Fig. 1. Antimicrobial properties of probiotic’s cell-free supernatant.

Flow cytometric quantification of antimicrobial properties of the cell-free supernatant (CFS) of the probiotic candidates (postbiotic) on the membrane permeability, as a proxy for viability, of periodontal pathobionts after 6 h of incubation in the postbiotic. Data presented as mean and standard deviation of log₁₀ of total events per mL (Log(Events/mL)) and percentage composition of the total divided into classes according to their permeability/viability: green = intact/live, red = permeable/dead and yellow = intermediate permeability/partially damaged membrane. Gates were defined according to the degree of red fluorescence through the entry of propidium iodide into healthy- and killed cultures (Supplementary Figs. 2 & 3). Statistical differences in remaining live cells compared to the control (n = 3, ANOVA with Tukey HSD) are depicted with an asterisk.