ABSTRACT
OBJECTIVES@#To study the effect of gut microbiota on hematopoiesis in a neonatal rat model of necrotizing enterocolitis (NEC).@*METHODS@#Neonatal Sprague-Dawley rats were randomly divided into a control group and a model group (NEC group), with 6 rats in each group. Formula milk combined with hypoxia and cold stimulation was used to establish a neonatal rat model of NEC. Hematoxylin and eosin staining was used to observe the pathological changes of intestinal tissue and hematopoiesis-related organs. Routine blood tests were conducted for each group. Immunohistochemistry was used to observe the changes in specific cells in hematopoiesis-related organs. Flow cytometry was used to measure the changes in specific cells in bone marrow. 16S rDNA sequencing was used to observe the composition and abundance of gut microbiota.@*RESULTS@#Compared with the control group, the NEC group had intestinal congestion and necrosis, damage, atrophy, and shedding of intestinal villi, and a significant increase in NEC histological score. Compared with the control group, the NEC group had significantly lower numbers of peripheral blood leukocytes and lymphocytes (P<0.05), nucleated cells in the spleen, thymus, and bone marrow, and small cell aggregates with basophilic nuclei in the liver (P<0.05). The NEC group had significant reductions in CD71+ erythroid progenitor cells in the liver, CD45+ lymphocytes in the spleen and bone marrow, CD3+ T lymphocytes in thymus, and the proportion of CD45+CD3-CD43+SSChi neutrophils in bone marrow (P<0.05). There was a significant difference in the composition of gut microbiota between the NEC and control groups, and the NEC group had a significant reduction in the abundance of Ligilactobacillus and a significant increase in the abundance of Escherichia-Shigella (P<0.05), which replaced Ligilactobacillus and became the dominant flora.@*CONCLUSIONS@#Multi-lineage hematopoietic disorder may be observed in a neonatal rat model of NEC, which may be associated with gut microbiota dysbiosis and abnormal multiplication of the pathogenic bacteria Escherichia-Shigella.