AUTHOR=Casaburi Giorgio , Wei Jingjing , Kazi Sufyan , Liu Junlin , Wang Kewei , Tao Guo-Zhong , Lin Po-Yu , Dunn James C. Y. , Henrick Bethany M. , Frese Steven A. , Sylvester Karl G. 

TITLE=Metabolic model of necrotizing enterocolitis in the premature newborn gut resulting from enteric dysbiosis

JOURNAL=Frontiers in Pediatrics

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.893059

DOI=10.3389/fped.2022.893059

ISSN=2296-2360

ABSTRACT=<p>Necrotizing enterocolitis (NEC) is a leading cause of premature newborn morbidity and mortality. The clinical features of NEC consistently include prematurity, gut dysbiosis and enteral inflammation, yet the pathogenesis remains obscure. Herein we combine metagenomics and targeted metabolomics, with functional <italic>in vivo</italic> and <italic>in vitro</italic> assessment, to define a novel molecular mechanism of NEC. One thousand six hundred and forty seven publicly available metagenomics datasets were analyzed (NEC = 245; healthy = 1,402) using artificial intelligence methodologies. Targeted metabolomic profiling was used to quantify the concentration of specified fecal metabolites at NEC onset (<italic>n</italic> = 8), during recovery (<italic>n</italic> = 6), and in age matched controls (<italic>n</italic> = 10). Toxicity assays of discovered metabolites were performed <italic>in vivo</italic> in mice and <italic>in vitro</italic> using human intestinal epithelial cells. Metagenomic and targeted metabolomic analyses revealed significant differences in pyruvate fermentation pathways and associated intermediates. Notably, the short chain fatty acid formate was elevated in the stool of NEC patients at disease onset (<italic>P</italic> = 0.005) dissipated during recovery (<italic>P</italic> = 0.02) and positively correlated with degree of intestinal injury (<italic>r</italic><sup>2</sup> = 0.86). <italic>In vitro</italic>, formate caused enterocyte cytotoxicity in human cells through necroptosis (<italic>P</italic> &lt; 0.01). <italic>In vivo</italic>, luminal formate caused significant dose and development dependent NEC-like injury in newborn mice. <italic>Enterobacter cloacae</italic> and <italic>Klebsiella pneumoniae</italic> were the most discriminatory taxa related to NEC dysbiosis and increased formate production. Together, these data suggest a novel biochemical mechanism of NEC through the microbial production of formate. Clinical efforts to prevent NEC should focus on reducing the functional consequences of newborn gut dysbiosis associated metabolic pathways.</p>