Probiotics for the prevention of necrotizing enterocolitis in neonates: an 8-year retrospective cohort study

Probiotic therapy has been shown to reduce morbidity and mortality of necrotizing enterocolitis (NEC) in premature infants in several international studies using various probiotic agents. The purpose of this study(*) is to describe our experience of using probiotic therapy in preventing NEC in infants with very low birth weight (VLBW) in a neonatal intensive care unit (NICU) and to evaluate whether our records provide evidence of effectiveness for probiotic therapy.

In a retrospective cohort study, the efficacy of probiotic therapy in preventing NEC in VLBW infants was investigated via chart review. A probiotic administration protocol using a three-strain (Streptococcus thermophilus, Bifidobacterium infantis and Bifidobacterium bifidum) supplement was implemented in August 2007. Patients admitted to the NICU from August 2003 through July 2011 were screened. Primary outcomes are the morbidity and mortality of NEC. The secondary outcomes were severity of NEC and incidence of where infant feeds were stopped but NEC was not diagnosed (NEC scare).

There was a significant increased baseline risk of NEC development in the probiotics group, including younger gestational age, higher incidence of patent ductus arteriosus (PDA) and use of indomethacin. The incidence of NEC is similar between the control group (2·8%) and probiotics group (2·4%) (hazard ratio, 1·15; 95% confidence interval [CI], 0·42, 3·12). Mortality of NEC is also not statistically different. Incidence of NEC scare was decreased from 2·8% in control group to 1·4% in probiotics group, although the difference was not statistically significant (P = 0·38).

Our findings suggest that probiotics are safe in NEC prevention in VLBW infants. We had no cases of infection related to the strains of bacteria used in our product. With the low incidence of NEC (2·8%) and NEC scare (2·8%) in our cohort, we do not have enough power to detect any change in outcome, particularly as our study was observational. However, it is hoped that our data give useful information for others on probiotic prophylactic therapy in the routine clinical management of VLBW infants.