Effects of probiotics on blood cytokines in very low birth weight infants with formula feeding

Abstract

Objective To explore the effects of oral probiotics on blood cytokines among very low birth weight infants (VLBWI) with formula feeding. Methods Preterm infants born at <34 weeks gestational age (GA) and birth weight (BW) <1 500 g admitted to NICU of our hospital from Jul.1, 2014 to Dec. 31, 2015 were enrolled and randomly divided into probiotics group and control group. The levels of blood cytokine, including IL-2, IL-4, IL-6, IL-8, IL-10, GM-CSF, IFN-γ, TNF-α, MIG were analyzed with multiplex flow cytometry within 24 h after birth, on the postnatal 14th and 28th day, and in the 36th week corrected GA. The clinical complications and changes of blood cytokines were compared between the two groups. Results The incidences of necrotizing enterocolitis (NEC), late-onset sepsis (LOS), parenteral nutrition associated cholestasis (PNAC) in the probiotics group were lower than those in the control group, but without statistically significant differences (P>0.05). The level of blood IL-6 was much higher in the NEC or death group than the others (94.91 pg/ml vs.5.71 pg/ml, P<0.05). In the septic infants, the levels of blood IL-8, IFN-γ in the probiotics group on the postnatal 14th day were significantly lower than those in the control group (7.83 pg/ml vs.40.58 pg/ml, 7.68 pg/ml vs.9.45 pg/ml; P<0.05). In the stable infants, the levels of blood IL-2, IL-4, GM-CSF in the probiotics group in the 36th week corrected GA were significantly higher than those in the control group (7.33 pg/ml vs.6.0 pg/ml, 0.37 pg/ml vs.0.31 pg/ml, 12.53 pg/ml vs.8.85 pg/ml; P<0.05). Conclusion Probiotics decreased the expression of pro-inflammatory factors and increased the expression of anti-inflammatory factors, which may play a protective role in the prevention of NEC or death in VLBWI with formula feeding through regulating the balance between pro- and anti-inflammatory factors. Key words: Probiotics; Very low birth weight infant; Necrotizing enterocolitis; Cytokines