Vogt Stefanie L, Peña-Díaz Jorge, Finlay B Brett
Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
Anaerobe. 2015 Aug;34:106-15. doi: 10.1016/j.anaerobe.2015.05.002. Epub 2015 May 7.
Gastrointestinal pathogens must overcome many obstacles in order to successfully colonize a host, not the least of which is the presence of the gut microbiota, the trillions of commensal microorganisms inhabiting mammals' digestive tracts, and their products. It is well established that a healthy gut microbiota provides its host with protection from numerous pathogens, including Salmonella species, Clostridium difficile, diarrheagenic Escherichia coli, and Vibrio cholerae. Conversely, pathogenic bacteria have evolved mechanisms to establish an infection and thrive in the face of fierce competition from the microbiota for space and nutrients. Here, we review the evidence that gut microbiota-generated metabolites play a key role in determining the outcome of infection by bacterial pathogens. By consuming and transforming dietary and host-produced metabolites, as well as secreting primary and secondary metabolites of their own, the microbiota define the chemical environment of the gut and often determine specific host responses. Although most gut microbiota-produced metabolites are currently uncharacterized, several well-studied molecules made or modified by the microbiota are known to affect the growth and virulence of pathogens, including short-chain fatty acids, succinate, mucin O-glycans, molecular hydrogen, secondary bile acids, and the AI-2 quorum sensing autoinducer. We also discuss challenges and possible approaches to further study of the chemical interplay between microbiota and gastrointestinal pathogens.
胃肠道病原体若要成功定殖于宿主，必须克服诸多障碍，其中尤其重要的是肠道微生物群的存在，即栖息于哺乳动物消化道中的数万亿共生微生物及其产物。众所周知，健康的肠道微生物群能为宿主提供保护，使其免受多种病原体的侵害，包括沙门氏菌属、艰难梭菌、致泻性大肠杆菌和霍乱弧菌。相反，病原菌已进化出一些机制，以便在与微生物群争夺空间和营养的激烈竞争中建立感染并茁壮成长。在此，我们综述相关证据，表明肠道微生物群产生的代谢产物在决定细菌病原体感染的结果中起关键作用。通过消耗和转化饮食及宿主产生的代谢产物，以及分泌自身的初级和次级代谢产物，微生物群定义了肠道的化学环境，并常常决定宿主的特定反应。尽管目前大多数由肠道微生物群产生的代谢产物尚未得到表征，但已知有几种经微生物群产生或修饰的、经过充分研究的分子会影响病原体的生长和毒力，包括短链脂肪酸、琥珀酸、粘蛋白O-聚糖、分子氢、次级胆汁酸和AI-2群体感应自诱导物。我们还讨论了进一步研究微生物群与胃肠道病原体之间化学相互作用的挑战和可能方法。
