南京地区早产儿坏死性小肠结肠炎病原体特点和益生菌干预效果及预后影响因素分析

目的探究南京地区早产儿坏死性小肠结肠炎(NEC)的病原体特点,并观察益生菌辅助治疗对患儿血清炎症因子水平的影响,分析影响NEC早产儿预后的因素。方法将2014年5月至2018年12月于东南大学附属中大医院就诊的87例NEC早产儿选为研究对象,分析其病原体特点,观察不同治疗方法对患儿血清炎症因子的影响,并通过Logistic回归分析影响NEC患儿预后的危险因素。结果革兰阴性菌是NEC早产儿的主要致病菌,主要包括肺炎克雷伯菌(25株,27.78%)和大肠埃希菌(21株,23.33%)。肺炎克雷伯菌和大肠埃希菌对美罗培南、亚胺培南/西司他丁、哌拉西林/他唑巴坦、多粘菌素和阿米卡星敏感。益生菌干预后的NEC早产儿血清IL-1β、IL-10、TNF-α水平及TLR4的表达均显著低于常规治疗患儿(均P0.05)。发病前3 d内输血、新生儿窒息、益生菌干预、非营养性吮吸、腹膜炎、败血症、加奶速度、PDA均是影响NEC早产儿预后的相关因素(均P0.05),其中发病前3 d内输血、新生儿窒息、加奶速度、PDA是影响NEC早产儿预后的独立危险因素(均P0.05)。结论革兰阴性菌是NEC早产儿的主要致病菌,益生菌干预可有效降低NEC早产儿血清炎症因子水平。对于NEC早产儿的治疗可选用碳青霉烯类、氨基糖苷类等抗生素,同时需关注影响NEC早产儿预后的独立危险因素。     

新生儿坏死性小肠结肠炎动物模型研究进展

新生儿坏死性小肠结肠炎(NEC)是新生儿时期严重的胃肠道疾病,病死率高,多见于早产儿,极低出生体重儿,但确切病因及发病机制尚未阐明。积极探寻其发病机制,需建立可靠的动物模型以助于对该病的病因、发病机制及防治等各方面进行深入研究,以改善NEC患儿预后有重要意义。     

联合应用BB-12和LGG对极低出生体重早产儿胃肠功能的影响

目的 探讨口服双歧杆菌(BB-12)和鼠李糖乳杆菌(LGG)混合的益生菌制剂对极低出生体重早产儿胃肠功能的影响并评估其安全性.方法 对97例极低出生体重早产儿的临床资料进行回顾性分析.益生菌组45例,对照组52例;益生菌组口服BB-12和LGG的混合益生菌制剂,余治疗同对照组.结果 益生菌组静脉营养、外周置入中心静脉导管(PICC)及鼻饲时间明显长于对照组,合并症例数明显高于对照组(P＜0.05),而坏死性小肠结肠炎(NEC)发病率(6.7％)较对照组(23.1％)明显下降(P＜0.05),且3例NEC(Ⅲ级)均发生在对照组.益生菌组胆汁酸、碱性磷酸酶明显低于对照组(P＜0.05),体重增长速度较对照组有增加趋势;而两组喂养不耐受及胃肠外营养相关性胆汁淤积发病率差异无统计学意义(P＞0.05).益生菌组无益生菌相关败血症、脑膜炎、腹泻、皮疹等不良反应.结论 口服BB-12和LGG混合的益生菌制剂可改善极低出生体重早产儿胃肠功能且相对安全.     

国内益生菌制剂预防新生儿坏死性小肠结肠炎的Meta分析

目的系统评价益生菌制剂在预防新生儿坏死性小肠结肠炎(NEC)的临床效果。方法计算机联机检索数据库,应用RevMan 5.3软件,对益生菌制剂治疗预防NEC的随机对照试验(RCT)所收集的数据资料进行Meta分析。结果纳入9篇RCT文献中包涵2 058例新生儿,对预防NEC的发生率进行Meta分析。结果显示益生菌制剂预防NEC的效果优于对照组[OR=0.20,95%CI(0.12,0.33),P0.000 01]。结论给予益生菌制剂治疗,可降低NEC的发生率。     

