Food-additive exposure increases permeability in a human gut cell co-culture model. Food-additive exposure increases permeability in a human gut cell co-culture model. Lucifer Yellow (LY) permeability following exposure of the Caco-2/HT29-MTX cell monolayer to: (A) TiO2 or TiO2-free (control) food digest for 4 h (n=6), (B) control (5 mM glucose+20 mM mannitol) or high-glucose (25 mM; HS) culture medium for 2 h (n=12, P<0.0001), or (C) control or HS culture medium for 24 h (n=12, P=0.0031). F-test-generated P-values denote significant differences between treatments and controls according to a non-linear fit for a linear model for each sample set. Matthew T. Pereira et al. Dis. Model. Mech. 2018;11:dmm034520 © 2018. Published by The Company of Biologists Ltd