Engineered\nBacteria for Visualization and Localization\nof Gastrointestinal Bleeding: A Promising Application

Gastrointestinal bleeding, especially obscure gastrointestinal\nbleeding (OGIB), is a common and serious clinical emergency with a\nnotable incidence rate. However, the current diagnostic method, gastroscopy,\nis invasive and often struggles to efficiently detect microhemorrhagic\nlesions, leading to diagnostic challenges and potential misdiagnoses.\nHere, we developed an intelligently engineered bacterium utilizing\nsynthetic biology techniques for in vivo localization detection of\ngastrointestinal bleeding. By constructing three gene circuit modules\nwithin <i>E. coli</i> Nissle 1917 for heme recognition,\nresponse, and output generation, we have successfully enabled specific\nheme sensing and real-time optical signal production in vivo. This\ninnovative strategy overcomes the limitations of the existing diagnostic\nmethods, offering a noninvasive and precise means of detecting gastrointestinal\nbleeding. These advancements hold promise for enhancing diagnostic\naccuracy and treatment efficacy in future clinical settings within\nthe realm of gastroenterology.