The intestinal tract, home to 100 trillion bacteria, also hosts a bevy of fungi that may contribute to inflammatory bowel ailments like Crohn’s disease and colitis, a study suggests.
Researchers at Cedars-Sinai Medical Center in Los Angeles found 200 different types of fungi in the guts of mice, half of which they couldn’t name, according to a report in the journal Science. They also uncovered a genetic variation in a protein called Dectin-1 that helps white blood cells recognize and kill fungi. Mice with the variation had more inflammation.
Future research may yield similar results in people, said David Underhill, director of Cedars-Sinai Medical Center’s graduate program in biomedical science and translational medicine. The researchers suggested the fungi may also play a role in ulcerative colitis, a disease marked by ulcers in the lining of the large intestine. Patients with a variant in the Dectin-1 gene had more severe disease, the study found.
“We can speculate wildly about whether immunity to the fungi in the gut, or altered immunity to fungi in the gut, is playing a role in the severity of the disease,” Underhill said in a telephone interview. “Further studies are required to determine in humans if that’s the case.”
The research shows the gene is important for controlling inflammation in animals like mice, said Underhill, the paper’s lead author. It may take years to figure out if it’s really a defective version of the gene of if something else is going on.
“We have recently developed a rich and growing understanding of how the immune system interacts with bacteria in the gut,” Underhill said. “This study will encourage folks to consider as well how the immune system is interacting with the fungal community in the gut.”
© Copyright 2025 Bloomberg News. All rights reserved.