Background
The gut–islets axis connects nutrient sensing in the intestine with insulin secretion from the pancreas and plays an essential role in glucose regulation. GLP-1 released by intestinal L cells can enhance β-cell insulin secretion, and bile acids have recently been shown to influence this process through receptors such as TGR5 and FXR. However, the interaction between gut-derived signals and islet responses is highly dynamic and difficult to reproduce with standard cell culture systems. Most in vitro models lack the three-dimensional structure and fluid environment needed to reflect physiological conditions. A platform that can better mimic gut–islets communication and allow controlled testing of metabolic regulators would therefore be valuable for studying glucose homeostasis and related diseases.
Research Progress
To address the limitations of conventional in vitro models, the research team developed a microfluidic platform that supports the three-dimensional growth of both intestinal L cells and pancreatic β cells. Using a porous hydrogel scaffold produced through droplet microfluidics, the cells were able to form uniform spheroids that remained stable and functional under continuous perfusion. This setup provided a more physiologically relevant environment for studying hormone secretion. Building on this structure, the team integrated a branching microchannel network capable of generating stable concentration gradients, allowing different bile acid levels to be tested in parallel. By connecting L-cell and β-cell compartments in sequence, the chip was able to reproduce a key feature of the gut–islets axis: bile acid–induced GLP-1 release and the resulting enhancement of insulin secretion. Among the bile acids examined, HCA produced the strongest effect on GLP-1 and showed a clear impact on downstream β-cell responses. The consistency of these results with known in vivo trends suggests that the platform can provide a reliable way to evaluate metabolic regulators under controlled conditions.
Future Prospects
The organ-on-a-chip platform offers a practical approach for examining communication between the gut and the islets under controlled conditions, and its applications can be expanded in several meaningful ways. Introducing additional cell types, such as liver cells or microbial components, would enable the system to represent more complex aspects of metabolic regulation. Its capacity to form stable chemical gradients and track hormone responses also makes it well suited for testing bile acid derivatives and other metabolic regulators. In the future, incorporating patient-derived cells may help establish personalized models that reflect individual differences in hormone secretion or drug sensitivity. As advances continue in microfluidic engineering, biomaterials, and analytical methods, such integrated platforms are expected to play an increasingly important role in studying metabolic diseases and supporting the development of new therapeutic strategies.
The complete study is accessible via DOI:10.34133/research.0923