Like other sites in the body, the majority of cutaneous microbes are bacteria, but some sites also have a relatively high number of resident fungi, collectively termed the mycobiome. Disordered fungal colonization in the skin has been associated with various disorders like dermatophytosis, atopic dermatitis and seborrheic dermatitis. 

Cutaneous fungi maintain host health, including colonization-resistance against pathogens and facilitating immune development and maintenance of the host. The dominance of the mycobiome by Malassezia is confirmed at most body sites (excluding scalp or foot) utilizing microbial sequencing for 18S or ITS rDNA. But changes in microbial community composition are seen throughout life. In general, the relative abundance of Malassezia is low in children but increases with age until adulthood. While at puberty, the dominant species within the genus Malassezia shifts from M. globosa to more host lipid-dependent members of Malassezia, as sebum production changes during adolescence. While in early life, the cutaneous mycobiome is dominated by the genus Candida. 

Since the composition of the cutaneous mycobiome has already been focused on, the next step warrants determining functional outcomes of colonization concerning diseases of the skin and systemic infection. Neonatal sepsis is mostly associated with organisms colonizing the skin of neonates and the mycobiome is also important to immune development during early life. This explains the potential of the mycobiome to influence human development in newborns.

Source: Willis KA, Peters BM, Pierre JF. A stable cutaneous mycobiome exists from birth. Pediatr Res. 2020;88(2):153-154. doi:10.1038/s41390-020-0959-6