Video 1_Postbiotic sequestration of micro- and nanoplastics: in vitro intestinal epithelial protection and proof of concept in the human mouth.mov

Transfer of PSNP fluorescence from Qi601–PSNP agglomerates to Caco-2 cells remained ≤ 0.057%. Atomic force, scanning electron, and confocal microscopy demonstrated close physical association between Qi601 and PSNPs with predominantly extracellular localization of Qi601-associated PSNPs. In a qualitative human proof-of-concept chewing-gum experiment, microscopy of saliva showed heterogeneous, Nile Red-positive polymers within or closely associated with Qi601 agglomerates.

Laser direct infrared (LDIR) chemical imaging showed that the number of rubber-class particles from the gum-plus-Qi601 saliva sample was 43% lower than from the gum-only sample (2,562 versus 4,529 particles; hit quality index ≥ 0.70); after procedural-control subtraction, the background-adjusted rubber particle count was approximately 91% lower (185 versus 2,152 particles; hit quality index ≥ 0.70). These findings establish proof of concept for postbiotic-mediated sequestration of dietary MNPs and support a model in which Qi601 limits their epithelial association and intracellular burden.

To our knowledge, this represents the first human in vivo proof-of-concept study directly demonstrating physical association between an administered intervention designed to capture microplastics and microplastic particles. Further studies should define the molecular basis of Qi601–MNP interactions, characterize their gastrointestinal fate, and validate these findings in larger studies.</p>