Exploring the emerging role of CRISPR-Cas systems in probiotic development.

Modification of the gut microbiota by beneficial microbes can enhance an organism's lifespan, giving rise to the concept of probiotics. Probiotics are live microorganisms that provide health benefits when taken in sufficient amounts. Owing to their outstanding health benefits, probiotics have experienced rapid expansion and gained interest for the development of new applications. The exploration of microbial applications via genetic modification is currently of great interest to researchers. Genetic engineering using the clustered regularly interspaced short palindromic repeat (CRISPR)-Cas system has received considerable attention and has established applications. Owing to these enhanced properties, the CRISPR-Cas system is currently used in medicine, agriculture, food, and biotechnology. Considering the adaptive immune system in bacteria, this genetic tool is used to alter the microbial genome. Lactic acid bacteria (LAB) are widely recognized for their probiotic potential, and over 40% of LAB species contain the CRISPR-Cas system. The rising demand for probiotics and their expanding applications necessitate the enhancement of their existing characteristics. The CRISPR-Cas system, recognized for its precision, accuracy, and speed, has enabled researchers to modify the genomes of probiotics, thereby enhancing their beneficial attributes. This system can enhance probiotic properties through additive, subtractive, or modulatory mechanisms. Various approaches have been developed to improve probiotic functionalities using the CRISPR-Cas system, such as substituting slow promoters with efficient alternatives, eliminating undesirable components, boosting metabolism, and increasing tolerance levels. Furthermore, CRISPR-engineered probiotics have emerged as next-generation probiotics with enhanced properties and advanced applications across diverse fields, including the food, medicine, agriculture, and pharmaceutical sectors.