Relationship between skin and gut microbiota dysbiosis and inflammatory skin diseases in adult patients: A systematic review

Introduction

The skin and gut microbiota significantly contribute to the body's homeostasis by modulating immune responses and protecting against pathogens. Dysbiosis, an imbalance in microbial communities, is increasingly recognized in inflammatory skin diseases such as psoriasis, atopic dermatitis, and rosacea. These diseases are interconnected through the gut-skin axis, involving complex immunological and neuroendocrine mechanisms. Understanding this bidirectional interaction is crucial, as it implies that alterations in gut microbiota can impact skin health and vice versa.

Objective

This systematic review aims to evaluate the association between dysbiosis of skin and gut microbiota and inflammatory skin diseases in adult patients, and to assess the efficacy of various therapeutic interventions targeting microbiota dysbiosis.

Methods

A systematic search was conducted in MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science to identify experimental studies and clinical trials exploring microbiota dysbiosis in adults with inflammatory skin diseases. Inclusion criteria were studies employing genetic sequencing or microbiological culture methods, along with interventions such as probiotics or fecal transplants.

Results

From the initial 1279 studies identified, 19 met the inclusion criteria. In patients with psoriasis, gut microbiota exhibited decreased Actinobacteria and increased Firmicutes, correlating with elevated inflammatory markers. Atopic dermatitis was characterized by reduced populations of beneficial bacteria, particularly Bifidobacterium and Lactobacillus, significantly associated with skin flare-ups and disease severity. Therapeutic interventions with probiotics demonstrated improvement in microbial diversity and a reduction in inflammation across several inflammatory skin conditions, including psoriasis and atopic dermatitis.

Discussion

The findings underscore the significant role microbial dysbiosis plays in the pathogenesis of inflammatory skin diseases. Microbiota modulation through probiotics and prebiotics emerges as a promising therapeutic approach. However, due to heterogeneity among reviewed studies, further controlled research is essential to confirm the long-term efficacy and mechanisms of microbiota-targeted interventions.