ABSTRACT
BACKGROUND: Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease with high morbidity and mortality, affecting preterm infants especially those with very low and extremely low birth weight. ß-glucan has manifested multiple biological effects including anti-inflammatory, regulation of gut microbiota, and immunomodulatory activities. This study aimed to investigate the effects of ß-glucan on NEC. METHODS: Neonatal C57BL/6 mice were randomly divided into three groups: Control group, NEC group and ß-glucan group. Newborn 3-day-old mice were gavaged with either 1 mg/ml ß-glucan or phosphate buffer saline at 0.03 ml/g for 7 consecutive days before NEC induction and a NEC model was established with hypoxia combined with cold exposure and formula feeding. All the pups were killed after 72-h modeling. Hematoxylin-eosin staining was performed to assess the pathological injury to the intestines. The mRNA expression levels of inflammatory factors in intestinal tissues were determined using quantitative real-time PCR. The protein levels of TLR4, NF-κB and tight junction proteins in intestinal tissues were evaluated using western blotting and immunohistochemistry. 16S rRNA sequencing was performed to determine the structure of the gut microbiota. RESULTS: ß-glucan administration ameliorated intestinal injury of NEC mice; reduced the intestinal expression of TLR4, NF-κB, IL-1ß, IL-6, and TNF-α; increased the intestinal expression of IL-10; and improved the expression of ZO-1, Occludin and Claudin-1 within the intestinal barrier. Pre-treatment with ß-glucan also increased the proportion of Actinobacteria, Clostridium butyricum, Lactobacillus johnsonii, Lactobacillus murinus, and Lachnospiraceae bacterium mt14 and reduced the proportion of Klebsiella oxytoca g Klebsiella in the NEC model. CONCLUSION: ß-glucan intervention prevents against NEC in neonatal mice, possibly by suppressing the TLR4-NF-κB signaling pathway, improving intestinal barrier function, and partially regulating intestinal microbiota.