Researchers have engineered bacteria that specifically targets colorectal cancer cells and converts a substance in some vegetables into an anticancer agent. The system reduced the number of tumors by 75 percent and shrank the remaining tumors by threefold in a mouse model of colorectal cancer. Published in Nature Biomedical Engineering, the study suggests that the probiotics taken together with a diet rich in cruciferous vegetables could help prevent colorectal cancer and its recurrence.