NICU内早产儿早期肠道内添加益生菌的临床观察

目的 探讨NICU病房早产儿在住院早期肠道内添加益生菌对临床治疗的影响.方法 本研究系前瞻性单中心初步研究.选择2011年1月至2011年12月期间在东南大学附属中大医院NICU住院,胎龄28 ～ 34周的早产儿,随机分为治疗组161例和对照组148例.治疗组予以肠道益生菌口服,对照组不使用益生菌.观察两组患儿第一次经口喂养时间、完全经口喂养时间、完全胃肠道营养时间、晚期败血症发生率、NEC发生率、住院时间和住院死亡率的差异.结果 在最终完成研究时,共有22例被排除,纳入研究的287例患儿中,治疗组149例,对照组138例.治疗组与对照组各观察指标相比较,完全经口喂养时间、完全胃肠道营养时间、晚期败血症发生率、NEC发生率、住院时间和住院死亡率分别为(7.3±4.7)vs(11.6 ±5.7)d、(9.8 ±4.7)vs( 16.9±6.8)d、6.7％ vs 15.2％、3.4％ vs 10.9％、(25.0±7.5)vs(30.8 ±7.0)d和4.0％ vs 6.5％.除死亡率外,其余各项比较差异均有统计学意义(均P＜0.05).结论 早期肠道内补充益生菌,有利于早产儿胃肠道功能建立,减少并发症,缩短住院时间,降低医疗成本.     

双歧杆菌预防早产儿坏死性小肠结肠炎的疗效观察

目的 探讨双歧杆菌预防早产儿坏死性小肠结肠炎(NEC)的疗效.方法 随机分成试验组和对照组,对照组给予常规治疗,试验组在对照组基础上给予双歧杆菌治疗.观察两组不同胎龄和不同出生体重早产儿NEC患病率、治疗前后肠道各菌群变化的差异.结果 (1)试验组NEC总发生率显著低于对照组,差异有统计学意义(P＜0.01);(2)试验组出生体重＜1500g早产儿NEC发生率显著低于对照组,差异有统计学意义(P＜0.05);(3)治疗后试验组细菌总数、球菌总数及杆菌总数上升幅度显著大于对照组,差异均有统计学意义(P＜0.01);治疗后试验组杆球菌比值较对照组显著下降,差异有统计学意义(P＜0.01).结论 双歧杆菌可有效预防早产儿坏死性小肠结肠炎.     

金双歧对早产儿坏死性小肠结肠炎预防作用的研究

目的探讨微生态制剂金双歧对早产儿早期应用是否能起到预防坏死性小肠结肠炎(NEC)的发生.方法对2000年1月～2002年12月入住青海省红十字医院新生儿,符合早产儿诊断126例,随机分治疗组、对照组.治疗组在治疗原发病的基础上,24 h内即加用双歧杆菌三联片(商品名:金双歧)口服或鼻饲,对照组只治疗原发病,观察2周内NEC的发生情况.结果治疗组62例,发生NEC 8例,对照组64例,发生NEC 20例.结论及早对早产儿补充微生态制剂,使其占据肠黏膜表面,作为生物屏障构成肠道的定植阻力,阻止致病菌入侵,或刺激机体免疫系统,增强机体免疫功能,从而起到降低早产儿NEC的发生.     

微生态制预防治早产儿坏死性小肠结肠炎的作用研究

目的 观察应用微生态制剂(金双歧)预防早产儿坏死性小肠结肠炎(NEC)的有效性.方法 2011年1月至2012年6月在成都市妇女儿童中心医院新生儿科住院治疗的279例生后存活7d并且开始胃肠道喂养的早产儿,预防组142例,对照组137例.预防组在对照组常规治疗原发病基础上每日给予双歧三联活菌片,每次0.5片,每日3次,用药至出院.观察治疗期间两组发生NEC的情况,对两组治疗前及治疗后7d分别留取新鲜粪便标本进行细菌学检查.结果 预防组NEC发病率为1.41％,对照组NEC发生率为5.84％,两组比较差异有统计学意义(P＜0.05).治疗后7d两组患儿肠道细菌总数、杆菌、球菌总数及杆球菌比值差异均有统计学意义(P＜0.05).预防组治疗前、治疗后7d杆球菌比值差异无统计学意义(P＞0.05).结论 给予早产儿预防性口服微生态制剂能够降低NEC发病率.其机制可能与口服微生态制剂后促进新生儿肠道正常菌群的定植和优势化、维持肠道正常菌群比率有关.     

