Department of Pediatric Gastroenterology, Harvard Medical School, Mucosal Immunology Laboratory, Massachusetts General Hospital for Children, Boston, MA 02129-4404, USA.
J Clin Gastroenterol. 2011 Nov;45 Suppl:S133-8. doi: 10.1097/MCG.0b013e318228b799.
Necrotizing enterocolitis (NEC) is a common gastrointestinal inflammatory necrosis affecting almost exclusively premature infants usually after oral nutrition has been started, for example, 10 day plus postpartum. Although the pathogenesis is incompletely understood, major risk factors include prematurity and incomplete bacterial colonization. Evidence has been shown that the premature infant because of rapid passage through the birth canal or because of delivery by cesarean section has an inadequate initial ingestion of maternal colonic and vaginal flora and therefore, an inadequate initial colonization with less diversity of bacteria phylla and fewer species of bacteria in the microbiota. As a result, they are more susceptible to environmental pathogens. In addition, prematures have immature intestinal defenses (glycocalyx, tight junctions, innate immune response, etc.) resulting in excessive inflammation in response to luminal stimuli. Recently, we reported that genes mediating the innate inflammatory immune response are developmentally expressed with an increase in toll-like receptors, signaling molecules and transgenic factors and decreased negative regulators of inflammation, which undoubtedly contribute to an excessive inflammatory response. Several clinical studies have suggested that the use of probiotics and ingestion of expressed maternal breast milk containing probiotics can help to stabilize colonization and to reduce the incidence and severity of NEC when given to premature infants at risk. Meta-analyses of multiple small studies strongly suggest a protective effect in the use of probiotics. A multicenter study in Taiwan suggests that Bifidobacteria infantis and Lactobacillus acidophilus in combination may prevent NEC. These meta-analyses suggest that these probiotics should be used in routine care of premature infants. Other clinicians, however, suggest caution, holding out for a single protocol multicenter trial before routine use can be suggested.
坏死性小肠结肠炎（NEC）是一种常见的胃肠道炎症性坏死，几乎仅影响早产儿，通常在开始口服营养后，例如，产后 10 天以上。尽管发病机制尚不完全清楚，但主要危险因素包括早产和不完全细菌定植。有证据表明，早产儿由于快速通过产道或由于剖宫产分娩，最初摄入的母体结肠和阴道菌群不足，因此最初定植的细菌种类较少，微生物群中的细菌种类也较少。因此，他们更容易受到环境病原体的影响。此外，早产儿的肠道防御机制不成熟（糖萼、紧密连接、先天免疫反应等），导致对腔道刺激过度炎症反应。最近，我们报告说，介导先天炎症免疫反应的基因随着 Toll 样受体、信号分子和转基因因子的增加以及炎症负调节因子的减少而在发育过程中表达，这无疑导致了过度的炎症反应。几项临床研究表明，给有风险的早产儿使用益生菌和摄入含有益生菌的表达母乳可以帮助稳定定植，并降低 NEC 的发病率和严重程度。对多项小型研究的荟萃分析强烈表明益生菌的使用具有保护作用。一项来自台湾的多中心研究表明，双歧杆菌和嗜酸乳杆菌联合使用可能预防 NEC。这些荟萃分析表明，这些益生菌应该在早产儿的常规护理中使用。然而，其他临床医生建议谨慎行事，在建议常规使用之前，需要进行单一方案的多中心试验。
