Study | Study design | No. of participants (experimental/control) | Age, yearsa (experimental/control groups) | Probiotics | Control group | Frequency and duration | Outcome measure | Main finding |
---|---|---|---|---|---|---|---|---|
Barichella et al. [9] | Randomized double-blind clinical trial | 80/40 | 71.8 ± 7.7/69.5 ± 10.3 | Fermented milk containing multiple probiotic strains and prebiotic fiber | Pasteurized, fermented, fiber-free milk | Once daily for 4 weeks | 1. Bowel movements 2. Bristol Stool Scale score 3. Treatment satisfaction 4. Treatment continuation | Probiotics were superior to placebo in improving constipation in patients with PD |
Borzabadi et al. [10] | Randomized double-blind clinical trial | 25/25 | 66.7 ± 10.7/ 66.9 ± 7.0 | Capsule 8 × 109 CFU Lactobacillus acidophilus Bifidobacterium bifidum L. reuteri Lactobacillus fermentum (2 × 109 CFU each) | Placebo capsule | Once daily for 12 weeks | 1. Gene expression (IL-1, IL-8, TNF-α, TGF-β, PPAR-γ, VEGF, and LDLR) 2. Biomarkers of oxidative stress (total glutathione and nitric oxide) | The probiotics group had significantly improved gene expression levels of IL-1, IL-8, TNF-α, TGF-β, and PPAR-γ; however, the gene expression of VEGF and LDLR and the number of biomarkers of inflammation and oxidative stress were unaffected |
Du et al. [25] | Randomized clinical trial | 23/23 | 68.39 ± 7.55/66.65 ± 8.66 | Capsule 5 × 109 CFU Bacillus licheniformis 1 × 107 CFU Lactobacillus acidophilus, Bifidobacterium longum, Enterococcus faecalis | None | Three times daily for 12 weeks | 1. Bowel movements 2. Bristol Stool Scale scores 3. Constipation (PAC-SYM) 4. Quality of life (PAC-QOL) | The probiotics group demonstrated improved bowel movements and improved scores on symptom scales associated with constipation (PAC-SYM scores and PAC-QOL scores) |
Georgescu et al. [11] | Randomized controlled clinical trial | 20/20 | 75.6 ± 9.7/69.8 ± 5.6 | Capsule 60 mg Lactobacillus acidophilus Bifidobacterium infantis | Trimebutine 200 mg three times daily | Twice daily for 12 weeks | 1. Abdominal pain 2. Bloating 3. Constipation | Probiotics improved abdominal pain and bloating similar to trimebutine; however, trimebutine was more effective for constipation with incomplete evacuation |
Ibrahim et al. [12] | Randomized double-blind clinical trial | 22/26 | 69.0 ± 5.2/70.5 ± 6.1 | Capsule 3 × 1010 CFU Lactobacillus sp. Bifidobacterium sp. fructo-oligosaccharides lactose | Fermented milk | Twice daily for 8 weeks | 1. Garrigues Questionnaire 2. Gut transit time 3. Quality of life (PDQ39-SI) 4. Motor symptoms (MDS-UPDRS) 5. Non-motor symptoms (NMSQ) | Probiotics led to improved bowel opening frequencies and whole gut transit times in PD |
Michela et al. [13] | Randomized double-blind clinical trial | 80/40 | N/R/N/R | Fermented milk containing multiple probiotic strains and prebiotic fiber | Pasteurized, fermented, fiber-free milk | Once daily for 4 weeks | 1. Complete bowel movements | Probiotics were superior to placebo in improving numbers of complete bowel movements |
Mehrabani et al. [26] | Randomized double-blind clinical trial | 40/40 | 68.2 ± 7.7/69.1 ± 8.2 | Powder in sachets 5 × 109 CFU Lactobacillus acidophilus Lactobacillus rhamnosus Lactobacillus plantarum Bifidobacterium longum Streptococcus thermophilus | Maltodextrin | Once daily for 12 weeks | 1. Biomarkers of oxidative stress (TAC, TOS, OSI, GSH, MDA) 2. Quality of life (PDQ39) 3. Mental status (Hospital Anxiety and Depression Scale) 4. Fatigue Severity Scale scores | The probiotics group had increased TAC, reduced MDA levels, and reduced OSI values, and it also had lower levels of depression and displayed improvements in well-being and cognitive impairment |
Sun et al. [24] | Randomized double-blind clinical trial | 48/34 | 66.46 ± 6.98/68.76 ± 6.91 | Capsule 3 × 1010 CFU Bifidobacterium animalis subsp. lactis | Maltodextrin | Once daily for 12 weeks | 1. Number of spontaneous defecation incidents 2. Bristol Stool Scale scores 3. Motor symptoms (MDS-UPDRS) 4. Quality of life (PAC-QOL) 5. Hamilton Anxiety Rating Scale scores 6. Hamilton Depression Scale scores | Probiotics improved sleep quality and alleviated anxiety and gastrointestinal symptoms |
Tamtaji, O. R., et al. (2019)[14] | Randomized double-blind clinical trial | 30/30 | 68.2 ± 7.8/67.7 ± 10.2 | Capsule 8 × 109 CFU Lactobacillus acidophilus Bifidobacterium bifidum Lactobacillus reuteri Lactobacillus fermentum (2 × 109 CFU each) | Placebo capsule | Once daily for 12 weeks | 1. Motor symptoms (MDS-UPDRS) 2. High-sensitivity CRP 3. Biomarkers of oxidative stress (total glutathione, malondialdehyde) 4. Diabetes markers (fasting plasma glucose, Insulin, Insulin sensitivity check index) 5. Dyslipidemia markers (triglycerides, VLDL, LDL, HDL) | Probiotics had useful impacts on MDS-UPDRS scores and some metabolic profiles |
Tan et al. [15] | Randomized double-blind clinical trial | 34/38 | 70.9 ± 6.6/68.6 ± 6.7 | Capsule 109 CFU Lactobacillus Acidophilus Lactobacillus reuteri Lactobacillus gasseri Lactobacillus rhamnosus Bifidobacterium bifidum Bifidobacterium longum Enterococcus faecalis Enterococcus faecium | Placebo capsule | Once daily for 4 weeks | 1. Bowel movements per week 2. Average stool consistency 3. Quality of life (PAC-QOL) 4. Constipation severity scores | Probiotics were effective for relieving constipation in patients with PD |
Yang et al. [16] | Randomized double-blind clinical trial | 63/59 | N/R/N/R | Fermented milk containing 109 CFU Lactobacillus casei strain | Placebo capsule | Once daily for 12 weeks | 1. Quality of life (PDQ39) 2. Non-motor symptoms (NMSQ) 3. Hamilton Anxiety Rating Scale scores 4. Hamilton Depression Rating Scale scores | Probiotics may be a useful approach in managing the non-motor symptoms of PD |