婴儿肠道菌群形成与喂哺方式及食物过敏的关系

目的观察健康婴儿在不同喂养方式下肠道菌群的定植过程及其在食物过敏时的变化,分析肠道菌群形成与婴幼儿食物过敏的相互关系及母乳喂养的意义。方法采用荧光定量PCR技术测定细菌16SrRNA,对健康无过敏症131例(其中母乳喂养71例,人工喂养60例)及100例过敏症婴儿粪便中乳酸杆菌、双歧杆菌和大肠杆菌进行定量检测。结果婴儿肠道菌群处于动态定植过程。母乳喂养婴儿肠道乳酸杆菌、双歧杆菌数量较人工喂养婴儿高(P<0.05),而大肠杆菌数量较人工喂养婴儿低(P<0.05)。食物过敏婴幼儿肠道乳酸杆菌、双歧杆菌数量较健康婴幼儿低(P<0.05),而大肠杆菌数量较健康婴幼儿高(P<0.05)。结论婴儿期肠道菌群处于动态演替过程。不同的喂养方式对肠道菌群有影响,过敏性疾病婴儿肠道菌群与健康婴幼儿不同,应大力提倡母乳喂养。     

不同分娩方式对母乳喂养婴儿肠道菌群的影响

目的新生儿出生后其肠道立即被来自母体和周围环境中的微生物定植,许多研究表明,消化道早期定植的肠道菌群在婴儿免疫系统的发育过程中起重要的作用。该研究探讨了分娩方式对母乳喂养婴儿肠道菌群和粪便性状的影响。方法以60例40～47日龄的健康足月母乳喂养婴儿为观察对象,按分娩方式分为自然分娩组和剖宫产组(n=30)。在6、8、10、12周龄采集婴儿粪便标本,并同时记录婴儿体质量、头围及粪便性状。应用实时荧光定量PCR技术对婴儿肠道乳酸杆菌属、双歧杆菌属及双歧杆菌亚种(长双歧杆菌和短双歧杆菌)进行定量检测。结果剖宫产娩出的婴儿肠道乳酸杆菌和长双歧杆菌数量低于自然分娩组(P<0.05);自然分娩的婴儿粪便pH值低于剖宫产组(6.2对6.9,P﹤0.05);分娩方式对粪便性状和婴儿的生长发育无影响。结论剖宫产降低母乳喂养婴儿肠道乳酸杆菌和双歧杆菌的水平。     

婴儿肠道菌群与分娩方式、喂养方式及胆汁淤积性肝病的关系

目的分析分娩方式和喂养方式对健康婴儿肠道菌群的影响,探讨肠道相关分子微生态在胆汁淤积性肝病中的作用及意义。方法收集37例健康婴儿(其中阴道分娩21例,剖宫产16例;母乳喂养15例,人工喂养22例)及84例胆汁淤积性肝病婴儿粪便,提取粪便中细菌DNA并测量A260值;应用实时荧光定量PCR反应测定粪便中双歧杆菌、乳酸杆菌及大肠杆菌3种代表菌的数量。结果阴道分娩婴儿与剖宫产婴儿比较,母乳喂养婴儿与人工喂养婴儿比较,粪便标本中细菌DNA A260值和3种代表菌数量差异均无统计学意义(Pa>0.05)。健康对照组与胆汁淤积性肝病组粪便标本中细菌的DNA A260值分别为(1.94±0.47)g.L-1和(0.40±0.09)g.L-1,2组比较差异有统计学意义(t=8.91,P=0.00);健康对照组与胆汁淤积性肝病组3种细菌数(lg拷贝数/g湿便)的对数值比较差异均有统计学意义(双歧杆菌9.49±0.59 vs 7.68±0.57;t=15.96,P=0.00;乳酸杆菌8.58±0.32 vs 8.16±0.70;t=3.46,P=0.00;大肠杆菌6.87±0.67 vs 7.26±0.86;t=-2.41,P=0.02)。结论不同的分娩方式、喂养方式对婴儿期肠道菌群无影响;胆汁淤积性肝病婴儿肠道菌群与健康婴儿不同,粪便中细菌总量减少,双歧杆菌及乳酸杆菌数量明显减少,大肠杆菌的数量则明显增多,提示肠道菌群失调与婴儿胆汁淤积性肝病的发生、发展有一定关系。     

