Targeting Lymphoma: A Multimodal Approach using Radiation, CART-19 Therapy, and Gut Microbiome Modulation - Our previous groundbreaking research, published in 2020 and 2023, unveiled the remarkable synergy achieved by combining oral Vancomycin with radiation therapy (RT) or Chimeric Antigen Receptor T-cell therapy (CART) in enhancing the antitumor response. This innovative approach exploited Vancomycin's unique ability to selectively deplete specific gut microbiota while promoting the cross-presentation of tumor-associated antigens (TAAs) by dendritic cells (DCs) post-therapy. Notably, our preclinical studies demonstrated significant improvements in antitumor effects across multiple mouse models, including metastatic melanoma, lung cancer, and lymphoma. Building upon these groundbreaking findings, we embarked on a pioneering randomized pilot study in stage I NSCLC patients, which yielded compelling results, including extended Progression-Free Survival (PFS) and Overall Survival (OS) when Vancomycin was integrated with RT. Subsequent investigations further illuminated Vancomycin's profound impact on bacterial populations, along with notable alterations in gene expression related to TAA cross-presentation and reductions in short-chain fatty acid (SCFA) concentration in the stool. Our proposed research represents a significant advancement in cancer treatment strategies as we seek to optimize the combination therapy of RT, CART, and gut microbiome modulation for maximal antitumor effects. This novel approach involves a meticulous exploration of optimal RT parameters, including dose, fractionation, and treatment volume, in tandem with CART therapy. Moreover, we aim to unravel the intricate mechanisms underlying Vancomycin-mediated gut microbiome modulation and its role in augmenting the antitumor effects of the combination therapy. To validate the transformative potential of our findings, we are poised to conduct the first controlled clinical trial of antimicrobial/RT/CART combination in lymphoma patients. This landmark trial, comprising two arms—RT alone plus CART and RT plus Vancomycin plus CART—will serve as a pivotal step towards revolutionizing cancer treatment paradigms. The comprehensive evaluation will encompass feasibility, toxicity, CART expansion as primary endpoints, alongside secondary endpoints such as PFS, OS, gut microbiome signature, SCFA levels in the stool, and molecular characterization. In summary, our research endeavors to push the boundaries of cancer therapy by harnessing the synergistic benefits of RT, CART, and gut microbiome modulation. By pioneering this innovative treatment approach, we aim to redefine the landscape of cancer treatment, offering newfound hope to patients and paving the way for transformative advancements in oncology.