Colorectal cancer is a common type of malignant tumor worldwide, and with a morbidity rising sharply in China. Though early detection and treatment would effectively prevent the development of advanced colorectal cancer, the noncompliance with endoscopic screening, as well as the inability of methods alike to detect cancer at the molecular level keeps many patients from being diagnosed in time.

Therefore, we aim to develop a non-invasive means to molecularly detect and locate the foci of colorectal-associated diseases, including colorectal cancer and colitis (which is a risk factor of cancer), using ultrasound. We plan to engineer bacteria that target colorectal cancer or respond to colitis, while producing gas vesicles to be detected by ultrasound. In this way, we hope to improve the screening method of colorectal cancer or pre-cancerous changes.