A berry-and-pomegranate compound may be the gut's secret repair tool

Researchers at the University of Louisville have discovered that urolithin A (UroA) — a compound naturally produced by gut bacteria when digesting pomegranates, walnuts, and berries — can activate a powerful protective mechanism in the intestinal lining. The findings, published in Nature Communications, could reshape how we think about treating inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis and affects millions worldwide.

The key lies in a protein called the aryl hydrocarbon receptor (AHR). Long known for its role in harmful inflammatory responses triggered by environmental toxins, AHR turns out to have a protective side too. When UroA activates AHR specifically in intestinal epithelial cells, it triggers the NLRP6 inflammasome — a cellular defense system — to repair the gut lining, boost protective mucus, and strengthen antimicrobial defenses rather than drive inflammation.

Key Takeaways:

• UroA selectively targets intestinal epithelial cells, making the response protective rather than harmful
• The mechanism was validated across cell studies, organoid models, and human IBD tissue samples
• This is the first study to show how a microbe-produced natural compound can regulate complex immune processes during intestinal injury

Why it matters: Current IBD treatments often broadly suppress the immune system, carrying significant side effects. This discovery points toward more targeted therapies that restore intestinal balance by harnessing the body's own repair pathways — a potentially safer and more precise approach for millions of IBD patients.