The role of probiotics in modulating cariogenic bacteria and oral health outcomes: A systematic review and risk of bias assessment.

This systematic review aims to evaluate the efficacy of probiotic interventions in the prevention of enamel demineralization, with a specific focus on randomized clinical trials (RCTs). A comprehensive literature search was conducted in the Cochrane Library, PubMed, Scopus, and Web of Science electronic databases, covering studies published until April 2025. The review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Article selection and data extraction were independently conducted, with methodological quality evaluated using the Jadad Score. A total of 34 RCTs were included, with 17 studies scoring 5 and 8 studies scoring 3 on the Jadad scale, indicating moderate to high methodological quality. The majority of the trials involved children aged 1 to 15 years, while eight studies focused on adult cohorts aged 18 to 65 years. Intervention durations varied from 6 days to 2 years. The most commonly used probiotic strains were Lactobacillus, Bifidobacterium, or a combination of both, delivered via dairy-based products, lozenges, mouth rinses, or probiotic tablets. Twenty-seven research studies demonstrated a significant reduction in the main cariogenic pathogen, Streptococcus mutans (p < 0.05 - p < 0.001), while findings on Lactobacillus reduction, plaque index, gingival status, salivary pH, and buffering capacity were inconsistent across studies. Long-term studies (≥ 6 months) showed more sustained effects, emphasizing the need for continuous probiotic intake to maintain oral health benefits. The findings suggest that probiotic interventions may represent a potential approach for preventing enamel demineralization, primarily through their ability to reduce cariogenic bacteria and increase salivary pH.