Periodontitis and the microbiome: a systematic review and meta-analysis

INTRODUCTION: The association between the oral microbiome and periodontal diseases is still unclear. We performed a systematic review and meta-analysis to quantify the association between the specific pathogens and periodontitis. EVIDENCE ACQUISITION: A computerized medical search was performed using MEDLINE and SCOPUS database between 1950 and May 2017 to identify all case-control studies that evaluated the association between specific pathogens and periodontitis. The pooled Odds Ratio with relative 95% confidence interval (95% CI) was calculated and plotted in the forest plot. EVIDENCE SYNTHESIS: 11 RCTs involving 2111 patients were included. The retrieved case-control studies evaluated the presence or absence of different targeted pathogens. Among the microrganisms evaluated Porphyromonas gengivalis [OR (95% CI) 2.93(0.98,8.87); P< 0.0001] and Streptococcus mutans [OR (95% CI) 1.77 (0.89-3.54); P=0.03] were found to be risk factors for the development of periodontitis, while Aggregatibacter actinomycetemcomitans [OR (95% CI) 0.52 (0.33-0.83)] played a protective role for periodontitis. CONCLUSIONS: It seems that changes in the taxonomic composition of the microbiome rather than single targeted pathogens is the key determinant of periodontitis.