Hi Asli, This is a very important question and thank you for asking this.
1. Current models are 2D monolayers, transwell models, bioreactor models. In the discussion section of the paper, we touched base on the limitation of these and especially why these models do not provide an attractive solution for host-microbiome interactions. And of course there are animal models which comes with its own challenges, the biggest one being differences in animal vs human microbiome.
2. It is known fact that current models can only sustain bacterial growth for <24 hours followed by overgrowth of this bacteria. Our dynamic chip helps bacteria to grow and provide in vivo like environment of multilayer epithelium, low O2 gradient and episodic flow.