Abstract
The microbiome is increasingly recognized as a key player in cancer pathogenesis and treatment response, acting through both local and systemic mechanisms. Microbial communities and their metabolites can directly influence drug metabolism, shape the immune landscape, and alter transcriptional and epigenetic programmes in the gut, systemically and in the tumour microenvironment. Emerging data support the potential of microbiome-targeted interventions (such as faecal microbiota transplantation, diet, prebiotics and probiotics) as adjuncts to conventional cancer therapies, with the goal of enhancing efficacy and reducing toxicity. This Review highlights the promise of the microbiome as a prognostic and predictive biomarker, a modifiable factor in cancer care and prevention, and a therapeutic target. We also discuss major knowledge gaps, limitations in current study designs, and the need for mechanism-guided, personalized strategies to advance clinical translation.
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The authors thank L. Busby (Mayo Clinic, Rochester, MN, USA) for the administrative assistance.
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P.C.K. is a member of the scientific advisory board of the International Observatory of Biocodex Microbiota Institute, chair of the scientific advisory board of the American Gastroenterology Association Center for Gut Microbiome Education and Research, ad hoc advisory board member for Pendulum and Intrinsic Medicine, and advisory board member for 32 Biosciences for which he receives equity option as compensation. R.A.T.M. serves as a founding adviser of Tiny Health. R.H. declares no competing interests.
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Hajjar, R., Mars, R.A.T. & Kashyap, P.C. Harnessing the microbiome for cancer therapy. Nat Rev Microbiol (2026). https://doi.org/10.1038/s41579-025-01268-6
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DOI: https://doi.org/10.1038/s41579-025-01268-6
