Department of Research and Education, Oli Health Magazine Organization, Kigali, Rwanda.
Clinton Global Initiative University, New York, New York, USA.
Brain Behav. 2022 Aug;12(8):e2728. doi: 10.1002/brb3.2728. Epub 2022 Jul 25.
Alzheimer's disease (AD) is a leading cause of dementia around the globe. Its pathogenesis is characterized primarily by the extracellular deposition of amyloid β peptides and intracellular neurofibrillary tangles. Despite the significant investments in neurological research, the exact molecular mechanism of AD pathogenesis is still not fully elucidated. Several studies converge on a hypothesis that pathogenic microbes might play a role in AD progression. Although this hypothesis has been considered relatively weak for decades, it has recently received considerable attention due to increasing evidence on the association between microorganisms and AD. There is a lack of experimental and scientific arguments conveying that these microorganisms engender cognitive and neuropathological deficits and modifications specific to AD, challenging the theory that it could be an infectious neurological disease. This review focuses on recent advances in the infection hypothesis and provides an overview of new findings portraying the significance of pathogenic microbes in AD and the challenges confronting the validity of the hypothesis.
Data were collected from medical journals published on PubMed, Ovid MEDLINE, ScienceDirect, and Embase bibliographical databases with a predefined search strategy. All articles considering neurological disorders, especially AD associated with infectious diseases, were included.
This work focused on providing an overview of new findings around the relationship between microorganisms and AD, challenges facing the validity of the theory, and recommendations on how the scientific community can best develop alternative approaches to address the pathophysiology of AD.
While many studies reinforce the suspicion of an infectious etiology of AD, it is important to note that it is yet not validated how microorganisms' presence in the brain can develop AD due to the limited available evidence. Certainly, ground-breaking work is mandatory in this field of research, and these reports so far warrant a thorough investigation into how a chronic infection may remain silent while progressing its neuroinflammation. Amid this uncertainty arises the hope that many researchers will take on this challenge and join this endeavor to benefit AD patients worldwide.
阿尔茨海默病（AD）是全球范围内导致痴呆的主要原因。其发病机制主要表现为细胞外淀粉样β肽的沉积和细胞内神经原纤维缠结。尽管在神经科学研究方面投入了大量资金，但 AD 发病机制的确切分子机制仍未完全阐明。有几项研究集中在一个假设上，即致病微生物可能在 AD 进展中起作用。尽管几十年来，这个假设一直被认为相对薄弱，但由于越来越多的证据表明微生物与 AD 之间存在关联，最近它受到了相当大的关注。目前缺乏能够证明这些微生物会导致 AD 特有的认知和神经病理学缺陷和改变的实验和科学论据，这对其可能是一种传染性神经疾病的理论提出了挑战。本综述重点介绍了感染假说的最新进展，并概述了新的发现，这些发现表明了致病微生物在 AD 中的重要性以及该假说所面临的挑战。
从发表在 PubMed、Ovid MEDLINE、ScienceDirect 和 Embase 文献数据库上的医学期刊中收集数据，并采用预设的搜索策略。所有考虑神经疾病，特别是与传染病相关的 AD 的文章都被纳入。
这项工作重点介绍了围绕微生物与 AD 之间关系的新发现、该理论有效性所面临的挑战，以及科学界如何最好地制定替代方法来解决 AD 病理生理学的建议。
虽然许多研究都加强了对 AD 感染病因的怀疑，但需要注意的是，由于现有证据有限，微生物在大脑中的存在如何导致 AD 尚待验证。当然，在这个研究领域需要有开创性的工作，到目前为止，这些报告值得对慢性感染如何在其神经炎症进展的同时保持沉默进行深入调查。在这种不确定性中，人们希望许多研究人员将接受这一挑战，并加入这一努力，使全球 AD 患者受益。