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目的以轮状病毒(RV)肠炎患儿和健康婴幼儿为研究对象,探讨荧光定量PCR技术在检测肠道菌群变化的实用性和可行性。方法应用荧光定量PCR技术测定细菌的16SrRNA,对RV肠炎患儿和健康婴幼儿粪便中双歧杆菌、乳酸杆菌和大肠杆菌进行定量检测和分析,并和其他专家用传统方法所获得的结果进行比较。结果RV肠炎患儿的肠道菌群与健康儿童比较发现肠道中双歧杆菌和乳酸杆菌的数量变化差异有显著性(P<0·05),而大肠杆菌的数量差异无显著性(P>0·05)。其结果与其他文献报道的用细菌培养的方法所得结果一致。结论RV肠炎患儿肠道中益生菌的数量较正常对照组明显减少。荧光定量PCR技术比传统方法特异性高、敏感性强,更省时和省力,临床上可用此方法对患儿肠道细菌变化进行定量分析。     

食物过敏婴儿和健康婴儿肠道菌群的差别

目的检测食物过敏(FA)婴儿和健康婴儿的主要肠道菌群,为食物过敏与肠道菌群关系研究提供线索。方法采用病例对照研究,检测2003年5~12月在重庆医科大学儿童医院儿保门诊体检的52例FA婴儿和100例健康婴儿的大便菌群(双歧杆菌属、乳酸杆菌属、肠杆菌科),大便菌群的分析采用GLM的广义析因法。结果FA婴儿大便双歧杆菌计数减少［(9.61±1.16) VS (10.31±1.20) Log10CFU/g,P<0.001］,肠杆菌计数增多［(9.54±0.60)VS (9.07±0.64) Log10CFU/g,P<0.001］。不同喂养方式下FA婴儿大便的肠道菌群改变相似。结论食物过敏婴儿肠道菌群与健康婴儿的肠道菌群存在显著差别。     

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目的检测食物过敏(FA)婴儿和健康婴儿的主要肠道菌群,为食物过敏与肠道菌群关系研究提供线索。方法采用病例对照研究,检测2003年5～12月在重庆医科大学儿童医院儿保门诊体检的52例FA婴儿和100例健康婴儿的大便菌群(双歧杆菌属、乳酸杆菌属、肠杆菌科),大便菌群的分析采用GLM的广义析因法。结果FA婴儿大便双歧杆菌计数减少[(9.61±1.16)VS(10.31±1.20)Log10CFU/g,P<0.001],肠杆菌计数增多[(9.54±0.60)VS(9.07±0.64)Log10CFU/g,P<0.001]。不同喂养方式下FA婴儿大便的肠道菌群改变相似。结论食物过敏婴儿肠道菌群与健康婴儿的肠道菌群存在显著差别。     

喂养方式对剖宫产婴儿大便性状及肠道菌群的影响

目的 研究纯母乳喂养或纯配方奶喂养组对婴儿大便性状及肠道菌群的影响.方法 以健康足月剖宫产婴儿为观察对象,母乳喂养组和配方奶喂养组婴儿各30例.在婴儿6周龄时采集婴儿粪便标本,同时记录婴儿体质量、头围及大便情况.应用实时荧光定量PCR技术对肠道乳酸杆菌属、双歧杆菌属,以及双歧杆菌的某些重要亚种如长双歧等,进行定量检测.结果 母乳喂养婴儿的大便次数及大便含水量明显高于配方奶喂养婴儿.母乳喂养婴儿的双歧杆菌数量明显高于配方奶喂养婴儿(P ＜ 0.05);长双歧数量母乳喂养婴儿高于配方奶喂养婴儿,但两组间差异无统计学意义.结论 剖宫产母乳喂养儿的肠道双歧杆菌数量明显高于配方奶喂养儿.     

