海藻酸钙微囊对乳酸乳球菌在胃肠道环境中的保护作用

Microcapsulation of Lactococcus lactis with calcium alginate can improve its survival capability in gastrointestinal tract

摘要:

乳酸菌是机体内一类重要的益生菌, 因其益生功能和安全性, 在食品行业和医疗保健领域有着广泛的应用, 此外将乳酸菌作为口服疫苗载体或药物传递载体也是目前的研究热点之一。乳酸菌到达肠道的活菌数是影响其功能有效性的一个重要因素, 需考虑为其提供一定的防护来抵御胃酸等恶劣环境。通过化学法制备能稳定表达Gfp的乳酸乳球菌海藻酸钙微囊, 以Gfp作为活菌标记, 检测了海藻酸钙微囊对乳酸乳球菌的保护作用。体外实验结果显示, 酸处理30、60、90、120 min后, 海藻酸钙微囊包裹使乳酸乳球菌的存活率分别提高了1 370、525、235和105倍。动物体内实验也表明, 在灌胃2 h后, 海藻酸钙微囊包裹使乳酸乳球菌在肠道内的活菌数增加90多倍。上述结果说明海藻酸钙微囊对乳酸乳球菌在胃肠道环境中具有明显的保护作用, 为今后乳酸乳球菌口服制剂的研究及开发提供重要的参考依据。

Abstract:

Lactic acid bacteria is an important probiotics in body. Because of its function and safety benefits, it has been widely used in the food industry and health care. In addition, Lactic acid bacteria, as an oral vaccine carrier and drug delivery carrier, has become a hotspot of research. However, the survival capability of Lactic acid bacteria is limited by the harsh environment of gastrointestinal tract. In this article, we used chemical method to prepare calcium alginate microcapsules of Lactococcus lactis, which can express Gfp stablely. Then we used Gfp as a viable marker to test the protective effect of calcium alginate microcapsules on Lactococcus lactis. In vitro experiments, it is showed that after acid treatment 30 min, 60 min, 90 min, 120 min, the survival rates of calcium alginate microencapsulated Lactococcus lactis were increased by 1 370, 525, 235 and 105 times, respectively. In vivo experiments, after 2 h stomach gavage, the number of alive Lactococcus lactis in calcium alginate microencapsules was increased by about 90 times in the intestine. The results suggested that microcapsulation of Lactococcus lactis with calcium alginate had significant protective effect on Lactococcus lactis in the gastrointestinal tract environment and provided an important frame for Lactococcus lactis in the future research of oral agents.