大肠杆菌（E.coli）是肠道中普遍存在的共生菌，大肠杆菌基因的多样性决定了其功能的多样性。本次综述创新性地提出了双刃剑理论。对于“我们如何利用大肠杆菌的矛盾性质来筛查和治疗结直肠癌？”这个问题，就结直肠癌筛查而言，不同人群中大肠杆菌的丰度和亚型的差异提供了利用它作为结直肠癌筛查的机会。就结直肠癌治疗而言，大肠杆菌对结直肠癌的天然有益作用可能有限，而工程化大肠杆菌，特别是某些具有益生菌潜力的亚型，确实可以在结直肠癌治疗中发挥重要作用。看来，大肠杆菌作为遗传工具的有利作用并不在于其对结直肠癌的直接影响，而在于其作为研究平台的潜力，可以与纳米粒子、成像方法和合成生物学修饰等各种技术相结合。由于肠道菌群复杂的多样性和相互作用，肠道菌群与结直肠癌之间的关系仍不清楚。因此，大肠杆菌的应用应基于“同一个健康”观，考虑大肠杆菌与其他微生物、宿主、环境因素的相互作用以及自身的变化。本文强调了大肠杆菌在结直肠癌中的双刃剑作用，以实现大肠杆菌在结直肠癌筛查和治疗中的巨大潜力。© 2024 作者。约翰·威利 (John Wiley) 出版的《微生物生物技术》

Escherichia coli (E. coli) is a ubiquitous symbiotic bacterium in the gut, and the diversity of E. coli genes determines the diversity of its functions. In this review, the two-edged sword theory was innovatively proposed. For the question 'how can we harness the ambivalent nature of E. coli to screen and treat CRC?', in terms of CRC screening, the variations in the abundance and subtypes of E. coli across different populations present an opportunity to utilise it as a biomarker, while in terms of CRC treatment, the natural beneficial effect of E. coli on CRC may be limited, and engineered E. coli, particularly certain subtypes with probiotic potential, can indeed play a significant role in CRC treatment. It seems that the favourable role of E. coli as a genetic tool lies not in its direct impact on CRC but its potential as a research platform that can be integrated with various technologies such as nanoparticles, imaging methods, and synthetic biology modification. The relationship between gut microflora and CRC remains unclear due to the complex diversity and interaction of gut microflora. Therefore, the application of E. coli should be based on the 'One Health' view and take the interactions between E. coli and other microorganisms, host, and environmental factors, as well as its own changes into account. In this paper, the two-edged sword role of E. coli in CRC is emphasised to realise the great potential of E. coli in CRC screening and treatment.© 2024 The Author(s). Microbial Biotechnology published by John Wiley & Sons Ltd.