过敏性紫癜患儿肠道菌群的变化

目的研究过敏性紫癜(HSP)患儿的肠道菌群变化。方法提取64例HSP患儿和25例健康儿童粪便标本,采用16S rRNA/DNA荧光定量PCR技术分析并比较粪便标本中乳酸杆菌、双歧杆菌和大肠杆菌。结果 HSP患儿粪便中的乳酸杆菌、双歧杆菌和大肠杆菌的含量与健康儿童比较,差异均无统计学意义(P0.05)。其中伴腹痛、呕吐等消化道症状HSP患儿的乳酸杆菌、双歧杆菌含量均低于无消化道症状的HSP患儿以及健康儿童,差异均有统计学意义(P均0.05)。结论 HSP患儿急性期可能存在肠道菌群结构失调的情况,尤其是伴有消化道症状的HSP患儿。     

PCR-变性梯度凝胶电泳法初探婴儿期肠道菌群菌种演替

目的通过研究婴儿粪便菌种组成,探索婴儿期肠道菌群定植规律。方法收集15例健康婴儿出生后第0、2、4、7、10、14、28天,以及3、6、12月时的新鲜粪便,采用PCR-变性梯度凝胶电泳(DGGE)检测肠道菌群结构,对其优势菌种进行测序,分析婴儿期肠道菌群菌种演替过程。结果 DGGE指纹图谱可见,婴儿期的肠道菌群结构随出生后时间变化显著;克隆测序结果显示,变形菌门的细菌定植最早,以专性需氧菌肠杆菌、假单胞菌为主,其次是厚壁菌门的专性厌氧菌(梭状芽孢杆菌、小韦荣球菌)和兼性厌氧菌(多枝梭菌)定植,随后疣微菌门定植,放线菌门定植最晚,以双歧杆菌为主,并逐渐成为优势菌群。结论婴儿期肠道中专性需氧菌首先定植,随后是专性厌氧菌和兼性厌氧菌。变形菌门细菌定植最早,厚壁菌门细菌次之,随后是疣微菌门细菌,以双歧杆菌为主的放线菌门细菌定植最晚。     

支气管肺炎患儿治疗过程中肠道双歧杆菌和大肠杆菌的变化

目的 研究支气管肺炎患儿治疗过程中肠道双歧杆菌和大肠杆菌的变化,并与同年龄段同性别的健康儿童进行比较.为采用微生态制剂防治抗生索引起的肠道菌群变化提供数据参考.方法 收集30例支气管肺炎患儿及30例健康儿童的粪便标本,提取目标细菌DNA,测量和比较肺炎患儿和健康儿童标本细菌的DNA-D(260)值;应用细菌的16S rRNA/DNA序列设计双歧杆菌和大肠杆菌的引物,行常规PCR完成细菌定性;然后取标准定量的两种细菌DNA经一序列稀释后行荧光定量PCR,并制成标准曲线;将待测标本同样行荧光定量PCR后与标准曲线进行对比,得出标本中两种细菌含量.结果 支气管肺炎患儿治疗后的肠道菌群与健康儿童比较发生了明显的变化(F=50.78,P＜0.01);肠道中双歧杆菌数量(拷贝数/克湿便)的对数值,患儿治疗第1天为7.10±0.59,治疗第3天为6.03±0.51,治疗第7天为6.34±0.52,健康儿童为9.48±0.44,经统计学处理差异有统计学意义(P＜0.01).而大肠杆菌数量的对数值,患儿治疗第1天为6.74±0.38,治疗第3天为6.13±0.35,治疗第7天为7.08±0.40.健康儿童为7.54±0.45,经统计学处理差异有统计学意义(P＜0.01).结论 支气管肺炎患儿治疗过程中肠道菌群比健康组低.因此在治疗支气管肺炎患儿时采用微生态制剂,调整细菌比例.改善肠道内环境,使肠道内益生菌的数量尽快恢复正常.     

