P-1653. Altered Gut Microbiome Composition in Early Childhood COVID-19

Background The gut microbiome plays a crucial role in immune function, and its dysregulation may influence the clinical course of infectious diseases, including coronavirus disease 2019 (COVID-19). Early childhood is a critical period for gut microbiome development, yet data on gut microbiome alterations in young children with COVID-19 remain limited. This study aimed to characterize gut microbiome changes in young children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods Stool samples were collected from 18 children under 2 years of age with confirmed SARS-CoV-2 infection and 7 healthy controls between December 2021 and June 2022. Gut microbiota composition was analyzed using 16S rRNA gene sequencing. Results In children with COVID-19, the gut microbiome exhibited an increase in Bacteroidetes and Firmicutes, whereas Actinobacteria and Proteobacteria were reduced, with higher abundances of Bifidobacterium, Escherichia, and Streptococcus and lower abundances of Faecalibacterium, Clostridium, and Ruminococcus compared to healthy controls. Children with COVID-19 exhibited reduced alpha diversity, indicating microbial dysbiosis, and significant differences in beta diversity compared to healthy controls. Several immune-related pathways, including NOD-like receptor, IL-17, Fc gamma R-mediated phagocytosis, Th17 differentiation, and Toll/Imd signaling, were significantly downregulated in the gut microbiome of children with COVID-19. Conclusion This study highlights significant alterations in the gut microbiome of young children with SARS-CoV-2 infection, emphasizing the need for further research into the potential long-term effects of gut dysbiosis on child health and development. Disclosures All Authors: No reported disclosures