Use of a simple duodenal capsule to study upper intestinal microflora.

The upper intestinal microflora was studied in 10 malnourished Indonesian children using the paediatric Enterotest Capsules. Trophozoites of Giardia lamblia were found in 2 specimens, profuse fungal mycelia in 3, and ascaris worms and eggs in 1. In 9 patients an abnormally profuse small intestinal bacterial flora was found. Provided precautions are taken to exclude artefactual contamination of the line on its withdrawal, this is a safe and simple method for studying the upper gut flora which could be applied to field conditions since it does not require radiological facilities.     

STOOL BACTERIAL AEROBIC OVERGROWTH IN THE SMALL INTESTINE OF CHILDREN WITH ACUTE DIARRHOEA

Abstract. The aerobic flora of 2 groups of children (normal and with malnutrition) with acute diarrhoea was studied, by intubation of the upper and middle small intestine and by stool culture. All the 27 children studied presented bacterial concentrations of 10⁵ germs/ml at one or both levels studied. In 9 cases enteropathogen bacteriae were isolated from stools, and in 6 of these they were also found in the small intestine. The results show the elevated incidence of overgrowth of the small intestinal aerobic flora in children with acute diarrhoea. This fact is mentioned as another etiological factor to be taken into consideration in this pathology.     

Upper small intestinal microflora in diarrhea and malnutrition in Nigerian children

The upper small intestinal microflora was determined quantitatively and qualitatively in a group of well-nourished diarrhea-free Nigerian children and compared with those of well-nourished children with acute diarrhea and malnourished children with or without diarrhea. Intestinal aspirate was collected by intubation after a 6-h fast. Well-nourished children without diarrhea had flora consisting predominantly of gram-positive cocci. Total bacterial counts were less than 10(5) organisms/ml; 18.2% of aspirates were sterile. In contrast, malnourished children with or withour diarrhea had a wider microbial spectrum including Enterobacteriaceae, Bacteroides, and Candida. Total bacterial counts were between 10(3) and 10(9) organisms/ml; none were sterile. In both well-nourished and malnourished groups, no significant quantitative bacteriologic differences were found between patients who had diarrhea and those who did not. Candida and Pseudomonas were found more frequently in malnourished patients with diarrhea. In such diarrheal patients, Pseudomonas, Klebsiella, and enteropathogenic Escherichia coli grew as pure isolates in intestinal aspirates and could be detected concomitantly in their stools. These results establish the upper small intestinal flora of well-nourished diarrhea-free Nigerian children, confirm bacterial overgrowth as a feature of malnourished children with or without diarrhea, and suggest that Candida, Pseudomonas, and Klebsiella may account partly for the diarrhea seen in malnourished children.     

辅助生殖技术与妊娠期糖尿病孕产妇肠道菌群的特异表达

目的通过检测和比较不同受孕方式及是否并发妊娠期糖尿病(gestational diabetes mellitus,GDM)孕产妇的肠道菌群,明确辅助生殖技术(assisted reproductive technology,ART)及GDM孕产妇肠道菌群的特异性表达,分析其机制,为今后预防干预、促进ART妊娠母婴健康提供理论基础。方法选取2016年2月至4月在厦门大学附属成功医院(陆军第73集团军医院)产科定期产检后住院分娩的足月妊娠、近3个月内未使用过抗生素并无肠道疾病的孕产妇,按ART和自然妊娠两种不同受孕方式及是否并发GDM纳入60例,分为4组,分别为ART并发GDM组18例、ART无GDM组14例、自然妊娠并发GDM组17例和自然妊娠无GDM组11例,记录孕妇的身高、体重、年龄、孕周、居住地、妊娠合并症并发症、近3 d饮食情况,以及分娩方式、分娩结局等临床资料;收集孕产妇入院或分娩之前24 h的粪便5~10 g;提取肠道菌群DNA;同时基于16S rRNA基因测序技术,分析样本中肠道菌群的分布情况;用于后续的菌群量化研究及代谢物分析。结果4组样本的肠道菌群主要由厚壁菌门和拟杆菌门组成;不论何种受孕方式,GDM孕产妇的双歧杆菌均比其他孕产妇减少;ART孕产妇肠道菌群的厚壁菌门丰度降低,变形菌门所属菌群丰度增加(P<0.05),肠道菌群中的Alpha多样性降低(P<0.05);ART并发GDM组肠道菌群的丰度、多样性降低,肠道菌群的组成比例失衡,且出现较高丰度的条件致病菌克雷伯氏菌;ART并发GDM组和ART无GDM组的Alpha多样性较为一致,而自然妊娠并发GDM组和自然妊娠无GDM组之间的Alpha多样性则存在明显差异。结论补充双歧杆菌可能有助于预防或者治疗GDM;ART并发GDM组的肠道菌群组成结构比例失调;ART大剂量激素的使用会导致孕产妇的肠道菌群失衡;ART导致的肠道菌群变化远大于GDM对肠道菌群的作用。     

