Haran John P, Bucci Vanni, Dutta Protiva, Ward Doyle, McCormick Beth
Department of Emergency Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
Center for Microbiome Research, University of Massachusetts Medical School, Worcester, MA, USA.
J Med Microbiol. 2018 Jan;67(1):40-51. doi: 10.1099/jmm.0.000640. Epub 2017 Nov 14.
The microbiome from nursing home (NH) residents is marked by a loss in diversity that is associated with increased frailty. Our objective was to explore the associations of NH environment, frailty, nutritional status and residents' age to microbiome composition and potential metabolic function.
We conducted a prospective longitudinal cohort study of 23 residents, 65 years or older, from one NH that had four floors: two separate medical intensive floors and two floors with active elders. Residents were assessed using the mini nutritional assessment tool and clinical frailty scale. Bacterial composition and metabolic potential of residents' stool samples was determined by metagenomic sequencing. We performed traditional unsupervised correspondence analysis and linear mixed effect modelling regression to assess the bacteria and functional pathways significantly affected by these covariates.Results/Key findings. NH resident microbiomes demonstrated temporal stability (PERMANOVA P=0.001) and differing dysbiotic associations with increasing age, frailty and malnutrition scores. As residents aged, the abundance of microbiota-encoded genes and pathways related to essential amino acid, nitrogenous base and vitamin B production declined. With increasing frailty, residents had lower abundances of butyrate-producing organisms, which are associated with increased health and higher abundances of known dysbiotic species. As residents became malnourished, butyrate-producing organisms declined and dysbiotic bacterial species increased. Finally, the microbiome of residents living in proximity shared similar species and, as demonstrated for Escherichia coli, similar strains.
These findings support the conclusion that a signature 'NH' microbiota may exist that is affected by the residents' age, frailty, nutritional status and physical location.
养老院（NH）居民的微生物群以多样性丧失为特征，这与身体虚弱加剧有关。我们的目标是探讨NH环境、身体虚弱、营养状况和居民年龄与微生物群组成及潜在代谢功能之间的关联。
我们对来自一家有四层楼的NH的23名65岁及以上居民进行了一项前瞻性纵向队列研究：两层独立的医疗重症监护楼层和两层住着活跃老年人的楼层。使用微型营养评估工具和临床虚弱量表对居民进行评估。通过宏基因组测序确定居民粪便样本的细菌组成和代谢潜力。我们进行了传统的无监督对应分析和线性混合效应建模回归，以评估受这些协变量显著影响的细菌和功能途径。结果/主要发现。NH居民的微生物群表现出时间稳定性（PERMANOVA P=0.001），并且随着年龄、身体虚弱和营养不良评分的增加，其失调关联有所不同。随着居民年龄的增长，与必需氨基酸、含氮碱基和维生素B产生相关的微生物编码基因和途径的丰度下降。随着身体虚弱程度的增加，居民中产生丁酸盐的生物体丰度较低，而丁酸盐与健康状况改善相关，同时已知的失调物种丰度较高。随着居民出现营养不良，产生丁酸盐的生物体减少，失调细菌物种增加。最后，居住在附近的居民的微生物群具有相似的物种，如大肠杆菌所示，还有相似的菌株。
这些发现支持这样的结论，即可能存在一种受居民年龄、身体虚弱、营养状况和地理位置影响的标志性“NH”微生物群。
