Modulating the Oral Microbiome Around Orthodontic Mini-Implants Through Lactobacillus reuteri Supplementation

Background: The orthodontic mini-implants may cause cavities that harbor biofilm causing inflammation of the gums and imbalance in the microbes. This study compared the impact of Lactobacillus reuteri supplementation on the status of the gingival and the composition of the oral microbiome surrounding orthodontic mini-implants. Methods: This prospective cross-sectional study (January and June 2023) included 60 patients of orthodontic mini-implants with probiotic (n= 30) or placebo (n= 30) protocols. The probiotic cluster was treated to chewable L. reuteri tablets twice daily over a period of 4 weeks; the placebo group was given the same non-active tablets. At baseline and after 4 weeks Gingival Index (GI), Plaque Index (PI), and Bleeding on Probing (BOP) were measured. Chi-square, paired and independent t-tests were used to analyze the data; p < 0.05 was taken to be significant. Results: At 4 weeks the probiotic group showed significant improvements in GI (1.23 ± 0.24; p = 0.001), PI (1.33 ± 0.28; p = 0.002) and BOP (34.6 ± 7.9; p = 0.001) compared with placebo. qPCR results (log₁₀ copies/mL) showed reductions in P. gingivalis (2.18 ± 0.33; p < 0.001) and S. mutans (3.21 ± 0.48; p = 0.002) and increases in L. reuteri (5.48 ± 0.36; p < 0.001) and A. naeslundii (5.01 ± 0.29; p = 0.01) in the probiotic group (p > 0.05). Conclusion: The 4-week Lactobacillus reuteri supplement enhanced the health of the gingiva and the composition of the oral microbiota in favor of a more desirable composition near orthodontic mini-implants.