Case Series Presentation: This clinical trial study (Case Series) was performed on 20 patients with deep second-degree burns. Patients had bilateral wounds; the wound on one side of the body was considered as control (treated with silver sulfadiazine) and the other side of the body as treatment (treated with bacteria-free supernatants (BFS) of L. plantarum). The wounds were evaluated by microbial assessments and assessments related to healing. Pseudomonas aeruginosa, Klebsiella pneumonia, and Staphylococcus aureus were isolated from 4 (22.2%), 0%, and 2 (11.1%) of wounds treated with L. plantarum on the fifth day of the treatment, respectively. Furthermore, 12 (66.7%) of wounds treated with L. plantarum were free from bacteria. The need for skin grafting was the same in both treatment and control groups, but graft rejection in the group treated with L. plantarum was (0%) (P=0.02). Conclusion: Regarding eliminating or reducing infection and wound healing, bacteria-free supernatants of L. plantarum can be considered a possible topical treatment option in the case of second-degree burn wounds.