BackgroundNecrotizing enterocolitis (NEC) is a serious gastrointestinal disorder that is often seen in premature infants. Probiotics decrease the risk of NEC; however, the mechanism by which probiotics work is not clear. The goal of this study was to evaluate the preventive effect of Bifidobacterium adolescentis in an NEC rat model.MethodsSprague-Dawley neonatal rats were obtained by caesarean section after 20-21 d gestation and randomly divided into the following 3 groups: dam fed (DF), formula fed (FF), and formula + B. adolescentis (FB). Those in the FF and FB groups developed NEC after exposure to asphyxia and cold stress. All rats were sacrificed 72 h after birth and intestinal injury and mRNA expression of TLR4, TOLLIP and SIGIRR were assessed.Results B. adolescentis significantly increased the 72-h survival rate from 56.3% in the FF group to 86.7% in the FB group. B. adolescentis significantly reduced the histological score from a median of 3.0 in the FF group to a median of 1.0 in the FB group,and significantly decreased the rate of NEC-like intestinal injury from 77.8% in the FF group to 23.1% in the FB group. The mRNA expression of TLR4 increased 3.6 fold in the FF group but decreased by 2 fold from B. adolescentis treatment. mRNA expression of TOLLIP and SIGIRR decreased 4.3 and 3.7 fold, respectively, in the FF group. B. adolescentis significantly increased mRNA expression of TOLLIP and SIGIRR by 3.7 fold and 2.6 fold, respectively.ConclusionsThis study demonstrated B. adolescentis prevents NEC in preterm neonatal rats and that the mechanism for this action might be associated with the alteration of TLR4, TOLLIP, and SIGIRR expression.

Objective The aim of this study was to validate impedance technique (IT) by investigating the agreement in cardiac output measurements performed by IT and echocardiography (ECHO). Study design This is a prospective observational study, including a total of 30 neonates who underwent hemodynamic measurements by IT and ECHO. To determine the agreement between both methods, we performed IT to measure stroke volume (SV-IT) and cardiac output (CO-IT) immediately before or after ECHO to measure SV (SV-ECHO) and CO (CO-ECHO). The precision and accuracy of the IT relative to ECHO were assessed. Results SV-ECHO and SV-IT were (4.45 ± 0.78) and (4.54 ± 0.81) mL, respectively. The bias and limits of agreement of SV-IT were 0.09 mL and ( –1.92 to 1.73) mL, respectively. The true precision of SV-IT was 27.3%. Furthermore, CO-ECHO and CO-IT were (0.62 ± 0.12) and (0.61 ± 0.12) L/min, respectively. The bias and LoA of CO-IT were 0.01L/min and (–0.33 to 0.31) L/min, respectively. The true precision of CO-IT was 28.3%. Conclusion Agreement between the IT and ECHO in the cardiac output measurement appeared acceptable. However, the accuracy and precision of the IT approach should be further investigated using a larger sample.