Antibiotics alter gut bacteria to boost chemotherapy delivery, MD Anderson study finds

Researchers improved nanoparticle chemotherapy delivery to tumors by altering gut bacteria with a short antibiotic course, boosting treatment efficacy in several cancers, a new study reports. Scientists at MD Anderson Cancer Center used metronidazole to deplete specific gut bacteria, lowering bile acids and slowing liver Kupffer cells that normally clear drug nanoparticles. This allowed more chemotherapy to accumulate in tumors, prolonging survival in colon, breast, pancreatic cancer and melanoma models. Fecal transplants confirmed the effect stemmed from microbes, not antibiotic residue. Published in Nature Materials, the study is the first to show gut microbiota directly impacts chemotherapy, opening new microbiome-targeting strategies.