Trevelline Brian K, Sprockett Daniel, DeLuca William V, Andreadis Catherine R, Moeller Andrew H, Tonra Christopher M
Cornell Lab of Ornithology, Cornell University, Ithaca, NY, USA.
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.
Funct Ecol. 2023 Nov;37(11):2840-2854. doi: 10.1111/1365-2435.14430. Epub 2023 Sep 27.
The gut microbiome can be thought of as a virtual organ given its immense metabolic capacity and profound effects on host physiology. Migratory birds are capable of adaptively modulating many aspects of their physiology to facilitate long-distance movements, raising the hypothesis that their microbiome may undergo a parallel remodeling process that helps to meet the energetic demands of migration.To test this hypothesis, we investigated changes in gut microbiome composition and function over the fall migration of the Blackpoll Warbler (), which exhibits one of the longest known autumnal migratory routes of any songbird and rapidly undergoes extensive physiological remodeling during migration.Overall, our results showed that the Blackpoll Warbler microbiome differed significantly across phases of fall migration. This pattern was driven by a dramatic increase in the relative abundance of Proteobacteria, and more specifically a single 16S rRNA gene amplicon sequence variant belonging to the family Enterobacteriaceae. Further, Blackpoll Warblers exhibited a progressive reduction in microbiome diversity and within-group variance over migration, indicating convergence of microbiome composition among individuals during long-distance migration. Metagenomic analysis revealed that the gut microbiome of staging individuals was enriched in bacterial pathways involved in vitamin, amino acid, and fatty acid biosynthesis, as well as carbohydrate metabolism, and that these pathways were in turn positively associated with host body mass and subcutaneous fat deposits.Together, these results provide evidence that the gut microbiome of migratory birds may undergo adaptive remodeling to meet the physiological and energetic demands of long-distance migration.
考虑到肠道微生物群巨大的代谢能力及其对宿主生理的深远影响，它可被视为一个虚拟器官。候鸟能够适应性地调节其生理的多个方面，以促进长途迁徙，这就提出了一个假说，即它们的微生物群可能会经历一个平行的重塑过程，以帮助满足迁徙的能量需求。为了验证这一假说，我们研究了黑顶白颊林莺秋季迁徙过程中肠道微生物群组成和功能的变化，黑顶白颊林莺展现出了鸣禽中已知最长的秋季迁徙路线之一，并且在迁徙过程中会迅速经历广泛的生理重塑。总体而言，我们的结果表明，黑顶白颊林莺的微生物群在秋季迁徙的不同阶段存在显著差异。这种模式是由变形菌门相对丰度的急剧增加驱动的，更具体地说是属于肠杆菌科的一个单一16S rRNA基因扩增子序列变体。此外，黑顶白颊林莺在迁徙过程中微生物群多样性和组内方差逐渐降低，这表明在长途迁徙过程中个体间微生物群组成趋同。宏基因组分析显示，处于停歇阶段个体的肠道微生物群富含参与维生素、氨基酸和脂肪酸生物合成以及碳水化合物代谢的细菌途径，而这些途径又与宿主体重和皮下脂肪沉积呈正相关。总之，这些结果提供了证据，表明候鸟的肠道微生物群可能会经历适应性重塑，以满足长途迁徙的生理和能量需求。
