Immune checkpoint inhibitor (ICI) therapies, such as those blocking the interaction of PD-1 with its ligands, can restore the immune-killing function of T cells. However, ICI therapy is clinically beneficial in only a small number of patients, and it is difficult to predict post-treatment outcomes, thereby limiting its widespread clinical use. Research suggests that gut microbiota can regulate the host immune system and affect cancer progression and treatment. Moreover, the effectiveness of immunotherapy is related to the composition of the patient's gut microbiota; different gut microbial strains can either activate or inhibit the immune response. However, the importance of the microbial composition within the tumor has not been explored until recently. This study describes recent advances in the crosstalk between microbes in tumors and gut microbiota, which can modulate the tumor microbiome by directly translocating into the tumor and altering the tumor microenvironment. This study focused on the potential manipulation of the tumor and gut microbiota using fecal microbiota transplantation (FMT), probiotics, antimicrobials, prebiotics, and postbiotics to enrich immune-boosting bacteria while decreasing unfavorable bacteria to proactively improve the efficacy of ICI treatments. In addition, the use of genetic technologies and nanomaterials to modify microorganisms can largely optimize tumor immunotherapy and advance personalized and precise cancer treatment.

中文翻译：

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有针对性地调节肠道和肿瘤内微生物群，以提高免疫检查点抑制剂反应的质量

免疫检查点抑制剂 (ICI) 疗法，例如阻断 PD-1 与其配体相互作用的疗法，可以恢复 T 细胞的免疫杀伤功能。然而，ICI治疗仅对少数患者有临床益处，且治疗后结果难以预测，从而限制了其广泛的临床应用。研究表明肠道微生物群可以调节宿主免疫系统并影响癌症的进展和治疗。此外，免疫治疗的有效性与患者肠道菌群的组成有关；不同的肠道微生物菌株可以激活或抑制免疫反应。然而，直到最近才探索肿瘤内微生物组成的重要性。这项研究描述了肿瘤微生物与肠道微生物群之间相互作用的最新进展，这种相互作用可以通过直接易位到肿瘤中并改变肿瘤微环境来调节肿瘤微生物组。这项研究的重点是使用粪便微生物群移植 (FMT)、益生菌、抗菌剂、益生元和后生元对肿瘤和肠道微生物群进行潜在的操纵，以丰富增强免疫的细菌，同时减少不利细菌，从而主动提高 ICI 治疗的疗效。此外，利用基因技术和纳米材料改造微生物可以很大程度上优化肿瘤免疫治疗，推进个性化、精准的癌症治疗。