Two studies published in Nature: The Clinical Microbiome reveal that certain gut fungi play a significant role in the development of immune dysregulation and pediatric allergic diseases, suggesting new possibilities for therapeutic interventions. The findings were announced on June 23 by research teams based at BC Children's Hospital Research Institute and the University of Calgary.
One study led by Dr. Stuart Turvey at BC Children's Hospital Research Institute analyzed data from the CHILD Cohort Study, indicating that specific fungal species serve as markers of early-life microbial development. The research found these markers may help predict whether a child could develop conditions such as atopic dermatitis or food allergy by age five.
A separate study conducted by Dr. Marie-Claire Arrieta and her team at the Snyder Institute for Chronic Diseases examined how infant antibiotic use affects yeast species in the gut, leading to immune dysregulation and allergic asthma. According to Arrieta, "These results reveal a previously unrecognized pathway linking early-life antibiotic exposure to allergic disease risk and show how the developing immune system is shaped by fungi within the gut microbiome during a critical window of development." She also said, "Antibiotics are an essential treatment for young children when needed, but this study shows that there is a previously overlooked effect on the gut mycobiome, allowing species like Malassezia to flourish, and directly impacting immunological function."
The studies highlight that while much research has focused on bacteria in the gut microbiome, less attention has been given to its fungal component—the mycobiome—and its potential impact on health outcomes related to immunity.
Turvey's team analyzed 2,256 samples from 1,409 participants during their first year of life. They observed distinct population changes among different fungal species: Saccharomycetaceae increased over time while Malassezia decreased; however, higher frequencies of Malassezia were associated with infants who later developed atopic dermatitis.
Arrieta's group further demonstrated through clinical observation and mouse models that antibiotics increase levels of Malassezia in infants' guts—a change linked with heightened allergic inflammation both in intestinal cells and airways. These concurrent findings underscore Malassezia’s significance in early life immunity and suggest targeting the infant mycobiome could help prevent pediatric allergic diseases.
