The gut microbiome is increasingly recognized as an active driver of tumor initiation, progression, and treatment response, according to a series of review articles published in a special issue of Cancer Biology & Medicine. The collection, guest-edited by Professor Jun Yu from The Chinese University of Hong Kong, underscores the shift from viewing microbes as passive bystanders to integral components of the tumor ecosystem, with implications for cancer prevention, diagnosis, and therapy.
Cancer remains difficult to treat partly because tumors co-opt their surrounding environment, including resident microbiota, to evade immune surveillance. The special issue, published in May 2026, features seven reviews covering hepatocellular carcinoma, colorectal cancer, gastric cancer, and pancreatic ductal adenocarcinoma. The articles explore mechanistic roles of gut and tumor-resident bacteria, the potential of probiotics as adjuvant therapies, and the emerging field of immunogenic cell death modulation by microbial metabolites.
One review examines how gut dysbiosis—loss of beneficial bacteria like Lactobacillus and Akkermansia and overgrowth of pathogens like Klebsiella pneumoniae—drives hepatocarcinogenesis through microbial translocation and chronic inflammation. Another outlines a multi-omics framework for decoding host-microbe interactions in colorectal cancer, integrating metagenomics, transcriptomics, and metabolomics to identify actionable targets. A third article highlights probiotics' capacity to restore gut barrier function and modulate immune responses as adjuncts to conventional therapy.
Perhaps most transformative, a review on tumor-resident bacteria reveals how these overlooked inhabitants can serve as diagnostic and prognostic biomarkers while influencing therapeutic outcomes. Additional contributions cover animal models for gastric cancer, the microbiome's role in pancreatic cancer, and a mechanistic framework linking microbial metabolites to immunogenic cell death, which could help convert 'cold' tumors into 'hot' ones responsive to checkpoint inhibitors.
“This collection shows that the next phase of cancer research isn't about choosing between genetics, immunology, or microbiology—it's about understanding how these systems interconnect and learning to modulate them in concert,” the authors noted. They emphasized that interventions—whether fecal microbiota transplantation, engineered bacteria, or metabolite-based drugs—must be designed with a holistic view of the tumor ecosystem.
These advances point toward an integrated model for personalized cancer care. Microbiome-derived biomarkers could enable early detection of gastric and colorectal cancers through non-invasive stool tests. Probiotic formulations tailored to individual gut profiles might boost immune checkpoint inhibitor efficacy while reducing adverse events. Fecal microbiota transplantation, already explored in melanoma, offers a path to reshape the gut ecosystem for anti-tumor immunity. For bacteria-infected tumors, targeted antimicrobial or nanodrug strategies could combat infection and malignancy simultaneously.
For more details, access the full special issue at Cancer Biology & Medicine online. Key articles include "Gut microbiome: an emerging player and therapeutic target in cancer" (DOI), "How the gut microbiome affects the immunotherapy response in hepatocellular carcinoma" (DOI), and "Microbiota-host interaction in colorectal cancer: emerging computational technology, multi-omics integration, and mechanisms" (DOI).
