Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA.
Experimental Physiopathology Laboratory, Graduate Program in Health Sciences, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil.
Pharmacol Res. 2021 Feb;164:105314. doi: 10.1016/j.phrs.2020.105314. Epub 2020 Nov 25.
The gut microbiota is a complex ecosystem that comprises of more than 100 trillion symbiotic microbial cells. The microbiota, the gut, and the brain form an association, 'the microbiota-gut-brain axis,' and synchronize the gut with the central nervous system and modify the behavior and brain immune homeostasis. The bidirectional communication between gut and brain occurs via the immune system, the vagus nerve, the enteric nervous system, and microbial metabolites, including short-chain fatty acids (SCFAs), proteins, and tryptophan metabolites. Recent studies have implicated the gut microbiota in many neurodegenerative diseases, including Alzheimer's disease (AD). In this review, we present an overview of gut microbiota, including Firmicutes, Bacteroidetes, SCFA, tryptophan, bacterial composition, besides age-related changes in gut microbiota composition, the microbiota-gut-brain axis pathways, the role of gut metabolites in amyloid-beta clearance, and gut microbiota modulation from experimental and clinical AD models. Understanding the role of the microbiota may provide new targets for treatment to delay the onset, progression, or reverse AD, and may help in reducing the prevalence of AD.
肠道微生物群是一个复杂的生态系统，由超过 1000 万亿个共生微生物细胞组成。微生物群、肠道和大脑形成了一个关联，即“微生物群-肠道-大脑轴”，并使肠道与中枢神经系统同步，改变行为和大脑免疫稳态。肠道和大脑之间的双向通信通过免疫系统、迷走神经、肠神经系统和微生物代谢物（包括短链脂肪酸 (SCFA)、蛋白质和色氨酸代谢物）发生。最近的研究表明，肠道微生物群与许多神经退行性疾病有关，包括阿尔茨海默病 (AD)。在这篇综述中，我们介绍了肠道微生物群的概述，包括厚壁菌门、拟杆菌门、SCFA、色氨酸、细菌组成，以及与年龄相关的肠道微生物群组成变化、微生物群-肠道-大脑轴途径、肠道代谢物在清除淀粉样β中的作用，以及来自实验和临床 AD 模型的肠道微生物群调节。了解微生物群的作用可能为治疗提供新的靶点，以延缓 AD 的发病、进展或逆转，并有助于降低 AD 的患病率。
