Table 1.
Characteristics of the included studies.
| First author | Year | Country | Study design | Inclusion criteria | Exclusion criteria | No. of patients | Basic treatment | Treatment group | Control group | Duration | Outcomes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Navarro-Lopez et al. (18) | 2019 | Spain | Randomized, double-blind, placebo-controlled | 18–70 years old, plaque psoriasis at least one year prior to study, mild or moderate severity (PASI>6) | Patients exposed to systemic corticosteroids, methotrexate, cyclosporine, biologic drugs in the previous 3 months, antibiotics in the previous 2 weeks, signs of bacterial infection, liver disease with Child-Pugh C, chronic renal insufficiency, chronic endocrine, respiratory, neurological or moderate to severe cardiovascular disease, concomitant skin disease | 88 | Patients with PASI≥6 were prescribed betamethasone dipropionate together with calcipotriol once a day, patients with PASI<6 were prescribed mometasone furoate | Bifidobacterium longum CECT 7347, B. lactis CECT 8145, Lactobacillus rhamnosus CECT 8361, 1 × 109 CFU per capsule, 1 capsule daily | A capsule containing only maltodextrin, matched for size, shape, and volume of contents | 12 wks | PASI, PGA, TNF-α, IFN-γ, IL-1β, IL-6, IL-12, IL-23 |
| Moludi (19) | 2021 | Iran | Randomized double-blind, placebo-controlled | 18–50 years old, recent psoriasis | Patients used any antibiotic or probiotics in last 8 weeks, malignancy, inflammatory bowel disease, cardiovascular disease, liver disease and inflammatory disease. | 50 | N/A | Lactobacillus acidophilus, Bifidobacterium bifidum, Bifidobacterium lactis, Bifidobacterium langum, 1.8 × 109 CFU per capsule, 1 capsule twice a day | Maltodextrin capsules with the same size and shape | 8 wks | DLQI, PSS, PASI, BDI-II, hs-CRP, IL-6, MDA, TAC |
| Moludi (13) | 2022 | Iran | Randomized double-blind, placebo-controlled | Patients being diagnosed with psoriasis or at least 6 months, and never treated with systemic disease-modifying anti-rheumatic drugs | Patients refused to participate or use any current unusual diet (macrobiotic diet), probiotics and antibiotic supplements, or an autoimmune disease, like inflammatory bowel disease or inflammatory arthritis | 46 | Take routine drugs, any antioxidants was forbidden | Lactobacillus acidophilus, Bifidobacterium bifidum, Bifidobacterium lactis, Bifidobacterium langum, 1.6 × 109 CFU/g, twice a day | Received maltodextrin capsules | PASI, QOL, hs-CRP, IL-6, IL-1β, LPS | |
| Akbarzadeh (20) | 2022 | Iran | Randomized double-blind, placebo-controlled | Psoriasis aged 18–60 years and a lack of history of consumption of probiotics and drugs 1–6 weeks before the beginning of the experiment, PASI ≥2% | Diabetic and immunosuppressant patients and patients with a history of immunosuppressing drug consumption | 52 | Weak corticosteroid or hydrocortisone topically | Lactocare® capsules contain 12 strains of probiotic species including Lactobacillus strains, Bifidobacteria strains, Streptococcus thermophilus, plus Fructo-oligosaccharides as the prebiotic (1 × 109 CFU/capsules) | Placebo | 12 wks | PASI, DLQI, VAS |
| Groeger (21) | 2013 | Ireland | Randomized, double-blind placebo-controlled | 18–60 years mild to moderate chronic plaque psoriasis with a PASI <16 | Pregnant or breast feeding females, individuals with lactose intolerance or immunodeficiency, individuals who had undergone any abdominal surgery and those with a psychiatric illness or significant hepatic, renal disease, receiving immunosuppressant therapy or probiotics. | 26 | N/A | 1 × 1010 CFU viable Bifidobacterium infantis 35,264 | 5 g Maltodextran as placebo | 8 wks | CRP, TNF-α, IL-6 |
| Suriano (14) | 2023 | Brazil | Randomized, double-blind placebo-controlled | 18 years old patients with plaque psoriasis | Pregnant females, patients having other skin diseases, neoplasms nor systemic inflammatory diseases (such as Crohn’s disease and inflammatory bowel disease) | 103 | Standard-of-care | Lactobacillus rhamnosus 6×10 CFU/ml, drink 5 mL daily | Placebo | 6 mths | PASI, DLQI |
| Gilli (22) | 2022 | Brazil | Randomized, double-blind placebo-controlled | Patients older than 18 years, clinically diagnosed with psoriasis | Patients started systemic medication in the 3 months prior to the study. During the study, if it was necessary to change the psoriasis medication, the patient would be excluded | 35 | Regular use of standard medication including topical therapy (Clobetasol, Betamethasone Dipropionate, Calcipotriol) combined with systemic treatment (Methotrexate and Secukinumab, Ustekinumab or Adalimumab) | 1 capsule of 5 × 109 CFU/g of L rhamnosus Lr-G14/day for 60 days | Placebo | 60 days | PASI, DLQI, BSA, IL-23, IL17 |
PASI, Psoriasis Area and Severity Index; PGA, Physician Global Assessment; DLQI, Dermatology Life Quality Index; QOL, quality of life; PSS, Psoriasis Symptom Scale; BSA, Body Surface Area; BDI-II, Beck Depression Inventory-II; VAS, Visual Analogue Scale; CRP, C-reactive protein; TNF-α, tumor necrosis factor α; IL-6, interleukin-6; MDA, malondialdehyde; TAC, total antioxidant capacity; CFU, colony-forming units.