Periodontal infectogenomics: systematic review of associations between host genetic variants and subgingival microbial detection

Background: Recent research is increasingly showing that host genetic variants can affect the colonization by specific microbes. The aim of this study was to systematically investigate the associations between host genetic variants and subgingival microbial detection and counts. Materials and Methods: A systematic search of the literature was conducted in Ovid Medline, Embase, LILACS and Cochrane Library for studies reporting data on host genetic variants and detection of microbes subgingivally. Results: A total of 43 studies were included in the review, from an initial search of 3887 titles. Studies consisted mainly of candidate gene studies and of one genome-wide analysis. Some promising associations were detected between single nucleotide polymorphisms and microbial detection. The only feasible meta-analysis failed to show any association between Interleukin 1 (IL1) genetic variants and detection of periodontopathogenic bacteria subgingivally. Conclusions: There is no evidence yet that neither IL1 genetic polymorphisms nor other investigated genetic polymorphisms are associated with presence and counts of subgingival bacteria. Further studies on large populations with replication samples should clarify the possible effects of other genetic variants on the subgingival microbiota.