Abstract / Summary
Cancer immunotherapy has achieved remarkable clinical success; however, therapeutic resistance remains a major challenge. Increasing evidence suggests that gut microbiota-derived metabolites play a critical role in modulating host immune responses and influencing treatment outcomes. This study aimed to systematically characterize the global research landscape and identify emerging trends in this field using bibliometric approaches. Publications were retrieved from the Web of Science Core Collection (WoSCC) and Scopus databases based on predefined search strategies. Only English-language articles and reviews were included. Bibliographic records were integrated and deduplicated using the bibliometrix R package. Descriptive analyses were performed to evaluate publication outputs, countries, institutions, authors, and journals. CiteSpace was used for reference burst detection, and VOSviewer was applied to construct keyword co-occurrence networks. A total of 2,979 publications from 1973 to March 2026 were included, comprising 1,593 reviews and 1,386 original articles. China contributed the largest number of publications (1,121; 37.63%), followed by the United States (499; 16.75%). Notably, the United States exhibited the highest H-index and centrality, indicating its leading role in global research impact and collaboration networks. Sichuan University was the most productive institution (115 publications), with six of the top ten institutions located in China. Laurence Zitvogel (28 publications) and Guido Kroemer (22 publications) were the leading authors in this field. Frontiers in Immunology published the highest number of relevant articles (277). Keyword and temporal analyses indicated a shift from descriptive microbiome profiling toward mechanism-oriented and translational research. Recent hotspots include "immunomodulation", "the gut-liver axis", "intratumoral microbiota", and "microbial metabolites". Microbial metabolites have emerged as key functional mediators shaping responses to cancer immunotherapy, reflecting a shift from microbiome composition toward metabolite-centered mechanisms. This field is undergoing a transition from descriptive profiling to mechanism-oriented and translational research. These findings provide important insights for developing microbiota-targeted strategies to enhance the efficacy of cancer immunotherapy.