The brain and gut have been shown to influence each other in a number of ways, one of which is the travel of secreted signaling compounds via the bloodstream. Signals and compounds induced or secreted from the complex microbiota of the gut can induce effects in the brain, which can play into the progression of neuropathological conditions.
Due to the complexities of both organs, culturing both types on a single platform can be difficult. Animal models do not address the bi-directionality of communication between the brain and gut. Ecological differences between animals and humans, particularly in the composition of the gut microbiota, cause data from animal models not to be accurately comparable to human trials.
In vitro models with three-dimensional, microfluidic environments allow cells to grow to in vivo functionality. With dynamic in vivo fluid flow, these models also permit the study of gut and brain barriers with mechanical factors like shear stress.