Unexpected cause of intestinal inflammation revealed

Inflammatory bowel diseases — Crohn's disease and ulcerative colitis — affect millions of people worldwide, yet the mechanism of their development still remains a mystery. Neither cell cultures nor animal experiments have made it possible to reproduce the disease in its entirety. Now scientists have presented a breakthrough development: the first comprehensive model of both diseases simultaneously, described in the journal Nature Biomedical Engineering.

Bioengineer Alican Ozkan from Harvard University, together with colleagues, created what is known as a "Colon-Chip" — a miniature microfluidic device populated with cells from patients with Crohn's disease and ulcerative colitis. The uniqueness of the platform lies in the fact that it reproduces not only the cellular environment of the intestine but also the mechanical stretching of its walls, simulating natural peristalsis.

However, the most striking finding was a discovery no one expected. Fibroblasts — connective tissue cells long considered merely passive "scaffolding" of organs — turned out to be active participants in the inflammatory process. When healthy epithelial cells were placed on the chip alongside fibroblasts taken from affected patients, the healthy cells began behaving as if they were diseased: the intestinal barrier weakened, and the levels of inflammatory markers increased. Moreover, fibroblasts alone — without any other components of the inflamed environment — proved sufficient to trigger the pathological cascade.

In addition, the "Colon-Chip" for the first time under laboratory conditions made it possible to reproduce flare-ups characteristic of pregnant women with inflammatory bowel