Hibernation alters the diversity and composition of mucosa-associated bacteria while enhancing antimicrobial defence in the gut of 13-lined ground squirrels
Hibernation alters the diversity and composition of mucosa-associated bacteria while enhancing antimicrobial defence in the gut of 13-lined ground squirrels
复制标题
DOI：
10.1111/mec.12884
复制
发表时间：
2014-09-01
影响因子：
4.9
通讯作者：
Carey, Hannah V.
中科院分区：
文献类型：
--
作者：
Dill-McFarland, Kimberly A.;Neil, Katie L.;Carey, Hannah V.
肠道菌群在动物营养和健康中起着重要作用。这种关系在冬眠的哺乳动物中尤其动态，禁食使肠道群落依赖于宿主来源的营养物质而不是外源底物。我们利用16S rRNA焦磷酸测序和盲肠组织蛋白分析研究了冬眠对13行地松鼠粘膜相关细菌微生物群和宿主反应的影响。冬眠鼠的粘膜菌群多样性低于春松鼠和夏松鼠。UniFrac分析显示，夏季和冬末微生物群明显重叠，而春季和冬初微生物群略有重叠，符合其过渡结构。各季节群落以厚壁菌门和拟杆菌门为主，变形菌门、Verrucomicrobia、Tenericutes和放线菌门贡献较小。冬眠动物中厚壁菌门的相对丰度较低，其中包括偏爱植物多糖的属，而拟杆菌门和Verrucomicrobia的相对丰度较高，其中一些细菌仅靠宿主来源的粘蛋白存活。所有个体共有9个操作分类单元的核心粘膜组合，平均总序列丰度为60.2%。这一核心群落以及特定分类群的适度变化表明，粘膜微生物群在年循环中保持相对稳定，但对底物的变化做出反应，同时在春季外源底物回归时，可能作为“播种”微生物群的池。与夏季相比，冬眠减少了盲肠隐窝长度，增加了冬初和春季MUC2的表达。冬眠也降低了盲肠TLR4的表达，增加了TLR5的表达，表明这是一种减少炎症的保护性反应。
The gut microbiota plays important roles in animal nutrition and health. This relationship is particularly dynamic in hibernating mammals where fasting drives the gut community to rely on host-derived nutrients instead of exogenous substrates. We used 16S rRNA pyrosequencing and caecal tissue protein analysis to investigate the effects of hibernation on the mucosa-associated bacterial microbiota and host responses in 13-lined ground squirrels. The mucosal microbiota was less diverse in winter hibernators than in actively feeding spring and summer squirrels. UniFrac analysis revealed distinct summer and late winter microbiota clusters, while spring and early winter clusters overlapped slightly, consistent with their transitional structures. Communities in all seasons were dominated by Firmicutes and Bacteroidetes, with lesser contributions from Proteobacteria, Verrucomicrobia, Tenericutes and Actinobacteria. Hibernators had lower relative abundances of Firmicutes, which include genera that prefer plant polysaccharides, and higher abundances of Bacteroidetes and Verrucomicrobia, some of which can survive solely on host-derived mucins. A core mucosal assemblage of nine operational taxonomic units shared among all individuals was identified with an average total sequence abundance of 60.2%. This core community, together with moderate shifts in specific taxa, indicates that the mucosal microbiota remains relatively stable over the annual cycle yet responds to substrate changes while potentially serving as a pool for 'seeding' the microbiota once exogenous substrates return in spring. Relative to summer, hibernation reduced caecal crypt length and increased MUC2 expression in early winter and spring. Hibernation also decreased caecal TLR4 and increased TLR5 expression, suggesting a protective response that minimizes inflammation.