Host–microorganism encounters take place in many different ways and with different types of outcomes. Three major types of microorganisms need to be distinguished: (1) pathogens that cause harm to the host and must be controlled; (2) environmental microorganisms that can be ignored but must be controlled at higher abundance; and (3) symbiotic microbiota that require support by the host. Recent evidence indicates that the aryl hydrocarbon receptor (AHR) senses and initiates signalling and gene expression in response to a plethora of microorganisms and infectious conditions. It was originally identified as a receptor that binds xenobiotics. However, it was subsequently found to have a critical role in numerous biological processes, including immunity and inflammation and was recently classified as a pattern recognition receptor. Here we review the role of the AHR in host–pathogen interactions, focusing on AHR sensing of different microbial classes, the ligands involved, responses elicited and disease outcomes. Moreover, we explore the therapeutic potential of targeting the AHR in the context of infection.

宿主与微生物的相遇以许多不同的方式发生，并产生不同类型的结果。需要区分的微生物主要有三大类：（1） 对宿主造成危害的病原体，必须加以控制;（2） 可以忽略但必须以较高丰度控制的环境微生物;（3） 需要宿主支持的共生微生物群。最近的证据表明，芳烃受体 （AHR） 在响应大量微生物和感染条件时感知并启动信号传导和基因表达。它最初被确定为结合外源性物质的受体。然而，随后发现它在许多生物过程中起着关键作用，包括免疫和炎症，最近被归类为模式识别受体。在这里，我们回顾了 AHR 在宿主-病原体相互作用中的作用，重点关注不同微生物类别的 AHR 感应、所涉及的配体、引发的反应和疾病结果。此外，我们探讨了在感染背景下靶向 AHR 的治疗潜力。