Fig. 4: Impact of Bacillus spore nasal spray on pro-inflammatory cytokines and nasal-mucosal immunity.

Pro-inflammatory cytokine levels (pg/mL) and IgA levels (mg/mL) (a1–d1) in nasopharyngeal samples of Control and Navax groups at day 3 compared to day 0. The association between reduced RSV load and ▵cytokine/IgA levels from day 0 to day 3 (a2–d2) was assessed using multiple logistic regression analysis. The Wilcoxon test was used to calculate the median differences in IL-6, IL-8, TNF-α, and IgA levels at day 0 and day 3 within each group. The differences in the associations between reduced RSV load and changes in IL-6 levels (a2), reduced RSV load and changes in IL-8 levels (b2), reduced RSV load and changes in TNF-α levels (c2), and reduced RSV loads and changes in IgA levels (d2) were validated using the energy test. Comparisons of cytokine concentrations between the two groups were made using the Mann-Whitney test. Only measurable samples at day 0 were included in the statistical analysis. 95% CI for the median in each group and the median difference between the two groups were shown. The significance level for all analyses was set at p < 0.05. Sample size: n = 50 biologically independent samples for all three cytokines and IgA in the Control group; n = 51 for IL-6 and TNF-α, and n = 50 for IL-8 and IgA in the Navax group.