健康婴儿与过敏性疾病婴儿肠道双歧杆菌构建差异初探

目的 通过比较健康婴儿与过敏性疾病婴儿肠道双歧杆菌的构建规律,探讨婴儿肠道双歧杆菌与过敏性疾病的关系。方法 收集48例婴儿生后第0（胎便）、2、7、15天,1、6、12月时共7个时间点的粪便样品,其中22例在1岁以前患过过敏性疾病的婴儿组成过敏组,26例健康婴儿作为健康组,使用实时荧光定量PCR技术对婴儿粪便中双歧杆菌属及8种双歧杆菌菌种进行定性及定量分析。结果 两组婴儿在0~1月期间肠道双歧杆菌构建过程不同,健康组第2天表现出双歧杆菌下降的"重建"特征,而过敏组不存在此特征。过敏组第1月时双歧杆菌属的检出量低于健康组（P < 0.05）;第15天时B.breve的检出率低于健康组（P < 0.05）,且B.infantis定植延迟。结论 婴儿出生后0~1月的肠道双歧杆菌及其构建规律可能与过敏性疾病的发生有关,该时期可能是婴儿出生后过敏性疾病的防治关键期。     

Prenatal stress alters bacterial colonization of the gut in infant monkeys

OBJECTIVE: The hypothesis that prenatal stress lowers the levels of protective microflora and increases the risk for postpartum Gram-negative pathogens was tested in infant monkeys. METHODS: Female monkeys were left undisturbed or were stressed during pregnancy using an acoustical startle paradigm for 6 weeks either early or late in their 24-week gestation. Several types of intestinal microflora were repeatedly enumerated by fecal culture while infants were reared normally by their mothers. RESULTS: Significant changes in microflora concentrations occurred during the first 6 months of life. The profile of total aerobes and facultative anaerobes was biphasic, with peak concentrations occurring between 2 and 16 weeks of age. The numbers of bifidobacteria and lactobacilli were low at 2 days after birth but rapidly increased to a peak between 8 and 16 weeks of age. Although similar temporal patterns were evident in all infants, prenatal stress reduced the overall numbers of bifidobacteria and lactobacilli. CONCLUSIONS: Moderate disturbance during pregnancy was sufficient to alter the intestinal microflora in the newborn infant. These alterations could result in enhanced susceptibility to infection and suggest a mechanism for some effects of maternal pregnancy conditions on infant health.     

Prebiotics in infant milk formulas: new perspectives

In recent years it has become accepted that healthy human intestinal microflora may play an important part in priming the infants' systemic and mucosal immunity. Dietary modulation of the gut microbiota is a topical area of nutritional sciences and the main focus of many current functional foods such as non-digestible oligosaccharides (NDOs). Fructo-oligosaccharides (FOS) and trans-β-galacto-oligosaccharides (TOS) have been claimed to benefit the health of the colon by selectively stimulating the growth of bifidobacteria and lactobacilli (prebiotic effect). It could be of clinical interest to manipulate colonic flora because it is supposed that specific bacteria in the gut microbial microflora could promote potentially antiallergenic processes and play a key part in atopic disease prevention. Supporting this view is the finding that analysis of the composition of the intestinal bacterial populations showed different microbial patterns between healthy and allergic individuals. Assuming that non-digestible TOS and FOS can affect the intestinal ecosystem beneficially, the opportunity for gut flora manipulation arises in bottle-fed infants. New preterm and term infant milk formulas, supplemented with a mixture of TOS and FOS as prebiotic ingredients induced a significantly higher colonization of bifidobacteria and lactobacilli. In the future, selective manipulation of the intestinal microbiota might be an approach to novel prophylactic and therapeutic intervention strategies of atopy, by redirecting allergic Th-2 responses in favour of Th-1 responses.     

