Leveraging probiotic biogeography to prevent dysbiosis in the neonatal intestine 4705

Abstract Description Neonatal infection is one of the leading causes of neonatal morbidity and mortality worldwide, particularly in those born prematurely or with low birth weight. Probiotic bacteria have been demonstrated to protect against the development of neonatal intestinal dysbiosis and are widely used in peri- and post-natal clinical settings. However, formulations and efficacy are highly variable, highlighting a critical gap in the current understanding of the mechanistic underpinnings of successful probiotic species in this population. Furthermore, current studies on probiotic efficacy largely rely on indirect or relative readouts of intestinal bacterial burden. Herein, we directly quantify the probiotic effects of Ligilactobacillus murinus V10 and Escherichia coli Nissle 1917 (EcN) against Klebsiella pneumonia dysbiosis across the span of the neonatal murine intestine. Further, we demonstrate that the extent of protection across the intestinal span is not dependent on priority effect and increases based on the natural biogeography of the probiotic species for both L. murinus V10 and EcN. Funding Sources NIH/NIAID AI164712-01 Topic Categories Mucosal and Regional Immunology (MUC)