Nasal Rinsing with Probiotics-Microbiome Evaluation in Patients with Inflammatory Diseases of the Nasal Mucosa.

: The evidence regarding the efficacy of probiotics in chronic rhinosinusitis (CRS) is very limited, prompting the EPOS2020 steering group to advise against their use in CRS treatment. Therefore, further research to evaluate the impact of probiotics on microbial communities is particularly important. This study aimed to assess the influence of probiotic nasal rinses on nasal microbiota profiles in patients with primary CRS, granulomatosis with polyangiitis (GPA), and nasal septal perforation (NSP) using 16S rRNA sequencing. : Thirty-six patients with nasal mucosal diseases, including sixteen with primary CRS, eleven with GPA, and nine with NSP, were randomly assigned to either a study group receiving nasal rinses with probiotics containing and , or a control group using nasal rinses with saline. Metagenomic analysis targeting the V3-V4 hypervariable region of the 16S rRNA gene was performed to characterize bacterial and archaeal populations. : At the genus level, the most abundant co-colonizers included , , and After one month of probiotic rinsing, a decrease in abundance of the genera ( = 0.010), ( = 0.020), ( = 0.027), ( = 0.033), ( = 0.035), ( = 0.049), ( = 0.055), ( = 0.055), and ( = 0.058) was observed. Conversely, the abundance of probiotic species and increased. Moreover, increases in the genera and were observed, although they did not reach statistical significance. : Probiotic nasal rinses may contribute to restoring microbial homeostasis by reducing genera associated with inflammatory dysbiosis in nasal inflammatory diseases, warranting further research on their clinical benefits.