Bonde Apurva, Daly Sean, Kirsten Julia, Kondapaneni Sainath, Mellnick Vincent, Menias Christine O, Katabathina Venkata S
From the Department of Radiology, University of Texas Health at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229 (A.B., S.D., J.K., V.S.K.); University of Texas at Austin, Austin, Tex (S.K.); Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (V.M.); and Department of Radiology, Mayo Clinic, Scottsdale, Ariz (C.O.M.).
Radiographics. 2021 Jul-Aug;41(4):1103-1122. doi: 10.1148/rg.2021200168. Epub 2021 May 14.
The human gastrointestinal tract houses trillions of microbes. The gut and various types of microorganisms, including bacteria, viruses, fungi, and archaea, form a complex ecosystem known as the gut microbiota, and the whole genome of the gut microbiota is referred to as the gut microbiome. The gut microbiota is essential for homeostasis and the overall well-being of a person and is increasingly considered an adjunct "virtual organ," with a complexity level comparable to that of the other organ systems. The gut microbiota plays an essential role in nutrition, local mucosal homeostasis, inflammation, and the mucosal immune system. An imbalanced state of the gut microbiota, known as dysbiosis, can predispose to development of various gastrointestinal malignancies through three speculated pathogenic mechanisms: direct cytotoxic effects with damage to the host DNA, disproportionate proinflammatory signaling inducing inflammation, and activation of tumorigenic pathways or suppression of tumor-suppressing pathways. Several microorganisms, including , Epstein-Barr virus, human papillomavirus, , , and , are associated with gastrointestinal malignancies such as esophageal adenocarcinoma, gastric adenocarcinoma, gastric mucosa-associated lymphoid tissue lymphoma, colorectal adenocarcinoma, and anal squamous cell carcinoma. Imaging plays a pivotal role in diagnosis and management of microbiota-associated gastrointestinal malignancies. Appropriate use of probiotics, fecal microbiota transplantation, and overall promotion of the healthy gut are ongoing areas of research for prevention and treatment of malignancies. RSNA, 2021.
人类胃肠道中栖息着数万亿微生物。肠道与包括细菌、病毒、真菌和古菌在内的各种微生物形成了一个复杂的生态系统，称为肠道微生物群，而肠道微生物群的全基因组则被称为肠道微生物组。肠道微生物群对于人体的内环境稳定和整体健康至关重要，并且越来越被视为一个辅助性的“虚拟器官”，其复杂程度与其他器官系统相当。肠道微生物群在营养、局部黏膜稳态、炎症和黏膜免疫系统中发挥着重要作用。肠道微生物群的失衡状态，即生态失调，可通过三种推测的致病机制导致各种胃肠道恶性肿瘤的发生：对宿主DNA造成损伤的直接细胞毒性作用、引发炎症的过度促炎信号传导以及致癌途径的激活或抑癌途径的抑制。几种微生物，包括爱泼斯坦-巴尔病毒、人乳头瘤病毒等，与胃肠道恶性肿瘤如食管腺癌、胃腺癌、胃黏膜相关淋巴组织淋巴瘤、结肠腺癌和肛门鳞状细胞癌有关。影像学在微生物群相关胃肠道恶性肿瘤的诊断和管理中起着关键作用。合理使用益生菌、粪便微生物群移植以及全面促进肠道健康是预防和治疗恶性肿瘤的持续研究领域。RSNA，2021年。
