Annual congress of the Swiss Society for Allergology and Immunology, Bern, Switzerland, 24 - 25 August 2023, no.42, pp.19
The barrier function of the epithelia is crucial for maintaining homeostasis. Environmental exposures, such as food additives may alter the epithelial barrier integrity and influence development of diseases. In the present study, a microfluidic-titer plate was used to enable the formation of an epithelial barrier by Caco-2 cells to examine the effects of commonly used food additives. Several commonly used food additives, such as sunflower- derived lecithin (SunLec), DATEM, sodium saccharin (NaSa) and carboxymethylcellulose (CMC), were examined at consumer-relevant doses using transepithelial-electrical resistance (TER) and targeted proteomics. Results showed that DATEM, SunLec and NaSa exhibited a dose-dependent cytotoxicity exceeding 40% when exposed to 0.25 mg/ml of DATEM, 0.39 mg/ml of SunLec and over 20% when exposed to NaSa above 1.56 mg/ml. However, CMC did not have any cytotoxic effect. DATEM, SunLec and NaSa elicited a dose- and time-dependent decrease of relative TER. Although CMC did not exhibit any effects on cytotoxicity and barrier integrity, it induced the production of pro-inflammatory molecules, as observed with DATEM, SunLec, and NaSa. SunLec and DATEM specifically upregulated cytokine-mediated signaling pathways, such as NOD-like receptor and MAP kinase pathways. Conversely, CMC resulted in upregulation of proinflammatory and profibrotic mediators. NaSa upregulated chemokines associated with granulocyte chemotaxis and response to IL-1β. In conclusion, current data show that commonly used food additives cause epithelitis and disrupt gut barrier integrity.