The Korea Research Institute of Bioscience & Biotechnology (KRIBB) said it has developed a smart microbial technology that allows intestinal microbes to detect nitrate produced by the intestinal inflammatory reaction and emit a fluorescent signal.

In detail, the research team, led by Professors Lee Dae-hee, Lee Seung-gu, and Hwang Jung-hwan at the institute, created an artificial genetic circuit based on synthetic biology and introduced it into probiotics to make it possible to diagnose non-invasive inflammatory bowel disease that does not cause pain to the human body.

The researchers expect the technology to develop a new type of diagnosis and treatment using intestinal microbes in the future.

To develop a gene circuit that can detect nitrate, the researchers noted that E. coli used nitrate when breathing in the absence of oxygen and used a signaling system unique to E. coli as a regulator to detect the nitrate.

The team then developed a gene circuit that can visualize and confirm nitrate's presence by fluorescence intensity by inducing a fluorescent protein expression through the detected signal. Afterward, the researchers introduced such a gene circuit into the probiotic E. coli to create a nitrate-sensing smart microorganism to optimize the smart microorganism in an in-vitro environment.

The optimized smart microorganism successfully detected nitrate even in the condition of an anaerobic medium containing mucin similar to the intestinal environment.

The team also obtained the same phenomenon and results when applying this technique to animal experiments.

"Using this research, it is possible to develop a non-invasive inflammatory bowel disease diagnosis technology using smart microorganisms that simultaneously detect nitrate and thiosulfate, which are indicators of inflammation in the intestine, and emit fluorescence," Professor Lee Dae-hee said.

If the fluorescent protein is replaced with a therapeutic agent that can treat inflammation, it is possible to develop a smart microbial technology that can treat inflammation simultaneously, he added.