Probiotic Therapy Shows Ability to Improve Motor and Nonmotor Symptoms of Parkinson Disease

Veronica Bruno, MD, MPH

Findings from a recently concluded randomized controlled trial showed that after 12 weeks of treatment with a four-strain probiotic therapy, patients demonstrated a significant reduction in motor and nonmotor symptoms, as explained through Unified Parkinson’s Disease Rating Scale (UPDRS) scores.^1,2

"Recently, there has been an increasing interest and broadening scope of research investigating the relationship between gut dysbiosis—an imbalance in the composition of gut bacteria—and the intricate interactions of the ‘gut-brain’ axis in the context of Parkinson's disease,” Veronica Bruno, MD, MPH, assistant professor, Department of Clinical Neurosciences, University of Calgary, said in a statement.¹ "The article by Leta et al. stands out as a significant contribution to this area of study, aiming to understand the impact of a four-strain probiotic on gut dysbiosis, motor symptoms and non-motor symptoms in PD patients with constipation."

The trial, presented at the 2023 International Congress of Parkinson’s Disease and Movement Disorders (MDS), held August 27-31 in Copenhagen, Denmark, featured 74 individuals who were randomly assigned to probiotic treatment (n = 38) or placebo (n = 36) for a 12-week period. Investigators observed specific between-group differences in the trial, as probiotic-treated patients demonstrated enriched bacteria of health-beneficial properties. These included bacterial families odoribacteraceae, enterococcaceae, genera veillonella, and species blautia faecicola. Treated patient also saw significant reduction in time to ON time (P = .027) and non-motor symptom total score (P = .005), which was mainly derived by reduction in sleep/fatigue (P = .007) and gastrointestinal (P <.001) domain scores.²

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Probiotics refers to food or nutritional supplements that contain micro-organisms, such as bacteria or yeast, meant to support health. Several trials in the past have proved that probiotics can be used effectively to treat PD constipation, but results have been inconsistent. One 2023 meta-analysis featuring 12 eligible studies of 8181 patients with PD showed that constipation symptoms were improved after probiotic treatment, including an increased stool frequency (weighted mean difference [WMD], 0.94 [95% CI, 0.53-1.34]; OR, 3.2 [95% CI, 1.97-5.29]) a reduced used of laxatives (WMD, –0.72; 95% CI, –1.04 to –0.41) and also a reduced UPDRS-III score (WMD, –6.58; 95% CI, –12.02 to –1.14).³

"While the implications of the observed changes in gut microbiota remain a captivating realm for further investigation, a particularly noteworthy finding revolves around the reduction in the ‘time to on’ observed within the active treatment group," Bruno added.¹ "People living with Parkinson's disease frequently express their frustration and challenges arising from the delay in the effectiveness of their medication. This delay can result in periods of diminished mobility, tremors and other disruptive symptoms that affect their daily routines. The identification that the four-strain probiotic contributes to shortening this ‘time to on’ phase holds promise for substantial enhancements in patients' lives by diminishing these difficult ‘off’ intervals and enhancing overall well-being."

Most clinical trials for probiotics in PD have focused on treatment of gastrointestinal symptoms such as constipation. A 2016 study assessing fermented milk containing probiotic strains and prebiotic fiber was found to be superior to placebo in improving constipation in patients with PD. For the primary end point, the consumption of fermented milk containing probiotics and prebiotics resulted in a higher increase in the number of complete bowel movements (mean, 1.2; 95% CI, 0.8-1.6) than placebo (mean, 0.1; 95% CI, –0.4 to 0.6; P = .002).⁴

Bruno added, “research efforts like the current study, enabled by a robust multicenter randomized controlled trial design, are pivotal in generating evidence-based solid treatments. This is especially vital for addressing specific PD non-motor symptoms that have historically received less attention. The discoveries arising from this study emphasize the need for further research, including efforts focused on confirming the lasting sustainability of the observed effects and revealing the underlying mechanisms at play."¹

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REFERENCES
1. Three months of probiotic therapy shown to reduce motor and nonmotor Parkinson’s disease symptoms. News release. Movement Disorder Society. August 27, 2023. Accessed August 28, 2023. https://www.movementdisorders.org/MDS/News/Newsroom/News-Releases/2023-Congress/probiotics-pd.htm
2. Leta V, Zinzalias P, Staunton J, et al. Efficacy of a four-strain probiotic on gut dysbiosis, motor and non-motor symptoms in Parkinson’s disease: a multicenter randomized controlled trial. Presented at: 2023 MDS Congress; August 27-31; Copenhagen, Denmark. Abstract 84.
3. Xie L, Chen D, Zhu X, Cheng C. Efficacy and safety of probiotics in Parkinson’s constipation: a systematic review and meta-analysis. Front Pharmacol. 2022;13:1007654. doi:10.3389/fphar.2022.1007654
4. Barichella M, Pacchetti C, Bolliri C, et al. Probiotics and prebiotic fiber for constipation associated with Parkinson disease: an RCT. Neurology. 2016;87(12):1274-80. doi:10.1212/WNL.0000000000003127