A Prospective, Interventional, Randomized, Double-Blinded, Placebo-Controlled, Monocentric Clinical Study to Evaluate the Efficacy and Safety of Alkalihalobacillus clausii 088AE in Resolution of Acute Allergic Rhinitis Symptoms.

Background: Allergic rhinitis (AR) is a common inflammatory disease of the upper respiratory tract mainly triggered by allergens such as dust mites, pollen, spores, and viral or bacterial infections. AR is primarily associated with symptoms such as nasal itching, sneezing, rhinorrhea, nasal congestion, and watery, itchy, or red eyes. AR significantly affects an individual's quality of life. Probiotics have been proven effective in the clinical management of AR through immunomodulation. However, studies on the use of Alkalihalobacillus clausii to alleviate the symptoms of AR have rarely been reported.

Objective: This study aimed to explore the clinical efficacy, safety, and possible underlying mechanism of Alkalihalobacillus clausii 088AE in alleviating the associated symptoms of acute AR in patients.

Methods: A prospective, interventional, randomized, double-blinded, placebo-controlled, monocentric clinical study was conducted on patients with acute AR (N = 40) randomized into two groups, test (N = 20) and placebo (N = 20). Patients in the test arm received a probiotic strain, A. clausii 088AE, whereas patients in the placebo arm received Maltodextrin. The primary endpoints (efficacy) were total 4 nasal symptoms scores (T4NSS), total 2 ocular symptoms scores (T2OSS), cough scores, and immunological parameters (T-helper 1 (Th1), Th2, Th17, and T-regulatory (Treg) cells, Interleukin (IL)-4, IL10, IL17, IL22, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) and -beta (TNF-β), and forkhead box P3 (FOXP3)) evaluated from baseline to end of treatment (EOT). The secondary endpoints (safety) assessed were vital physical signs, hematology, and biochemical parameters, along with an assessment of adverse or serious adverse events (AEs and SAEs).

Results: A. clausii 088AE supplementation significantly reduced the T4NSS (rhinorrhoea, nasal stuffiness, nasal itching, and sneezing; P < 0.001), T2OSS (itching and watery eyes; P < 0.001), and cough scores (P < 0.01) by the EOT compared to baseline. The placebo group reported a significant increase in all the above symptom scores at the EOT from their baseline values (P < 0.001). The intergroup analysis between A. clausii 088AE and placebo indicated a significant change in T4NSS, T2OSS, and cough score (P < 0.001). Further, the immunological parameters were improved (non-significant, P-value ≥ 0.05) with the probiotic supplementation. No adverse events (AEs) or serious adverse events (SAEs) leading to termination of study participation were reported with the use of A. clausii 088AE in the study. No clinically significant vital signs and physical examinations were reported as AEs or SAEs by the investigator.

Conclusion: A. clausii 088AE supplementation improved the clinical symptoms in patients with AR. At the administered oral dose, A. clausii 088AE was found to be safe and tolerable in adult subjects with acute allergic rhinitis. A. clausii 088AE can be recommended to support the clinical pathophysiology of AR-related symptoms of the host. Besides, clinical studies with a larger population, multiple centres, and prolonged intervention periods are necessary to validate the significance of this study further.