Acute rhinosinusitis (ARS) is an inflammation of the nasal passages and the lining of the sinuses due to an infection. Clinical symptoms and signs of ARS include nasal blockage/obstruction/congestion or runny nose, sneezing, headache, sinus pain (facial pain), and loss of smell. According to statistics in the US, there are about 18-22 million ARS visits to the doctor each year that estimated cost of treatment of up to 11 billion dollars. Up to 28.9 million adults were diagnosed with rhinosinusitis, accounting for 11.6% of the population. In a 5-year statistics at the National Otorhinolaryngology Hospital of Vietnam, rhinosinusitis patients in the working age group from 16 to 50 years old account for 87%. Acute otitis media (AOM) is inflammation of the middle ear mucosa accompanied by effusion into the middle ear due to infection, which may be associated with the presence or absence of perforation of the tympanic membrane. Symptoms of AOM include fever, purulent discharge from the ear canal (ear discharge or otorrhea), earache (rubbing or pulling on the earlobe, tossing or turning, difficulty sleeping or crying), headache, and hearing loss temporary (poor response to sound), vomiting or diarrhea. AOM is children's most common ear disease and a common cause of hearing loss. About 90% of children under two years of age have had at least one episode, and about 80% of preschool children have otitis media. The prevalence is now about 20% at 2 years and 8% at the age of 8 years. Bacteria that cause acute rhinosinusitis and acute otitis media include S. pneumoniae, H. influenzae, M. catarrhalis, and S. aureus... Rhinosinusitis and bacterial otitis media usually require antibiotic treatment; however, inappropriate antibiotic therapy will increase drug resistance and side effects, thereby increasing medical costs. In recent years, the role of probiotics in respiratory diseases has also been mentioned in convincing studies. However, these probiotic products are mainly used orally, with very few products being prepared as nasal spray suspensions. Here, the investigators conducted a study that the direct spray of probiotics into the nose effectively supports treating acute rhinosinusitis and acute otitis media.

The objective was to investigate the symptomatic support treatment effects of the probiotic product LiveSpo Navax® as a liquid-suspension form containing Bacillus spores of safe B. subtilis ANA4 and B. clausii ANA39 strains in children and adults having ARS and children having ARS accompanied by AOM caused by bacteria, investigators evaluation of improved symptom efficacy of LiveSpo Navax® in patients; and measurement of changes in bacterial concentrations, and major cytokine indicators in the nasopharyngeal and ear samples before and after 3 days or 7 days using LiveSpo Navax®.

Methods: A randomized, blind, controlled clinical trial is conducted. The patients or parents of patients must provide the following information: full name, sex, age, address...After informed consent,120 eligible patients are divided into 2 groups (n = 60/group each) including the ARS group and the ARS accompanied by the AOM (ARS \& AOM) group. 60 patients with ARS will be randomized into two subgroups (n = 30/subgroup): the control - acute rhinosinusitis subgroup (named Control - ARS subgroup) uses 0.9% NaCl physiological saline and an experimental - acute rhinosinusitis subgroup (called the Navax - ARS subgroup) use the probiotics LiveSpo Navax®. And similarly, 60 children with ARS accompanied by AOM will be randomized into two subgroups (n = 30/subgroup): the control - acute rhinosinusitis accompanied by acute otitis media group (named Control - ARS \& AOM group) uses 0.9% NaCl physiological saline and an experimental - acute rhinosinusitis accompanied by acute otitis media group (called the Navax - ARS \& AOM group) use the probiotics LiveSpo Navax®. The patient is given a coded spray in the form of a blind sample to ensure the study's objectivity. After the follow-up patient time, nasopharyngeal samples on both ARS and ARS accompanied by AOM groups and ear samples on the ARS accompanied by AOM group will be collected at day 0 and day 3 or/and 7 to evaluate potential reductions in bacteria load and modulation of cytokine, IgA, and the presence of probiotic spores in the patient's the nasopharyngeal and ear samples.

Real-time polymerase chain reaction (Real-time PCR) for detection of microorganisms in nasopharyngeal and ear samples: semi-quantitative assays for measuring changes in bacterial concentrations are conducted by the real-time PCR routine protocol, which has been standardized under International Organization for Standardization 5189:2012 (ISO 15189:2012) criteria and used in Vietnam National Children's Hospital. Detection of B. subtilis ANA4 and B. clausii ANA39 are also conducted by real-time PCR SYBR® Green (SYBR® Green is a dsDNA-binding dye), standardized routinely in Spobiotic Research Center, ANABIO R\&D Ltd.

ELISA assays for cytokine levels: pro-inflammatory cytokines levels (pg/mL), including interleukin (IL-6, IL-8) and TNF-alpha, and immunoglobin A (ng/mL) are quantified using an enzyme-linked immunosorbent assay kit (ELISA) according to the manufacturer's instructions. The patients are monitored for symptoms of ARS and AOM at days 0, 3, or/and 7, depending on the degree of compliance with the follow-up re-examination of the outpatients. Doctors observe the patient's health conditions, and their patients of information are filled into medical records. During this study, patients are asked to abstain from the consumption of other probiotics, either via nasal spray or oral administration.

Data collection and statistical analysis: individual medical records are collected, and the patient's information is gathered and systematized. The efficacy of LiveSpo Navax® is evaluated and compared to 0.9% Sodium Chloride (NaCl) physiological saline based on the following clinical and sub-clinical criteria obtained in Navax and Control groups: (i) effective the symptomatic-relieving; (ii) the reduction levels (2\^△Ct) of bacteria concentrations.△Ct for target genes is calculated as Ct (threshold cycle of real-time PCR assay) at day 3 or/and 7 - Ct at day 0 while Ct of internal control is adjusted to be equal among all samples; (iii) the reduction levels of IL-6, IL-8, and TNF-alpha cytokines and IgA. The tabular analysis is performed on dichotomous variables using the χ2 test or Fisher's exact test when the expected value of any cell is below five. Continuous variables are compared using the Wilcoxon test, t-test, or the Mann-Whitney test when data are not normally distributed. The correlations among the variables are assessed by Spearman's correlation analysis. Statistical and graphical analyses are performed on GraphPad Prism v8.4.3 software (GraphPad Software, CA, USA). The significance level of all analyses is set at p \< 0.05. P-values.