RETRACTED: Clinical and metabolic response to probiotic administration in people with Parkinson's disease: A randomized, double-blind, placebo-controlled trial
Open accessAbstract
BACKGROUND & AIMS The investigation was done to assess the impacts of probiotic supplementation on movement and metabolic parameters in individuals with Parkinson's disease (PD). METHODS The study is randomized, double-blind, placebo-controlled clinical trial, which was done in sixty people with PD. Individuals were randomly divided into two groups in order to take either 8 × 109 CFU/day probiotic or placebo (n = 30 each group) that lasted 12 weeks. The Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) was recorded at pre- and post-intervention. RESULTS Compared with the placebo, consuming probiotic decreased MDS-UPDRS (-4.8 ± 12.5 vs. +3.8 ± 13.0, P = 0.01). Probiotic supplementation also reduced high-sensitivity C-reactive protein (-1.6 ± 2.5 vs. +0.1 ± 0.3 mg/L, P < 0.001) and malondialdehyde (-0.2 ± 0.3 vs. +0.1 ± 0.3 μmol/L, P = 0.006), and enhanced glutathione levels (+40.1 ± 81.5 vs. -12.1 ± 41.7 μmol/L, P = 0.03) in comparison with the placebo. Additionally, probiotic consumption resulted in a statistically significant reduction in insulin levels (-2.1 ± 3.4 vs. +1.5 ± 5.1 μIU/mL, P = 0.002) and insulin resistance (-0.5 ± 0.9 vs. +0.4 ± 1.2, P = 0.002), and a statistically significant rise in insulin sensitivity (+0.01 ± 0.02 vs. -0.006 ± 0.02, P = 0.01) in comparison with the placebo. Probiotic intake had no any significant impact on other metabolic profiles. CONCLUSIONS Our study evidenced that 12 weeks of probiotic consumption by individuals with PD had useful impacts on MDS-UPDRS and few metabolic profiles. Registered under ClinicalTrials.gov Identifier no. http://www.irct.ir: IRCT2017082434497N4.
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The exact mechanisms and safety of using probiotics in Parkinson's disease have not fully been clarified.
“However, the exact mechanisms and safety of using probiotics in Parkinson's disease have not fully been clarified, although the mechanisms may involve relieving symptoms, inhibiting inflammation, avoiding antioxidant stress and neuronutrition.254,255”
From The role of gut dysbiosis in Parkinson’s disease: mechanistic insights and therapeutic options (2021) · cites this paper as [255]
The Discussion (sections 4.1–4.2; page unavailable) proposes possible mechanisms and says further work on gene expression could help identify them, supporting the point that mechanisms remain unclear. The Results (section 3; page unavailable) report no side effects during the 12-week trial, but the paper does not state that the safety of probiotics in Parkinson’s disease remains unclarified. (LLM, conf=0.82)
Experimental — accuracy not yet measuredThe mechanisms of probiotics in Parkinson's disease may involve relieving symptoms, inhibiting inflammation, avoiding antioxidant stress and neuronutrition.
“although the mechanisms may involve relieving symptoms, inhibiting inflammation, avoiding antioxidant stress and neuronutrition.254,255”
From The role of gut dysbiosis in Parkinson’s disease: mechanistic insights and therapeutic options (2021) · cites this paper as [255]
Section 4.1 reports improved Parkinson’s symptom scores and markers of inflammation and oxidative stress after probiotic supplementation, and discusses possible pathways for those effects. It also mentions effects on central neurochemistry, but does not describe a neuronutrition mechanism. No page number is available in our copy. (LLM, conf=0.86)
Experimental — accuracy not yet measuredA 12-week consumption of several probiotics (Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum) may improve motor impairments in subjects with Parkinson's disease, and has positive effects on their insulin metabolism, markers of inflammation, and markers of oxidative stress.
“In a randomized double-blind placebo-controlled clinical trial, Tamtaji et al. [444] reported that a 12-week consumption of several probiotics (Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum) may improve motor impairments in subjects with Parkinson's disease, but also it has positive effects on their insulin metabolism, markers of”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) improved scores on the Movement Disorders Society-Unified Parkinson's Disease Rating Scale.
“Unified Parkinson's Disease Rating Scale”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) reduced insulin levels.
“insulin levels”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) diminished insulin resistance.
“diminished insulin resistance”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) reduced malondialdehyde levels.
“malondialdehyde”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) enhanced insulin sensitivity.
“as well as insulin sensitivity”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) enhanced glutathione levels.
“enhanced glutathione levels”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
In patients with Parkinson's disease, probiotic supplementation (10^9 CFU/day of Lactobacillus acidophilus, Bifidobacterium bifidum, Lactobacillus reuteri, and Lactobacillus fermentum for 12 weeks) reduced high-sensitivity C-reactive protein levels.
“reduced high-sensitivity C-reactive protein”
From The Role of Microbiota-Gut-Brain Axis in Neuropsychiatric and Neurological Disorders (2021) · cites this paper as [444]
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References 32 · Cited by 398
- Authors
- Tamtaji, O. R., Taghizadeh, M., Daneshvar Kakhaki, R., Kouchaki, E., Bahmani, F., Borzabadi, S., Oryan, S., Mafi, A., & Asemi, Z.
- Affiliations
- Kashan University of Medical Sciences (IR)
- Islamic Azad University, Tehran (IR)
- Corresponding author
- Asemi, Zatollah
- ORCID
- Venue
- Clinical Nutrition
- Publisher
- Elsevier BV
- Published
- 2019-06
- Volume
- 38
- Issue
- 3
- Pages
- 1031-1035
- ISSN
- 0261-5614 (ISSN-L)
- OpenAlex
- W2806735213
- Semantic Scholar
- f4a83017f2c0a4b493cbbd452d9a6687efcfb2bd
- Cited by
- 398
- References
- 32
- Citations by year
- 2026: 21 · 2025: 61 · 2024: 74 · 2023: 70 · 2022: 70 · 2021: 47 · 2020: 35 · 2019: 16 · 2018: 4
- FWCI
- 17.43
- Type
- journal article
- Language
- en
- Status
- Retracted
- Open access
- bronze
- doi.org
- Locations
- Clinical Nutrition (publishedVersion)
- PubMed (publishedVersion)
- Funders
- KAUMS ((no.1396.29))
- Topics
- Health Sciences › Medicine › Neurology › Parkinson's Disease Mechanisms and Treatments
- Life Sciences › Agricultural and Biological Sciences › Food Science › Probiotics and Fermented Foods
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gut microbiota and health
- Keywords
- Parkinson's disease, probiotics, probiotic supplementation, motor symptoms, MDS-UPDRS, C-reactive protein, oxidative stress, malondialdehyde, glutathione, insulin resistance, insulin sensitivity, metabolic profile
- MeSH terms
- Aged, Aged, 80 and over, Cholesterol, Double-Blind Method, Humans, Middle Aged, Parkinson Disease, Oxidative Stress, Probiotics
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