Fig. 4. Comparison of the effects of Fusobacterium nucleatum and Streptococcus pneumoniae on inflammatory cytokine production. BEAS-2B (a), A549 (b), and Detroit 562 (c) cells were treated with heat-inactivated F. nucleatum (1 × 10⁸ CFU/ml) or heat-inactivated S. pneumoniae (1 × 10⁸ CFU/ml) for 12 h. IL-8 and IL-6 levels in the cell culture supernatants were determined using ELISA and expressed as pg/ml. Data are presented as the mean ± SD. *; a value below the detection limit.