Biogeography of protists and nematodes in the wild non-human primate gut microbiome. Primate Gut Eukaryotes

Documenting the natural diversity of eukaryotic organisms in the non-human primate (NHP) gut is important for understanding the evolution of the mammalian gut microbiome, its role in health and disease, and the consequences of anthropogenic change and increasing human encroachment into NHP habitats. Despite the ecological significance of gut-associated eukaryotes, little is known about the factors that influence their assembly and diversity in mammals. In this study, we used an 18S rRNA gene amplicon approach to assess the eukaryotic assemblage of 62 individuals representing 16 NHP species. We find that cercopithecoids, and especially the cercopithecines, have substantially higher diversity than other NHPs. Common gut eukaryotes such as nematodes and Entamoeba are widespread among NHPs and consistent with their association with NHP hosts over long evolutionary time scales. However, we did not detect a consistent signal of co-diversification or host-species specificity. Instead, gut eukaryotes are weakly structured by primate phylogeny and no detectable patterns by diet are observed, in contrast to previous reports of NHP gut bacteria. The results of this study affirm the importance of gut-associated eukaryotes in understanding mechanisms that structure the gut microbiome.

记录非人类灵长类（non-human primate, NHP）肠道内真核生物的自然多样性，对于解析哺乳动物肠道微生物组的演化历程、其在宿主健康与疾病中的作用，以及人为活动改变与人类持续侵入非人类灵长类栖息地所带来的生态后果均具有重要意义。尽管肠道相关真核生物具备重要的生态学价值，但目前学界对调控哺乳动物肠道真核生物组装与多样性的关键因素仍知之甚少。本研究采用18S rRNA基因扩增子测序技术，对隶属于16个非人类灵长类物种的62个个体的肠道真核生物群落进行了分析。研究发现，疣猴超科（Cercopithecoidea），尤其是猕猴亚科（Cercopithecinae），其肠道真核生物多样性显著高于其他非人类灵长类类群。常见的肠道真核生物如线虫与内阿米巴虫在非人类灵长类中广泛分布，这与其与宿主之间长期演化的共生关系相符。然而，本研究并未检测到一致的共分化或宿主物种特异性信号。与之相反，肠道真核生物仅受灵长类系统发育关系的微弱调控，且未观察到由饮食驱动的群落结构模式，这与此前关于非人类灵长类肠道细菌的研究结论形成鲜明对比。本研究结果证实了肠道相关真核生物在解析肠道微生物组群落构建机制中的重要价值。