Abstract
We assessed the impact of probiotics on outcomes related to caries in children and/or adolescents without underlying systemic diseases. We performed a comprehensive meta-analysis of randomised controlled trials (RCTs). Searches were performed in Embase, PubMed, Scopus and Web of Science until March 2023 for RCTs assessing probiotics with a minimum intake duration of 0.2 months vs. control (no treatment or placebo) and reporting at least one primary or secondary outcome. Primary outcomes were number of carious, Streptococcus mutans count, and Lactobacillus count; secondary outcomes were bacterial plaque index, gingival index, salivary pH, and bleeding index. We performed meta-analyses with random effects models and the inverse variance method. Effects were described as mean difference (MD) with their 95% confidence intervals (95%CI). The risk of bias was assessed with the RoB 2.0 tool. The GRADE methodology was used to assess the quality of evidence (QoE). Nineteen RCTs were included (n = 2622), with a follow-up range of 0.2 to 108 months. Probiotics had no effect on reduction of dental caries (MD -0.24 carious pieces, 95%CI -0.72 to 0.23; I2 = 52%, low QoE) or Lactobacillus count (MD -0.78 CFU/mL, 95%CI -1.65 to 0.09; I2= 52%, very low QoE) vs. control. However, probiotics probably reduced S. mutans count vs. control (MD -0.40 CFU/mL, 95%CI -0.57 to -0.24; I2 = 11%, moderate QoE). Probiotics had no effect on bacterial plaque index (MD 0.21 units of bacterial plaque, 95%CI -0. 55-0.96; I2 = 80%, very low QoE), gingival index (MD 0.04 units of gingival index, 95%CI -0.18 to 0.27; I2= 0%, low QoE), and salivary pH (MD -0.12 pH units, 95%CI -0.72 to 0.48; I2 = 92%, very low QoE) vs. control. Probiotics were found to likely reduce S. mutans counts. However, no significant effect of probiotics was observed in reducing other outcomes compared to the control group.