Chemotherapy rewires gut bacteria to block metastasis

Chemotherapys gut damage turns out to have a surprising upside. By changing nutrient availability in the intestine, it alters gut bacteria and increases levels of a microbial molecule that travels to the bone marrow. This signal reshapes immune cell production, strengthening anti-cancer defenses and making metastatic sites harder for tumors to colonize. Patient data suggest this immune rewiring is linked to better survival.