Factors influencing gastrointestinal tract and microbiota immune interaction in preterm infants

The role of microbial colonization is indispensable for keeping a balanced immune response in life. However, the events that regulate the establishment of the microbiota, their timing, and the way in which they interact with the host are not yet fully understood. Factors such as gestational age, mode of delivery, environment, hygienic measures, and diet influence the establishment of microbiota in the perinatal period. Environmental microbes constitute the most important group of exogenous stimuli in this critical time frame. However, the settlement of a stable gut microbiota in preterm infants is delayed compared to term infants. Preterm infants have an immature gastrointestinal tract and immune system which predisposes to infectious morbidity. Neonatal microbial dynamics and alterations in early gut microbiota may precede and/or predispose to diseases such as necrotizing enterocolitis (NEC), late-onset sepsis or others. During this critical period, nutrition is the principal contributor for immunological and metabolic development, and microbiological programming. Breast milk is a known source of molecules that act synergistically to protect the gut barrier and enhance the maturation of the gut-related immune response. Host-microbe interactions in preterm infants and the protective role of diet focused on breast milk impact are beginning to be unveiled.M.C. acknowledges a “Rio Hortega” Research Fellowship Grant (CM13/0017) and M.V. acknowledges grants PI11/0313 and RD12/0026/0012 (Red SAMID) from the Instituto Carlos III (Spanish Ministry of Economy and Competitivity). M.C.C. and G.P-M. were supported by the grant AGL2013-47420-R from the Spanish Ministry of Science and Innovation.Peer reviewe

A role for neonatal bacteremia in deaths due to intestinal perforation: spontaneous intestinal perforation compared with perforated necrotizing enterocolitis.

ObjectiveTo examine the relationship between intestinal perforations (caused by either spontaneous perforation (SIP) or necrotizing enterocolitis (NEC)) and the outcome "death due to intestinal perforation".MethodsMultivariable logistic regression analyses were used to compare infants <28 weeks' gestation with SIP (n = 32) and perforated-NEC (n = 45) for the outcome perforation-related death.ResultsIn univariate analyses the incidence of death due to perforation was higher among infants with perforated-NEC (36%) than infants with SIP (13%). However, infants with perforated-NEC were more likely to be older than 10 days and have bacteremia/fungemia with non-coagulase-negative staphylococci (non-CONS) organisms than infants with SIP. After adjusting for confounding the only variable that was significantly associated with mortality due to perforation was the presence of non-CONS bacteremia/fungemia at the onset of perforation.ConclusionsThe apparent association between death and perforated-NEC could be explained by the higher incidence of non-CONS bacteremia/fungemia among infants with perforated-NEC