益生菌干预治疗对非小细胞肺癌化疗患者肠道菌群、免疫功能及相关并发症的影响

目的:研究观察益生菌干预治疗对非小细胞肺癌化疗患者肠道菌群、免疫指标及相关并发症的影响。方法:选取自2016年1月-2018年12月赤峰学院附属医院收诊的80例非小细胞肺癌(NSCLC)需要化疗患者作为观察对象,将其随机分为益生菌给药组及安慰剂对照组,每组各40例。测量两组患者化疗前后体格指标,观察患者化疗相关并发症的发生情况,定量检测治疗前后双歧杆菌属、乳酸杆菌属、大肠杆菌和肠球菌属,血清CD3^+、CD4^+、CD8^+T细胞水平,粪便悬浮液中的粪便SIg A含量的变化。结果:化疗后,益生菌给药组患者的BMI、WHR均显著高于安慰剂对照组(P<0.05);益生菌给药组的双歧杆菌、乳酸杆菌含量及粪便SIg A含量与安慰剂对照组相比显著增加,肠球菌、大肠杆菌的含量显著减少(P<0.05);化疗后,益生菌给药组CD3^+、CD4^+T细胞比例显著增加(P<0.05),CD8^+T细胞比例显著下降(P<0.05),安慰剂对照组无明显改善(P>0.05);益生菌给药组的CD4^+/CD8^+比例与安慰剂对照组相比较显著升高(P<0.05)。结论:益生菌干预能调节NSCLC化疗患者的肠道菌群失衡,提高其免疫功能,并减少患者化疗期间相关并发症。     

酪酸梭菌预防早产儿坏死性小肠结肠炎的疗效观察

目的探讨宝乐安（酪酸梭菌CGMCC0313．1散剂）预防早产儿坏死性小肠结肠炎（NEC）的疗效。方法将胎龄在28—35周的早产几90例,随机分为预防组和对照组,预防组在原发病治疗的基础上出生后即喂服宝乐安,500mg／次,2次／d;对照组仅予原发病治疗。全部早产儿观察NEC的发病率及轻重程度、病程时间、NEC并发肺部感染及早产儿体重增长情况,予大便培养进行病原菌的检测。结果预防组的早产儿在NEC的发病率及轻重程度、病程时间、NEC并发肺部感染、体重增长、病原菌克雷伯菌及大肠埃希菌检出情况等方面与对照组的早产儿比较,差异均具有显著性（P〈0．05）。结论早期服用宝乐安可以降低早产儿坏死性小肠结肠炎的发病率,并能缩短NEC的病程,减轻NEC病情,降低NEC并发肺部感染的发病率,有助于早产儿体重的恢复增长。     

Antibiotics Increase Gut Metabolism and Antioxidant Proteins and Decrease Acute Phase Response and Necrotizing Enterocolitis in Preterm Neonates

Background

The appropriate use of antibiotics for preterm infants, which are highly susceptible to develop necrotizing enterocolitis (NEC), is not clear. While antibiotic therapy is commonly used in neonates with NEC symptoms and sepsis, it remains unknown how antibiotics may affect the intestine and NEC sensitivity. We hypothesized that broad-spectrum antibiotics, given immediately after preterm birth, would reduce NEC sensitivity and support intestinal protective mechanisms.

Methodology/Principal Findings

Preterm pigs were treated with antibiotics for 5 d (oral and systemic doses of gentamycin, ampicillin and metrodinazole; AB group) and compared with untreated pigs. Only the untreated pigs showed evidence of NEC lesions and reduced digestive function, as indicated by lowered villus height and activity of brush border enzymes. In addition, 53 intestinal and 22 plasma proteins differed in expression between AB and untreated pigs. AB treatment increased the abundance of intestinal proteins related to carbohydrate and protein metabolism, actin filaments, iron homeostasis and antioxidants. Further, heat shock proteins and the complement system were affected suggesting that all these proteins were involved in the colonization-dependent early onset of NEC. In plasma, acute phase proteins (haptoglobin, complement proteins) decreased, while albumin, cleaved C3, ficolin and transferrin increased.

