increased survivability in contact with the eukaryotic cells and cell culture medium (p < 0.001). Bifidobacterium adolescentis showed significant changes in membrane potential, which was decreased in the presence of eukaryotic cells (p < 0.01), eukaryotic cells in an inflammatory state (p < 0.01), cell culture medium (p < 0.01) and cell culture medium with TNF-α (p < 0.05). In contrast, Bifidobacterium longum ssp. longum did not modulate membrane potential. Instead, bacteria significantly decreased the redox activity in response to milieus such as eukaryotic cells presence, inflamed eukaryotic cells as well as the culture medium (p < 0.001). The redox activity was significantly different in the cells culture medium vs the presence of eukaryotic cells (p < 0.001). The ability to β-galactosidase production was different for selected strains: Bifidobacterium longum ssp. longum indicated 91.5% of positive cells, whereas Bifidobacterium adolescentis 4.34% only. Both strains significantly reduced the enzyme production in contact with the eukaryotic milieu but not in the cell culture media.
CONCLUSIONS: The environmental-induced changes may shape the probiotic properties of bacterial strains. It seems that the knowledge of the sensitivity of bacteria to the external environment may help to select the most promising probiotic strains, reduce research costs, and contribute to greater reproducibility of the obtained probiotic effects.