Fungi and bacteria in the gut can also impact human health and the severity of disease.

The gut microbiome has received a lot of attention, but new research shows that fungi in the gut are also an important microorganism in the functioning and health of the gut, which in turn affects human health.

Intestinal health. Image Credit: metamorworks / Shutterstock.com

Contrasting effects of fungal communities in the gut

In recent years, the role of microbial diversity and richness in the gut has prompted extensive research into the benefits of maintaining a healthy gut microbiome. This has led to the rise of probiotic supplements, microbial treatments, but research now shows that bacterial communities are not the only players in the gut to generate such benefits.

In a new study by scientists at the University of Utah Health, fungi have also been shown to be key players in the balance of healthy bowel function. The study, published in the journal Nature, describes how fungi thrive in a healthy gut, but they can also cause intestinal damage that can contribute to inflammatory bowel disease (IBD).

Fungi have been totally under-studied in part because they are vastly outnumbered by bacteria. This work adds an important element to the bigger picture. “

June Round, Ph.D., professor of pathology at the U of U Health

To explore the role of fungi in the gut, researchers conducted experiments with mice to demonstrate how a healthy immune system maintains healthy diversity and abundance of fungi, but when the system is out of balance, IBD is more likely to happen. Initial hypotheses were made after Round noted that a common medical test to diagnose Crohn’s disease, a type of IBD, relies on the detection of antibodies to fungi, but the role of fungi themselves on them. antibody is unknown.

To fill this knowledge gap, researchers investigated the trigger for the immune response to IBD. Data from samples from patients affected by the disease were used to design experiments in mice, from which the researchers found that the yeast Candida albicans elicited the strongest immune response. This species is one of the main species of fungi that reside in the human gut, providing key information for the team to further explore the role of gut fungi.

Upon detection, scientists found that antibodies produced by the immune response targeted hyphae, which are types of fungal cells, which bind to proteins that help microbes adhere to surfaces and become invasive. This mechanism was key evidence for researchers to demonstrate the role of fungi in balancing gut health.

A fragile balance in the gut but with potential supportive treatments

Using a series of experiments on mice, the researchers found that mice inoculated with Candidiasis in its normal state has remained healthy, but when administered with Candidiasis in its invasive form, it caused intestinal damage that looked like IBD. The results demonstrated how a healthy immune response in the gut inhibits disease by recognizing the harmful hyphae form of the fungi.

However, IBD is just one of the many health problems associated with fungi, which also include conditions such as vaginal yeast infections. The researchers therefore used existing vaccines tested for yeast infections and found that the vaccine elicited an immune reaction against adhesin proteins similar to the reaction in patients with Crohn’s disease.

The vaccine has been effective in the population of mice prone to IBD-like disease, and researchers are now convinced that similar vaccines could help alleviate IBD and related diseases in humans.

Kyla Ost, Ph.D., postdoctoral fellow in Round’s lab and lead author of the described study; “The immune system is binding Candidiasis at its least pathogenic form, “adding,” This shows us that communication between host and microbe can be friendly, as opposed to antagonistic, to the benefit of both. “

Usually, a typical immune response is to clear infections by eliminating invasive organisms. However, fungi benefit from their interaction with antibodies, as they push fungi from their invasive state to their rounded and budding state, which improves the survival of the fungi in the gut.

These results provide important information on how the gut works as it is the first study to show that fungi benefit from the production of antibodies, which could offer potential treatments to fight gastrointestinal disease. but also that mushrooms are essential for maintaining a healthy gut.