Engineered Probiotics: A New Frontier for Gastrointestinal Cancer Treatment

**Researchers at Washington University School of Medicine have developed an innovative method to treat gastrointestinal cancers using a probiotic engineered to deliver immunotherapy directly to the gut.** Gastrointestinal cancers, such as stomach, liver, and colorectal cancers, are particularly challenging due to their location, which complicates treatment and diagnosis, often resulting in high mortality rates. Existing immunotherapy treatments are delivered intravenously and struggle to effectively reach tumor sites. This research utilizes a yeast strain, _Saccharomyces cerevisiae var. boulardii_, a safe and common probiotic, engineered to produce immune checkpoint inhibitors—drugs that help the immune system recognize and fight cancer cells. In experiments with mice, those receiving the probiotic showed fewer tumors than those given the immunotherapy drug systemically. This probiotic not only serves as a potential oral cancer treatment but also has applications for other gut diseases, such as Clostridioides difficile, by directly targeting disease-causing agents without affecting beneficial gut microbes. The researchers have filed patents for this novel approach, highlighting its promise in cancer treatment and beyond.