Environmental fungi found to alter vaginal mycobiome and cervical disease progression during dysbiosis

In an interesting discovery that redraws the boundaries of human vaginal ecology, scientists have demonstrated for the first time that environmental fungi actively interact with the vaginal bacteriome and mycobiome with likely implications for cervical disease progression.

The study published June 3 in mSystems reveals that when the vaginal ecosystem falls into a state of dysbiosis—an unhealthy bacterial imbalance dominated by non-Lactobacillus communities—ubiquitous environmental fungi seize the opportunity to settle, initiate cross-kingdom cross-talk, and influence the trajectory toward tissue malignancy.

While standard medical literature has long viewed the vaginal fungal community (the mycobiome) through a narrow lens—primarily focusing on the opportunistic yeast Candida albicans—this new research highlights a highly dynamic, individualized ecosystem heavily shaped by external exposures.

Lead investigator Dr. Filipa Godoy-Vitorino and a multi-disciplinary team of researchers analyzed 86 Hispanic women from Puerto Rico. This specific population experiences disproportionately high rates of human papillomavirus (HPV) infection and cervical cancer. Utilizing high-resolution ITS1 amplicon sequencing, the team identified 173 distinct fungal species hypotheses – a digital proxy for a fungal species like a bacterial ASV - dominated surprisingly by non-human-associated environmental molds and wood-decaying basidiomycetes.

Cross-kingdom structural weaknesses

The most profound insight from the study lies in how these environmental fungi exploit cross-kingdom structural weaknesses during vaginal dysbiosis.

When the vaginal bacteriome is healthy and dominated by protective bacteria like Lactobacillus crispatus (known as Community State Type I), the colonization of external environmental fungi is tightly restricted. The beneficial bacteria act as an ecological shield.

However, when the ecosystem shifts into bacterial dysbiosis (Community State Type IV)—characterized by a severe depletion of lactobacilli and an overgrowth of anaerobic bacteria—the protective barrier collapses. This open ecological niche allows rare, external airborne fungal strains to proliferate. Far from being inert contaminants, these invading molds are hypothesized to have local immune impacts, promote chronic inflammation, and drive further microbial imbalances.

Striking correlation

Furthermore, the researchers discovered a striking correlation between mycobiome structure and advanced cervical health. Fungal alpha diversity was found to drop drastically in patients diagnosed with high-grade squamous intraepithelial lesions (HGSIL) compared to those with low-grade lesions or normal cytology. This severe contraction in fungal diversity points to a compromised, less resilient microbial network that allows aggressive, pathogen-dominated processes to take root. This permissive, highly inflamed microenvironment ultimately facilitates HPV persistence and accelerates neoplastic progression.

Aside from human-associated yeasts, environmental fungi such as Agaricomycetes sp., Scopuloides dimorpha, and Trametes cubensis were found consistently across multiple individuals, showing an unexpected resilience within the human body.

“Humans are continuously exposed to environmental fungi through inhalation and dermal contact,” the study emphasizes. The persistent presence of these airborne spores within mucosal niches underscores a finely tuned balance between immune recognition and tolerance. By proving that external bioaerosols continuously interface with internal bacterial states to alter disease trajectories, this research opens up a new paradigm for women’s health. It paves the way for comprehensive, dual-kingdom diagnostic screening and novel therapeutic interventions designed to stabilize mucosal barriers against environmental invasion.

Dr Filipa Godoy-Vitorino from the Department of Microbiology at the University of Puerto Rico Medical Sciences Campus is the AMI Global Ambassador for Puerto Rico.