Massachusetts General Hospital, Harvard Medical School, 165 Cambridge Street, Boston, Massachusetts 02114, USA.
University of Manitoba IBD Clinical and Research Centre, 804-F-175 McDermot Avenue, Winnipeg Manitoba R3E 3P4, Canada.
Nat Rev Gastroenterol Hepatol. 2018 Jan;15(1):39-49. doi: 10.1038/nrgastro.2017.136. Epub 2017 Oct 11.
A number of environmental factors have been associated with the development of IBD. Alteration of the gut microbiota, or dysbiosis, is closely linked to initiation or progression of IBD, but whether dysbiosis is a primary or secondary event is unclear. Nevertheless, early-life events such as birth, breastfeeding and exposure to antibiotics, as well as later childhood events, are considered potential risk factors for IBD. Air pollution, a consequence of the progressive contamination of the environment by countless compounds, is another factor associated with IBD, as particulate matter or other components can alter the host's mucosal defences and trigger immune responses. Hypoxia associated with high altitude is also a factor under investigation as a potential new trigger of IBD flares. A key issue is how to translate environmental factors into mechanisms of IBD, and systems biology is increasingly recognized as a strategic tool to unravel the molecular alterations leading to IBD. Environmental factors add a substantial level of complexity to the understanding of IBD pathogenesis but also promote the fundamental notion that complex diseases such as IBD require complex therapies that go well beyond the current single-agent treatment approach. This Review describes the current conceptualization, evidence, progress and direction surrounding the association of environmental factors with IBD.
许多环境因素与 IBD 的发展有关。肠道微生物群的改变，或称为菌群失调，与 IBD 的发生或进展密切相关，但菌群失调是原发性还是继发性事件尚不清楚。然而，生命早期的事件，如出生、母乳喂养和接触抗生素，以及后来的儿童时期的事件，被认为是 IBD 的潜在危险因素。空气污染是无数化合物对环境不断污染的结果，也是与 IBD 相关的另一个因素，因为颗粒物或其他成分可以改变宿主的黏膜防御并引发免疫反应。与高海拔相关的缺氧也是一个正在研究的潜在新的 IBD 发作触发因素。一个关键问题是如何将环境因素转化为 IBD 的发病机制，系统生物学越来越被认为是揭示导致 IBD 的分子改变的战略工具。环境因素增加了对 IBD 发病机制理解的复杂性，但也促进了这样一个基本概念，即像 IBD 这样的复杂疾病需要复杂的治疗方法，远远超出当前的单一药物治疗方法。本文综述了目前关于环境因素与 IBD 关联的概念化、证据、进展和方向。