Conclusions/Significance

Depressed bacterial colonization following AB treatment increases mucosal integrity and reduces bacteria-associated inflammatory responses in preterm neonates. The plasma proteins C3, ficolin, and transferrin are potential biomarkers of the colonization-dependent NEC progression in preterm neonates.     

Delayed Initiation but Not Gradual Advancement of Enteral Formula Feeding Reduces the Incidence of Necrotizing Enterocolitis (NEC) in Preterm Pigs

Enteral formula feeding is a risk factor for necrotizing enterocolitis (NEC) in premature infants, yet studies are conflicting regarding the safest timing for introduction and advancement of feeds. Our aim was to test the effects of early vs. late initiation and abrupt vs. gradual advancement of enteral feeding of an intact vs. hydrolyzed protein formula on NEC incidence and severity in preterm pigs. In Experiment 1, preterm pigs received total parenteral nutrition (TPN) at birth with abrupt initiation of enteral formula feeds (50% full intake) on d of life (DOL) 2 (EA) or 5 (LA) while PN continued. Pigs were also fed formula containing either intact or hydrolyzed protein. In Experiment 2, preterm pigs received TPN at birth with enteral, hydrolyzed-protein formula feeds introduced on DOL 2 either abruptly (EA; 50% full feeds) or gradually (EG; 10–50% full feeds over 5 d) while PN continued. NEC incidence and severity were assessed based on macroscopic and histological scoring. In Experiment 1, NEC incidence (41% vs. 70%, P<0.05) and severity were reduced in LA vs. EA groups and LA was associated with a higher survival rate, daily weight gain and jejunum villus height. Piglets fed hydrolyzed vs. intact protein formula had lower stomach content weights and similar NEC incidence. In Experiment 2, NEC incidence and severity were not different between pigs the EG vs. EA group. Proinflammatory gene expression (IL-1β, IL-6 and S100A9) in the ileum was lower in both LA and EG vs. EA groups. In conclusion, delayed initiation but not gradual advancement of enteral feeding is protective against NEC in preterm pigs. Feeding hydrolyzed vs. intact protein formula improved gastric transit without affecting the NEC incidence.     

Nutritional modulation of the gut microbiota and immune system in preterm neonates susceptible to necrotizing enterocolitis

The gastrointestinal inflammatory disorder, necrotizing enterocolitis (NEC), is among the most serious diseases for preterm neonates. Nutritional, microbiological and immunological dysfunctions all play a role in disease progression but the relationship among these determinants is not understood. The preterm gut is very sensitive to enteral feeding which may either promote gut adaptation and health, or induce gut dysfunction, bacterial overgrowth and inflammation. Uncontrolled inflammatory reactions may be initiated by maldigestion and impaired mucosal protection, leading to bacterial overgrowth and excessive nutrient fermentation. Tumor necrosis factor alpha, toll-like receptors and heat-shock proteins are identified among the immunological components of the early mucosal dysfunction. It remains difficult, however, to distinguish the early initiators of NEC from the later consequences of the disease pathology. To elucidate the mechanisms and identify clinical interventions, animal models showing spontaneous NEC development after preterm birth coupled with different forms of feeding may help. In this review, we summarize the literature and some recent results from studies on preterm pigs on the nutritional, microbial and immunological interactions during the early feeding-induced mucosal dysfunction and later NEC development. We show that introduction of suboptimal enteral formula diets, coupled with parenteral nutrition, predispose to disease, while advancing amounts of mother's milk from birth (particularly colostrum) protects against disease. Hence, the transition from parenteral to enteral nutrition shortly after birth plays a pivotal role to secure gut growth, digestive maturation and an appropriate response to bacterial colonization in the sensitive gut of preterm neonates.     

