(1) Background: To substantiate the clinical efficacy and investigate the real-world effectiveness of the herbal medicinal product BNO 1016 in acute rhinosinusitis (ARS) in the context of antibiotic stewardship. (2) Methods: Clinical efficacy: We performed a meta-analysis of the clinical trials ARhiSi-1 and ARhiSi-2 comprising 676 patients, analysing the reduction of the Major Symptom Score (MSS) and improvement of SNOT-20. Real-world effectiveness: In addition, we performed a retrospective cohort study including 203,382 patients, comparing the real-life effectiveness of BNO 1016 in reducing ARS-related adverse outcomes in comparison to antibiotics and several other established therapies. (3) Results: Clinical efficacy: Treatment with BNO 1016 ameliorated symptoms of ARS by reducing MSS by 1.9 points (p<0.0001) and improved quality of life (QoL) for patients by improving SNOT-20 by 3.5 points (p=0.001) in comparison to placebo. In patients with moderate/severe symptoms, the positive effects of BNO 1016 were even more pronounced (MSS: –2.3 points (p<0.0001); SNOT-20: –4.9 points (p=0.0158)) compared to placebo. Real-world effectiveness: Treatment with BNO 1016 was as effective or significantly more effective in reducing the risk for adverse ARS-related outcomes such as follow-up antibiotic prescriptions, sick leave ≥7 days or medical appointments due to ARS, especially when compared to antibiotics. (4) Conclusions: BNO 1016 is a safe and effective treatment for ARS that can help reduce the overuse of antibiotics.

Epithelial surfaces in humans are home to symbiotic microbes (i.e., microbiota) that influence the defensive function against pathogens depending on the health of the microbiota. Healthy microbiota contribute to the well-being of their host in general (e.g., via the gut-brain-axis), and their respective anatomical site in particular (e.g., oral, urogenital, skin or respiratory microbiota). Despite efforts towards a more responsible use of antibiotics, they are often prescribed for uncomplicated, self-limiting infections and can have a substantial negative impact on the gut microbiota. Treatment alternatives such as non-steroidal anti-inflammatory drugs may also influence the microbiota and thus can have lasting adverse effects. Herbal drugs offer a generally safe treatment option for uncomplicated infections of the urinary or respiratory tract. Additionally, their microbiota preserving properties allow for a more appropriate therapy of uncomplicated infections without contributing to an increase in antibiotic resistance or disturbing the gut microbiota. Here, herbal treatments may be a more appropriate therapy with a generally favorable safety profile.