The Salivary Mycobiome Contains 2 Ecologically Distinct Mycotypes.

Area of Science:

• Microbiology
• Oral Health
• Mycology

Background:

• The oral mycobiome, comprising various fungi, is understudied regarding individual variations and clinical relevance.
• Understanding oral fungal commensals is crucial for insights into oral health and disease.

Purpose of the Study:

• To investigate interindividual variability and ecological significance of oral fungal communities.
• To identify distinct oral mycobiome community types (mycotypes) and their associations with clinical parameters and bacteria.

Main Methods:

• Internal transcribed spacer 1 (ITS1) amplicon sequencing of salivary samples from 59 subjects.
• Analysis of fungal community structure and correlation with clinical data and coexisting bacterial communities.
• Validation in an independent cohort of 24 subjects using cultivation methods.

Main Results:

• Two distinct mycotypes were identified, primarily defined by Candida and Malassezia genera.
• The Candida mycotype showed lower fungal diversity and correlated with cancer, steroid use, smoking, caries, prosthesis use, and plaque index.
• Mycotypes were associated with distinct bacterial communities, with aciduric bacteria in the Candida mycotype and inflammophilic bacteria in the Malassezia mycotype.

Conclusions:

• The oral mycobiome exhibits distinct community structures (mycotypes) influenced by ecological factors.
• Mycotypes show specific associations with clinical parameters and coexisting bacterial communities, suggesting shared environmental pressures.
• Further research is needed to explore the potential of mycotypes as biomarkers for oral diseases.