Over the last decade, there has been increasing interest in the use of probiotic microorganisms. However, certain doubts have arisen around probiotics, because of the beneficial effects of these microorganisms are not clear yet, and in many occasions those beneficial effects have not been proven. Therefore, it would be of interest if these probiotic strains were able to acquire new attributes to allow them improve and increase their beneficial characteristics. Genetic engineering can be used for human applications; for instance, the resistance to antibiotics is removed and the probiotic bacteria are modified in its own DNA. This process can be achieved by: (1) the use of food-grade vectors derived from lactic acid bacteria and/or bifidobacteria cryptic plasmids, (2) the genes integration or deletion in the chromosome of the probiotic strain, by site-specific recombination using the attP/integrase system, or by homologous recombination, using either suicide vectors, (3) using the clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated (Cas) nuclease. Through genetic engineering, the knowledge of probiotic strains as well as its use could be improved, and the doubts about probiotics could be crumped.

在过去的十年中，人们对益生菌微生物的使用越来越感兴趣。然而，由于这些微生物的有益作用尚不明确，因此在益生菌周围也产生了一些疑问，而且在许多情况下，这些有益作用尚未得到证实。因此，如果这些益生菌菌株能够获得新的特性以允许它们改善和增加其有益特性，那将是令人感兴趣的。基因工程可用于人类。例如，消除了对抗生素的抗性，并在其自身的DNA中修饰了益生菌。该过程可以通过以下方式实现：（1）使用源自乳酸菌和/或双歧杆菌隐性质粒的食品级载体，（2）益生菌菌株染色体中的基因整合或缺失，通过使用attP /整合酶系统进行位点特异性重组，或通过使用自杀载体进行同源重组，（3）使用聚簇的规则间隔的短回文重复序列（CRISPR）和CRISPR相关的（Cas）核酸酶。通过基因工程，可以提高益生菌菌株的知识及其用途，并且可以消除对益生菌的疑问。