Abstract：
Alzheimer\'s disease (AD) comprises a group of neurodegenerative disorders with some changes in the brain, which could lead to the deposition of certain proteins and result in the degeneration and death of brain cells. Patients with AD manifest primarily as cognitive decline, psychiatric symptoms, and behavioural disorders. Short-chain fatty acids (SCFAs) are a class of saturated fatty acids (SFAs) produced by gut microorganisms through the fermentation of dietary fibre ingested. SCFAs, as a significant mediator of signalling, can have diverse physiological and pathological roles in the brain through the gut-brain axis, and play a positive effect on AD via multiple pathways. Firstly, differences in SCFAs and microbial changes have been stated in AD cases of humans and mice in this paper. And then, mechanisms of three main SCFAs in treating with AD have been summarized, as well as differences of gut bacteria. Finally, functions of SCFAs played in regulating intestinal flora homeostasis, modulating the immune system, and the metabolic system, which were considered to be beneficial for the treatment of AD, have been elucidated, and the key roles of gut bacteria and SCFAs were pointed out. All in all, this paper provides an overview of SCFAs and gut bacteria in AD, and can help people to understand the importance of gut-brain axis in AD.
摘要：
阿尔茨海默病（AD）包括一组神经退行性疾病，在大脑中有一些变化，这可能导致某些蛋白质的沉积，并导致脑细胞的退化和死亡。AD患者主要表现为认知能力下降，精神症状,和行为障碍。短链脂肪酸（SCFA）是由肠道微生物通过摄入的膳食纤维发酵产生的一类饱和脂肪酸（SFA）。SCFA,作为信号的重要调解人，可以通过肠-脑轴在大脑中发挥不同的生理和病理作用，并通过多种途径对AD发挥积极作用。首先,本文阐述了在人和小鼠的AD病例中SCFA和微生物变化的差异。然后,总结了三种主要的SCFAs治疗AD的机制，以及肠道细菌的差异。最后,SCFA在调节肠道菌群稳态方面的功能，调节免疫系统，和代谢系统，被认为对AD的治疗有益，已经被阐明，并指出了肠道细菌和SCFA的关键作用。总而言之，本文概述了SCFA和肠道细菌在AD中的作用，并且可以帮助人们了解肠-脑轴在AD中的重要性。
