CRS NASAL MICROBIOME COMPOSITION: HIGH DISSIMILARITY SEEN OVERALL AND IN EACH INDIVIDUAL OVER TIME

Abstract

Introduction Chronic rhinosinusitis is a disease of complex inflammatory and microbial interactions. Prior studies show a significant nasal microbiome shift in CRS patients but these studies have inconsistent data on which bacteria increases in CRS. Furthermore, there are no prior longitudinal studies evaluating bacterial community changes at different time points among CRS cases. Methods Middle meatus swab samples were collected under endoscopy guide in CRS patients and controls at two different time points six months apart. All microbiomes were analyzed. To investigate the variation among microbial communities, the Bray–Curtis dissimilarity method was used. Analysis was conducted at the genus level. Results Greater dissimilarity of bacterial species was found within the 16 CRS patients as compared to the 10 controls with a Bray-Curtis value closer to 1 in the CRS group. Within the same individual, nasal microbiome in 16 CRS patients showed higher dissimilarity at two different time points compared with controls. Corynebacterium and Peptoniphilus genera were significantly decreased in CRS nasal microbiomes. Conclusions In CRS patients, there is greater nasal microbiome dissimilarity overall and within the same individual at different time points suggesting that these microbes overgrow in various patterns without following a specific trend. This might be the reason for inconsistency in previous studies. Healthy individuals share more bacteria and have higher relative abundance of Corynebacterium and Peptoniphilus suggestive of a protective pattern of this homeostatic flora. The loss of healthy flora may create bacterial imbalance causing overgrowth of bacteria that result in the inflammatory processes in CRS.