# Human Gut–Brain Interaction Chip for Dissecting the Gut-Derived LPS and Butyrate Regulation of the Blood–Brain Barrier

## TL;DR

A new organ chip is developed to study how gut-derived substances like LPS and butyrate affect the blood-brain barrier, offering insights into gut-brain interactions and potential therapies.

## Contribution

A novel organ chip with 3D multicellular cultivation and microfluidics is introduced for studying gut-brain axis interactions.

## Key findings

- The chip's IEB and BBB models showed better barrier function and transporter activity compared to static transwell systems.
- Butyrate protected the BBB from LPS-induced dysfunction by improving intestinal barrier function.
- The chip simulates fluidic shear stress, making it a promising tool for gut-brain interaction research.

## Abstract

The gut–brain axis (GBA) interaction is important for human health and disease prevention. Organ chips are considered a solution for GBA research. Three-dimensional (3D) cultures and microfluidics engineered in an organ chip could improve the scientific knowledge in the GBA interactions field. In this study, a novel organ chip is developed, which achieves multicellular three-dimensional cultivation by utilizing a decellularized matrix. In addition, this paper reports the rapid prototyping process of the GBA microfluidic chip in polydimethylsiloxane (PDMS) using 3D printing interconnecting poly(ethylene/vinyl acetate) (PEVA) microchannel templates. In comparison to the static culture system of the transwell model, the intestinal epithelial barrier (IEB) and blood–brain barrier (BBB) models on our chip demonstrated superior barrier function and the efflux functionality of transporters under appropriate fluidic conditions. Additionally, it is observed that butyrate protected against BBB dysfunction induced by gut-derived lipopolysaccharide (LPS) via enhancing intestinal barrier function. These results demonstrate that this multicellular, three-dimensional cultivation integrated with a fluidic shear stress simulation chip offers a promising tool for gut–brain interaction study to predict therapy of intestinal and neurological disorders.