功能性便秘儿童肠道菌群DNA的PCR-SSCP和BOX-PCR指纹图谱分析及临床意义

目的 探讨功能性便秘(functional constipation,FC)儿童肠道微生态菌落的构成及其在便秘发生过程中的作用.方法 研究对象分为便秘组和对照组,便秘组15例,平均年龄6.5岁,对照组35例,平均年龄6岁.取所有儿童粪便提取细菌基因组DNA, 应用基于细菌16SrDNA的PCR-SSCP技术和基于细菌基因组的BOX-PCR技术对肠道菌落的DNA指纹图谱分析,结合克隆测序和生物信息学技术对FC儿童的肠道菌落进行初步鉴定,并对其组成结构进行分析.结果 对照组和便秘组的所有样品分别进行3 次以上的PCR-SSCP和BOX-PCR指纹图谱分析,得到了稳定可重复的图谱,便秘组菌种的种类较对照组明显增多,差异有统计学意义;对照组优势菌主要为拟杆菌属、埃希氏菌属、双歧杆菌属、乳杆菌属;便秘组的优势菌主要为脆弱拟杆菌属、埃希氏菌属、真杆菌属和梭菌属.结论 功能性便秘儿童肠道菌群的菌属多样性增加,各肠道菌属间存在比例失调,肠道微生态失调可能参与了便秘的产生或加重过程.     

Urea utilization by the intestinal flora, of infants fed mother's milk and a formula diet, as measured with the 15N-tracer technique

15N-Incorporation by intestinal bacteria was measured under different feeding conditions in 16 infants after a single oral loading of 165 mg [15N2]urea X kg-1 body weight as a tracer. In five subjects on a mother's milk diet, the 15N-excess in the isolated intestinal bacteria was 1.08 (0.17-1.85) atom-%. The mean 15N-excess in the intestinal flora of five formula-fed subjects did not differ significantly from these values [0.63 (0.17-1.05) atom-%]. A trend to a higher incorporation of 15N from labeled urea by the intestinal flora was seen in four infants, who were adapted to an increased nutritional urea supply on a special formula, containing 14 g of milk protein, 80 g lactose, 36 g fat, and 0.35 g urea X L-1. The same observation was made in two infants with chronic renal failure. The incorporation of urea nitrogen by the putrefactive intestinal flora of infants on a formula diet as well as by the bifidobacterial flora of those on mother's milk feeding indicates the utilization of ureas as a source of bacterial protein and nucleic acid synthesis. The adaptive usage of urea for the bacterial metabolism can be considered as a sign of supportive detoxification by the intestinal flora.     

