Gut microbiota and 1,8-Cineol

Background: Chronic rhinosinusitis (CRS) is a widespread inflammatory disease of the paranasal sinuses that occurs in about 10% of the European population, either without (CRSsNP) or with a manifestation of nasal polyps (CRSwNP). The standard treatment includes surgery and the administration of corticosteroids or antibiotics. Antibiotics are well known to influence the microbial composition of the gut, including a decrease in bacterial diversity and an increase in antibiotic resistance. This underlines the need for alternative treatment approaches, especially regarding vulnerable patients like children. Therefore, we evaluated the intestinal microbiota of CRSwNP patients regarding plant-based anti-inflammatory monoterpene 1,8-Cineol, which is commonly used as the clinically approved drug Soledum® for the treatment of different chronic and acute airway diseases including CRS. Methods: Microbiome analysis from stool samples were performed from 31 CRSwNP patients before and after 14 days of 1,8-Cineol administration using 16S rRNA gene next generation sequencing using dissimilarity-based and taxonomic approaches. Results: Data revealed highly diverse microbial community with elevated abundances of certain taxa including Bacteroides and Faecalibacterium as part of the physiologic gut microbial community. No overall disturbances of the microbial abundance and diversity upon 1,8-Cineol treatment of CRSwNP patients could be observed. Of note, abundances of intestinal Akkermansia muciniphila tend to increase during the course of 1,8-Cineol administration. Conclusion: Our data recommend 1,8-Cineol as a valuable addition to the current standard treatment of inflammatory diseases, without running the risk of profound changes of the gut microbial community.