# Gut microbiota dysbiosis at the interface of neuropsychiatric disorders and their dermatological comorbidities

## TL;DR

This review explores how gut microbiota imbalances may link mental health disorders with skin conditions, suggesting gut-targeted therapies could help both.

## Contribution

The paper introduces the concept of a gut microbiota–brain–skin axis linking neuropsychiatric and dermatological conditions.

## Key findings

- Gut microbiota dysbiosis is consistently observed in both neuropsychiatric and dermatological conditions.
- Microbial changes correlate with increased inflammation and altered amino acid metabolism.
- Probiotics show early promise in improving symptoms of both mental and skin disorders.

## Abstract

Neuropsychiatric disorders such as autism spectrum disorder (ASD), generalized anxiety disorder (GAD), major depressive disorder (MDD), and schizophrenia (SZ) frequently co-occur with dermatological conditions, including atopic dermatitis, psoriasis, rosacea, and chronic urticaria. The biologic basis remains incompletely understood. A growing body of evidence implicates gut microbiota dysbiosis as a shared pathogenic factor linking these conditions. This review synthesizes preclinical and clinical findings demonstrating consistent microbial alterations across both neuropsychiatric and dermatologic conditions, including fluctuations in alpha diversity, disrupted Firmicutes/Bacteroidetes ratios, and depletion of short-chain fatty acid (SCFA)–producing taxa such as Faecalibacterium, Roseburia, and Eubacterium species. These microbial shifts parallel elevations in inflammatory mediators such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and interleukin-17 (IL-17), and cause perturbations in amino acid metabolism, altered glutamate-GABA signaling and increased branched-chain amino acids, indicating convergence on immune and metabolic pathways. Experimental rodent studies support the concept by demonstrating that microbiota dysbiosis can both impact psychiatric-like behaviors and cutaneous inflammation. Microbiota-targeted therapies such as probiotics show preliminary efficacy in improving symptoms across both domains. These findings support a gut microbiota–brain–skin axis and suggest that targeting gut dysbiosis may offer an integrated therapeutic approach for neuropsychiatric disorders and their dermatologic comorbidities.