Poultry-derived <i>Lactiplantibacillus</i> sp. PCE3 cell-free supernatant inhibits <i>Candida albicans</i> biofilm biomass and hyphal morphogenesis <i>in vitro</i>

AIMS: To evaluate whether the cell-free supernatant (CFS) of a poultry-derived Lactiplantibacillus sp. strain PCE3 can inhibit biofilm biomass accumulation and hyphal morphogenesis of Candida albicans ATCC 10231 in vitro. METHODS AND RESULTS: Biofilm biomass was quantified by crystal violet staining after 48 h growth in RPMI 1640 plus 2% glucose with 10%, 20%, or 40% (v/v) CFS. Filamentation was induced in RPMI 1640 plus 10% fetal bovine serum at 37°C and assessed qualitatively by light microscopy, scanning electron microscopy, and representative 24 h microscopy observations. Planktonic growth was summarized by 24 h colony-forming unit counts. CFS inhibited biofilm biomass in a concentration-dependent manner, with mean inhibition of 29.6 ± 8.3%, 48.1 ± 7.2%, and 79.8 ± 5.8% at 10%, 20%, and 40% (v/v), respectively (all p < 0.05 vs control). Under hypha-inducing conditions, 40% CFS shifted morphology from extensive filamentation in untreated controls to predominantly moderate or suppressed filamentation, and representative microscopy supported persistence of this non-filamentous phenotype over the observation period. Planktonic viable counts decreased by up to approximately 1.1 log10 at 40% CFS, indicating partial growth inhibition without eradication. CONCLUSIONS: Poultry-derived Lactiplantibacillus sp. strain PCE3 CFS showed in vitro anti-virulence activity against C. albicans, reducing biofilm biomass and restraining filamentation more strongly than planktonic growth. These findings support avian-derived postbiotic preparations as an underexplored source of anti-Candida activity for further characterization and validation.