Researchers in Belgium have discovered, in a mouse study, that a gene mutation long linked to psoriasis also affects gut function. Psoriasis is a chronic, non-contagious skin condition caused by an overactive immune system. It leads to red, scaly patches and skin inflammation and may affect other organs, including the gut.  

Scientists at the VIB-UGent Center for Inflammation Research, an EARA Member, studied the role of the gene CARD14, which was already known for driving inflammation in the skin of psoriasis patients, in the gut. They engineered mice to carry a psoriasis-related CARD14 mutation in their intestinal lining. The animals showed slower gut transit, subtle inflammation and changes in gut microbes, even though their intestinal tissue remained intact. 

The researchers found that the CARD14 mutation altered the activity of intestinal cells, including cells that help control bacterial populations. This reduced antimicrobial defences and increased the animals’ susceptibility to bacterial gut infection. 

“Our study shows that CARD14’s impact isn’t limited to the skin,” said Aigerim Aidarova, first author of the work published in EMBO Molecular Medicine. “In the intestine, this mutation leads to subtle but important changes that may contribute to symptoms in patients who carry it.” 

By linking a skin-disease gene to intestinal health, the study highlights how genetic factors can influence multiple organs and adds to the understanding of the mechanisms underlying autoimmune diseases, which are still poorly characterised.