Fungi help to balance a healthy gut

Bacteria are not the only microorganisms in the gut that influence human health and disease. According to a new study, fungi play an overlooked role in the gut microbiome and immune system. 

Study senior author Dr. June Round is a professor of Pathology at the University of Utah Health. 

“Fungi have been wholly understudied in part because they are vastly outnumbered by bacteria,” explained Dr. Round, who noted that new tools and technologies are starting to make investigations like this one possible. “This work adds an important piece to the bigger picture.”

The study suggests that while fungi thrive in the healthy gut, they can cause intestinal damage that may contribute to inflammatory bowel disease (IBD).

Dr. Round said she became interested in this research after noting that a common medical test for diagnosing Crohn’s disease, a type of IBD, works by detecting antibodies against fungi. 

The researchers set out to investigate how antibodies affect fungi’s influence on disease by looking for the trigger of the immune response. 

Experiments and tests revealed that the yeast Candida albicans induced the strongest immune response. This particular type of fungi is one of the main species found in the human gut.

The researchers found that mice populated with the yeast in its normal, rounded state remained healthy. By contrast, the invasive form of Candida caused intestinal damage that resembled IBD. 

The results indicate that the gut’s antibody responses prevent disease by recognizing the harmful form of fungi. This new insight may lead to the development of therapies for treating IBD and for improving overall gut health.

Beyond the implications for disease, the findings also suggest fungi may play an important role in balancing a healthy gut. 

“The immune system is constraining Candida to its least pathogenic form,” said study lead author Dr. Kyla Ost. “This is showing us that the communication between host and microbe can be friendly, as opposed to antagonistic, in order to benefit both.”

The study is published in the journal Nature.

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By Chrissy Sexton, Earth.com Staff Writer