When the patients is hospitalized in neonatology, we screen the premature infants according to the selection criteria and exclusion criteria. After sighed the informed consent, they are classified into two groups: premature infants diagnosed as necrotizing enterocolitis (NEC group) and premature infants without necrotizing enterocolitis (control group). Their stool and blood (usually 2 times ) are collected for intestinal flora and FABP (including L-FABP and I-FABP) analysis, respectively.
Study Description~The goal of this observational study is to detect intestinal flora and the metabolic products in premature infants diagnosed as necrotizing enterocolitis. The main questions it aims to answer are:~1. Whether there is intestinal flora in the stool of premature infants.~2. Are there dysregulated intestinal flora and their metabolic products in premature infants diagnosed as necrotizing enterocolitis.~3. The detailed role and underlying mechanism of the intestinal dysbacteriosis and the metabolic products in premature infants diagnosed as necrotizing enterocolitis.~Participants, premature infants diagnosed as necrotizing enterocolitis (NEC group), will be asked to collect stool (usually 2 times) for intestinal flora analysis.~If there is a comparison group: Researchers will compare premature infants without necrotizing enterocolitis (control group) to see if their intestinal flora and the metabolic products also changed as their NEC counterparts.