The Human Mycobiome: Diagnostic Potential, Therapeutic Opportunities, and Future Directions

The human mycobiome, although representing a minor fraction of the gut microbiota, plays a disproportionately significant role in health and disease. Predominantly comprising members of the Ascomycota and Basidiomycota phyla – such as Candida , Saccharomyces , Debaryomyces , Malassezia , and Cladosporium – its composition is shaped by host age, genetics, diet, geography, and medical interventions. Mycobiome development parallels that of the bacterial microbiome, with early influences including delivery mode, feeding type, and dietary transitions. Fungi contribute to immune modulation through recognition pathways such as Dectin-1 and Toll-like receptors, driving Th17 responses, and participate in nutrient metabolism, fermentation, and bioactive molecule production. Advances in high-throughput sequencing and multiomics have illuminated the diagnostic potential of fungal signatures as biomarkers for inflammatory bowel disease, colorectal cancer, and systemic infections. Therapeutic strategies targeting the mycobiome include probiotics, prebiotics, antifungals, and microbiota modulation, with emerging precision interventions integrating fungal–bacterial dynamics. Notably, interkingdom interactions involve nutrient competition, metabolic cross-feeding, and cooperative biofilm formation, shaping microbial resilience and pathogenicity. Despite these advances, significant challenges remain, including methodological limitations, temporal variability, and the need for integrative analyses that capture functional and ecological complexity. Future research should emphasize longitudinal, multiomics studies, standardized workflows, and mechanistic models to enable targeted diagnostic and therapeutic applications. Understanding the mycobiome as an integral component of the gut ecosystem will refine microbiome-based clinical strategies and broaden insights into host–microbe–microbe interactions, offering novel avenues for precision medicine.