In Vivo Evaluation of Lacticaseibacillus reuteri and Lacticaseibacillus rhamnosus Lysates for Oral Wound Healing.

This study evaluated the effects of bacterial lysates derived from Lacticaseibacillus rhamnosus and L. reuteri on oral wound healing in a rat model. Forty-eight female Wistar rats were randomly assigned to four groups: PBS (group A), L. rhamnosus lysate (group B), L. reuteri lysate (group C), and a combination of both (group D). Full-thickness 1×1 mm wounds were created on the buccal mucosa, and treatments (50 μg/mL) were applied topically every other day. Wound healing was assessed on days 3, 7, 14, and 21 through macroscopic evaluation, histological analysis (H&E staining), and measurement of wound length. On day 7, group D showed complete wound closure (0.00 ± 0.00 mm), significantly shorter than group A (0.99 ± 0.20 mm, P < 0.0001). Significant reductions were also observed in group C (P = 0.0093). By day 14, all probiotic-treated groups exhibited complete healing, while histological repair in group A remained incomplete. Microscopic evaluation confirmed improved epithelial restoration and mucosal architecture in treated groups, particularly in group D, which showed no scarring signs. These findings demonstrate that topical application of non-viable L. rhamnosus and L. reuteri lysates can accelerate oral wound healing in vivo. Further studies in microbiota-intact or inflamed models are needed to evaluate clinical relevance and underlying mechanisms.