Background/Objectives: Over the past two decades, the incidence of early-onset colorectal cancer (EoCRC) has been increasing, although its underlying causes remain unclear. Gut microbiome is known to play a role in carcinogenesis of colorectal cancer. This scoping review aims to systematically map and synthetize current evidence on gut microbiome characterization in EoCRC (vs. late-onset colorectal cancer (LoCRC) and healthy individuals), describe the methodology used, and identify knowledge gaps to inform and guide future research. Methods: This systematic scoping review followed the Joanna Briggs Institute (JBI) methodology for scoping reviews. Searches were conducted in PubMed, Web of Science, and Scopus between January and February 2025. Two reviewers independently screened and selected the studies. One reviewer extracted the relevant information, using an adapted version of the JBI template. Results: Seven studies met eligibility criteria. Compared to healthy young adults, EoCRC patients had a predominance of lower α diversity, different β diversity, and greater abundance ofFlavonifractor plautii,Akkermansia muciniphila,Bacteroides, andFusobacteria.Comparisons with LoCRC showed that EoCRC had distinct β diversity and a higher abundance inFusobacterium,Akkermansia,Bacteroides, andActinomyces. Only three studies correlated the microbiota composition of EoCRC with clinicopathology features and suggested positive associations betweenFusobacteriumabundance, rectal tumors and lower survival andAkkermansiaabundance with body mass index (BMI) ≥ 25 kg/m2, rectal EoCRC, and better survival. Conclusions: There is a lack of large, methodologically robust studies linking gut microbiota with clinicopathological, lifestyle, and tumor molecular features in EoCRC. Our review highlights critical knowledge gaps, the need for standardized methodologies, and key areas for future investigation.
背景/目的：近二十年来，早发性结直肠癌发病率持续上升，但其潜在病因尚未明确。肠道微生物组在结直肠癌发生发展中具有重要作用。本范围综述旨在系统梳理和整合当前关于早发性结直肠癌肠道微生物组特征的研究证据（对比晚发性结直肠癌及健康人群），描述现有研究方法，识别知识缺口，为未来研究提供方向指引。方法：本系统范围综述遵循乔安娜·布里格斯研究所范围综述方法学框架。于2025年1月至2月期间检索PubMed、Web of Science和Scopus数据库。由两名评审员独立完成文献筛选，一名评审员使用改编的JBI模板提取数据。结果：共纳入7项符合标准的研究。与健康青年人群相比，早发性结直肠癌患者普遍呈现较低的α多样性、差异化的β多样性，以及更高丰度的普拉梭菌、阿克曼氏菌、拟杆菌和梭杆菌。与晚发性结直肠癌比较显示，早发性结直肠癌具有独特的β多样性，且梭杆菌属、阿克曼氏菌属、拟杆菌属和放线菌属丰度更高。仅三项研究分析了微生物组成与临床病理特征的关联，提示梭杆菌丰度与直肠肿瘤及较低生存率呈正相关，阿克曼氏菌丰度则与体重指数≥25 kg/m²、直肠早发性结直肠癌及较好生存率相关。结论：目前缺乏大规模、方法学严谨的研究来阐明早发性结直肠癌肠道微生物组与临床病理特征、生活方式及肿瘤分子特征间的关联。本综述揭示了关键知识缺口，强调了方法学标准化的重要性，并指明了未来研究的重点方向。
肿瘤(癌症)患者之家