Genetic Polymorphism of IL-1A, IL-1B and TNFA Predicting the Presence of Periodontopathogenic Bacteria

<b>Background/Objectives:</b> Periodontitis is a chronic inflammatory disease characterized by complex interactions between periodontal pathogens and the host immune response. Pro-inflammatory cytokines, particularly interleukins, may influence bacterial colonization and disease expression, but their association with specific periodontal pathogens remains unclear. This study investigated the associations between single-nucleotide polymorphisms in <i>IL-1A</i>, <i>IL-1B</i>, and <i>TNFA</i> and the presence of key periodontopathogenic bacteria in patients from Croatia. <b>Methods</b>: A cross-sectional study included 63 participants. Genotypes were determined, and subgingival plaque samples were analyzed for <i>Aggregatibacter actinomycetemcomitans</i>, <i>Porphyromonas gingivalis</i>, <i>Prevotella intermedia</i>, <i>Tannerella forsythia</i>, and <i>Treponema denticola</i> using real-time PCR. Multivariable logistic regression models assessed associations between cytokine gene polymorphisms and periodontopathogenic bacteria presence, adjusting for age, gender, smoking status, and the presence of systemic diseases. <b>Results</b>: Among participants (median age 57.0 years, IQR 43.5-67.0; 58.7% female), <i>P. intermedia</i> (87.3%), <i>T. forsythia</i> (85.7%), and <i>T. denticola</i> (69.8%) were the most prevalent pathogens. The <i>IL-1A</i> CC genotype significantly increased the odds of <i>P. gingivalis</i> (OR = 5.54; <i>p</i> = 0.009) and <i>T. denticola</i> (OR = 3.77; <i>p</i> = 0.041) presence. The <i>IL-1B</i> CC genotype was independently associated with <i>T. forsythia</i> (OR = 8.48; <i>p</i> = 0.026). No significant associations were observed for <i>TNFA</i> polymorphism. Model performance ranged from moderate to good (AUC up to 0.89). <b>Conclusions</b>: Genetic variants in <i>IL-1A</i> and <i>IL-1B</i> may influence periodontal bacterial colonization, while demographic and lifestyle factors showed limited impact. Further studies in larger cohorts are warranted.