Table_1_Altered gut microbiota in older adults with mild cognitive impairment: a case-control study.pdf

IntroductionThe microbiota-gut-brain axis is implicated in Alzheimer’s disease. Gut microbiota alterations in mild cognitive impairment (MCI) are inconsistent and remain to be understood. This study aims to investigate the gut microbial composition associated with MCI, cognitive functions, and structural brain differences.MethodsA nested case-control study was conducted in a community-based prospective cohort where detailed cognitive functions and structural brain images were collected. Thirty-one individuals with MCI were matched to sixty-five cognitively normal controls by age strata, gender, and urban/rural area. Fecal samples were examined using 16S ribosomal RNA (rRNA) V3–V4 sequencing. Compositional differences between the two groups were identified and correlated with the cognitive functions and volumes/thickness of brain structures.ResultsThere was no significant difference in alpha and beta diversity between MCIs and cognitively normal older adults. However, the abundance of the genus Ruminococcus, Butyricimonas, and Oxalobacter decreased in MCI patients, while an increased abundance of nine other genera, such as Flavonifractor, were found in MCIs. Altered genera discriminated MCI patients well from controls (AUC = 84.0%) and were associated with attention and executive function.ConclusionThis study provides insights into the role of gut microbiota in the neurodegenerative process.

引言：微生物群-肠道-大脑轴与阿尔茨海默病密切相关。在轻度认知障碍（MCI）患者中，肠道微生物群的改变并不一致，且其机制尚未明确。本研究旨在探究与MCI、认知功能及大脑结构差异相关的肠道微生物组成。方法：本研究采用嵌套病例对照研究方法，在社区为基础的前瞻性队列中收集了详细的认知功能和结构脑图像。将31名MCI患者与65名认知正常对照者按年龄层、性别和城乡地区进行匹配。通过16S核糖体RNA（rRNA）V3–V4测序技术对粪便样本进行分析。识别两组之间的组成差异，并将其与认知功能和大脑结构的体积/厚度相关联。结果：MCI患者与认知正常老年人在alpha和beta多样性方面无显著差异。然而，在MCI患者中，瘤胃球菌属、丁酸菌属和草酸杆菌属的丰度降低，而在MCI患者中发现了其他九个属（如黄酮发酵菌属）的丰度增加。这些改变的属能够有效区分MCI患者与对照者（AUC = 84.0%），并且与注意力和执行功能相关。结论：本研究揭示了肠道微生物群在神经退行性过程中的作用。