Abstract
BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated allergy, primarily affecting infants and children, with potentially severe gastrointestinal impacts. As with other allergic diseases, the cause of FPIES is unknown. Preliminary research suggests that the gut microbiome may play a role in FPIES, as well as other allergy, yet data on the mycobiome are limited. OBJECTIVE: We sought to examine the role of the gut mycobiome in FPIES by comparing the stool mycobiome of children with FPIES to that of children who have outgrown FPIES. METHODS: Caregivers of children with FPIES and children who had outgrown FPIES completed a demographic and lifestyle survey. DNA was extracted and sequenced from stool samples of 23 children with FPIES and 17 children with resolved FPIES. Fungal diversity and composition between the 2 groups were compared using QIIME2 (Quantitative Insights Into Microbial Ecology 2). RESULTS: Children with resolved FPIES had significantly more Saccharomyces than children with current FPIES. Children with current FPIES had significantly more diverse samples and included opportunistic pathogens, such as Candida spp. Children with resolved FPIES reported significantly less infant antibiotic usage and proton pump inhibitor usage. DISCUSSION: This study identified distinct mycobiome profiles in children with current versus resolved FPIES. Resolved FPIES was associated with Saccharomyces enrichment, whereas children with current FPIES had more diverse, opportunistic pathogen-associated communities and greater infant antibiotic and proton pump inhibitor usage. Although these associations do not establish causality, they underscore the need for larger, longitudinal studies to determine whether the mycobiome and early-life exposures influence FPIES outcomes, because it could have implications for treatment and prevention.