The Effects of the Probiotic, Lactobacillus reuteri, on Experimental Gingivitis

Objective: The clinical effects of the probiotic, Lactobacillus reuteri (L. reuteri), on experimental gingivitis in humans were evaluated, including the likelihood for oral colonization.

Method: 53 healthy adult volunteers were randomized into 2 groups (double-blinded), received a dental examination, baseline professional cleaning, and at day 1 were directed to refrain from all oral hygiene measures for 14 days. The test group (N=26) chewed gum once daily with L. reuteri, the control group (N=27) chewed a placebo gum. On day 1 and day 14 a gingival index (GI) and plaque index (PI) were recorded and unstimulated saliva samples (5 mL) were obtained. Saliva samples from each group were compared for the presence of L. reuteri, using 16s rDNA PCR (Mo Bio). Student’s t-test and paired t-test were performed.

Result: The demographics of the groups were not significantly different. Mean baseline clinical parameters between the groups: control GI 0.6 (0.26 SD), PI 1.7 (0.50 SD); test GI 0.7 (0.35 SD), PI 1.7 (0.48 SD) and 2-week interval control GI 1.1 (0.27 SD), PI 1.2 (0.47 SD) did not differ. In contrast, mean clinical parameters within each group demonstrated significant differences. For control group: baseline GI 0.6 (0.26 SD), 2-week GI 1.1 (0.27), p<0.05; baseline PI 1.7 (0.50 SD), 2-week PI 2.9 (0.54 SD), p<0.05 and test group baseline GI – 0.7 (0.35 SD), 2-weeks GI 1.2 (0.47), p<.05; baseline PI 1.7 (0.48 SD), 2-weeks PI 3.0 (0.50 SD), p<.05. No adverse effects were noted. Saliva samples from the control group tested negative for L. reuteri; however 40% of test subjects were positive for L. reuteri.

Conclusion: The probiotic, L. reuteri, in chewing gum did not demonstrate a significant effect on clinical parameters of experimentally-induced gingivitis in healthy adults. However, chewing gum to introduce this probiotic and promote oral colonization is feasible in some individuals.