(865.1) The Pandemic Effects on the Microbiome of Infants in the Neonatal Intensive Care Unit (NICU)

Poster Board Number: E188

Jason Xia (The University of Chicago, Whitney Young Magnet High School), Kaitlyn Oliphant (The University of Chicago), Erika Claud (The University of Chicago)

The microbiome is an *invisible organ* that affects health and disease. Early life microbial colonization is critical for development of the immune system, postnatal growth, and long-term health. The dynamic and nascent microbiomes of children are highly individualized. SARS-CoV-2(Covid-19) is known to impact the adult microbiome. However, pandemic impact on the infant microbiome is unknown. In the current study we hypothesized that infants born prior to pandemic regulations may demonstrate differences compared to those born during the pandemic.  Fecal samples (n=307) were collected from infants (1-19 weeks) in the NICU at The University of Chicago. DNA was extracted for 16S rRNA sequencing, and 4576 taxa were analyzed using R. We performed alpha diversity analysis within the samples and beta diversity between the samples to measure and compare bacterial communities.  Alpha diversity did not demonstrate a significant difference between before pandemic and during pandemic groups, while Beta diversity did achieve a significant difference between the two groups. Multivariate analysis showed that in before pandemic and during pandemic groups, post menstrual age (PMA), weeks of life (WOL), as well as the interactions of pandemic grouping by PMA, and PMA by WOL were significant. Lastly, we identified the top 5 positively associated and top 5 negatively associated bacteria at the species/genus level associated with the pandemic grouping. Of these, Serratia marcescens and Acinetobacter johnsonii are associated with antibiotic resistance, and reduction of human pathogens such as Shigella and Salmonella. This study illustrates that differences in microbiome diversity exist between infants before and after pandemic regulations. Any disruptions in microbial colonization can contribute to shifts in normal microbial colonization that persist past the first 1000 days of life.  Our study suggests the possible influences of secondary factors during the pandemic on microbiome development. In future studies we plan to further explore the interaction of cofounders (e.g. PMA) as well as follow up on the long-term effects of the pandemic on the infant microbiome.

Sequencing by Argonne National Laboratory, Sequence processing by Bingqing Xie, PhD PreSET University of Chicago, Sample Collection Supported by NIH HD083481, OD023281 and SET.