Meta-Analysis: Probiotics Improve Motor, Nonmotor Symptoms in Parkinson Disease

Oral probiotics improved motor symptoms as well as gastrointestinal, anxiety, and depressive symptoms in patients with Parkinson disease, according to findings from a meta-analysis published in the journal Food & Function. 

The meta-analysis included 9 randomized controlled trials that looked at the effects of probiotics on motor and nonmotor symptoms in 663 patients with Parkinson disease.

Patients’ motor symptoms, constipation and constipation-related quality of life, and anxiety and depression parameters improved with probiotic treatment, the meta-analysis found. Specifically, standardized mean differences were −0.28 for Unified Parkinson Disease Rating Scale-III scores, 0.54 for Bristol Stool Chart scores, 0.83 for bowel movement scores, 0.56 for complete spontaneous bowel movement scores, −0.84 for Patient Assessment of Constipation Quality of Life scores, −0.35 for Hamilton Anxiety Rating Scale scores, and −0.33 for Hamilton Depression Rating Scale-17 scores.

Probiotic supplements also reduced the use of laxatives (−0.27 standardized mean difference) and increased glutathione levels in patients (0.52 standardized mean difference), according to the study. However, low rates of abdominal bloating were reported in two trials.

Researchers graded the certainty of evidence as very low for most of the findings, and low for bowel movement scores.

“In future studies,” they advised, “more high-quality evidence from large-scale randomized controlled trials is needed to determine the exact effects of probiotic treatment on Parkinson disease.” 

Reference:
Chu C, Yu L, Li Y, Guo H, Zhai Q, Chen W, Tian F. Meta-analysis of randomized controlled trials of the effects of probiotics in Parkinson’s disease. Food Funct. Published online March 28, 2023. doi:10.1039/d2fo03825k