Gut Fungi Imbalance Could Cause Intestinal Damage

New research led by scientists at the University of Utah Health shows how fungi thrive in the healthy gut, but they can also cause intestinal damage that may contribute to inflammatory bowel disease. Their study was published in Nature. 

"Fungi have been wholly understudied in part because they are vastly outnumbered by bacteria," says senior author June Round. "This work adds an important piece to the bigger picture." To dig deeper into fungi’s influence on disease, her team explored how its imbalance triggers immune responses. Working with patient samples and carrying out tests with mice, they determined that the yeast Candida albicans elicited the strongest immune response. Further investigation showed that antibodies zeroed in hyphae, specifically binding to proteins called adhesins that help microbes stick to surfaces and become invasive.

With this target in hand, the researchers could more definitively probe the fungi's role in gut health. They found that mice populated with the yeast in its normal, rounded state remained healthy. In contrast, mice populated with Candida in its invasive form caused intestinal damage that resembled IBD. The results show that normal antibody responses in the gut inhibit disease by recognizing the harmful, hyphal form of fungi.

The researchers are now investigating whether vaccines could help mitigate IBD in people—and whether the same approach can be applied more broadly to shape other microbial communities in the gut. "We aim to exploit interactions with commensal microbes and the host immune system to harness microbial products for therapies," Round concludes.