Role of probiotic supplementation in the development and evolution of Alzheimer’s and Parkinson’s diseases: A narrative review

Abstract

With the globally aging of the population, neurodegenerative diseases have become more prevalent, affecting the quality of life of the elderly. Additionally, they entail elevated costs for these patients’ care and may foster adverse emotional consequences for their families. On the other hand, the gut microbiota has emerged as a research-growing field, to the point of being considered as a new organ with a very important role in the individual health-disease process. Recent studies have characterized the possible gut microbiota leading role in Alzheimer’s and Parkinson’s diseases pathogenesis. Consequently, it has created a new field of interest regarding how the modification of gut microbiota, through probiotics supplementation, could impact the progression of symptoms, such as cognitive impairment in Alzheimer’s disease, and improve the motor and non-motor symptoms in Parkinson’s disease. In this respect, some investigations have found encouraging results not only in the cognitive performance and metabolic profile in patients with Alzheimer’s disease, but also in the Unified Parkinson’s Disease Rating Scale (UPDRS) improvement and constipation in patients with Parkinson’s disease. These findings prompt the need to design studies that establish the realistic scope of this novel therapy. If the usefulness as a co-adjuvant treatment is proven, it potentially could modify the progression of symptoms and improve the quality of life in patients with these catastrophic diseases.