Mycotoxins, secondary metabolites produced by molds, pose significant health risk through contamination of globally consumed cereals. Ochratoxin A (OTA), a prevalent mycotoxin in cereals, is associated with various health hazards, including immunotoxicity. This study explores the bioaccessibility of OTA in bread and its impact on the gastrointestinal barrier. A focus is placed on grape pomace (GP), a by-product of the wine industry, as a potential mitigator of OTA toxicity. Results demonstrate that GP reduces OTA bioaccessibility in the human gastrointestinal system from 94% to 81% at intestinal level, showing promise in limiting the absorption of the harmful toxin. Additionally, GP exhibits cytoprotective effects, enhancing cell viability and mitigating OTA-induced toxicity in both Caco-2 and Jurkat T cells. In view of the above, to understand the mechanisms by which OTA exhibits its toxic effects, flow cytometry was chosen as the main technique for the analysis of cell cycle, reactive oxygen species levels and mitochondrial parameters. Cytofluorimetric evaluation indicates GP's potential in limiting OTA-induced damage at cellular level. The study suggests that GP could serve as functional ingredient to reduce mycotoxin bioaccessibility and toxicity in cereal-based foods, offering a novel and promising approach to enhance food safety and protect public health. The finding highlights the potential of utilizing grape pomace in food formulations to mitigate mycotoxin contamination, providing a valuable contribution to the ongoing efforts to ensure the safety of globally consumed cereal products.