Researchers at MD Anderson reported that tumor-infiltrating Fusobacterium nucleatum can induce a reversible quiescent state in cancer epithelial cells, reducing immune detection and driving resistance to chemotherapy in oral and colorectal cancers. The work—published in Cancer Cell and presented in summary materials—shows bacteria accumulate between tumor cells, disrupt epithelial signaling, and correlate with lower expression of immune-related genes in patient cohorts. Preclinical models demonstrated the bacterium’s capacity to create pockets of quiescence that reduce chemotherapy sensitivity and promote metastasis. Susan Bullman, corresponding author, said the findings open a new layer of tumor biology and suggest microbiome-aware therapies could be designed to sensitize resistant tumors. The study points to potential biomarker strategies (spatial microbial profiling) and adjunctive interventions—antibiotics, microbiome modulation, or microbe-targeting agents—to improve outcomes in microbe-enriched tumors.