Clinical efficacy and gut microbiota profiling by 16S rRNA sequencing in children with Henoch-Schönlein purpura treated with integrated Chinese and Western medicine.

Background: Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children. Recent studies have suggested that gut microbiota dysbiosis may contribute to its pathogenesis, but microbial alterations and treatment-related changes remain unclear. Methods: A total of 142 children were initially enrolled, including 103 HSP patients and 39 healthy controls. After excluding 30 patients due to incomplete follow-up, 112 participants were included in the final clinical analysis: 39 healthy controls, 38 HSP patients treated with integrated Chinese and Western medicine (integrated group), and 35 treated with Western medicine (WM group). Both patient groups received an identical Western medicine regimen; the integrated group additionally received Compound Tuizi Decoction, an oral herbal formulation prescribed according to the TCM syndrome pattern of "blood-heat with stasis-toxin." For microbiota analysis, fecal samples were collected at baseline and after 4 weeks of treatment in the integrated group, at baseline in the WM group, and once in healthy controls. A total of 78 stool samples passed quality control and were included in microbiota analyses. All samples were sequenced in a single Illumina NovaSeq 6000 run to minimize batch effects. Gut microbiota was analyzed using 16S rRNA gene sequencing, alpha and beta diversity metrics, differential abundance analysis, functional prediction (KEGG), and machine learning models. Multivariate analyses (PERMANOVA) adjusting for age, sex, and baseline diversity were performed to isolate treatment-related effects. Results: At baseline, HSP patients exhibited reduced microbial diversity compared to healthy controls (Shannon index: INT-BL, 4.12 ± 0.67, Conclusion: Pediatric HSP is associated with gut microbiota dysbiosis. Both treatment approaches were associated with partial microbiota restoration, with more pronounced compositional and functional changes observed in the integrated group. Given the add-on design of this study, the microbiota changes observed in the integrated group can be largely attributed to the herbal intervention. These findings suggest that microbiota modulation may play a role in the treatment of pediatric vasculitis, though the clinical significance of these changes needs to be confirmed in larger randomized controlled trials.