Commensal protists and gut bacterial communities exhibit complex relationships, mediated at least in part through host immunity. To improve our understanding of this tripartite interplay, we investigated community and functional dynamics between the murine protist Tritrichomonas musculus (Tmu) and intestinal bacteria in healthy and B cell-deficient mice. We identified dramatic, protist-driven remodeling of resident microbiome growth and activities, in parallel with Tmu functional changes, which were accelerated in the absence of B cells. Metatranscriptomic data revealed nutrient-based competition between bacteria and the protist. Single cell transcriptomics identified distinct Tmu life stages, providing new evidence for trichomonad sexual replication and the formation of pseudocysts. Unique cell states were validated in situ through microscopy and flow cytometry. Our results reveal complex microbial dynamics during the establishment of a commensal protist in the gut, and provide valuable datasets to drive future mechanistic studies.

中文翻译：

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共生原生生物肌毛滴虫表现出动态的生命周期，可诱导肠道微生物群的广泛重塑

共生原生生物和肠道细菌群落表现出复杂的关系，至少部分是通过宿主免疫介导的。为了加深对这种三方相互作用的理解，我们研究了健康小鼠和 B 细胞缺陷小鼠中鼠原生生物三滴虫 (Tmu) 和肠道细菌之间的群落和功能动态。我们发现，原生生物驱动的常驻微生物组生长和活动发生了戏剧性的重塑，同时 Tmu 功能发生了变化，而在没有 B 细胞的情况下，这种变化会加速。宏转录组数据揭示了细菌和原生生物之间基于营养的竞争。单细胞转录组学鉴定了不同的 Tmu 生命阶段，为滴虫有性复制和假囊肿的形成提供了新的证据。通过显微镜和流式细胞术原位验证了独特的细胞状态。我们的结果揭示了肠道共生原生生物建立过程中复杂的微生物动态，并为推动未来的机制研究提供了有价值的数据集。