Oral vaccine strategy used modified bacterium to combat colorectal cancer
Medical Xpress
February 19, 2026
AI-Generated Deep Dive Summary
A groundbreaking study led by Stony Brook immunologist Brian Sheridan, Ph.D., reveals a novel approach to treating colorectal cancer using a modified version of the bacterium *Listeria monocytogenes* as an oral vaccine. This innovative strategy primes the immune system directly within the gut, where anti-tumor cells are generated to combat cancer progression. The research, published in the *Journal for the ImmunoTherapy of Cancer*, offers promising insights into a potential new treatment for colorectal cancer, one of the most common and deadly cancers worldwide.
The study focuses on repurposing *Listeria monocytogenes*, a bacterium known for its ability to infect and replicate within host cells. By modifying it to be less virulent while retaining its immunogenic properties, the researchers created a safe yet effective platform for delivering cancer antigens directly to the gut. This approach leverages the body’s natural immune response, triggering the production of cytotoxic T lymphocytes (CTLs) and anti-tumor antibodies that target and destroy cancer cells.
The research highlights the importance of targeting the gut microbiome in cancer immunotherapy. Colorectal cancer is particularly challenging to treat due to its resistance to traditional therapies and its ability to evade the immune system. By delivering the vaccine orally, the researchers were able to induce a localized immune response in the intestinal environment, where many colorectal cancers originate. This method not only enhances the body’s ability to detect and fight tumor cells but also avoids the systemic side effects often associated with other forms of cancer treatment.
The findings underscore the potential for bacterial-based vaccines as a versatile tool in the fight against cancer. The oral delivery system is a significant advancement, as it is non-invasive and could be easily incorporated into routine medical care. Furthermore, the use of *Listeria monocytogenes* as a vector offers a unique advantage over traditional vaccine platforms by its ability to stimulate
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Originally published on Medical Xpress on 2/19/2026