* Corresponding author: Anggi Gayatri Department of Pharmacology and Therapeutic, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia. Copyright © 2022 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Probiotic as supplementary therapy for chronic rhinosinusitis Fernando Wahyu 1 and Anggi Gayatri 2, * 1 Clinical Pharmacology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia. 2 Department of Pharmacology and Therapeutic, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia. International Journal of Scientific Research Updates, 2022, 04(01), 103–107 Publication history: Received on 11 June 2022; revised on 18 July 2022; accepted on 20 July 2022 Article DOI: https://doi.org/10.53430/ijsru.2022.4.1.0085 Abstract Chronic Rhinosinusitis is an inflammation in paranasal sinus and nasal cavity that can last up to a minimum of 12 weeks with prevalence 1% to 12% globally. The etiology of chronic rhinosinusitis is usually caused by combination of various factors such as pathogenic organism and obstruction of the sinus tract. The latest study also found imbalance in natural microbiome can cause chronic rhinosinusitis. One of the alternative therapies to help alleviate chronic rhinosinusitis is using probiotic. Probiotic is a living microorganism that, if given in adequate dosage, will provide health benefits for the host by keeping the balance of microbiome or commensal bacteria count in the body. Some latest studies showed the efficacy of probiotic in rhinitis allergy, atopic prevention such as eczema, asthma, diarrhea and food allergy. Aim of this narrative review is to understand the efficacy of probiotic and possible side effects that might occur in the use of probiotics as supplementary therapy on chronic rhinosinusitis. Keywords: Chronic rhinosinusitis; Probiotic; Microbiome; Immune system; Sinus cavity; Commensal bacteria 1 Introduction Chronic Rhinosinusitis is a symptomatic inflammation in paranasal sinus and nasal cavity that can occur for minimum 12 weeks. The prevalence of chronic rhinosinusitis varies around the world, ranging from 1% to 12.1% [1]. In the United States, based on 2012 health survey, 1 out of 8 adults suffer chronic rhinosinusitis in the last 12 months. 2 The prevalence of chronic rhinosinusitis with polyp in Sweden was 2.7% from the entire population, 0.5% in Korea, and 2.1% in France. 3 Chronic rhinosinusitis can occur in various race and can greatly impact the medication cost [4]. The total indirect and direct cost of yearly treatment for chronic rhinosinusitis in America is estimated around 22 billion US dollar in 2014, along with additional cost caused by decreased productivity and work effectiveness [2,3]. The etiology of chronic rhinosinusitis is not entirely understood but it might be caused by combination of various factors such as pathogenic organism and obstruction of the sinus tract [5]. The latest study showed that imbalance in natural microbiome can be caused by antibiotic therapy and it may cause chronic rhinosinusitis [6]. Staphylococcus aureus and Staphylococcus epidermidis are the two most common pathogenic bacteria that causes chronic rhinosinusitis [5]. Due to its uncertain etiology, therapy that is given to alleviate chronic rhinosinusitis is generally symptomatic such as, saline solution irrigation, antihistamine, decongestant and topical or systemic corticosteroid and on some cases an antibiotic is also prescribed if the patient is diagnosed with infection. For some patient, perfect remission is not achieved through the prescription of the previous medication [7]. One of the other possible alternative treatments to alleviate chronic rhinosinusitis is the use of probiotic. Probiotic is a living microorganism that, if given in adequate dosage, will provide health benefits for the host. The purpose of using probiotic is for keeping the balance of microbiome or commensal bacteria counts in the body. Probiotic may help alleviate chronic rhinosinusitis by keeping commensal