Intestinal Microbial Ecology and Environmental Factors Affecting Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the most devastating intestinal disease affecting preterm infants. In addition to being associated with short term mortality and morbidity, survivors are left with significant long term sequelae. The cost of caring for these infants is high. Epidemiologic evidence suggests that use of antibiotics and type of feeding may cause an intestinal dysbiosis important in the pathogenesis of NEC, but the contribution of specific infectious agents is poorly understood. Fecal samples from preterm infants ≤32 weeks gestation were analyzed using 16S rRNA based methods at 2, 1, and 0 weeks, prior to diagnosis of NEC in 18 NEC cases and 35 controls. Environmental factors such as antibiotic usage, feeding type (human milk versus formula) and location of neonatal intensive care unit (NICU) were also evaluated. Microbiota composition differed between the three neonatal units where we observed differences in antibiotic usage. In NEC cases we observed a higher proportion of Proteobacteria (61%) two weeks and of Actinobacteria (3%) 1 week before diagnosis of NEC compared to controls (19% and 0.4%, respectively) and lower numbers of Bifidobacteria counts and Bacteroidetes proportions in the weeks before NEC diagnosis. In the first fecal samples obtained during week one of life we detected a novel signature sequence, distinct from but matching closest to Klebsiella pneumoniae, that was strongly associated with NEC development later in life. Infants who develop NEC exhibit a different pattern of microbial colonization compared to controls. Antibiotic usage correlated with these differences and combined with type of feeding likely plays a critical role in the development of NEC.     

Probiotics for preterm infants – time to end all controversies

Mortality, necrotising enterocolitis (NEC), late onset sepsis (LOS) and feeding intolerance are significant issues for very preterm (< 32 weeks) and extremely preterm (< 28 weeks) infants. The complications of ≥ Stage II NEC [e.g. Resection of the gangrenous gut, survival with intestinal failure, recurrent infections, prolonged hospital stay, and long-term neurodevelopmental impairment (NDI)] impose a significant health burden. LOS also carries significant burden including long-term NDI due to adverse effects of inflammation on the preterm brain during the critical phase of development. Frequent stopping of feeds due to feeding intolerance is a significant iatrogenic contributor to postnatal growth failure in extremely preterm infants. Over 25 systematic reviews and meta-analyses of RCTs (~12 000 participants) have reported that probiotics significantly reduce the risk of all-cause mortality, NEC ≥ Stage II, LOS and feeding intolerance in preterm infants. Systematic reviews and meta-analysis of non-RCTs have also shown that the benefits after adopting probiotics as a standard prophylaxis for preterm infants are similar to those reported in RCTs. No intervention comes close to probiotics when it comes to significant reduction in death, NEC, LOS and feeding intolerance at a cost of less than a dollar a day irrespective of the setting and baseline incidence of NEC. The common controversies that are preventing the rapid uptake of probiotics for preterm infants are addressed in this paper.     

Probiotics and neonatal necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC) is one of few diseases for which probiotics have appeared to have clear benefit in clinical trials, however safety concerns persist. Clinical trials of probiotics have preceded our understanding of the effect of probiotics on the developing gut and microbial colonization patterns of the preterm infant. Colonization of the preterm intestine begins with the birthing process and is then influenced by the neonatal intensive care unit and iatrogenic manipulations. Resulting altered microbiota may have significant implications for the immature preterm gut and susceptibility to NEC.     

Enteral feeding induces diet-dependent mucosal dysfunction, bacterial proliferation, and necrotizing enterocolitis in preterm pigs on parenteral nutrition

Preterm neonates have an immature gut and metabolism and may benefit from total parenteral nutrition (TPN) before enteral food is introduced. Conversely, delayed enteral feeding may inhibit gut maturation and sensitize to necrotizing enterocolitis (NEC). Intestinal mass and NEC lesions were first recorded in preterm pigs fed enterally (porcine colostrum, bovine colostrum, or formula for 20-40 h), with or without a preceding 2- to 3-day TPN period (n = 435). Mucosal mass increased during TPN and further after enteral feeding to reach an intestinal mass similar to that in enterally fed pigs without TPN (+60-80% relative to birth). NEC developed only after enteral feeding but more often after a preceding TPN period for both sow's colostrum (26 vs. 5%) and formula (62 vs. 39%, both P < 0.001, n = 43-170). Further studies in 3-day-old TPN pigs fed enterally showed that formula feeding decreased villus height and nutrient digestive capacity and increased luminal lactic acid and NEC lesions, compared with colostrum (bovine or porcine, P < 0.05). Mucosal microbial diversity increased with enteral feeding, and Clostridium perfringens density was related to NEC severity. Formula feeding decreased plasma arginine, citrulline, ornithine, and tissue antioxidants, whereas tissue nitric oxide synthetase and gut permeability increased, relative to colostrum (all P < 0.05). In conclusion, enteral feeding is associated with gut dysfunction, microbial imbalance, and NEC in preterm pigs, especially in pigs fed formula after TPN. Conversely, colostrum milk diets improve gut maturation and NEC resistance in preterm pigs subjected to a few days of TPN after birth.     

