Microbial Therapeutics in Cancer: Translating Probiotics, Prebiotics, Synbiotics, and Postbiotics From Mechanistic Insights to Clinical Applications: A Topical Review

The gut microbiome plays a pivotal role in cancer development, progression, and treatment response, driving interest in microbiome-based interventions. This review examines probiotics, prebiotics, synbiotics, and postbiotics (PPSPs) as precision tools in oncology, highlighting their mechanisms, clinical applications, and challenges. Gut microbiota influence cancer through immune modulation, metabolic regulation, and inflammatory control, while also shaping chemotherapy pharmacokinetics and immunotherapy efficacy. PPSPs demonstrate antitumor effects via: (1) immune activation, (2) intestinal barrier reinforcement, (3) pathogen suppression, and (4) carcinogen neutralization. Clinically, probiotics/postbiotics reduce chemotherapy-induced mucositis and enhance checkpoint inhibitor responses, while synbiotics/prebiotics selectively nourish beneficial microbes. Despite promise, hurdles like strain-specific variability, dosing optimization, and individual microbiome differences hinder translation. By integrating preclinical and clinical data, this review underscores PPSPs' potential to bridge gut ecology with antitumor immunity, advancing precision oncology. Future priorities include large-scale trials, standardized protocols, and mechanistic insights into host-microbiome-cancer crosstalk. Personalized microbiota therapies, engineered consortia, and combination regimens represent promising frontiers. With robust evidence, PPSPs may emerge as essential adjuvants, improving outcomes while minimizing toxicity in cancer care.