Characterization of the Fungal Microbiota (Mycobiome) in Healthy and Dandruff-Afflicted Human Scalps

Abstract

The human scalp harbors a vast community of microbial mutualists, the composition of which is difficult to elucidate as many of the microorganisms are not culturable using current culture techniques. Dandruff, a common scalp disorder, is known as a causative factor of a mild seborrheic dermatitis as well as pityriasis versicolor, seborrheic dermatitis, and atopic dermatitis. Lipophilic yeast Malassezia is widely accepted to play a role in dandruff, but relatively few comprehensive studies have been reported. In order to investigate fungal biota and genetic resources of dandruff, we amplified the 26S rRNA gene from samples of healthy scalps and dandruff-afflicted scalps. The sequences were analyzed by a high throughput method using a GS-FLX 454 pyrosequencer. Of the 74,811 total sequence reads, Basidiomycota (Filobasidium spp.) was the most common phylum associated with dandruff. In contrast, Ascomycota (Acremonium spp.) was common in the healthy scalps. Our results elucidate the distribution of fungal communities associated with dandruff and provide new avenues for the potential prevention and treatment of dandruff.

A systematic literature review of the human skin microbiome as biomarker for dermatological drug development

“…In general, Malassezia spp. were found to be more abundant on dandruff scalp compared to healthy scalp 47, 48, 50. In addition to the mycobiota, a dysbiosis in Staphylococcus and Propionibacterium spp.…”

“…Four case–control studies investigated the microbiome in SD patients 47, 48, 49, 50, Table 1. In general, Malassezia spp.…”

“…However, future studies will have to confirm this potential. In SD, three different sequencing methods were used in the three different studies 47, 49, 50. This, together with the small sample populations, single time point sampling and poor study designs, might explain the heterogeneity in findings.…”

Mycobiota: Micro-Eukaryotes Inhabiting Our Body as Commensals or Opportunistic Pathogens

“…Specific genera that were increased in patients with severe dandruff included Filobasidium, which jumped to 94% of the total basiomycetes, and Malassezia (5%), which represents a twofold increase over healthy samples. By contrast, healthy scalps were dominated by basiomycete fungi of the genus Cryptococcus [67].…”

“…Eleven body sites were found to be dominated by Malassezia fungi but by contrast [38], foot sites (plantar heel, toe nail, and toe web) exhibited the greatest fungal diversity (40-80 genera), with the presence of a wide range of fungal genera (i.e Rhodoturola, Debaromyces, Cryptococcus, and Candida), of which Candida species were mostly represented by C. tropicalis, C. parapsilosis and C. orthopsilosis. Changes in the fungal microbiota of the scalp that accompany dandruff have been also examined [67].…”