Human milk oligosaccharide effects on intestinal function and inflammation after preterm birth in pigs

Human milk oligosaccharides (HMOs) may mediate prebiotic and anti-inflammatory effects in newborns. This is particularly important for preterm infants who are highly susceptible to intestinal dysfunction and necrotizing enterocolitis (NEC). We hypothesized that HMO supplementation of infant formula (IF) improves intestinal function, bacterial colonization and NEC resistance immediately after preterm birth, as tested in a preterm pig model. Mixtures of HMOs were investigated in intestinal epithelial cells and in preterm pigs (n=112) fed IF supplemented without (CON) or with a mixture of four HMOs (4-HMO) or >25 HMOs (25-HMO, 5–10 g/L given for 5 or 11 days). The 25-HMO blend decreased cell proliferation and both HMO blends decreased lipopolysaccharide-induced interleukin-8 secretion in IPEC-J2 cells, relative to control (P<.05). All HMOs were found in urine and feces of HMO-treated pigs, and short-chain fatty acids in the colon were higher in HMO vs. CON pigs (P<.05). After 5 days, NEC lesions were similar between HMO and CON pigs and 25-HMO increased colon weights (P<.01). After 11 days, the 4-HMO diet did not affect NEC (56 vs. 79%, P=.2) but increased dehydration and diarrhea (P<.05) and expression of immune-related genes (IL10, IL12, TGFβ, TLR4; P<.05). Bacterial adherence and diversity was unchanged after HMO supplementation. Conclusion: Complex HMO-blends affect intestinal epithelial cells in vitro and gut gene expression and fermentation in preterm pigs. However, the HMOs had limited effects on NEC and diarrhea when supplemented to IF. Longer-term exposure to HMOs may be required to improve the immature intestinal function in formula-fed preterm neonates.     

Transition from parenteral to enteral nutrition induces immediate diet-dependent gut histological and immunological responses in preterm neonates

Necrotizing enterocolitis (NEC) in preterm infants develops very rapidly from a mild intolerance to enteral feeding into intestinal mucosal hemorrhage, inflammation, and necrosis. We hypothesized that immediate feeding-induced gut responses precede later clinical NEC symptoms in preterm pigs. Fifty-six preterm pigs were fed total parenteral nutrition (TPN) for 48 h followed by enteral feeding for 0, 8, 17, or 34 h with either colostrum (Colos, n = 20) or formula (Form, n = 31). Macroscopic NEC lesions were detected in Form pigs throughout the enteral feeding period (20/31, 65%), whereas most Colos pigs remained protected (1/20, 5%). Just 8 h of formula feeding induced histopathological lesions, as evidenced by capillary stasis and necrosis, epithelial degeneration, edema, and mucosal hemorrhage. These immediate formula-induced changes were paralleled by decreased digestive enzyme activities (lactase and dipeptidylpeptidase IV), increased nutrient fermentation, and altered expression of innate immune defense genes such as interleukins (IL-1α, IL-6, IL-18), nitric oxide synthetase, tight junction proteins (claudins), Toll-like receptors (TLR-4), and TNF-α. In contrast, the first hours of colostrum feeding induced no histopathological lesions, increased maltase activity, and induced changes in gene expressions related to tissue development. Total bacterial density was high after 2 days of parenteral feeding and was not significantly affected by diet (colostrum, formula) or length of enteral feeding (8-34 h), except that a few bacterial groups (Clostridium, Enterococcus, Streptococcus species) increased with time. We conclude that a switch from parenteral to enteral nutrition rapidly induces diet-dependent histopathological, functional, and proinflammatory insults to the immature intestine. Great care is required when introducing enteral feeds to TPN-fed preterm infants, particularly when using formula, because early feeding-induced insults may predispose to NEC lesions that are difficult to revert by later dietary or medical interventions.