Necrotizing enterocolitis (NEC) is a major cause of mortality (25%) and morbidity including recurrent sepsis, dependence on parenteral nutrition, need for surgery, and survival with short bowel syndrome in preterm very low birth weight infants. Mortality (45-100%) and morbidity including the risk of long-term neurodevelopmental impairment are higher in extremely preterm infants needing surgery for NEC. Systematic reviews of randomized controlled trials (RCT) indicate that probiotics significantly reduce the risk of NEC (RR 0.39; 95% CI 0.29-0.52; p <0.00001) and all-cause mortality (RR 0.52; 95% CI 0.40-0.69; p <0.00001) while facilitating enteral feeds in preterm infants. At present, data from 25 RCT (∼5,000 neonates) and reports on routine use (∼3,000 neonates) indicates that significant adverse effects of probiotics are rare. Despite the robust evidence, there is still reluctance in incorporating routine probiotic prophylaxis in clinical practice. If the goal is to have zero tolerance for NEC, then probiotic prophylaxis must be adopted as soon as possible. Current gaps in knowledge can be addressed by continued research while providing routine probiotic supplementation. We believe that the concept of evidence-based practice of medicine has been stretched too far in this case. Trial sequential analysis has already shown that the evidence for probiotic supplementation was conclusive after 10 trials. Results of the ongoing trials are unlikely to change the conclusions of the systematic reviews significantly. Currently we are at trial number 25; how many more trials do we need? What will it take to change clinical practice? © 2013 S. Karger AG, Basel.