Review: Gut Microbiota Dysbiosis Linked With AD, Psoriasis, and HS
Key Takeaways
A new review of evidence indicates gut microbiota dysbiosis is increasingly linked with inflammatory skin diseases including atopic dermatitis (AD) psoriasis, and hidradenitis suppurativa (HS).
The researchers reported reduced microbial diversity and depletion of anti-inflammatory bacterial taxa as the most common findings across dermatoses.
Major research gaps remain, particularly in adult AD and HS cohorts.
A new systematic review suggests that alterations in gut microbial composition may contribute to atopic dermatitis (AD), psoriasis, and hidradenitis suppurativa (HS).
The authors for the systematic review of studies indexed in PubMed through January 2025, investigators evaluated current evidence on gut microbiota composition and functional alterations associated with these dermatologic conditions. Eligible studies included human observational, interventional, and genetic causal-inference studies that used microbiome profiling techniques or genetic analyses to assess gut microbial changes in AD, psoriasis, or HS.
A total of 62 studies met the inclusion criteria, including 38 examining AD, 22 investigating psoriasis, and 5 focusing on HS; three studies evaluated more than one disease. In AD, most studies were conducted in pediatric populations, highlighting a relative lack of adult-specific data.
Reduced microbial alpha-diversity and decreased abundance of beneficial commensal species such as Faecalibacterium prausnitzii, Bifidobacterium species, and Akkermansia muciniphila were the most common recurrent findings across studies. Dysbiosis was also commonly observed in those with psoriasis. Evidence in HS remains limited, according to the authors, but the noted available studies reported reduced microbial diversity and increased Ruminococcus gnavus (commonly present in inflammatory bowel diseases).
"Despite advances in microbiota analysis, significant gaps remain—especially in adult AD and HS," the authors wrote. "Future research should prioritize standardised methodologies, larger and more diverse cohorts, and leverage emerging tools such as Mendelian randomization and AI-based models to develop precision medicine interventions."
Source: Malgesini A, et al. Journal of Experimental Dermatology. 2026. Doi:doi.org/10.1111/exd.70234