- Atopic dermatitis (AD) is a chronic inflammatory skin disease with complex immune and microbiome components; conventional therapies such as immune-modulators often provide incomplete or temporary relief.
- Growing evidence links gut microbiome dysbiosis to systemic inflammation and skin barrier dysfunction via the gut–skin axis.
- Washed fecal microbiota transplantation (WFMT) — a microbiome transfer procedure that enriches beneficial taxa while removing unwanted components — offers a targeted approach to restore microbial balance with reduced risk compared to conventional fecal transplantation.
- WFMT enriches for beneficial bacteria while reducing the risk of pathogen transfer.
- Demonstrating clinical efficacy and microbiome shifts in AD establishes a proof of concept for microbiome-based interventions in immune-mediated skin disorders.
Key Findings: Deng et al. conducted a prospective study of 23 individuals with moderate to severe atopic dermatitis who received at least 2 courses of washed fecal microbiota transplantation (WFMT) derived from screened healthy donors.1 This was a prospective before–and–after study. Clinical outcomes, peripheral blood, gut microbiome composition, and serum metabolomics were assessed before and after treatment.
- Clinical improvement: Participants exhibited statistically significant decreases in validated AD severity scores (e.g., EASI, SCORAD, NRS, DLQI) following treatment compared with baseline. Positive outcomes were more pronounced in adult vs pediatric subjects, which showed significant improvements in NRS (itch) scores alone.
- Peripheral blood: absolute basophils counts were significantly reduced (P < 0.05), but other indicators were unchanged.
- Altered gut microbiome composition: Recipients showed increases in microbial diversity and relative abundance of putative beneficial taxa (e.g., Bifidobacterium, Faecalibacterium) and decreases in pro-inflammatory taxa compared to baseline.
- Metabolomic shifts: Post-WFMT fecal samples from 17 subjects exhibited changes in microbiome-associated metabolites implicated in immune and barrier function, including short-chain fatty acids (SCFAs) and bile acid derivatives, aligning with improved clinical phenotype.
- Gut–skin axis correlation: associations between specific gut taxa/metabolites and AD severity were observed, supporting the mechanistic relevance of microbiota modulation.
- Altered skin microbiome composition: β-diversity analysis indicated remodeling of the AD skin microbiome, shifting towards less inflammatory skin populations.
- Safety and tolerability: WFMT was well tolerated; no serious adverse events related to transplantation were reported, underscoring feasibility for therapeutic application.
Bigger Picture: This study adds to a growing body of evidence supporting the gut–skin axis as a therapeutic target in inflammatory skin diseases. By applying washed microbiota transplantation — a refined microbiome therapy with improved safety over traditional FMT — the authors demonstrate clinically meaningful improvement in atopic dermatitis severity accompanied by durable changes in gut microbial composition and metabolic output. These findings have broad implications for microbiome-based therapeutics, suggesting that targeted manipulation of gut ecosystems can modulate systemic immune responses and influence distal organ systems such as the skin. Future research will be needed to optimize donor selection, define responder phenotypes, and assess long-term efficacy and safety in larger, controlled trials.
(Image Credit: iStock/ Rasi Bhadramani)
References:
- Deng et al. 2026. Washed Microbiota Transplantation Relieves Atopic Dermatitis via Gut–Skin Microbiome Rebalancing. BMC Microbiology.
