Intestinal bacteria interact closely with human health and diseases. With the development of high-throughput sequencing technologies, researchers have discovered the potential of intestinal bacteria in the diagnosis and treatment of diseases. Meanwhile, synthetic biology strategies are applied to engineer these bacteria for clinical applications. These engineered intestinal microbial are constructed by designing editing tools and feedback loops to gain functions of diagnose or targeted therapy. Consequently, these engineered bacteria are capable of sensing, calculating and responding to the environment. In this review, we summarize the recent advances in engineered intestinal bacteria in disease diagnosis and treatment. Furthermore, we also discuss the current status and future prospect of the engineered intestinal bacteria regarding their clinical applications, market, and safety issues.
Bacteria ; High-Throughput Nucleotide Sequencing ; Humans ; Synthetic Biology

A new wave of research has been inspired by the CRISPR-Cas system with respect to their application in genome editing. The CRISPR-Cas system can not only be applied in gene knockout and insertion, but also be used in base editing, transcriptional regulation and recombination of gene clusters. However, the low efficiency of homology-directed repair (HDR) limits its application. Unlike the CRISPR-Cas system, mobile genetic elements (MGE) can insert DNA fragments into cell chromosomes without the aid of HDR. Recently, it is reported that CRISPR-related transposable elements can guide targeted DNA insertion. Their transposition mechanisms and reprogramming abilities have brought novel opportunities to the development of this field. This review summarized the research progress and application development of natural CRISPR-related transposable elements in recent years, as well as the applications of fused dCas9-transposase. It proposed the application prospects and potential challenges of CRISPR-related transposable elements in the future, which provided a reference for the development direction of gene editing tools.
DNA Transposable Elements/genetics* ; Gene Editing ; CRISPR-Cas Systems/genetics*