Galacto-oligosaccharides and long-chain fructo-oligosaccharides as prebiotics in infant formulas: A review

The present review summarizes clinical and experimental data concerning the possible effects of a prebiotic mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides. The results from several studies, made up of over 400 preterm and term infants, clearly demonstrate that the prebiotic mixture under examination specifically stimulates the growth of bifidobacteria and lactobacilli and reduces the growth of pathogens. As a consequence of the changed intestinal flora by the dietary galacto-oligosaccharides and fructo-oligosaccharides, the faecal pH values and the short-chain fatty acid pattern were similar to those found in breastfed infants. In addition, the stool consistency was the same as in breastfed infants. In vitro experiments have demonstrated that the specific short-chain fatty acid pattern, at a pH similar to that found in faecal samples of breastfed infants, reduces the growth of pathogens in a dose-dependent manner but does not influence the growth of bifidobacteria and lactobacilli. In an animal vaccination model, the prebiotic mixture improved the response to vaccination. In an allergy model (sensitization by ovalbumin), the allergic reaction was reduced by the prebiotic mixture. The data obtained from animal experiments are in agreement with preliminary data from clinical trials which indicate a reduced allergic response (reduced plasma IgE/IgG4 ratio) and reduced episodes of upper airway infection during the first year of life.
Conclusion: Experimental evidence demonstrates that the prebiotic mixture employed in these studies modulates the intestinal flora and modulates the immune system as human milk does. There are sufficient experimental data to put forward the hypothesis that substances like the prebiotic mixture under study will substantially contribute to the improvement of the protective properties of infant formulas.     

Galacto-oligosaccharides and long-chain fructo-oligosaccharides as prebiotics in infant formulas: a review

The present review summarizes clinical and experimental data concerning the possible effects of a prebiotic mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides. The results from several studies, made up of over 400 preterm and term infants, clearly demonstrate that the prebiotic mixture under examination specifically stimulates the growth of bifidobacteria and lactobacilli and reduces the growth of pathogens. As a consequence of the changed intestinal flora by the dietary galacto-oligosaccharides and fructo-oligosaccharides, the faecal pH values and the short-chain fatty acid pattern were similar to those found in breastfed infants. In addition, the stool consistency was the same as in breastfed infants. In vitro experiments have demonstrated that the specific short-chain fatty acid pattern, at a pH similar to that found in faecal samples of breastfed infants, reduces the growth of pathogens in a dose-dependent manner but does not influence the growth of bifidobacteria and lactobacilli. In an animal vaccination model, the prebiotic mixture improved the response to vaccination. In an allergy model (sensitization by ovalbumin), the allergic reaction was reduced by the prebiotic mixture. The data obtained from animal experiments are in agreement with preliminary data from clinical trials which indicate a reduced allergic response (reduced plasma IgE/IgG4 ratio) and reduced episodes of upper airway infection during the first year of life. CONCLUSION: Experimental evidence demonstrates that the prebiotic mixture employed in these studies modulates the intestinal flora and modulates the immune system as human milk does. There are sufficient experimental data to put forward the hypothesis that substances like the prebiotic mixture under study will substantially contribute to the improvement of the protective properties of infant formulas.     

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??Intestinal microbiota is a general term of microbial communities that reside in the human intestine?? which can affect the systemic immune system by expansion of extra-intestinal T cell populations?? production of short-chain fatty acids??development of oral tolerance?? and control of inflammation.
Intestinal intestinal dysbiosis may be involved in a variety of disease processes. Animal experiments have found that normal intestinal flora is beneficial to increase lung immunity against bacterial pneumonia. This interaction between intestinal and lung is known as "Gut-Lung axis". Although the specific mechanism of the "Gut-Lung axis" is still poorly undertood??the proposal of which provides new insights into the use of
microecologic products or fecal bacteria transplantation to
regulate or restore the intestinal flora and then to treat lung
diseases.     

