Wildlife Ecology and Conservation Science Lab, Department of Biology, Northern Michigan University, Marquette, MI, 49855, USA.
Department of Applied Ecology, North Carolina State University, Raleigh, NC, 27607, USA.
Sci Rep. 2020 Nov 27;10(1):20779. doi: 10.1038/s41598-020-77282-w.
The gut microbiome (GMB), comprising the commensal microbial communities located in the gastrointestinal tract, has co-evolved in mammals to perform countless micro-ecosystem services to facilitate physiological functions. Because of the complex inter-relationship between mammals and their gut microbes, the number of studies addressing the role of the GMB on mammalian health is almost exclusively limited to human studies and model organisms. Furthermore, much of our knowledge of wildlife-GMB relationships is based on studies of colonic GMB communities derived from the feces of captive specimens, leaving our understanding of the GMB in wildlife limited. To better understand wildlife-GMB relationships, we engaged hunters as citizen scientists to collect biological samples from legally harvested black bears (Ursus americanus) and used 16S rRNA gene amplicon sequencing to characterize wild black bear GMB communities in the colon and jejunum, two functionally distinct regions of the gastrointestinal tract. We determined that the jejunum and colon of black bears do not harbor significantly different GMB communities: both gastrointestinal sites were dominated by Firmicutes and Proteobacteria. However, a number of bacteria were differentially enriched in each site, with the colon harboring twice as many enriched taxa, primarily from closely related lineages.
肠道微生物组（GMB）由位于胃肠道内的共生微生物群落组成，在哺乳动物中共同进化，以执行无数的微生态系统服务，促进生理功能。由于哺乳动物与其肠道微生物之间的复杂相互关系，研究肠道微生物组对哺乳动物健康的作用的数量几乎完全限于人类研究和模式生物。此外，我们对野生动物-肠道微生物组关系的了解很大程度上基于从圈养标本的粪便中获得的结肠肠道微生物组群落的研究，这使得我们对野生动物肠道微生物组的理解有限。为了更好地了解野生动物-肠道微生物组的关系，我们邀请猎人作为公民科学家，从合法捕获的黑熊（Ursus americanus）身上采集生物样本，并使用 16S rRNA 基因扩增子测序来描述肠道微生物组群落，研究了两个功能上不同的胃肠道区域——空肠和回肠。我们发现黑熊的空肠和回肠并不存在显著不同的肠道微生物组群落：两个胃肠道部位都以厚壁菌门和变形菌门为主。然而，有许多细菌在每个部位都有不同程度的富集，其中结肠中含有两倍多的富集类群，主要来自密切相关的谱系。
