01 July 2026

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Comparative effectiveness of probiotics, prebiotics, synbiotics, and postbiotics in preventing dental caries: a meta-analysis from an oral microbiota modulation perspective.

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This peer-reviewed oral hygiene & prevention article summarizes clinical evidence from BMC oral health (2026). It focuses on findings that may help dental professionals evaluate treatment decisions, patient outcomes, or clinical protocols.

Abstract

BACKGROUND: Dental caries remains one of the most prevalent non-communicable diseases worldwide, imposing substantial health and economic burdens despite conventional preventive measures such as fluoride use and oral hygiene. Increasing recognition of caries as a dysbiosis-driven biofilm disease has prompted exploration of microbiota-modulating strategies, including probiotics, prebiotics, synbiotics, and postbiotics. AIM: This systematic review and meta-analysis aimed to compare the effectiveness of probiotics, prebiotics, synbiotics, and postbiotics in preventing dental caries and to assess associated microbiological and ecological outcomes. METHODS: A comprehensive search of MEDLINE, Embase, Cochrane CENTRAL, Web of Science, Scopus, trial registries, and grey literature was performed from inception to 2024. Randomized controlled trials and controlled clinical trials assessing caries outcomes or validated intermediate endpoints were included. Data extraction and risk-of-bias assessments were conducted independently by two reviewers. Random-effects meta-analysis was applied to estimate pooled risk ratios (RRs) with subgroup analyses by age, strain, delivery format, and duration. Certainty of evidence was graded using GRADE methodology. RESULTS: Twenty-five studies met inclusion criteria; 18 randomized trials contributed to meta-analysis. Probiotics demonstrated the strongest clinical signal. In pediatric populations (12 RCTs; n ≈ 2,300), probiotics significantly reduced new or progressive caries (RR = 0.80; 95% CI, 0.68–0.95). Adult probiotic trials (6 RCTs; n ≈ 1,100) showed no significant benefit (RR = 0.95; 95% CI, 0.80–1.12). Evidence for prebiotics (n = 3), synbiotics (n = 2), and postbiotics (n = 3) was sparse, heterogeneous, and largely limited to microbiological endpoints, including reductions in Streptococcus mutans and favorable plaque pH shifts. Reported adverse events were mild and infrequent. DISCUSSION: Probiotics, particularly Lactobacillus rhamnosus and L. reuteri delivered via lozenges or dairy products, show moderate-certainty evidence for modest caries prevention in children. Other microbiota-modulating approaches remain promising but under-investigated, constrained by small sample sizes, heterogeneous interventions, and lack of standardized outcomes. CONCLUSION: Probiotics represent a safe and acceptable adjunct to conventional preventive strategies in pediatric populations, though benefits are modest. Prebiotics, synbiotics, and postbiotics require further validation through large, long-term, strain-specific RCTs with standardized clinical endpoints and mechanistic analyses to clarify their role in caries prevention.

Key takeaway

Key takeaway: This review-level evidence helps clinicians interpret the consistency and strength of available clinical findings in this topic area.

Introduction from full text

Dental caries is a biofilm-dependent disease that continues to challenge conventional preventive strategies, such as fluoride application and mechanical plaque removal. Biofilm-targeted therapies (BTT), including probiotics, photodynamic therapy, enzymatic treatments, and natural compounds, represent promising alternatives to disrupt pathogenic biofilms effectively. However, the available evidence remains fragmented, with inconsistent methodologies and limited clinical data hindering comprehensive conclusions.

Peer-reviewed source

Chuan Lu, Shuai Zhang, Guang Hong

BMC oral health. 2026

DOI: 10.1186/s13643-025-02921-0

PMID: 41593561

PubMed: https://pubmed.ncbi.nlm.nih.gov/41593561/

Image: Diana Polekhina (Unsplash)