Determination of the ability of native potential probiotic lactobacillus strains in nanoplastic bioremoval in an in-vitro Model

Nanoplastics (NPs) are emerging environmental pollutants that pose significant health risks, particularly due to their accumulation in the gastrointestinal tract. This study evaluates the ability of 88 native probiotic Lactobacillus strains to remove polystyrene nanoplastics (PS-NPs) in an in-vitro model. Three resistant strains L. plantarum RP13, RP134, and RP225-were selected based on disk diffusion screening. A cocktail of these strains demonstrated high percentages of NP binding: 77 % ± 2.5 at 0.1 mg/mL, 76 %± 2.1 at 0.2 mg/mL, and 67 %± 3.0 at 0.4 mg/mL. Among individual strains, RP13 exhibited the highest removal capacity. Fluorescence and electron microscopy confirmed PS-NP adhesion to bacterial surfaces. Zeta potential measurements showed a shift from -30.32 mV to -21.87 mV after bacterial exposure, indicating surface interaction. Cytotoxicity assays on HT-29 cells revealed dose-dependent toxicity of PS-NPs, which was significantly reduced by treatment with the Lactobacillus cocktail most notably at concentrations between 62.5 and 15.62 µg/mL. These promising in-vitro results suggest that our native probiotic Lactobacillus strains may offer a sustainable strategy for mitigating nanoplastic toxicity in the gastrointestinal tract; however, validation through in-vivo studies is essential to confirm their therapeutic potential and translational relevance.