11A bio-inspired coating consisting of pectin (polygalacturonic acid) and cationic cellulose nano-12 fibers were successfully produced by the Layer-by-layer method. The build-up and the morphol-13 ogy of the resulting coatings were studied with spectroscopic ellipsometry and atomic force mi-14 croscopy, respectively. The coating was able to survive the exposure of a simulated gastric fluid, 15 but was partially degraded upon exposure to pectinase enzyme, which simulate the action of the 16 microbial symbionts present in the human colon. Prior to exposure, the oxygen permeability co-17 efficient of the coating (0.033 ml (STP) mm m -2 day -1 atm -1 at 23°C and 20% RH) was in the 18 same order of magnitude as for ethylene vinyl alcohol films (0.001-0.01 ml (STP) mm m -2 day -19 1 atm -1 ). However after exposure to the mimicked gastrointestinal (GI) tract conditions, the con-20 tribution of coating to the overall barrier properties was not measurable. 21 22