Cedars-Sinai Blog

Research Closeup: Fungus and Crohn's disease

Illustration by Edmon de Haro

It's true: There's fungus among us. And on us. And inside us.

The "fungome" is the fungal community within our body's microbiome. The microbiome is the ecosystem of organisms—mostly bacteria—that lives on our skin and in our guts.

Microbiome research has mostly focused on how the bacteria might influence our health, but now Cedars-Sinai researchers are uncovering ways fungi can affect us, too.

In Discoveries: FUNGOME /fuhng-ohm/

Crohn's disease and the fungome

A recent study by Jose Limon-Tello, PhD and David Underhill, PhD, found the presence of a specific fungus—Malassezia—in some patients with Crohn's disease.

Researchers specifically studied patients with Crohn's disease who also carry a gene mutation known to be important for defending against fungal infections. They compared the gut fungus of this group with that of a group of healthy patients.

In patients who have Crohn's disease and the gene mutation, Underhill and Limon-Tello found high concentrations of Malassezia.

"This suggests that there's something going on both from a microbiome and a genetics point of view," says Underhill.

Headshot for David Underhill, PhD

David Underhill, PhD

Physician Specialities

David Underhill, PhD

Physician Specialities
In-person Visits

What is Malassezia's function?

Malassezia is an organism commonly found on the skin of all sorts of mammals, including humans. On the skin and in hair follicles, Malassezia is usually linked to dandruff.

Underhill and Limon-Tello are now curious whether the overgrowth of this particular fungus in the gut might be making Crohn's symptoms worse.

Investigators maintain there's a lot we don't know about Malassezia's purpose in our bodies: Does it protect us from other conditions? Does it truly make Crohn's worse?

Eventually, Underhill and Limon-Tello hope to develop clinical trials aiming to rid the body of Malassezia to figure out its impact on the debilitating disease.

"We know the bacteria in your microbiome influence diverse areas of health—everything from digestion, immune response, reactions to cancer therapy, and even our behavior," Underhill says.

"We're excited to discover whether fungi also have such broad influence in our bodies."