Prevention of antibiotic-associated diarrhea in children by Clostridium butyricum MIYAIRI

BACKGROUND: Clostridium butyricum MIYAIRI (CBM) is a probiotic bacteria used for anti-diarrheal medicine in Japan. The preventive effect of CBM was investigated for antibiotic-associated diarrhea (AAD) in children. METHODS: One hundred and ten children who suffered from upper respiratory tract infection or gastroenteritis were divided into three groups. Twenty-seven of the patients received only antibiotics, 38 received CBM from the mid point of the antibiotic treatment and 45 concomitantly received CBM from the beginning of the antibiotic treatment. To examine the effects of CBM on AAD, the changes in intestinal flora were investigated. RESULTS: Diarrhea was observed in 59% of the subjects who received only antibiotics, and total fecal anaerobes, especially Bifidobacterium, were remarkably decreased. In contrast, diarrhea in the subjects who received CBM from either the middle or the beginning of the antibiotic therapy was decreased to 5% and 9%, respectively. Concomitant administration of CBM increased anaerobes and prevented the decrease of Bifidobacterium in the subjects who received antibiotics. CONCLUSIONS: Clostridium butyricum MIYAIRI is effective for both the treatment and the prophylaxis of AAD in children, as it normalizes the intestinal flora disturbed by antibiotics.     

基于高通量测序分析早产认知障碍大鼠肠道菌群结构特征

目的 分析早产认知障碍大鼠肠道菌群结构特征，探讨肠道菌群改变与早产认知障碍的关系。方法 给孕16~17 d Sprague-Dawley大鼠连续2 d腹腔注射脂多糖（LPS）建立认知障碍模型，以腹腔注射PBS为对照。孕21 d行剖宫术，将早产大鼠随机分配给代母鼠喂养。于生后30 d利用Morris水迷宫中的定位航行实验对早产大鼠进行认知评估，并分为早产认知障碍组（n=21）与正常对照组（n=10）。采用苏木精-伊红染色观察两组大鼠海马病理改变，提取各组大鼠粪便进行16S rRNA测序并分析。同时对两组大鼠肠道菌群进行主成分分析（PCA）。结果 与对照组相比，早产认知障碍大鼠海马可见大量神经元变性坏死；肠道菌群丰富度及多样性降低（P < 0.05）；门水平上变形菌门丰度增加（P < 0.05）；目、科、属水平上，普氏菌属、乳杆菌属等丰度显著降低，葡萄球菌科、寡养杆菌属等丰度显著增加（P < 0.05）。PCA显示两组大鼠在肠道菌群构成上差异明显。结论 早产认知障碍大鼠肠道菌群结构发生明显变化，可为早产认知障碍导致的微生态变化的治疗及干预提供依据。     

子痫前期对母婴肠道菌群影响的研究进展

子痫前期是妊娠期特有的并发症,影响母婴健康.肠道菌群在人体代谢和免疫方面发挥着重要的调节作用,并与许多疾病相关.研究表明,子痫前期的发生发展可导致母亲肠道菌群的改变,甚至与子代肠道菌群的定植与发展密切相关.该文就子痫前期对母婴肠道菌群影响的相关研究进行综述,为子痫前期相关母婴并发症的预防及治疗提供新思路.引     

人乳低聚糖对婴儿肠道菌群影响的研究进展北大核心CSCD

婴儿期是肠道菌群形成和发展最为关键的时期,作为肠道菌群演替速度较快的重要阶段,稳定的肠道菌群定植对机体健康、免疫系统的建立及完善有着重大且长远的意义。母乳中富含人乳低聚糖(HMOs),能够有效促进婴儿肠道中有益细菌的生长,抑制病原菌的侵袭,改善肠道菌群组成,提高菌种多样性,促进婴儿生长发育。现就HMOs的研究现状及其对婴儿肠道菌群的影响进行综述。     

Influence of infant diets on the ecology of the intestinal tract of human flora-associated mice.

