Response to antihistamines in post-burn pruritus is associated with gut microbiota composition and function: A prospective cohort study with a nested case-control analysis.
Jung Y, Yeo S, et al. • Burns : journal of the International Society for Burn Injuries • 2026
Gut microbiota composition and function are associated with antihistamine responsiveness in patients with post-burn pruritus, with distinct microbial signatures identified among non-pruritic individuals, antihistamine responders, and non-responders.
Key Findings
Results
Overall microbial diversity did not differ significantly between no-pruritus, antihistamine-responsive, and antihistamine-nonresponsive groups in burn patients with post-burn pruritus.
A total of 56 male burn patients were categorized into three groups: no-pruritus, antihistamine-responsive (HR), and antihistamine-nonresponsive (HNR)
Fecal samples were collected at baseline and after 8 weeks of antihistamine treatment
Microbial composition was analyzed using 16S rRNA gene sequencing
Despite similar overall diversity metrics, distinct taxonomic and functional features were identified between groups
Results
The antihistamine-responsive (HR) group was characterized by enrichment of Sutterella at baseline.
Sutterella enrichment was identified as a distinguishing taxonomic feature of the HR group
This finding was identified through 16S rRNA gene sequencing analysis
The HR group showed distinct microbial signatures compared to both the no-pruritus and HNR groups
Results
The antihistamine-responsive (HR) group showed a temporal increase in microbial diversity and Bifidobacterium abundance after 8 weeks of antihistamine treatment.
Both microbial diversity and Bifidobacterium abundance increased over the 8-week treatment period specifically in the HR group
This temporal change was accompanied by enrichment of redox-related microbial functions
The temporal shift suggests that antihistamine treatment itself may influence gut microbiota in responsive patients
Results
The antihistamine-nonresponsive (HNR) group showed increased abundance of Akkermansia and Acidaminococcus compared to other groups.
Akkermansia and Acidaminococcus were identified as taxonomic features enriched in the HNR group
These taxa were identified through 16S rRNA gene sequencing and comparative analysis between groups
These microbial differences were present alongside distinct functional pathway differences
Results
The antihistamine-nonresponsive (HNR) group showed reduced antioxidant defenses and activation of non-histaminergic pruritic pathways at the functional level.
Functional prediction was conducted using PICRUSt2
Reduced antioxidant defenses were identified as a functional characteristic of the HNR group
Activation of non-histaminergic pruritic pathways in the HNR group may help explain the lack of response to antihistamine treatment
This functional profile contrasted with the redox-related microbial function enrichment seen in the HR group
Conclusions
This study is the first to suggest that gut microbiota composition and function are associated with antihistamine responsiveness in patients with post-burn pruritus.
The study used a prospective cohort design with a nested case-control analysis
All 56 participants were male burn patients
Prior to this study, altered gut microbial communities had been observed in histamine intolerance but no studies had examined the relationship in burn patients
Findings indicate a potential involvement of gut microbes in the pathophysiology of post-burn pruritus
What This Means
This research suggests that the composition of bacteria living in the gut may be linked to why some burn patients respond well to antihistamine medications for itch relief while others do not. The study followed 56 male burn patients divided into three groups — those without itching, those whose itching responded to antihistamines, and those whose itching did not respond — collecting stool samples at the start and after 8 weeks of treatment to analyze their gut bacteria. Patients who responded to antihistamines had higher levels of certain bacteria (like Sutterella and Bifidobacterium) and showed increases in microbial diversity over the treatment period, while non-responders had more of different bacteria (Akkermansia and Acidaminococcus) along with functional changes suggesting reduced antioxidant capacity and activation of itch pathways that don't involve histamine.
This research suggests that the reason some burn patients don't benefit from antihistamines may be partly rooted in their gut microbiome, with non-responders potentially experiencing itch through biological mechanisms that antihistamines simply cannot block. The finding that non-responders showed signs of activated 'non-histaminergic' itch pathways is particularly notable because it offers a possible biological explanation for treatment failure beyond just drug tolerance or dosing issues.
This is the first study to examine this relationship in burn patients, and while the findings are preliminary — limited to male patients and relying on functional predictions rather than direct measurements — they open up the possibility that gut microbiota profiling could one day help predict which patients will respond to antihistamines and whether microbiome-targeted treatments (such as probiotics) might help improve itch management in burn survivors.
Jung Y, Yeo S, Kim R, Seo C, Joo S, Shin J, et al.. (2026). Response to antihistamines in post-burn pruritus is associated with gut microbiota composition and function: A prospective cohort study with a nested case-control analysis.. Burns : journal of the International Society for Burn Injuries. https://doi.org/10.1016/j.burns.2026.108005