For the millions living with Crohn's disease or ulcerative colitis, the microbiome narrative has long centered on bacteria — but fungi in the gut may be a silent, underappreciated variable. A comprehensive narrative review now challenges the clinical assumption that detecting Candida in stool samples meaningfully informs IBD management, while simultaneously laying out why dismissing fungal biology altogether may also be premature.

Drawing on 43 studies — including longitudinal cohorts, mechanistic experiments, and interventional trials — the review reveals that fungal alterations in IBD are highly heterogeneous and strongly dependent on detection methodology. Longitudinal data does associate elevated relative abundance of Candida genus with active disease states, yet this association has failed to replicate consistently across diverse populations. A mechanistically important nuance emerges: stool sequencing cannot distinguish viable fungi from dead cellular debris, nor can it determine whether Candida has shifted from its benign yeast form to the invasive hyphal morphology that drives inflammatory signaling. Strain-specific virulence factors appear to matter, meaning genus-level taxonomic data likely obscures more than it reveals. Interventional approaches — antifungal drugs, fecal microbiota transplantation, and select nutraceuticals — show some capacity to shift microbial or inflammatory markers, but none has yet demonstrated consistent, reproducible clinical benefit in IBD cohorts.

This review arrives at a pivotal moment in gut microbiome science. Mycobiome research lags roughly a decade behind bacteriome research in methodological standardization, and the field is still resolving fundamental questions about what constitutes a pathological versus commensal fungal state. The practical implication for clinicians and patients is important: a positive stool Candida signal should be interpreted within full clinical context rather than triggering reflexive antifungal treatment. For researchers, the review underscores an urgent need for mucosal biopsy-based studies, viability-confirmed sequencing, and strain-level resolution. This is confirmatory of existing skepticism around fecal mycobiome diagnostics, but its systematic framing provides a useful conceptual scaffold for the next generation of IBD-fungal studies.