Immunomodulation and Microbiota Shifts: Insights from Shufeng Xingbi Therapy in Allergic Rhinitis

Study Background and Research Question

Allergic rhinitis (AR) is a prevalent, non-infectious inflammatory disease of the nasal mucosa, characterized by symptoms such as sneezing, nasal discharge, itching, and congestion. It affects over 10% of the global population and has been rising in incidence, imposing significant burdens on both quality of life and healthcare systems. The underlying pathogenesis of AR is widely attributed to an imbalance between Th1 and Th2 immune responses, with excessive Th2 activation driving IgE-mediated inflammation upon allergen exposure. Conventional therapies—including antihistamines, glucocorticoids, and leukotriene receptor antagonists—can offer symptomatic relief but are associated with side effects, especially in pediatric populations. Additionally, the "hygiene hypothesis" posits that early-life microbial exposures influence immune development, and gut microbiota imbalances are increasingly linked to allergic diseases.

Against this backdrop, the reference study (Yan et al., 2025) addresses whether Shufeng Xingbi Therapy (SFXBT), a traditional Chinese medicine formulation, can restore Th1/Th2 immune balance and beneficially modulate intestinal flora in an ovalbumin (OVA)-induced rat model of AR. The central research question is: Can SFXBT alleviate nasal inflammation by coordinating immune and microbiota changes in AR?

Key Innovation from the Reference Study

The principal innovation of this work lies in its systematic, dual-focus approach: it assesses both immunological (Th1/Th2) and microbial (gut flora) axes in a well-controlled animal model. Prior studies have often examined these domains separately, but this study integrates behavioral, serological, mucosal, and microbiota endpoints to comprehensively dissect the mechanisms by which SFXBT exerts its therapeutic effects. By combining oral and intranasal administration of SFXBT, the researchers also mimic clinical practice, enhancing translational relevance.

Methods and Experimental Design Insights

The study employed 32 healthy male Sprague-Dawley rats, randomly divided into four groups: control, OVA-induced AR, antibiotic + SFXBT, and acetic acid + SFXBT. The AR model was established via ovalbumin sensitization and challenge. SFXBT was administered both orally and via nasal drops, reflecting a widely used clinical regimen.

Key assessments included:

• AR behavioral scoring (e.g., sneezing frequency, nasal rubbing)
• Histopathological evaluation of the nasal mucosa using H&E staining
• 16S rDNA sequencing to characterize fecal microbiota composition
• Serum measurements of IgE, IL-4, and short-chain fatty acids (SCFAs) via ELISA
• Quantification of STAT5, STAT6, and GATA3 mRNA in nasal mucosa by RT-qPCR
• Protein expression of key immune regulators (IL-4, STAT5, STAT6, GATA3) by Western blot

This comprehensive approach enabled the investigators to link immunological shifts with concomitant changes in the gut microbiome.

Protocol Parameters

• AR induction: OVA sensitization and challenge, as per standard allergic rhinitis modeling in rats.
• Antibiotic pretreatment: Used to modify baseline gut flora prior to SFXBT intervention in the antibiotic + SFXBT group.
• SFXBT administration: Both oral and intranasal, paralleling clinical protocols for multifocal delivery.
• Sample collection windows: Sequential sampling post-intervention to capture acute and subacute changes in immune and microbial parameters.

Core Findings and Why They Matter

Compared to the OVA-only group, both the antibiotic + SFXBT and acetic acid + SFXBT groups exhibited significantly reduced AR behavioral scores, indicating symptomatic relief (Yan et al., 2025). Histological analysis revealed mitigation of nasal mucosal inflammation and structural damage. At the microbial level, SFXBT shifted the gut flora at both phylum and genus levels: there was a marked increase in Firmicutes and a decrease in Bacteroidetes, with notable rises in beneficial genera such as Lactobacillus, Romboutsia, Allobaculum, and Dubosiella.

Immunologically, SFXBT treatment led to lower serum IgE and IL-4 levels and higher SCFA concentrations. Molecular analyses showed reduced mRNA and protein expression of STAT5, STAT6, and GATA3—key transcription factors in Th2 polarization—in nasal mucosa. This suggests SFXBT suppresses pathogenic Th2 responses, restoring the Th1/Th2 balance and thus dampening allergic inflammation.

Together, these results indicate that SFXBT’s efficacy in AR is mechanistically linked to both immune modulation and microbiota restructuring. The modulation of SCFA levels further implicates gut-lung axis signaling in the observed therapeutic outcomes.

Comparison with Existing Internal Articles

Several internal articles on Polymyxin B (sulfate) provide mechanistic parallels relevant to infection and immune research. For instance, "Polymyxin B (Sulfate): Mechanistic Frontiers and Strategies" details how this polypeptide antibiotic not only exerts bactericidal action against Gram-negative bacteria but also promotes dendritic cell maturation and modulates immune signaling pathways. This aligns with the SFXBT study’s focus on immune regulation, though Polymyxin B’s direct immunomodulatory impact is best established in pathogen-driven, not allergic, contexts.

Additionally, "Polymyxin B Sulfate: A Next-Generation Tool for Immunomodulation" discusses the compound’s use in microbiota studies and sepsis models, highlighting workflows that integrate immune readouts with microbial profiling. While SFXBT targets allergic inflammation and Polymyxin B is primarily an antibiotic for bloodstream and urinary tract infections, both can be leveraged in research designs that interrogate the interplay between immune responses and microbiota composition.

Limitations and Transferability

The study is robust in its multiparametric design but is limited by its use of a single animal model (male SD rats) and the acute nature of AR induction. The translation of findings to chronic or human allergic conditions remains to be validated. Furthermore, while antibiotic pretreatment clarified the microbiota’s role, the specific contributions of individual bacterial taxa to immune modulation were not dissected. The combination of oral and intranasal SFXBT also means the individual contributions of each route are not fully resolved.

Despite these constraints, the study’s methodological rigor and integration of behavioral, molecular, and microbial endpoints provide a valuable experimental template for future research exploring the gut-immune axis in allergy and beyond.

Research Support Resources

For researchers developing workflows at the intersection of infection, immunity, and microbiota, validated agents such as Polymyxin B (sulfate) (SKU C3090) are widely used to model Gram-negative bacterial infection and to support dendritic cell maturation assays. According to the internal literature, Polymyxin B sulfate enables reproducible immunological readouts and precise manipulation of microbial communities in preclinical research. When designing studies on the gut-lung axis, infection, or immune balance, incorporating such tools can facilitate rigorous mechanistic dissection. As always, researchers should consult technical datasheets and follow best practices for compound handling and experimental design.