Shufeng Xingbi Therapy Modulates Immune and Microbiota Profiles in Allergic Rhinitis: Evidence from a Rat Model

Study Background and Research Question

Allergic rhinitis (AR) is a prevalent, non-infectious chronic inflammatory disease of the nasal mucosa characterized by symptoms such as sneezing, nasal discharge, itching, and congestion. Its pathogenesis is primarily attributed to an imbalance in T-helper cell (Th1/Th2) immune responses, with increased Th2 activity driving IgE-mediated inflammation. Global AR prevalence exceeds 10% and is rising, impacting quality of life and healthcare resources (reference paper). Traditional treatments—glucocorticoids, antihistamines, leukotriene antagonists—are effective but can cause adverse effects, especially in pediatric populations. Emerging research highlights the gut–immune axis: the composition of intestinal flora can influence respiratory immune responses. Notably, short-chain fatty acids (SCFAs) produced by beneficial bacteria modulate immune signaling, suggesting the microbiome as a therapeutic target. This study asked: Can Shufeng Xingbi Therapy (SFXBT), a traditional Chinese medicine (TCM) regimen, restore Th1/Th2 balance and beneficially alter intestinal flora in AR rats?

Key Innovation from the Reference Study

The principal innovation lies in integrating multi-omics (immunological, microbial, molecular) analysis to dissect how SFXBT impacts both immune polarization and gut microbial communities in a validated rat AR model. By combining behavioral scoring, mucosal histopathology, 16S rDNA sequencing, serum biomarker quantification, and gene/protein expression profiling, the study delivers a comprehensive mechanistic portrait of SFXBT’s actions (reference paper).

Methods and Experimental Design Insights

Thirty-two male Sprague Dawley rats were randomly allocated into four groups: (1) Control, (2) Ovalbumin (OVA)-induced AR, (3) Antibiotic + SFXBT, and (4) Acetic acid + SFXBT. The OVA model is widely regarded for its fidelity in mimicking human AR immune pathology. SFXBT was administered both orally (decoction) and intranasally (gel drops), reflecting clinical practice in TCM. Endpoints included:

• AR behavioral scoring (sneezing, nasal scratching)
• Nasal mucosa histopathology (H&E staining)
• Colonic content microbiota profiling (16S rDNA sequencing)
• Serum IgE, IL-4, and SCFA levels (ELISA)
• Nasal mucosa mRNA (STAT5, STAT6, GATA3: RT-qPCR)
• Nasal mucosa protein (IL-4, STAT5, STAT6, GATA3: Western blot)

Controls for antibiotic and acetic acid pre-treatment were included to parse direct SFXBT effects from baseline flora disruption and mucosal irritation.

Protocol Parameters

• AR induction | OVA 1 mg + Al(OH)₃ 100 mg, i.p. | Rat AR model | Standardized AR induction protocol | paper
• 16S rDNA sequencing | V3–V4 region, MiSeq platform | Microbiota diversity/profiling | High-resolution genus/species quantification | paper
• SFXBT administration | Oral decoction + nasal gel drops | Combined systemic/local delivery | Mimics clinical TCM use | paper
• Serum marker analysis | IgE, IL-4, SCFAs by ELISA | Immune/gut axis readouts | Quantifies systemic and local immune state | paper
• Gene/protein expression | RT-qPCR (STAT5/6, GATA3); Western blot | Nasal mucosa immunomodulation | Captures Th1/Th2 molecular polarization | paper

Core Findings and Why They Matter

SFXBT treatment produced several statistically significant outcomes compared to the OVA-only AR group (reference paper):

• Behavioral improvement: AR clinical scores (sneezing, scratching) decreased (P < 0.01).
• Mucosal restoration: Pathological changes (edema, cellular infiltration) were alleviated.
• Microbiota modulation: At the phylum level, Firmicutes abundance increased, Bacteroidetes decreased. Genus-level increases were seen in Lactobacillus, Romboutsia, Allobaculum, and Dubosiella.
• Immunological rebalancing: Serum IgE and IL-4 levels fell (P < 0.05); SCFAs rose (P < 0.05).
• Th2 pathway downregulation: STAT5, STAT6, and GATA3 mRNA/protein expression in nasal mucosa declined (P < 0.05), indicating suppression of Th2 signaling.

These findings support the hypothesis that SFXBT improves AR symptoms by dual modulation: suppressing Th2-driven inflammation and fostering a more anti-inflammatory, SCFA-producing gut microbiota. This cross-talk aligns with current models of the gut–lung axis in allergic and inflammatory diseases.

Comparison with Existing Internal Articles

Several internal resources have explored the intersection of microbiota modulation, immune signaling, and transporter pharmacology, notably through the use of compounds like Metronidazole (2-(2-methyl-5-nitroimidazol-1-yl)ethanol):

• Metronidazole: A Powerful Tool for OAT3 Inhibition & Microbiota Modulation discusses how selective antibiotics can be leveraged to probe immune-microbiota interactions and drug-transporter crosstalk.
• Metronidazole as a Precision Modulator: Bridging Microbiota and Immunity highlights the mechanistic rationale for using targeted inhibitors to study transporter roles in drug-drug interaction modulation and immune balance.

While the reference study employs a herbal TCM route, these internal articles underscore the utility of pharmacological tools—such as Metronidazole—for dissecting the mechanistic underpinnings of microbiota and immune modulation, particularly via inhibition of organic anion transporters and targeted disruption of anaerobic bacteria (internal article).

Limitations and Transferability

The rat OVA model, while robust, may not capture all aspects of human AR pathophysiology or microbiota diversity. The SFXBT formulation includes multiple herbal components, complicating direct attribution of effects to specific molecules. Furthermore, while 16S rDNA sequencing provides high-level taxonomic resolution, functional metagenomic or metabolomic analyses would yield deeper mechanistic insights. Translating findings from animal models to clinical settings requires caution, particularly regarding immune responses and gut flora variability among human populations. Nonetheless, the experimental framework and multi-parameter endpoints offer a valuable template for future mechanistic studies in microbiota-immune crosstalk.

Why this cross-domain matters, maturity, and limitations

The study bridges traditional herbal therapy with contemporary immunology and microbiome science, supporting the concept of integrated multi-modal interventions for immune-allergic disorders. The maturity of this approach is evidenced by reproducible improvements in both clinical and molecular endpoints. However, limitations include the inability to pinpoint which SFXBT components drive observed effects, and the lack of direct transporter or drug-drug interaction studies within this specific work (reference paper).

Research Support Resources

For researchers aiming to replicate or extend similar immune-microbiota investigations, precise pharmacological tools can complement herbal approaches. Metronidazole (SKU B1976) is a nitroimidazole antibiotic and validated OAT3 inhibitor—widely used for inhibition of organic anion transporters, targeting anaerobic bacteria, and modulating drug-drug interactions in preclinical models (source: internal article). Researchers can employ Metronidazole for targeted depletion of gut anaerobes or to probe transporter-mediated immune–drug–microbiota dynamics, paralleling the multifaceted analysis demonstrated in the SFXBT study. APExBIO provides high-purity, data-supported reagents to facilitate such workflows and ensure reproducibility in experimental microbiome and immunology research.