Antibiotics are life-saving drugs, but they can also harm the beneficial microbes that live in the human gut, and this can put some patients at risk of developing inflammation or opportunistic infections such as Clostridiodes difficile. As a potential strategy for reducing those risks, MIT engineers have developed a way to help protect the natural flora of the human digestive tract. The scientists took a strain of Lactococcus lactis bacteria that is safe for human consumption, and engineered it to produce an enzyme that breaks down a class of commonly used antibiotics called β-lactams..