Core Viewpoint - Immune checkpoint inhibitors (ICIs) have shown significant breakthroughs in cancer treatment, but only about 20% of patients benefit long-term, necessitating exploration of resistance mechanisms and ways to enhance clinical benefits [2][3]. Group 1: Role of Gut Microbiome - The gut microbiome plays a crucial role in the effectiveness of ICIs, with ongoing clinical trials combining fecal microbiota transplantation with ICIs showing promising results [2][3]. - Research indicates that the intratumoral microbiome is associated with cancer progression, prognosis, and treatment response, highlighting its potential in enhancing immunotherapy effects [2][3]. Group 2: Recent Research Findings - A recent study published in Cell Reports Medicine identified and validated intratumoral bacteria that can synergize with anti-PD-1 therapy, inhibiting tumor growth and enhancing anti-tumor immunity [3][6]. - The study utilized bioinformatics to extract intratumoral microbiome information from RNA sequencing data of clinical cohorts treated with ICIs, establishing correlations between specific microbial modules and patient responses [5][6]. Group 3: Key Discoveries - The study's core findings emphasize the association between the intratumoral microbiome and immune therapy responses, with specific microbial features linked to tumor microenvironment characteristics [7][9]. - The identified intratumoral bacteria, including Burkholderia cepacia, Priestia megaterium, and Corynebacterium kroppenstedtii, were shown to enhance anti-tumor immunity in mouse models when injected intratumorally [6][7].