Genome editing of probiotic bacteria: present status and future prospects.

Human body is colonized by a complex ecosystem of microbes that play a significant role in determining the fitness of the host. The epigenetic signatures of probiotic microorganisms also define the functional role of microbiota in the intestine and further facilitate exploring their beneficial properties. Development in the areas of molecular biology and genomics has paved way for engineering of microorganisms. The advent of genome editing tools such as CRISPR-Cas, has revolutionized new possibilities for genetic engineering in probiotics for enhanced immune response, antimicrobial properties and applications in biotherapeutics. Here, we discuss the present status of genome editing used in epigenome engineering of the gut microbiota and role of different types of CRISPR-Cas systems. Applications of CRISPR-Cas system can be harnessed to modify probiotic microbes in order to regulate gene expressions and produce desired metabolite. These techniques illuminate novel approaches to metabolic engineering and draw attention towards poorly characterized biosynthetic pathways. In addition, future prospects of these tools can be applied to investigate the interactions between gut microbiome and the host, hence, contributing to the development of novel therapeutics. [ABSTRACT FROM AUTHOR]