Prebiotics in infant milk formulas: new perspectives

In recent years it has become accepted that healthy human intestinal microflora may play an important part in priming the infants' systemic and mucosal immunity. Dietary modulation of the gut microbiota is a topical area of nutritional sciences and the main focus of many current functional foods such as non-digestible oligosaccharides (NDOs). Fructo-oligosaccharides (FOS) and trans-beta-galacto-oligosaccharides (TOS) have been claimed to benefit the health of the colon by selectively stimulating the growth of bifidobacteria and lactobacilli (prebiotic effect). It could be of clinical interest to manipulate colonic flora because it is supposed that specific bacteria in the gut microbial microflora could promote potentially antiallergenic processes and play a key part in atopic disease prevention. Supporting this view is the finding that analysis of the composition of the intestinal bacterial populations showed different microbial patterns between healthy and allergic individuals. Assuming that non-digestible TOS and FOS can affect the intestinal ecosystem beneficially, the opportunity for gut flora manipulation arises in bottle-fed infants. New preterm and term infant milk formulas, supplemented with a mixture of TOS and FOS as prebiotic ingredients induced a significantly higher colonization of bifidobacteria and lactobacilli. In the future, selective manipulation of the intestinal microbiota might be an approach to novel prophylactic and therapeutic intervention strategies of atopy, by redirecting allergic Th-2 responses in favour of Th-1 responses.     

Comparison of fecal microflora in children with atopic eczema/dermatitis syndrome according to IgE sensitization to food

Atopic eczema/dermatitis syndrome (AEDS) commonly often arises during early infancy. In several intervention studies a beneficial influence on AEDS course of certain intestinal bacteria, administered as 'probiotics', has been described. To evaluate the possible role of the natural intestinal microflora in children with allergic eczema/dermatitis syndrome regarding immediate type hypersensitivity to food allergens, children with food allergy (AAEDS, n = 68) have been compared with children without detectable food allergy (NAEDS, n = 25). All children (n = 93) in preschool age, mean age of 2.6 (+/-1.8) years, diagnosed with AEDS who were treated as inpatients in 2003 in a dermatological hospital were included. The correlation between fecal microflora, parasites and specific immunoglobulin E (IgE) antibodies against common food allergens was analyzed. A similar composition of intestinal microflora in children with AAEDS and NAAEDS was found. The food allergens that were most frequently detected were egg white, cow milk, casein, peanut and hazelnut. Furthermore, a significant association between IgE sensitization against important food allergens and components of the fecal microflora could not be demonstrated. With aging changes occur in the intestinal microbiota [Proteus/Klebsiella and age (rho = -0.607) and Enterococcus and age (rho = -0.428)]. In two subjects of the AAEDS group Blastocystis hominis was found. The composition of natural intestinal microflora in children with AAEDS and NAAEDS was similar. Hence, there is no evidence of a role of the intestinal microflora with regard to the development of infant (food) allergy in children with AEDS. The possible consequences for allergic diseases later in life require further investigation.     

Factors controlling the bacterial colonization of the intestine in breastfed infants

This article summarizes the published data on the intestinal microflora in breastfed infants published during the last 15 y. Enterobacteria and enterococci are found in high numbers in most infants during the first week of life. Bifidobacteria and Bacteroides spp. are found in increasing numbers at the following weeks. The intestinal microflora in breastfed infants can also be followed by different biochemical parameters. Acetic acid is found in higher concentrations in breastfed than in formula-fed infants. Degradation of mucin starts later in breastfed than in formula-fed infants. The conversion of cholesterol to coprostanol is also delayed by breastfeeding. Geographical differences in the composition of the intestinal microflora in infants have been reported, i.e. enterobacteria, enterococci, bifidobacteria, lactobacilli and bacteroides show different occurrences in developed and developing countries. There are minor differences in the infant's intestinal microflora due to breastfeeding or/and formula feeding.     

