Protective Effects of Lactobacillus reuteri on Intestinal Barrier Function in a Mouse Model of Neonatal Necrotizing Enterocolitis

Abstract

Objective The intestinal mucosal and immune barriers play considerable roles in the pathogenesis of necrotizing enterocolitis (NEC). The present research was designed to assess the protective effects of Lactobacillus reuteri (LR) DSM 17938 (LR 17938) on the intestinal barriers and its beneficial effects on inflammation in a neonatal mouse model of NEC. Study Design Overall, 7-day-old 75 C57BL/6 neonatal mice were separated into three groups (n = 25) as follows: (1) control, (2) NEC, and (3) NEC + LR17938 (LR group). NEC mice were administered a hypertonic feeding formula and subjected to asphyxia and hypothermia. Hematoxylin and eosin (HE) staining and pathological scores were used to assess the pathological changes in the intestine. Oxidative stress was evaluated based on the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels were detected to assess inflammation. Gut permeability levels, bacterial translocation, and the levels of secretory idioglobulin A (sIgA), β-defensin, and tight junction (TJ) proteins were detected to evaluate gut mucosal and immune barrier function, and gut microbial diversity was detected to assess the composition of the gut flora. Results LR 17938 administration decreased the NEC-induced increase in intestinal scores, mortality rate, gut damage, the MDA level, and TNF-α and IL-1β expressions. Besides, LR 17938 improved the survival rate of NEC mice. Moreover, LR 17938 administration improved gut permeability levels, SOD activity and the bacterial translocation, ameliorated the expression of TJ proteins, and improved the gut microbiota compared with those of NEC mice. Conclusion LR 17938 reduced intestinal inflammation and played a protective role in a neonatal animal model of NEC, possibly by regulating oxidative stress and exerting a protective effect on the gut mucosal and immune barriers. Key Points