EFFECT OF PROBIOTICS ON COGNITIVE AND MNEMONIC FUNCTIONS IN PATIENTS WITH ALZHEIMER'S DISEASE

Abstract

Alzheimer's disease is a neurodegenerative disorder that mainly affects the central nervous system, especially in the elderly. Recently, the role of the gut microbiota in the pathophysiology and development of neurodegeneration has been discussed. In the elderly, there is a significant change in the gut microbiome, which can lead to loss of functionality and increased susceptibility to gastrointestinal infections and the formation of bacterial products such as bacterial amyloids and lipopolysaccharides, which activate an immune cascade that leads to neuroinflammation and amplification of the neurodegenerative process. Given this scenario, the consumption of probiotics has proven to be an important ally in the treatment of dysbiosis and, indirectly, of the common pathological conditions of AD. Thus, the objective of this review is to systematically evaluate the effectiveness of probiotics in improving cognitive and mnemonic symptoms in patients with Alzheimer's disease, in addition to observing dosage and strain patterns in the studies. This work is a systematic review, in which, after the screening process, five articles met the inclusion criteria. The studies analyzed used different types of strains, mainly Lactobacillus and Bifidobacterium, but in various forms of administration, such as capsules, suspensions, and dairy products. The results were not consistent, and only two of the studies found cognitive improvements. The risk of bias analysis demonstrated a lack of robustness and clear methodology in the execution of the studies. Thus, although they appear promising, the absence of solid evidence and the large number of biases make the data inconclusive and unreliable.