Effect of probiotic lozenges containing Lactobacillus reuteri on oral wound healing: a pilot study

It has been suggested that beneficial bacteria may stimulate wound healing. The aim was to investigate the effect of topical applications of probiotic lactobacilli on the healing of standardised oral wounds. This pilot study employed a randomised, placebo-controlled, double-blind cross-over design. Standardised biopsies were punched in the oral mucosa of 10 healthy volunteers, with and without exposure to two strains of Lactobacilli reuteri administrated as lozenges and topical oil. The healing was scored clinically after 2, 5 and 8 days. The amount of exudate was quantified through filter papers and the levels of selected cytokines and chemokines were determined with multiplex immunoassays. Saliva samples were collected before the biopsy and after healing for determination of oxytocin with ELISA. Subjectively perceived pain and discomfort was reported through a daily logbook. There was a clear tendency of improved healing in test group at the 2-and 5-day check-ups but the difference compared with the placebo intervention was not statistically significant (P=0.08). Higher but non-significant expressions of the tumour necrosis factor (TNF) superfamily ligand members 13 (APRIL) and 13B (BAFF), as well as the chemokine interleukin 8 (IL-8), were displayed in wound exudates from the probiotic group as compared with placebo, particularly after 5 and 8 days. The salivary levels of oxytocin were significantly lower (P<0.05) in the placebo group at the 8-day follow-up. The mean number of days with pain and/or discomfort after the biopsies was similar in both groups. No side-effects were reported. The findings of this pilot study justify a larger clinical trial to elucidate the possible role of probiotic supplements on oral wound healing.