罗伊氏乳杆菌J1胃肠道耐受性评价及其对免疫相关基因调控的体外研究

以分离自传统发酵乳制品中的罗伊氏乳杆菌(Lactobacillus reuteri,L.reuteri)J1为研究对象,对其黏附性能、生长特性、对胃肠道环境的耐受能力以及该菌株作用于Caco-2细胞不同时间后免疫相关基因表达量的动态变化进行评价。结果显示,罗伊氏乳杆菌J1具有良好的黏附性,黏附率达87.93%,具有定植于肠道中的潜力。该菌株在4 h进入对数期,14 h进入稳定期。在肠道耐受性评价中,菌株在pH为2.0和3.0条件下处理3 h后,其存活率分别为86.77%、97.12%;在胆盐质量浓度分别为0.3、0.5和1.0 g/100 mL的培养基中处理4 h后,其存活率分别为105.00%、82.60%和82.18%;经模拟人工胃液处理3 h后转入人工肠液继续培养8 h,存活率达82.71%;该菌株在7 g/100 mL的盐溶液中处理24 h后,其存活率为80.36%。此外,10⁸CFU/mL的罗伊氏乳杆菌J1可刺激Caco-2细胞中免疫相关因子IL-1β的表达,抑制促炎因子IL-6和趋化因子IL-8的表达。综上表明,罗伊氏乳杆菌J1具有定植于肠道上皮细胞的潜力,耐受胃肠道环境,并发挥一定的免疫调节作用。

Evaluation of Gastrointestinal Tolerance and Regulation of Immune-related Genes of Lactobacillus reuteri J1 in Vitro

Lactobacillus reuteri J1,a probiotic strain isolated from traditional fermented dairy products was used as the research object to investigate on the adhesion property,tolerance in the gastrointestinal environment and its immunomodulatory activity. The results showed that the adhesion rate of L. reuteri J1 was 87.93%. L. reuteri J1 reached the logarithmic phase after 4 h and then reached the stable period after 14 h. In the evaluation of tolerance to gastrointestinal,the survival rates of the strain were 86.77% and 97.12% after treatment in the medium of pH2.0 and pH3.0 for 3 h,respectively. Treated with the bile salt in concentration of 0.3、0.5 and 1.0 g/100 mL for 4 h,the survival rates of the strain were 105.00%,82.60% and 82.18%,respectively. After being cultured with simulated artificial gastric juice for 3 h and then the cells were transferred to artificial intestinal juice for 8 h,the survival rate was 82.71%. In addition,the survival rate was 80.36% after treated with 7 g/100 mL of high-quality salt solution for 24 h. Moreover,108 CFU/mL of L. reuteri J1 could regulate the expression of cytokines interleukin-1β(IL-1β),IL-6 and IL-8. In summary,L. reuteri J1,a probiotic strain with immunomodulatory activity could colonize in the intestinal epithelial cells and tolerate to the environment of gastrointestinal.