Malassezia restricta passport

The Malassezia genus includes several species of yeast that are naturally present on the skin. These yeasts have recently undergone significant taxonomic revisions and are attracting considerable interest in human and animal pathology. Among them are M. globosa, M. furfur, and M. restricta, which we will focus on in this review.

What is Malassezia restricta?

Malassezia restricta is a lipophilic yeast. It is part of the skin microbiota. This species mainly colonizes sebum-rich areas such as the scalp, face, and ears.

Clinical associations:

Although generally harmless, M. restricta can contribute to skin disorders when its balance with the microbiota is disrupted. It is associated with two common conditions: 

• Seborrheic dermatitis: an inflammatory skin disorder characterized by red patches covered with scales or oily dandruff, often accompanied by itching.

• Dandruff: a non-inflammatory condition marked by the formation of scales. 

Mechanisms of action:

Sebum production promotes the proliferation of Malassezia yeast naturally present on the skin. M. restricta secretes lipases, which break down sebum into triglycerides and then into free fatty acids. These fatty acids alter the skin barrier and, in some cases, trigger an inflammatory response. In turn, the body abnormally accelerates keratinocyte turnover, leading to excessive flaking associated with the appearance of dandruff. 

Contributing factors: 

Certain conditions can promote excessive growth of M. restricta:

• Excessive sebum production 

• An imbalance in the skin's microbiota 

• A hot andhumid environment

What are the solutions?

The goal is to restore the natural balance of the microbiota, and several approaches can help achieve this:

• Use of antifungal shampoos or lotions to regulate yeast proliferation. 

• Use of prebiotics and postbiotics to support a healthy microbiota.