Polysorbate 80 (P80), a widely used food emulsifier present in ice creams, sauces, baked goods, and many processed foods, has been linked to gut barrier disruption and inflammation, though the underlying mechanisms remain unclear and the relevance to chronic inflammatory and allergic disease is poorly defined. We investigated P80's effects on the intestinal barrier and systemic inflammation in Caco-2 cells, iPSC-derived intestinal organoids (HIOs), mice, and primary human B cells.
Caco-2 cells and HIOs were exposed to P80 across a dose range. Cytotoxicity was assessed by MTT, ROS by DCFDA, NF-κB and AhR activation in HCT116 and HepG2 reporters, and mitochondrial potential by JC-1. Barrier integrity was evaluated by transepithelial electrical resistance (TEER) and FITC-dextran flux, with tight junction architecture assessed by ZO-1 and occludin staining. Mice received acute (2.5%, 4 days) or chronic (1%, 6 weeks) P80, followed by multi-organ proteomics, spatial transcriptomic profiling (STRIDE), bulk transcriptomics, 16S sequencing, and lipidomics. Single-cell metabolic state was profiled by SCENITH (Single Cell ENergetIc metabolism by profilIng Translation inHibition). Primary B cells from two donors were exposed to 0.005% or 0.02% P80 and assayed for immunoglobulin class-switch transcripts.
P80 reduced viability at 0.05%, with dose-dependent rises in ROS (up to 4-fold) and NF-κB (up to 150-fold), both reversed by N-acetylcysteine. JC-1 showed loss of mitochondrial potential in organoids, accompanied by reduced TEER and increased paracellular permeability. In mice, P80 induced oxidative and ER stress, impaired DNA repair, triggered apoptosis, elevated inflammatory mediators (S100a4, IL-5, MAP2K6, CCL2, TGF-α), and caused mitochondrial DNA breaks. SCENITH revealed a shift toward fatty acid oxidation, and PPARα or CPT-1 inhibition reversed ROS and NF-κB. RNA-Seq of the colon revealed increased inflammation and fatty acid catabolism in treated mice alongside decreased mitochondrial translation. GSVA of GO Biological Process pathways confirmed coordinated upregulation of lipid oxidation, lipid catabolism, fatty acid metabolism, regulation of fatty acid oxidation, ROS biosynthesis, and TOR signaling in P80 treated colons, paralleled by enrichment of acute inflammatory response, B cell receptor signaling, leukocyte and neutrophil chemotaxis, lymphocyte and T cell differentiation, and T helper 17 type immune response, while protein import into mitochondrial matrix and mitochondrial translation were suppressed. In primary human B cells, 0.02% P80 significantly increased IGHE transcripts (log2FC ≈ 4.5, p < 0.0001) over positive control across both donors, while IGHG1 was not significantly affected (p = 0.994 and p = 0.283), suggesting selective promotion of IgE class switching that warrants validation in larger donor cohorts.
P80 drives oxidative stress, mitochondrial dysfunction, and NF-κB inflammation via PPARα driven fatty acid oxidation, causing barrier breakdown and systemic immune activation. Rescue by N-acetylcysteine and CPT-1 inhibition identifies fatty acid metabolism derived oxidative stress as the central driver, while chronic exposure skews mucosal immunity toward Th17 and IgE biased responses. Given the ubiquity of P80 in the Western diet, these findings position emulsifier exposure as a plausible environmental contributor to inflammatory bowel disease, food allergy, and other Th17 and IgE associated pathologies, and identify CPT-1 and PPARα as candidate intervention nodes.