Effectiveness of probiotic therapy as an adjunct in the management of periodontal disease in type 2 diabetics: A systematic review and meta-analysis.

BACKGROUND

Periodontal disease and diabetes mellitus are chronic diseases with a high global prevalence and are closely associated. Adjunctive probiotic therapy has garnered increasing attention in the management of type 2 diabetes mellitus (T2DM) with periodontal disease.

OBJECTIVE

This review elucidates the effect of probiotic therapy on inflammatory markers, periodontal parameters, and glycated hemoglobin (HbA1c) in people with both T2DM and periodontal disease.

METHODS

A comprehensive literature search was conducted across seven electronic databases from their inception to June 08, 2025. Randomized controlled trials (RCTs) and quasi-experimental studies (QERs) comparing adjunctive probiotic therapy and Non-Surgical Periodontal Treatment (NSPT) monotherapy were selected. Two reviewers independently screened studies, extracted data, and assessed the risk of bias using the Cochrane Risk of Bias 2 (RoB 2) tool for RCTs and the Joanna Briggs Institute (JBI) critical appraisal tool for QERs.

RESULTS

Seven studies (five RCTs and two QERs) involving 514 patients were included. Compared with NSPT monotherapy, adjunctive probiotic therapy improved interleukin-6 (IL-6) levels (standardized mean difference [SMD] -1.07; 95 % CI: -1.91 to -0.24; P = 0.01) and probing depth (SMD -1.13, 95 % CI: -2.19 to -0.07, p = 0.04).

CONCLUSION

Adjunctive probiotic therapy effectively reduces IL-6 levels and probing depth in patients with T2DM complicated by periodontal disease.