Mouthrinses differentially rewire salivary virus-microbiome interaction dynamics in COVID-19 patients: A randomized...

In this randomized clinical trial (RCT) we evaluated the efficacy of mouthrinses containing sodium chlorite (NaClO₂), povidone iodine (PVP-I), cetylpyridinium chloride (CPC) compared to sterile water control in modulating salivary SARS-CoV-2 viral load and the oral microbiome in COVID-19 patients.

Forty PCR-confirmed COVID-19 patients were randomly allocated to four groups (n = 10 each) and rinsed with 10 ml of their assigned solution for 30 s. Saliva was collected pre-rinse and at 5-min, 3-hour, and 6-hour post-rinse. Viral load was quantified via RT-qPCR targeting N and ORF1ab genes, and oral microbiome was analyzed using 16S rRNA sequencing.

CPC reduced viral load by 1.5-fold (P = 0.12), PVP-I by 1.2-fold (P = 0.18), and NaClO₂ by 1.1-fold (P = 0.34) at 6-hour, though not statistically significant. Overall oral microbiome diversity and composition remained stable (P = 0.67), although CPC and PVP-I significantly altered specific taxa such as Leptotrichia sp. and Lautropia mirabilis. Moreover, CPC and PVP-I disrupted the salivary microbiome network with SARS-CoV-2 genes, namely N and ORF1ab genes.

This study to provide new insight into the modulation dynamics of mouthrinses on salivary SARS CoV-2 and oral microbiome, suggesting that CPC and PVP-I may provide potential health benefits by reducing viral load and modulating microbiome-virus networks.