What’s gut got to do with it?
New insight reveals how the gut microbiome is reshaping dermatology and skin cancer care.
U058 – The Gut Microbiome 101 for Dermatologists
8-9 a.m. | Sunday, March 29
Mile High 1D
A growing body of research is transforming how dermatologists understand and treat inflammatory skin diseases and skin cancers. That research points to the human gut microbiome, with its toxic collection of bacteria, fungi, and viruses that play an important role in a range of diseases.
The Sunday session, U058 – The Gut Microbiome 101 for Dermatologists, will deliver key insights that tie the gut microbiome to cutaneous inflammation, autoimmunity, and oncology, which ultimately impact the dermatologic health of patients.
What drives gut microbes?
“Over the last decade, gut microbiome research in dermatology has evolved from observational associations to increasingly mechanistic and translational insights,” said session presenter Sonal Choudhary, MD, FAAD, an assistant professor of dermatology at the University of Pittsburgh School of Medicine in Pennsylvania.
“We now have consistent data demonstrating altered gut microbial diversity and functional imbalance, often referred to as dysbiosis, in common inflammatory and autoimmune skin diseases, such as atopic dermatitis, psoriasis, acne, rosacea, hidradenitis suppurativa, vitiligo, and alopecia areata,” he said. “Emerging studies highlight not only taxonomic shifts but also changes in microbial metabolites, intestinal barrier integrity, and immune signaling pathways that link the gut to cutaneous inflammation.”
According to Dr. Choudhary, the gut microbiome is central to educating and regulating the immune system. When dysbiosis disrupts the intestinal barrier, microbial byproducts can enter circulation and skew immune activity toward Th2 and Th17 inflammation, the same pathways involved in eczema and psoriasis. Microbial metabolites such as short‑chain fatty acids also influence regulatory T‑cell function, providing a direct link between gut health and autoimmune balance in the skin, he said.
Although microbiome‑targeted therapies are not yet standard of care, Dr. Choudhary said, dermatologists are increasingly integrating dietary strategies, pre‑ and probiotics, and interventions aimed at restoring gut barrier function as supportive tools in managing chronic inflammatory skin disease. He cautioned that these should complement — not replace — evidence‑based therapies and stressed the need for physicians to counter misinformation by providing guidance grounded in science.
Implications for skin cancer
The gut microbiome is now recognized as an important regulator of systemic immune function in oncology as well, with specific relevance to skin cancers that are treated with immune-based therapies. Alan Zhou, MD, MSc, FAAD, is among the session speakers addressing this connection. Dr. Zhou is an associate professor of dermatology at Northwestern University Feinberg School of Medicine in Chicago.
The strongest and most mature data come from melanoma, he said, where multiple studies have shown that gut microbial composition and diversity are associated with response to immune checkpoint inhibitors, treatment durability, and immune-related adverse events.
“Beyond melanoma, emerging evidence suggests that microbiome-driven immune modulation may also influence outcomes in cutaneous squamous cell carcinoma and basal cell carcinoma, particularly in immunosuppressed patients and in those receiving systemic immunomodulatory therapies,” Dr. Zhou said. “In cutaneous T-cell lymphoma (CTCL), growing data indicate that patients exhibit distinct gut microbial profiles that correlate with disease severity and immune dysfunction. Collectively, these findings suggest that microbiome-immune interactions are broadly relevant across skin cancers, although mechanisms and clinical implications vary by tumor type.”
Supportive treatment approach
Microbiome‑based treatment approaches in oncology remain adjunctive, Dr. Zhou said. Maintaining microbiome health may enhance immunotherapy effectiveness in melanoma, although overuse of antibiotics may worsen outcomes. In CTCL, reducing Staphylococcus aureus colonization often leads to improvements in disease severity, demonstrating how host‑microbe interactions can be leveraged even without direct gut interventions. More intensive treatments — such as fecal microbiota transplantation — remain investigational.
“For other skin cancers, including squamous cell carcinoma and basal cell carcinoma, the microbiome’s role is less well-defined but may become increasingly relevant as immunomodulatory therapies are more widely used,” he said.
Looking ahead
Through updated research, dermatologists are seeing proof that the gut microbiome is a clinically meaningful factor in both inflammatory skin diseases and skin cancers. Drs. Choudhary and Zhou agree that as the field expands, dermatologists must navigate the science with nuance, balancing excitement with evidence while guiding patients away from overgeneralized or unproven claims.
“Patient interest in the microbiome is extremely high, and dermatologists play a critical role in translating rapidly evolving science into responsible, practical guidance,” Dr. Choudhary said. “This session aims to empower physicians to do exactly that, by separating what we know, what is emerging, and what remains investigational.”
Future research must also address confounding factors, such as diet, antibiotics, and infections and include diverse populations to ensure equity, said Dr. Zhou.
“Although the microbiome is unlikely to replace established cancer treatments, it represents a promising avenue for improving treatment response, reducing toxicity, and personalizing care across dermatologic oncology in the future,” he said.
The session will also feature presentations by Jean McGee, MD, PhD, MS, FAAD, and Cecilia Larocca, MD, FAAD.
