Madrid, 16 July. (European Press) –
Much has been researched on the role of bacteria in gut health in recent years, but a new study led by scientists at the University of Utah Health in the US shows that fungi, another microorganism that lives inside us, can be just as important to health. and disease.
Fungi thrive in a healthy gut, but they can also cause damage to the gut that can contribute to inflammatory bowel disease (IBD), according to the study published in Nature. Experiments in mice show that the immune system usually keeps the fungus at bay, attacking the microbe when it gets into a condition that can cause harm. When the system becomes unbalanced, disease is more likely to occur.
Dr. John Round, UCSD Professor of Pathology and lead author of the study explains: “Fungi have been studied very little, in part because they are so much more numerous than bacteria. New tools and techniques have begun. To make research like this possible and this work adds an important piece to the picture. The big one.”
This knowledge opens up new avenues for developing treatments that improve gut health. The study shows proof of concept that vaccines could one day be used to reduce gastrointestinal disease by promoting natural immune responses that promote a healthy balance of fungi and other gut microbes.
Round became interested in this type of research after noticing that a common medical test for diagnosing Crohn’s disease, a type of inflammatory bowel disease, works by detecting antibodies against the fungus. However, how antibodies affect the disease has not yet been studied.
To dig deeper, his team looked for the trigger for the immune response. Working with patient samples and testing mice, they found that the yeast Candida albicans – one of the main types of fungi found in the human gut – elicits the strongest immune response.
Other research has shown that the antibodies targeted elongated types of fungal cells called hyphae, which specifically bind to proteins called adhesions that help microbes adhere to surfaces and become invasive.
With this goal in hand, researchers have been able to more specifically investigate the role of fungi in gut health. They found that the yeast-inhabited mice in their normal, rounded state remained healthy. Instead, mice inhabited with “candida” in its invasive form caused intestinal damage similar to IBD. The results showed that normal antibody responses in the gut prevent disease by recognizing the harmful form of the fungus.
Inflammatory bowel disease is not the only health problem associated with fungi. Another is a vaginal yeast infection. The researchers found that a vaccine being investigated as a treatment for fungal infections elicited an immune reaction against adhesion proteins similar to that of Crohn’s disease patients. When the vaccine was vaccinated, mice normally exposed to a condition similar to IBD were less likely to develop the disease.
Researchers are now studying whether vaccines can help alleviate IBD in people, and whether the same approach can be applied more broadly to forming other gut microbial communities. “Our goal is to exploit interactions between the commensal microbes and the host’s immune system to harness microbial products for therapeutic purposes,” says Round.
In addition to the effects on disease, the findings also suggest that fungi may be important in a healthy gut. Normally, the immune system is responsible for eliminating the infection by getting rid of the invading organisms. In this case, the fungi benefit from their interaction with the antibodies. The immune reaction causes the fungus to transition from its invasive state to its round and budding state, improving its survival in the intestine.
“The immune system limits Candida to its least pathogenic forms,” says Dr. Kyla Ost, a postdoctoral researcher in the Round lab and lead author of the study. Friendly, not hostile, to the benefit of both.
