There are significant risks associated with preterm birth. This is due in part to the immaturity of the body systems required to support life. Necrotising Enterocolitis (NEC) is a leading cause of mortality and morbidity in those with VLBW (Very Low Birth Weight, <1500g). It is agreed that NEC is an inflammatory condition that arises in the immature intestine but can rapidly evolve and cause damage to extraintestinal sites. The exact cause is unclear but a disruption to the bacteria normally found in the intestine, the gut microbiome, is thought to be central. Probiotics are live microorganisms that can be given as a dietary supplement and are recognised to confer a health benefit to the host. When given to the preterm population, it is thought that probiotics have a protective effect against the development of NEC. Despite a rich field of research in support of this theory, there is a lack of consensus around the composition and dosing of the probiotics used. We plan to analyse data collected on preterm infants born in Cork University Maternity Hospital between 2009 and 2019. This timeframe includes two equivalent time periods, one before and one after the introduction of routine administration of the probiotic supplement Infloran. We aim to conduct an analysis of the data to establish if the introduction of probiotics to clinical practice has had any impact on the number of cases of NEC in the VLBW population. (250 Words max)