Background Allergic Rhinitis is a chronic Th2-mediated inflammatory disorder associated with significant disease burden and impaired quality of life. Emerging evidence highlights the role of the gut-immune axis, intestinal permeability, and microbial-metabolic signaling in modulation of allergic immune responses. In , Agni is considered the fundamental regulator of digestion, metabolism, and physiological homeostasis. Disturbance in Agni may contribute to altered gut homeostasis and immune dysregulation. However, the relationship between Agni, gut permeability-associated mechanisms, and Th2-mediated immune response in allergic rhinitis remains insufficiently explored.

Aim To evaluate the effect of an Agni-modulating Ayurvedic intervention on Th2-mediated immune response and gut permeability-associated mechanisms in individuals with allergic rhinitis.

Objectives The primary objective is to evaluate the effect of an Agni-modulating Ayurvedic intervention on serum immunoglobulin E (IgE) and interleukin-4 (IL-4) levels in allergic rhinitis. Secondary objectives include assessment of gut permeability-associated biomarkers including serum zonulin and lactulose-mannitol test parameters, evaluation of changes in Agni status and clinical symptom severity, and exploration of associations between Agni status, gut permeability-associated biomarkers, and immune response. The study also aims to explore inter-individual variability based on Agni types and Prakriti.

Methods This study is designed as a randomized, controlled, assessor-blinded, parallel-group clinical trial with an embedded exploratory mechanistic component. A total of 104 participants aged 18-60 years diagnosed with allergic rhinitis based on standard clinical criteria and positive skin prick test will be recruited and randomized in a 1:1 ratio into intervention and control groups. The intervention group will receive a standardized Agni-modulating Ayurvedic treatment protocol consisting of Deepana-Pachana formulations followed by Amrita Ghritham along with Pathya-Apathya advice, in addition to standard conventional management. The control group will receive standard conventional management. Primary outcome measures include serum IgE, IL-4, serum zonulin, and lactulose-mannitol test parameters. Secondary outcomes include Agni assessment, Total Nasal Symptom Score (TNSS), eosinophil count, and subgroup analysis based on Agni and Prakriti.

Expected Outcome The study is expected to provide preliminary evidence regarding the relationship between Agni modulation, gut permeability-associated mechanisms, and Th2-mediated immune response in allergic rhinitis, and may contribute to biomarker-oriented translational and integrative approaches in allergic disease management.

Allergic rhinitis is a common chronic inflammatory disorder characterized by IgE-mediated and Th2-skewed immune responses, resulting in symptoms such as sneezing, rhinorrhea, nasal obstruction, and itching. Although current therapies provide symptomatic relief, they have limited influence on upstream mechanisms involved in immune sensitization and regulation.

Emerging evidence suggests that the gut-immune axis plays an important role in allergic diseases. Alterations in gut microbial balance, intestinal permeability, and microbial-metabolic signaling have been implicated in modulation of immune responses and allergic inflammation. In addition, growing interest has focused on the gut-lung axis and its contribution to respiratory allergic disorders.

In Ayurveda, Agni is considered the fundamental regulator of digestion, metabolism, and physiological homeostasis. Disturbance of Agni is traditionally associated with impaired digestive and metabolic function and may contribute to systemic dysregulation. Contemporary research has suggested possible links between metabolic homeostasis, gut physiology, epithelial barrier integrity, and immune responsiveness, providing a potential translational framework for exploring Ayurvedic concepts in allergic disease.

This randomized controlled clinical trial is designed to evaluate the effects of an Agni-modulating Ayurvedic intervention in individuals with allergic rhinitis. The study incorporates an exploratory mechanistic component to investigate potential associations between Agni modulation, gut permeability-associated mechanisms, and Th2-mediated immune responses. Biomarker-based assessment will be used to explore changes in immune activation and gut barrier function alongside clinical outcomes.

The intervention is based on classical Ayurvedic principles of Deepana and Pachana and includes standardized Ayurvedic formulations administered under clinical supervision along with dietary regulation intended to support Agni and gut homeostasis. Participants in the control arm will receive standard conventional management.

The study is expected to generate preliminary evidence regarding the relationship between Agni modulation, gut permeability-associated mechanisms, and allergic immune responses. Findings may contribute to the development of biomarker-oriented translational approaches for understanding integrative mechanisms in allergic rhinitis and may provide a foundation for future mechanistic and personalized medicine research.

**Inclusion Criteria:**

• Participants aged 18-40 years.
• Clinical diagnosis of Allergic Rhinitis based on standard diagnostic criteria.
• Positive skin prick test to relevant allergens.
• Presence of active allergic rhinitis symptoms at the time of recruitment.
• Willingness to participate and provide written informed consent.
• Willingness to comply with study procedures, laboratory investigations, and follow-up assessments.

**Exclusion Criteria:**

• Severe systemic illness.
• Immunodeficiency disorders.
• Autoimmune diseases.
• Chronic gastrointestinal disorders that may influence gut permeability parameters.
• Other chronic inflammatory conditions that may influence immune response.
• Long-term immunosuppressive therapy.
• Systemic corticosteroid therapy.
• Biologic therapy.
• Use of medications known to significantly alter immune response or gut microbiota.
• Use of antibiotics within the previous 3 months.
• Use of probiotics within the previous 3 months.
• Use of prebiotics within the previous 3 months.
• Pregnancy.
• Lactation.
• Known food allergy or hypersensitivity to study medications.
• Severe psychiatric illness.
• Inability to comply with study procedures.
• Current participation in another clinical trial.