Activating the aryl hydrocarbon receptor (AhR) increased β-defensin 1 production in colon cells, which restored gut microbiota balance and reduced colitis in mice and human tissue samples.
3 colitis models + human tissueAhR-driven β-defensin 1 induction reduced colitis across multiple experimental systems
What the researchers found
AhR activation induced β-defensin 1 expression in colonic epithelial cells, which regulated gut microbiota composition and immune cross-talk to attenuate colitis in both human tissue samples and three mouse colitis models.
Why it matters
Antimicrobial peptides are the body's frontline defense against gut pathogens. Showing that a natural receptor can be activated by dietary compounds to boost these peptides opens a potential therapeutic strategy for inflammatory bowel disease that works with the body's own defense systems.
The numbers in context
- BD-1 decreased in both UC and CD patients and in 3 mouse colitis models
- AhR ligands induced BD-1 through 2 dioxin-responsive elements on the promoter
- Blocking BD-1 with antibodies abolished the protective effect
- IEC-specific AhR deletion prevented BD-1 induction and colitis protection
How the study worked
Combined human and animal study. Analyzed β-defensin 1 expression in UC and CD patient tissue. Tested AhR ligands (dietary and environmental) in three mouse colitis models. Assessed microbiota changes and immune cell responses.
Who was studied
Human UC and CD tissue samples plus three mouse colitis models. Intestinal-epithelial-cell-specific AhR knockout mice for pathway validation.
What this study cannot tell us
Mouse colitis models may not fully replicate human IBD; AhR activation has broad effects beyond defensin induction; long-term safety of AhR ligand supplementation unknown; specific dietary compounds and doses for clinical benefit not established.
How to read the evidence
Strong preclinical evidence with human tissue validation across multiple disease models. Translational potential is high but requires clinical trials.
When this study was published
Published in 2025, at the forefront of microbiome-immune-peptide research.
The bigger picture
This connects diet, the immune system, and gut microbiota through a single molecular pathway. AhR ligands are found in cruciferous vegetables and other foods, suggesting dietary interventions could complement pharmaceutical approaches for IBD management.
Questions still open
- Could dietary AhR ligands (from broccoli, kale, etc.) provide meaningful clinical benefit for IBD patients?
- Does β-defensin 1 restoration also help prevent colitis-associated colorectal cancer?
- What is the optimal balance of AhR activation to boost antimicrobial defenses without over-stimulating other immune pathways?
Common questions
What is β-defensin and why does it matter for gut health?
Could eating certain foods boost this antimicrobial peptide?
Read the original research
AhR-Dependent Induction of β-Defensin 1 in Colonic Epithelial Cells Regulates Cross-Talk between Gut Microbiota and Immune Response Leading to Attenuation of Colitis.
Advanced science (Weinheim, Baden-Wurttemberg, Germany), 12(25), e2416324
Citation
Palrasu, Manikandan; Marudamuthu, Amarnath; Kakar, Khadija; Hamida, Hamida; Thada, Shruthi; Gupta, Rohan; Wilson, Kiesha; Carter, Taylor; Zhong, Yin; Saxena, Archana; Yang, Xiaoming; Singh, Narendra; Busbee, Philip Brandon; Li, Jie; Garcia-Buitrago, Monica; Nagarkatti, Prakash; Nagarkatti, Mitzi. (2025). AhR-Dependent Induction of β-Defensin 1 in Colonic Epithelial Cells Regulates Cross-Talk between Gut Microbiota and Immune Response Leading to Attenuation of Colitis.. Advanced science (Weinheim, Baden-Wurttemberg, Germany), 12(25), e2416324. https://doi.org/10.1002/advs.202416324