Clinical therapeutic effects of probiotics in patients with constipation associated with Parkinson disease: A protocol for systematic review and meta-analysis

BACKGROUND: Constipation is the most predominant symptom of Parkinson disease (PD), preceding the occurrence of motor symptoms in some patients, leading to reduced quality of life (QOL). The general approaches for the treatment have some side effects, but probiotics are live or attenuated microorganisms attributed to ameliorating constipation effects. Moreover, as treatments are generally well tolerated and side effects are scarce, there is room for further research. Therefore this work aims at investigating the clinical effectiveness and safety of probiotics for constipation in PD. METHODS: Published RCTs will be retrieved by searching Medline, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), VIP, Wan Fang database, and China Biology Medicine Database (complete bowel movement), which will be searched from establishment of the database to October 10, 2021. Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines are used to design this protocol. RevMan V.5.3 software will be used for meta-analysis, risk of bias will be assessed by the Cochrane Collaboration tool and the collected evidence will be narratively synthesized. We will also perform a meta-analysis to pool estimates from studies considered to be homogenous. Subgroup analyses will be based on intervention or overall bias. CONCLUSION: The meta-analysis will assess the effectiveness and safety of using probiotics to treat and heal the constipation of PD. ETHICS AND DISSEMINATION: Ethics approval is unrequired. REGISTRATION NUMBER: CRD42021276215.