Factors controlling the bacterial colonization of the intestine in breastfed infants

This article summarizes the published data on the intestinal microflora in breastfed infants published during the last 15 y. Enterobacteria and enterococci are found in high numbers in most infants during the first week of life. Bifidobacteria and Bacteroides spp. are found in increasing numbers at the following weeks. The intestinal microflora in breastfed infants can also be followed by different biochemical parameters. Acetic acid is found in higher concentrations in breastfed than in formula-fed infants. Degradation of mucin starts later in breastfed than in formula-fed infants. The conversion of cholesterol to coprostanol is also delayed by breastfeeding. Geographical differences in the composition of the intestinal microflora in infants have been reported, i.e. enterobacteria, enterococci, bifidobacteria, lactobacilli and bacteroides show different occurrences in developed and developing countries. There are minor differences in the infant's intestinal microflora due to breastfeeding or/and formula feeding.     

rRNA probes used to quantify the effects of glycomacropeptide and alpha-lactalbumin supplementation on the predominant groups of intestinal bacteria of infant rhesus monkeys challenged with enteropathogenic Escherichia coli

OBJECTIVES: Certain milk factors may help to promote the growth of a host-friendly colonic microflora (e.g. bifidobacteria, lactobacilli) and explain why breast-fed infants experience fewer and milder intestinal infections than those who are formula-fed. The effects of supplementation of formula with two such milk factors was investigated in this study. MATERIALS AND METHODS: Infant rhesus macaques were breast-fed, fed control formula, or formula supplemented with glycomacropeptide (GMP) or alpha-lactalbumin (alpha-LA) from birth to 5 months of age. Blood was drawn monthly and rectal swabs were collected weekly. At 4.5 months of age, 10(8) colony-forming units of enteropathogenic E.coli O127, strain 2349/68 (EPEC) was given orally and the response to infection assessed. The bacteriology of rectal swabs pre- and post-infection was determined by culture independent fluorescence in situ hybridization. RESULTS: Post-challenge, breast-fed infants and infants fed alpha-LA-supplemented formula had no diarrhea, whilst those infants fed GMP-supplemented formula had intermittent diarrhea. In infants fed control formula the diarrhea was acute. CONCLUSIONS: Supplementation of infant formula with appropriate milk proteins may be useful for improving the infant's ability to resist acute infection caused by E.coli.     

Bacterial counts of intestinal Lactobacillus species in infants with colic

Intestinal colonization by lactobacilli is suggested to be a prerequisite to normal mucosal immune functions. An inadequate level of lactobacilli may be involved in appearance of allergic disease of which, infantile colic, is often considered an early clinical manifestation. The aim of the study is to evaluate intestinal lactobacilli in breast-fed infants with infantile colic and healthy infants. Fifty-six breast-fed infants, aged 15-60 days were enrolled in the study and divided into two groups: colicky (30 cases) and healthy (26 cases) according to Wessel's criteria. Stool samples were collected, diluted and cultured on selective media. The colonies were counted, reported as colony forming unit (cfu) per gram of faeces and identified by biochemical methods. Different colonization patterns of lactobacilli were found among colicky and healthy infants. Lactobacillus brevis (4.34 x 10(8) cfu/g) and L. lactis lactis (2.51 x 10(7) cfu/g) were found only in colicky infants while L. acidophilus (2.41 x 10(7) cfu/g) was found only in healthy infants. Lactobacillus brevis and L. lactis lactis might be involved in the pathogenesis of infantile colic increasing meteorism and abdominal distension. Further studies are required to understand how the observed differences may be involved in the pathogenesis of this common disorder.