Researchers have revealed an important and unexpected role for fungi found in children's intestines in the development of the immune system and the emergence of allergies at an early age.
Two concurrent studies suggest that these fungi, which have been less studied compared to gut bacteria, may be a crucial element in understanding the causes of diseases such as atopic dermatitis, food allergies and asthma, and may even represent a promising target for future treatments.
In the first study, a research team led by Dr. Stuart Turvey from the Children’s Hospital Research Institute of British Columbia analyzed data from a large study known as CHILD Cohort, which included more than 1,400 children during their first year of life.
The researchers found that the types of fungi in infants' intestines change significantly with growth, and that some of them may later be linked to the development of allergies.
The results showed that fungi of the Saccharomycetaceae family gradually increase during the first year of life, while other types, such as Malassezia, decrease. Importantly, the high presence of Malassezia in some infants was subsequently associated with an increased likelihood of developing atopic dermatitis.
Turvey says that understanding these early changes in the gut microbiome could help predict which children are most susceptible to allergies, and perhaps open the door to preventing them before they appear.
The second study, led by Dr. Marie-Claire Arrieta of the Snyder Institute for Chronic Diseases and the University of Calgary, focused on the effect of antibiotics on intestinal fungi in infants. It showed that antibiotic use in the first months of life leads to an increase in certain types of fungi, particularly Malassezia.
In subsequent animal experiments, researchers observed that this change in the fungi may cause an increase in allergy-related inflammation in the digestive and respiratory systems.
Arrieta explains that these findings reveal a new biological pathway linking early antibiotic exposure to an increased risk of allergic diseases, through its indirect effect on the balance of fungi within the gut.
Both studies agree that intestinal fungi, although less well known than bacteria, play a key role in shaping the immune system in children in their early stages, making them a promising area for research and treatments that may contribute to the prevention of allergies in the future.
