Microbiome-based Modulation of Immunotherapy Response in Solid Tumors: Predictive Signatures and Therapeutic Interventions

The field of cancer immunotherapy has seen dramatic transformations with the adoption of immune checkpoint inhibitors (ICIs) across a growing range of solid tumors. Despite this progress, only a subset of patients experience durable responses, highlighting the complex interplay of factors underlying therapeutic efficacy. Accumulating evidence implicates the gut microbiome as a potent modulator of systemic immune function, capable of influencing antigen presentation, T cell activation, and tumor microenvironment dynamics. Dysregulation of the gut microbial ecosystem, shaped by antibiotics, dietary habits, comorbid conditions, and antecedent therapies, has been linked to impaired anti-tumor immunity and resistance to ICIs. While mechanistic studies and emerging translational research have identified specific bacterial taxa, metabolites, and pathways associated with improved or diminished treatment outcomes, inconsistencies in findings and confounding variables remain prominent. This reflects differences in geographical cohorts, dietary exposures, analytic pipelines, tumor types, and clinical protocols. Furthermore, translating microbiome insights into reliable, actionable interventions poses practical and regulatory challenges, leaving critical gaps in our understanding and application.This Research Topic aims to advance the field toward robust, clinically relevant applications of microbiome science in solid tumor immunotherapy. The overarching goal is to clarify causal mechanisms and refine predictive signatures that can stratify patients for personalized therapies, enhance response rates, reduce immune-related adverse events, and overcome both primary and acquired resistance. By promoting studies that bridge basic immunology with translational science and clinical endpoints, this collection seeks to accelerate the development and standardization of microbiome-guided interventions, including fecal microbiota transplantation, defined microbial consortia, next-generation probiotics, and metabolite-based therapeutics. Key questions include how best to identify and validate microbiome-dependent biomarkers, optimize therapeutic design, and integrate these approaches within existing treatment regimens across diverse tumor contexts.We welcome articles addressing, but not limited to, the following themes:-Microbiome-based patient stratification: predictive microbial taxa/functions, risk scores, and clinically actionable biomarkers for ICI response and toxicity across solid tumors-Mechanistic immunomodulation: elucidating pathways by which microbes and metabolites influence antigen presentation, T cell priming, myeloid cell regulation, and tumor microenvironment remodeling-Fecal microbiota transplantation (FMT) optimization: donor selection, responder-derived FMT protocols, quality -control, safety, timing, and combination strategies with ICIs-Defined microbial consortia and next-generation probiotics: rational design, engraftment dynamics, -pharmacological profiling, and preclinical or clinical translation-Postbiotics and metabolite therapeutics: identification and delivery of microbiota-derived bioactives and their immune mechanisms-Longitudinal microbiome dynamics and resistance reversal: monitoring during treatment, early warning signatures, and interventions to overcome acquired resistance Topic editors: Marco Soriani, Manuele Biazzo, Konstantinos N. Syrigos, Alok Kumar Source: https://www.frontiersin.org/research-topics/79003/microbiome-based-modulation-of-immunotherapy-response-in-solid-tumors-predictive-signatures-and-therapeutic-interventions