Fig. 3

Microbial co-culture on a human intestinal epithelial layer in a gut-liver axis chip. Both wild type and experimental microbial were cultured on the surface of an epithelial layer grown within a gut-liver axis chip (HY7014 and HY7207 probiotic; HY7014w and HY7207w as a control of the wild type; seeding density 1 × 10⁹ CFU/mL). Green fluorescence views from above of probiotics and Caco-2 cell co-cultured for 5 and 10 days at low and high (white-dotted rectangle) magnification, which shows microcolonies of the microbial (green spots) that remain tightly adherent to the apical surface of the epithelial layer after exposure to continuous fluidic flow. Scale bars are 100 μm