Diverse Human Skin Fungal Communities in Children Converge in Adulthood

Abstract

Understanding the skin mycobiome (fungal communities) is important because both commensal and pathogenic fungi can drive cutaneous disease depending on host status and body sites, including the scalp, feet, and groin. Interestingly, age may also affect skin fungal infections as certain dermatophytoses (i.e. tinea capitis) are more frequent in children than adults. We previously described the skin mycobiomes in healthy adults, showing lipophilic fungi Malassezia predominate in most skin sites. Since children have less sebaceous skin before puberty, we compared the fungal communities of primary clinical samples from healthy children and adults, based on sequencing of a fungal phylogenetic marker. While Malassezia predominated on trunk, head and arm skin of adults (age 20s–30s), children (age <14) had more diverse fungal communities, for example, Eurotiomycetes which includes common dermatophytes. Species-level classification showed M. globosa predominated in children. Collectively, our findings indicate that prepubertal skin is colonized by diverse fungi, whereas adult skin is predominantly obligatory lipophilic Malassezia, suggesting that fungal communities on skin profoundly shift during puberty. Mycobiome shifts during puberty are likely due to alterations in sebaceous gland activation and sebum composition. This study provides a foundational framework for studies investigating interactions between fungi, skin, and pediatric dermatophytosis.

Performing Skin Microbiome Research: A Method to the Madness

“…Bacteria have been the main focus, but several have used sequencing methods to examine skin fungal (Findley et al , 2013; Jo et al , 2016a; Paulino et al , 2006; Zhang et al , 2011), viral (Foulongne et al , 2012; Hannigan et al , 2015; Oh et al , 2014; Oh et al , 2016; Wylie et al , 2014) and archaeal communities (Probst et al , 2013). …”

“…sebaceous sites hosting lipophilic bacteria). Skin bacterial communities in neonates, infants, and young children are notably distinct from those in sexually mature children and adults, particularly at certain skin sites (Capone et al , 2011; Costello et al , 2013; Dominguez-Bello et al , 2010; Jo et al , 2016a; Oh et al , 2012; Ying et al , 2015). The skin microbiomes in patients with different cutaneous and general medical conditions show distinctive patterns of skin microbiomes, but heterogeneity in the experimental study designs highlights the challenges in comparing results between studies and emphasizes a need for minimal standards.…”

Fungal dysbiosis: immunity and interactions at mucosal barriers

“…Genera such as Aspergillus, Tremellomycetes and Penicillium are abundant in infants whereas the overall diversity of fungal community decreases with age 42,64 . Similarly, the diversity of the skin mycobiota decreases with age, probably due to the increasingly sebaceous skin that favours colonization by Malassezia species 65 .…”

Commensal Fungi in Health and Disease

“…require long chain fatty acids for optimal growth and are found on most skin areas, but are most closely associated with lipid-rich sebum secreted by sebaceous glands (Gaitanis et al, 2012). In children, who have less sebaceous gland activity on their skin than adults, fungal communities are more diverse and include organisms such as Aspergillus , Epicoccum , and Phoma in addition to Malassezia (Jo et al, 2016). It is unknown whether the presence of Malassezia provides any beneficial effects for the skin in healthy hosts, but Malassezia have been reported to produce potent aryl hydrocarbon receptor (Ahr) ligands that may promote epithelial cell health and protection from ultraviolet radiation (Velegraki et al, 2015).…”