The stability of the gut barrier is very important for keeping the gut healthy and stopping dangerous substances from getting into the bloodstream. Several diseases, including cancer, have been linked to the gut barrier being broken. Live bacteria called probiotics that are good for the host have been shown to have the ability to improve the gut barrier and lower the risk of cancer in the gastrointestinal system. This review looks at how probiotics affect the health of the gut barrier and what that might mean for preventing cancer. Researchers have found that probiotics strengthen the connections between intestine cells, encourage the production of protective mucins, and change the make-up and balance of the gut bacteria. These processes help keep the gut barrier strong and stop harmful chemicals from getting into the bloodstream. Probiotics may help lower the chance of cancer by reducing inflammation throughout the body and protecting the GI tract from harmful substances. But more study is needed to fully understand the benefits of different probiotic strains, the best amounts to take, and how they affect the health of the gut barrier. Understanding how probiotics, the health of the gut barrier, and the risk of cancer all work together can help us come up with new ways to avoid and treat cancer.