The human gastrointestinal tract is home to a thriving community of microbes including the fungal 'mycobiota'. Although sequencing methodology has enumerated diverse fungal genera within this niche, discerning persistent symbiotic residents from contaminants and purely environmental transients remains a challenge. Recent advances in culturomics and sequencing employing metagenomics, metatranscriptomics and longitudinal studies have begun to reveal a human symbiont 'core mycobiome' that may contribute to human health and disease. Trans-kingdom interactions between the bacterial microbiota and evolution within the niche have defined C. albicans as a true symbiont, setting a bar for defining other fungi. Additionally, elegant investigations of mammalian antifungal immunity have examined mononuclear phagocytes, neutrophils, antigen-specific recognition by T cells and other mechanisms important for local and systemic effects on the host, providing further evidence supporting gut persistence. In this review we discuss current research aimed at investigating the symbiotic mycobiota and propose four criteria aiding in the differentiation of fungal symbionts from environmental transients.

中文翻译：

---

仔细检查肠道菌群：真菌共生菌还是环境短暂性菌？

人的胃肠道是包括真菌“分枝杆菌”在内的繁华微生物群落的所在地。尽管测序方法已经列举了这个利基市场中的各种真菌属，但是要从污染物和纯粹的环境瞬态中识别持久的共生居民仍然是一个挑战。利用宏基因组学，元转录组学和纵向研究在培养组学和测序方面的最新进展已开始揭示人类共生体的“核心菌群”，这可能对人类健康和疾病做出贡献。细菌微生物群与生态位内进化之间的跨王国相互作用已将白色念珠菌定义为真正的共生体，从而为定义其他真菌树立了标杆。此外，对哺乳动物抗真菌免疫力的详尽研究还检查了单核吞噬细胞，嗜中性粒细胞，T细胞对抗原的特异性识别以及对宿主的局部和全身作用重要的其他机制，为支持肠道持久性提供了进一步的证据。在这篇综述中，我们讨论了旨在研究共生真菌菌群的当前研究，并提出了四个标准来帮助从环境瞬态中区分真菌共生体。