Micro(nano)plastics (MNPs) behaviour in the gastrointestinal (GI) tract is modulated by co-ingested food components, yet these effects remain poorly quantified. This study aimed to investigate how ghee, casein, and cellulose influence the transformation and cellular interactions of 200 nm polystyrene (PS) under simulated GI digestion. Changes in PS aggregation were evaluated in stomach and small intestinal digesta by the flow cytometer. The potential mucus penetration capacity of digested PS particles was further assessed through the spinning disk confocal microscopy, while mitochondrial activity and cellular interaction were examined using Caco-2 cells. The results showed that upon in vitro digestion, casein reduced PS aggregation, while cellulose and ghee promoted PS aggregation. The percentage of cells interacting with PS in cellulose, casein and ghee small intestinal digesta were 18.4% ± 3.1%, 36.0% ± 5.2% and 34.6% ± 7.8%, respectively. These results demonstrate that dietary composition influenced MP physicochemical evolution and downstream biological interactions.
Humans spend much of the day in the postprandial state, yet how acute dietary fat formulations shape lipid signatures associated with circulating extracellular vesicle (EV)-enriched fractions remains poorly understood. We conducted a randomized acute crossover pilot trial in apparently healthy adults who consumed fat-free, saturated fatty acid (SFA)-, monounsaturated fatty acid (MUFA)-, or MUFA-based meals supplemented with ω3 long-chain polyunsaturated fatty acids (MUFA + ω3). Plasma SEC-derived EV-enriched fractions were collected at fasting baseline (B), 2–3 h after meal ingestion (postprandial peak, P), and 5–6 h after ingestion (late postprandial phase, LP), and characterized by electron microscopy, nanoparticle tracking analysis, bead-based surface-marker profiling, untargeted UHPLC-MS/MS lipidomics, and targeted integration of proteomic markers. The recovered fractions showed vesicle-like morphology, comparable NTA-derived particle size distributions and concentrations, dynamic surface-marker profiles, and broad lipidomic coverage comprising 373 lipid species. Significant within-diet species-level changes were detected only at LP under SFA and MUFA + ω3, involving 45 and 57 lipid species, respectively. Eighteen altered species were shared between both formulations, all of them triacylglycerols (TG), whereas 27 were specific to SFA and 39 to MUFA + ω3. Between-diet analyses revealed persistent differences dominated by TG but also involving glycerophospholipids and sphingolipids, with the strongest divergence between SFA and MUFA + ω3 and greater concordance between MUFA and MUFA + ω3. Integration with plasma biochemistry identified an exploratory TG-centered systemic pattern, while proteomic analyses revealed associations of lipid remodeling with both EV-associated tetraspanins and ApoA/ApoB-related signals. These findings support plasma SEC-derived EV-enriched fractions as a dynamic postprandial molecular interface in which dietary fat quality is reflected through coordinated lipid remodeling across vesicular and apolipoprotein-related features.
