Therapeutic Targets of Probiotics in Parkinson Disease: A Systematic Review of Randomized Controlled Trials

Abstract

Introduction: Parkinson's disease is the world's second most prevalent neurological disease. In Parkinson’s disease intracytoplasmic neuronal inclusions are observed in enteric neurons in the gastrointestinal tract, and the composition of the intestinal microbiome is altered. These changes correlate with the motor phenotype. A systematic review was conducted to determine the effect of probiotics with individuals with Parkinson’s disease. Methods: Scopus, PubMed, Web of Science, The Cochrane Library, Science Direct and OVID-LWW were searched until April 2021 and total 27.395 records were reached according to inclusion and exclusion criteria with the following outcomes: Parkinson's disease rating; oxidative stress, and gastrointestinal system markers. Data searches, article selection and data extraction assessments were performed according to the PRISMA guidelines. The Jadad scale was used to rate the evidence's quality. Results: The information gathered from 5 randomized controlled trials involving 350 individuals with Parkinson’s disease receiving probiotic supplements. Parkinson’s disease rating and non-motor symptoms test were performed. Oxidative stress (Glutathione, malondialdehyde) and gastrointestinal system symptoms (bowel opening frequency, gut transit time, complete bowel movement, spontaneous bowel movements) were evaulated for 4-12 weeks of usage. Conclusion: While all high-quality studies demonstrate progress, there is currently insufficient data to recommend the use of probiotics for people with Parkinson's disease in clinical practice.