Mammalian microbiomes have coevolved with their host to establish a stable homeostatic relationship. Multifaceted commensal-host and commensal–commensal interactions contribute to the maintenance of the equilibrium with an impact on diverse host physiological processes. Despite constant exposure to physical and chemical insults from the environment, the skin harbors a surprisingly stable microbiome. The fungal compartment of the skin microbiome, the skin mycobiome, is unique in that it is dominated by a single fungus, Malassezia. The lack in diversity suggests that the skin may provide a unique niche for this fungal genus and that Malassezia may efficiently outcompete other fungi from the skin. This opinion article examines aspects in support of this hypothesis, discusses how changes in niche conditions associate with skin mycobiome dysregulation, and highlights an emerging example of Malassezia being displaced from the skin by the emerging fungal pathogen C. auris, thereby generating a predisposing situation for fatal-invasive infection.

哺乳动物微生物群与宿主共同进化，建立稳定的稳态关系。多方面的共生-宿主和共生-共生相互作用有助于维持平衡，影响不同的宿主生理过程。尽管不断暴露于环境中的物理和化学损伤，皮肤仍拥有令人惊讶的稳定微生物组。皮肤微生物组的真菌区室，即皮肤真菌组，其独特之处在于它以单一真菌马拉色菌为主。多样性的缺乏表明，皮肤可能为这种真菌属提供了独特的生态位，并且马拉色菌可以有效地在皮肤上击败其他真菌。这篇评论文章研究了支持这一假设的各个方面，讨论了生态位条件的变化如何与皮肤真菌组失调相关，并强调了马拉色菌被新兴真菌病原体耳念珠菌从皮肤中取代的新例子，从而产生了一种易感情况致命的侵袭性感染。