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）由位于胃肠道的共生微生物群落组成，已在哺乳动物中共同进化，以执行无数的微生态系统服务，以促进生理功能。由于哺乳动物与其肠道微生物之间复杂的相互关系，因此针对GMB对哺乳动物健康的作用的研究数量几乎完全限于人类研究和模型生物。此外，我们对野生生物-GMB关系的很多了解都是基于对圈养标本粪便的结肠GMB群落的研究，因此我们对野生生物中GMB的了解有限。为了更好地了解野生动物GMB关系，我们从事的猎人作为公民科学家收集来自合法采伐黑熊生物样品（熊属美洲），并使用16S rRNA基因扩增子测序来表征结肠和空肠（胃肠道的两个功能截然不同的区域）中的野生黑熊GMB群落。我们确定黑熊的空肠和结肠没有明显不同的GMB群落：两个胃肠道部位均由Firmicutes和Proteobacteria主导。但是，每个位置的细菌数量差异很大，而结肠中的细菌数量主要来自密切相关的血统，而细菌的数量却是其两倍。