Chronic Diseases Associated with Malassezia Yeast

Abstract

Malassezia are a lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with certain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in the investigated body site or were they contaminated by other body sites, adjacent or not? Does this DNA contamination come from living or dead yeast? If these yeasts are alive, do they belong to the resident mycobiota or are they transient colonizers which are not permanently established within these niches? Finally, are these yeasts associated with certain chronic diseases or not? In an attempt to shed light on this knowledge gap, we critically reviewed the 31 published studies focusing on the association of Malassezia spp. with chronic human diseases, including psoriasis, atopic dermatitis (AD), chronic rhinosinusitis (CRS), asthma, cystic fibrosis (CF), HIV infection, inflammatory bowel disease (IBD), colorectal cancer (CRC), and neurodegenerative diseases.

Keywords: Malassezia; associated; body sites; chronic diseases; detection.

Figure 1

Selection flow-chart of the studies included in the review.

Figure 2

Malassezia in different anatomical sites detected in the context of chronic diseases or healthy individuals outside the skin. Malassezia was abundantly detected in the digestive tract and was shown to be associated with Crohn’s disease by exacerbating colitis and inflammation. Furthermore, it was highly abundant in colorectal cancer patients compared to healthy subjects, suggesting a potential role in tumorigenesis. It was also shown to be able to migrate from the gastrointestinal tract lumen to the pancreas and to exacerbate pancreatic adenocarcinoma progression. High abundance was also found in the gastrointestinal tracts of HIV patients, probably due to HIV-related immunosuppression. It was highly detected in the upper and lower respiratory tract. Within the upper respiratory tract, it has been shown to interact with specific bacteria (Pseudomonas aeruginosa and Staphylococcus aureus) and to increase chronic rhinosinusitis-associated inflammation. Within the lower respiratory tract, it was shown to be associated with cystic fibrosis pulmonary exacerbations. Finally, Malassezia were detected with a relatively high prevalence and abundance in brain tissue samples of patients with neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, etc.