Antimicrobial effects of equine regenerative medicine products: A systematic review and meta‐analysis of in vitro and in vivo studies
Shuyao Chen, Yuchen Jia, Luo Yang, Yuxin Xie, Yiping Zhu, Jing LiAbstract
Background
Equine regenerative medicine products involving platelet‐rich plasma (PRP), mesenchymal stromal cells (MSCs), and their derivatives are increasingly explored for antimicrobial and therapeutic roles, but their efficacy and between‐study variability remain unclear.
Objectives
To systematically review and meta‐analyse in vitro and in vivo evidence on antimicrobial effects of equine regenerative medicine products and to evaluate their efficacy against key pathogens.
Study Design
Systematic review and meta‐analysis:
Methods
We followed Preferred Reporting Items for Systematic Reviews and Meta‐Analyses and searched studies (2010–2025) reporting PRP/MSC antimicrobial interventions in equine models. In vitro studies reporting colony‐forming unit (CFU) outcomes were meta‐analysed. Continuous outcomes were pooled as standardised mean differences (SMD; the mean difference divided by the pooled standard deviation with 95% confidence intervals [CI]), using a random‐effects model. Heterogeneity was assessed by I 2 and significance as p < 0.05. Predefined subgroup analyses by product class and pathogen were performed. Risk of bias was assessed with a predefined checklist. In vivo outcomes were synthesised narratively.
Results
Twenty‐four studies met inclusion criteria; 13/17 in vitro studies contributed CFU data for meta‐analysis. Platelet‐derived products showed a pooled SMD of 0.94 (95% CI 0.33–1.54; p = 0.003; I 2 = 27%) against Staphylococcus aureus . Against Escherichia coli , regenerative products showed a non‐significant effect (SMD 1.07; 95% CI 0.01–2.13; p = 0.05; I 2 = 65%). MSC‐based products produced a non‐significant SMD of 0.55 (95% CI −0.46–1.55; p = 0.29; I 2 = 38%) versus S. aureus . Seven in vivo studies reported clinical improvements, and combination therapies with antibiotics often enhanced bacterial clearance.
Main Limitations
Interpretation is limited by substantial methodological heterogeneity across studies and by potential risk of bias.
Conclusion
Platelet‐derived regenerative products demonstrate in vitro antimicrobial activity against a representative Gram‐positive bacterium, S . aureus ; however, current heterogeneous and limited in vivo evidence provides only tentative support for their use as adjuncts, rather than standalone antimicrobial therapies. Well‐designed, standardised in vitro and in vivo studies are needed.