The bacterium at the center of this experiment is one that people already swallow on purpose. Bifidobacterium longum turns up in infant guts, in supplements, and on the ingredient panel of yogurt drinks. A team at the University of Chicago gave it a gene, and it became something closer to a drug factory that only switches on inside a tumor.
The work, published July 23 in Science Advances, describes a strain the researchers call BifidoSumIL-2. When administered systemically to mice with pancreatic tumors, it colonized the tumors and suppressed their growth, and the effect was stronger when the animals also received chemotherapy, radiotherapy, or anti-PD-L1 immunotherapy.
