Gomes de Sousa Rita, Guerreiro Catarina Sousa, Santos Inês, Cravo Marília
Gastroenterology Department, Hospital da Luz Lisboa, 1500-650 Lisboa, Portugal.
Nutrition Department, Hospital da Luz Lisboa, 1500-650 Lisboa, Portugal.
Cancers (Basel). 2025 May 31;17(11):1863. doi: 10.3390/cancers17111863.
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.
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.
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 of , , , and Comparisons with LoCRC showed that EoCRC had distinct β diversity and a higher abundance in , , , and . Only three studies correlated the microbiota composition of EoCRC with clinicopathology features and suggested positive associations between abundance, rectal tumors and lower survival and abundance with body mass index (BMI) ≥ 25 kg/m, rectal EoCRC, and better survival.
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：在过去二十年中，早发性结直肠癌（EoCRC）的发病率一直在上升，但其潜在原因仍不清楚。已知肠道微生物群在结直肠癌的致癌过程中起作用。本综述旨在系统地梳理和综合目前关于EoCRC（与晚发性结直肠癌（LoCRC）和健康个体相比）肠道微生物群特征的证据，描述所使用的方法，并确定知识空白，以为未来的研究提供信息和指导。
本系统综述遵循乔安娜·布里格斯研究所（JBI）的综述方法。于2025年1月至2月在PubMed、科学网和Scopus中进行检索。两名 reviewers 独立筛选和选择研究。一名reviewer 使用 JBI 模板的改编版本提取相关信息。
七项研究符合纳入标准。与健康的年轻成年人相比，EoCRC 患者的α多样性较低、β多样性不同，且 、 、 和 的丰度更高。与 LoCRC 的比较表明，EoCRC 具有独特的β多样性，且在 、 、 和 中的丰度更高。只有三项研究将 EoCRC 的微生物群组成与临床病理特征相关联，并表明 丰度、直肠肿瘤与较低生存率之间以及 丰度与体重指数（BMI）≥25 kg/m²、直肠 EoCRC 和较好生存率之间存在正相关。
缺乏将肠道微生物群与 EoCRC 的临床病理、生活方式和肿瘤分子特征联系起来的大型、方法学严谨的研究。我们的综述强调了关键的知识空白、对标准化方法的需求以及未来研究的关键领域。
