Maria Lucia Andrews
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Candel Therapeutics.
Tanya Mateo
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; CEDIMAT, Santo Dominto, Dominican Republic
Luisa Cruz
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Federica Rossetto
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA;F ondazione Don Carlo Gnocchi Onlus, Italy.
Abisoye Ajayi
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Memorial Sloan Kettering Group
Oludolapo Omoyiola
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Memorial Sloan Kettering Group
Andres Gomez
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Daniel Villarreal
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Shailza Kathuria
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Jerry Li
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Alessandro Solis
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Universidad de Ciencias Medicas UCIMED, San Jose, Costa Rica
Natalia Soto
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Tecnologico de Monterrey, CCM
Hebe Castillo
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Dorcas Thairu
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Giannina Melgarejo
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Oluwatosin Ajibola
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Memorial Sloan Kettering Group
Erica Adissy
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Hospital do Coracao, Brazil
Daniela Godoy
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Hospital del Trabajador, Santiago, Chile.
Branda Arismendy
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
Ahmed Salem Alsuliamani
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA
David Rodriguez
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Abbott EPD, Bogota, Colombia.
Ana Fandinho
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Instituto D'or de Pesquisa e Ensino, Rio de Janeiro, Brazil.
Susy Cedeno Arevalo
Harvard T. H. Chan School of Public Health - ECE - PPCR Program, Boston, MA, USA; Fundacion Valle del Lili, Cali, Colombia.
Abstract
Background: Probiotics are being explored for symptom relief in patients with fibromyalgia. Studies have shown that the gut-brain axis can modulate neuronal-mediated symptoms, including pain. This systematic review aims to evaluate the efficacy of probiotics in alleviating pain in individuals with fibromyalgia.
Methods: A systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines. Databases searched included MEDLINE (PubMed), Embase, Scopus, Web of Science, Cochrane CENTRAL, and ClinicalTrials.gov up to April 2025. Eligible studies were randomized controlled trials (RCTs) evaluating the use of probiotics for pain management in adults (age ≥18 years) with fibromyalgia. Studies involving pediatric populations, other chronic pain conditions, or lacking standardized pain outcomes were excluded. Risk of bias was assessed using the Cochrane Risk-of-Bias 2 tool. (OSF Registries: https://doi.org/10.17605/OSF.IO/KHVR7)
Results: Of 923 records, 3 double-blind, placebo-controlled RCTs (2018–2024; n=213; 198 women; ages ~46–55; Spain/Turkey) met inclusion. Interventions were multistrain probiotics for 8–12 weeks; outcomes included VAS pain, FIQ/FIQR, and SF-36. Pain was assessed as a primary and secondary outcome. One trial showed a greater VAS pain reduction with probiotics at 8 weeks (per-protocol; p=0.032; moderate effect), while the other two reported no between-group differences in pain; SF-36 improvements favoring probiotics/prebiotics appeared in one study only. Heterogeneity in strains, dosing, and outcome reporting precluded meta-analysis.
Conclusions: Overall, despite the limited number of studies for this topic, the evidence for pain improvement using VAS, FIQ (FIQR), or SF-36 remains weak and inconclusive. Furthermore, the risk of bias assessment indicates the need for cautious interpretation of the current findings. It underscores the need for larger, high-quality randomized controlled trials to generate more reliable evidence regarding the efficacy of probiotics in managing pain among patients with fibromyalgia.
