Young woman with a stomach ache in the bedroom, sitting holding her abdomen

Could a Fungus Be Causing Crohn’s Disease?

Crohn’s disease is a serious condition in which the immune system attacks and destroys portions of the intestines, causing pain, bleeding, diarrhea, fevers, and more—for reasons that are far from clear.

Now, new research suggests that a fungus may play a role in triggering this inflammatory bowel disease (IBD), which affects as many as 700,000 Americans. Crohn’s can happen at any age, even during childhood, although it’s most often diagnosed in teens or young adults.

An international research team found a link between a fungus, called Candida tropicalis, and Crohn’s disease in humans. (Previously, fungi have only been linked to the disease in mice.)

“Our study adds significant new information to understanding why some people develop Crohn’s disease,” the study’s senior author, Mahmoud Ghannoum, PhD, said in a news release. The findings could lead to new treatments, said Ghannoum, a professor and director of the Center for Medical Mycology at Case Western Reserve and University Hospitals Cleveland Medical Center.

In the study, the researchers analyzed fecal samples from nine families in France and Belgium. They included 20 Crohn’s patients and 28 close relatives who did not have the disease. They also examined samples from 21 Crohn’s-free individuals from four families living in same region.

Normal human intestines contain hundreds of bacteria and fungi species (known as the microbiome), which help digest food and protect against disease-causing germs. The researchers found an association between two types of bacteria, Escherichia coli and Serratia marcescens, and the fungus, C. tropicalis. Levels of these three were higher in family members with the disease, suggesting that they interact in the intestines. Further lab testing suggests that the bacterial-fungal trio forms a thin, slimy film. When that “biofilm” clings to a portion of the intestines, it may cause inflammation that results in Crohn’s disease symptoms, the news release noted.