discoveries magazine

No-Fun Fungus: Head and Shoulders and Gut

Illustration: Alexei Vella

Crohn’s disease inflames the digestive tract, causing abdominal pain, diarrhea, fever, nausea and other unpleasant symptoms. While the chronic disease can be managed, its causes remain a mystery. But Cedars-Sinai investigators may have found a clue.

David Underhill, PhD, and his team found that many patients with Crohn’s also had high concentrations of a fungus called Malassezia in their digestive tracts. Malassezia is omnipresent on human skin and can cause dandruff but is harmless for most people.

“This suggests that there’s something going on both from a microbiome and a genetics point of view,” says Underhill, the Janis and William Wetsman Family Chair in Inflammatory Bowel Disease.

The team now wants to learn whether Malassezia gut overgrowth might be making Crohn’s symptoms worse. But the fungus might not be all bad. Underhill says we still have much to learn about its purpose in our bodies: Does it protect us from other conditions? Does it truly make Crohn’s worse?

The investigators hope to develop clinical trials to remove Malassezia from the body to answer these questions. And maybe even reduce dandruff.