Engineered Bacteria for Visualization and Localization of Gastrointestinal Bleeding: A Promising Application

Area of Science:

• Synthetic biology
• Microbiology
• Gastroenterology

Background:

• Gastrointestinal bleeding, particularly obscure gastrointestinal bleeding (OGIB), presents diagnostic challenges due to limitations of current methods like gastroscopy.
• Gastroscopy is invasive and often fails to detect subtle microhemorrhagic lesions, leading to potential misdiagnosis.

Purpose of the Study:

• To develop a novel, noninvasive diagnostic tool for in vivo localization of gastrointestinal bleeding.
• To engineer a bacterium capable of specifically detecting and signaling gastrointestinal bleeding sites.

Main Methods:

• Utilized synthetic biology techniques to engineer *E. coli* Nissle 1917.
• Constructed three gene circuit modules for heme recognition, response, and optical signal output.
• Achieved in vivo heme sensing and real-time optical signal generation.

Main Results:

• Successfully engineered bacteria specifically sense heme, a marker for gastrointestinal bleeding.
• Demonstrated in vivo localization and real-time optical signal production at bleeding sites.
• Overcame limitations of traditional diagnostic methods for obscure gastrointestinal bleeding.

Conclusions:

• The engineered bacterium offers a noninvasive and precise method for detecting gastrointestinal bleeding.
• This synthetic biology strategy enhances diagnostic accuracy and holds potential for improved gastroenterology clinical practice.
• Advancements promise to improve treatment efficacy for patients with gastrointestinal bleeding.