Zhang Shujun, Xu Xiaotao, Li Qian, Chen Jingyao, Liu Siyu, Zhao Wenming, Cai Huanhuan, Zhu Jiajia, Yu Yongqiang
Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
Research Center of Clinical Medical Imaging, Hefei, China.
Front Neurosci. 2022 Mar 29;16:814477. doi: 10.3389/fnins.2022.814477. eCollection 2022.
Increasing evidence indicates that gut microbiota can influence cognition the gut-brain axis, and brain networks play a critical role during the process. However, little is known about how brain network topology and structural-functional connectivity (SC-FC) coupling contribute to gut microbiota-related cognition. Fecal samples were collected from 157 healthy young adults, and 16S amplicon sequencing was used to assess gut diversity and enterotypes. Topological properties of brain structural and functional networks were acquired by diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (fMRI data), and SC-FC coupling was further calculated. 3-Back, digit span, and Go/No-Go tasks were employed to assess cognition. Then, we tested for potential associations between gut microbiota, complex brain networks, and cognition. The results showed that gut microbiota could affect the global and regional topological properties of structural networks as well as node properties of functional networks. It is worthy of note that causal mediation analysis further validated that gut microbial diversity and enterotypes indirectly influence cognitive performance by mediating the small-worldness ( and ) of structural networks and some nodal metrics of functional networks (mainly distributed in the cingulate gyri and temporal lobe). Moreover, gut microbes could affect the degree of SC-FC coupling in the inferior occipital gyrus, fusiform gyrus, and medial superior frontal gyrus, which in turn influence cognition. Our findings revealed novel insights, which are essential to provide the foundation for previously unexplored network mechanisms in understanding cognitive impairment, particularly with respect to how brain connectivity participates in the complex crosstalk between gut microbiota and cognition.
越来越多的证据表明，肠道微生物群可通过肠-脑轴影响认知，且大脑网络在此过程中发挥着关键作用。然而，关于大脑网络拓扑结构和结构-功能连接性（SC-FC）耦合如何促进与肠道微生物群相关的认知，我们却知之甚少。我们收集了157名健康年轻成年人的粪便样本，并采用16S扩增子测序来评估肠道多样性和肠型。通过扩散张量成像（DTI）和静息态功能磁共振成像（fMRI数据）获取大脑结构和功能网络的拓扑特性，并进一步计算SC-FC耦合。采用3-back任务、数字广度任务和Go/No-Go任务来评估认知。然后，我们测试了肠道微生物群、复杂大脑网络和认知之间的潜在关联。结果表明，肠道微生物群可影响结构网络的全局和区域拓扑特性以及功能网络的节点特性。值得注意的是，因果中介分析进一步证实，肠道微生物多样性和肠型通过介导结构网络的小世界特性（和）以及功能网络的一些节点指标（主要分布在扣带回和颞叶）间接影响认知表现。此外，肠道微生物可影响枕下回、梭状回和额上回中部的SC-FC耦合程度，进而影响认知。我们的研究结果揭示了新的见解，这对于为理解认知障碍中先前未探索的网络机制提供基础至关重要，特别是在大脑连接性如何参与肠道微生物群与认知之间复杂的相互作用方面。
