Mapping the knowledge landscape: a bibliometric analysis of gut microbiota in cancer immunotherapy with implications...

Although cancer immunotherapy has significantly improved the clinical outcomes of tumors, the heterogeneity of individual responses remains a major challenge. The gut microbiota profoundly influences the efficacy of immune checkpoint inhibitors (ICIs) through mechanisms such as metabolite secretion, immune cell regulation, and tumor microenvironment remodeling. The regulatory roles of specific microbiota features (such as Ruminococcus and Bifidobacterium) and metabolites (such as L-selenomethionine) have been confirmed. With the rapid development of research, the literature in this field has grown explosively, and traditional review methods are difficult to systematically analyze its knowledge structure, hotspots evolution, and interdisciplinary trends.

This study aims to map the knowledge landscape of gut microbiota in cancer immunotherapy using bibliometrics, to identify research trends, key contributors, and emerging hotspots.

Literature published from 1 January 2001, to 7 July 2025 was retrieved from the Web of Science Core Collection (WoSCC). After strict screening, 2,669 publications were included for bibliometric analysis using CiteSpace. Key analytical parameters were set as follows: time slicing =1 year, top N =50 per slice, pathfinder pruning. The analysis encompassed temporal publication trends, collaboration networks (countries/institutions/authors), keyword co-occurrence, clustering, and burst detection.

The research showed a three-stage growth pattern of "germination-development-explosion," peaking at 525 articles in 2024. China (988 articles) and the United States (762 articles) were the high-yield countries; England had the highest centrality (0.30) and was the global cooperation hub. The University of Texas System (149 articles), Institut National de la Sante et de la Recherche Medicale (INSERM) (124 articles), and MD Anderson Cancer Center (123 articles) are high-yield institutions; the University of California System has the highest centrality (0.19). The top 3 authors in terms of publication volume were Zitvogel, Laurence (50 articles), Routy, Bertrand (47 articles), and Wargo, Jennifer A (39 articles). Authors with high centrality (0.03) include Kroemer, Guido; Trinchieri, Giorgio; Ascierto, Paolo Antonio; and Marincola, Francesco M. The most frequent keywords were gut microbiota (frequency = 690), immunotherapy (509), and colorectal cancer (358). Keywords with the highest centrality included immunotherapy (centrality = 0.30), t cells (0.22), and gut microbiota (0.20). The strongest emerging keywords were microsatellite instability (burst strength = 10.09), health (9.85), and diversity (9.65). Keyword cluster analysis (Modularity Q = 0.4276, Silhouette = 0.6724) revealed five major research directions: immune checkpoint inhibitor, breast cancer, colorectal cancer, efficacy, tumor microenvironment.

This study systematically delineated a "microbiota-immunity-tumor" triangular knowledge framework that currently underpins the field, highlighting its maturation through bibliometric evidence. In the future, it is critical to integrate cross-scale mechanism exploration, standardized clinical translation pathways, and a global collaboration network to promote breakthroughs in personalized immunotherapy strategies, with direct relevance for clinical and perioperative care in oncology.