TRANSLATIONAL AND CLINICAL MEDICINE - Georgian Medical Journal

Abstract

Background

Periodontitis is defined as an inflammatory disease of the supporting tissues of the teeth caused by specific microorganisms or groups of specific microorganisms, resulting in progressive destruction of the periodontal ligament and alveolar bone with increased probing depth formation, recession, or both (1)

Current evidence from microbiome studies indicates that periodontal disease is not caused by a single pathogen, but by complex polymicrobial interactions. The development of sequencing technologies has significantly expanded the understanding of microbial diversity, composition, and function in periodontal diseases (2, 3)

Aim

This review critically evaluates methodologies used to investigate the gingival microbiome in patients with periodontitis, focusing on their advantages, limitations, and clinical relevance.

Methods

A structured literature review was conducted using existing studies. The studies included human studies investigating the gingival or subgingival microbiota in periodontitis using culture-based, molecular, and high-throughput sequencing techniques. The methodologies included polymerase chain reaction (PCR), DNA-DNA hybridization, 16S rRNA gene sequencing, next-generation sequencing (NGS), and shotgun metagenomics (4)

Results

Analysis of studies shows that culture-independent molecular approaches are preferred in modern research on the periodontal microbiome. 16S rRNA gene sequencing is the most commonly used technique for taxonomic profiling, whereas shotgun metagenomics provides higher-resolution profiling at the species and functional levels. Studies consistently report increased microbial diversity and enrichment of anaerobic, proteolytic taxa during periodontitis. However, significant differences in sampling strategies, sequencing platforms, and workflows limit reproducibility and comparability across studies (5)

Conclusion

Modern microbiome research has significantly improved our understanding of periodontitis as a disease caused by dysbiosis. Despite these advances, standardization of protocols and integration of multi-omics approaches remain challenges.

 Keywords:  Periodontitis; Gingival microbiome; Subgingival biofilm; Dysbiosis; 16S rRNA sequencing; Shotgun metagenomics; Next-generation sequencing; Oral microbiota