Microbiote cutané et dermatite atopique : vers une nouvelle prise en charge thérapeutique ?

Washed microbiota transplantation: a case report of clinical success with skin and gut microbiota improvement in an adolescent boy with atopic dermatitis

Atopic dermatitis (AD) is a chronic, recurrent inflammatory disease characterized by itching. The gut microbiome can help maintain skin immune homeostasis by regulating innate and adaptive immunity. Here, we report a case of AD in a 15-year-old adolescent boy who benefited from washed microbiota transplantation (WMT). WMT was performed for three courses, with each course lasting for three consecutive days and an interval of one month between two courses. Clinical assessments were conducted at each WMT course, and skin, blood, and stool samples were collected for microbial analysis. After three months of WMT treatment, the boy's itchiness was effectively controlled: his skin showed noticeable improvement, with reduced Staphylococcus aureus in the skin lesions. The scores of SCORAD (SCORing Atopic Dermatitis), EASI (Eczema Area and Severity Index), NRS (Numerical Rating Scale), and DLQI (Dermatology Life Quality Index) significantly decreased compared to the baseline. Serum levels of eosinophil ratio, tumor necrotic factor-α, and interleukin-6 also reduced to the normal levels. There was a significant decrease in S. aureus in the skin lesions. Additionally, the intestinal flora became more diverse, and the abundance of Bifidobacterium species, significantly increased after WMT. No adverse events were reported during the treatment and the 1-year follow-up period. This case report provides direct clinical evidence for WMT as a novel promising treatment strategy for AD, and preliminary experimental data suggests the existence of an intestinal-skin axis in terms of the gut microbiota and the skin immune homeostasis.

Atopic Dermatitis as a Multifactorial Skin Disorder. Can the Analysis of Pathophysiological Targets Represent the Winning Therapeutic Strategy?

Atopic dermatitis (AD) is a pathological skin condition with complex aetiological mechanisms that are difficult to fully understand. Scientific evidence suggests that of all the causes, the impairment of the skin barrier and cutaneous dysbiosis together with immunological dysfunction can be considered as the two main factors involved in this pathological skin condition. The loss of the skin barrier function is often linked to dysbiosis and immunological dysfunction, with an imbalance in the ratio between the pathogen Staphylococcus aureus and/or other microorganisms residing in the skin. The bibliographic research was conducted on PubMed, using the following keywords: 'atopic dermatitis', 'bacterial therapy', 'drug delivery system' and 'alternative therapy'. The main studies concerning microbial therapy, such as the use of bacteria and/or part thereof with microbiota transplantation, and drug delivery systems to recover skin barrier function have been summarized. The studies examined show great potential in the development of effective therapeutic strategies for AD and AD-like symptoms. Despite this promise, however, future investigative efforts should focus both on the replication of some of these studies on a larger scale, with clinical and demographic characteristics that reflect the general AD population, and on the process of standardisation, in order to produce reliable data.

Microbiome in healthy skin, update for dermatologists

The skin is a complex barrier organ made of a symbiotic relationship between microbial communities and host tissue via complex signals provided by the innate and the adaptive immune systems. It is constantly exposed to various endogenous and exogenous factors which impact this balanced system potentially leading to inflammatory skin conditions comprising infections, allergies or autoimmune diseases. Unlike the gut and stool microbiome which has been studied and described for many years, investigations on the skin or scalp microbiome only started recently. Researchers in microbiology and dermatology started using modern methods such as pyrosequencing assays of bacterial 16S rRNA genes to identify and characterize the different microorganisms present on the skin, to evaluate the bacterial diversity and their relative abundance and to understand how microbial diversity may contribute to skin health and dermatological conditions. This article aims to provide an overview on the knowledge about the skin microbiota, the microbiome and their importance in dermatology.