The effect of diet on intestinal ecology was studied in germ-free mice that were inoculated orogastrically with predominant intestinal flora components isolated from the feces of breast-fed human infants. The flora components colonized the intestines of mice and persisted at fixed population levels. Groups of flora- associated mice were fed either human milk, bovine milk, whey-dominant formula, or formula modifications exclusively for 2 weeks, and then examined for changes in small intestinal and cecal flora composition, cecal pH, and resistance to intestinal colonization with Salmonella typhimurium. Dietary variations influenced the composition of the flora to a moderate degree but the differences were generally not statistically significant. However, the addition of bovine lactoferrin to the whey-dominant formula resulted in significantly greater counts of Bifidobacterium, Bacteroides, Enterococcus and total aerobes in the small intestine when compared with mice fed unsupplemented formula. Bifidobacterium was present in large numbers in both the ceca and small intestines of mice fed the lactoferrin-supplemented formula. Despite similarities in intestinal flora patterns among mice fed the various diets, human milk consumption resulted in a lower pH of cecal contents and a greater resistance to colonization by Salmonella typhimurium after orogastric challenge than the consumption of the other diets.     

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目的探讨儿童幽门螺杆菌(H.pylori)感染及抗H.pylori治疗对儿童肠道菌群状态的影响。方法将浙江大学医学院附属儿童医院2004年410月门诊收治的68例慢性胃炎、十二指肠球炎患儿分为H.pylori阳性组36例、H.pylori阴性组32例二组。称取68例患儿新鲜粪便1.0g,分别进行需氧和厌氧培养,分离肠道菌群中最有代表性的三种需氧菌(肠杆菌、肠球菌、酵母菌)和四种厌氧菌(双歧杆菌、乳杆菌、类杆菌、产气荚膜梭菌),菌落记数,同时计算B/E比值来代表定植抗力。对36例H.pylori阳性组中的26例患儿进行“三联”抗H.pylori治疗1周后留取新鲜粪便进行肠道菌群分析,5例患儿在停药1个月后再次进行肠道菌群分析。结果H.pylori阳性组和H.pylori阴性组上述三种需氧菌和四种厌氧菌的菌落检出率比较,差异无统计学意义(P>0.05)。抗H.pylori治疗1周后双歧杆菌、乳杆菌、类杆菌菌落数量较治疗前明显降低(P<0.05),B/E值明显下降(P<0.01),酵母菌的检出率明显增加(P<0.05),产气荚膜梭菌检出率下降(P<0.05)。5例患儿在停药1个月后,乳酸杆菌数量仍继续下降,肠杆菌数量继续增加,双歧杆菌、类杆菌数量有所恢复,但仍低于治疗前。结论儿童H.pylori感染后对肠道菌群影响不大;三联疗法抗H.pylori治疗对儿童肠道菌群产生明显的影响,因此在治疗H.pylori感染时须考虑到大量抗生素治疗后可能对患儿的副作用及潜在的危险。     

Features of intestinal flora in children with food protein-induced proctocolitis based on high-throughput sequencing北大核心CSCD

目的 通过高通量测序分析食物蛋白诱导性直肠结肠炎（food protein-induced proctocolitis，FPIP）患儿肠道菌群特征。 方法 选取2018年10月至2021年2月遵义医科大学第三附属医院门诊就诊的小于6月龄纯母乳喂养发生FPIP患儿31例纳入FPIP组，正常健康婴儿31例纳入健康对照组；采集两组粪便样本提取DNA并通过PCR扩增，采用高通量测序分析粪便样品中的16S rDNA V3~V4片段并进行相关生物信息学分析。 结果 肠道菌群多样性分析示FPIP组菌群多样性Shannon指数低于健康对照组，但差异无统计学意义（P>0.05）；菌群丰富度Chao指数高于健康对照组（P<0.01）。在门水平上，两组菌群组成均主要由厚壁菌门、放线菌门、变形菌门、拟杆菌门4个菌门构成；与健康对照组相比，FPIP组中放线菌门构成比显著降低（P<0.001），变形菌门构成比明显增加（P<0.05）。在属水平上，FPIP组主要由大肠埃希氏菌属、梭状芽孢杆菌属、肠球菌属、克雷伯氏菌属和双歧杆菌属组成；健康对照组主要由双歧杆菌属、链球菌属组成；与健康对照组相比，FPIP组中双歧杆菌属和瘤胃球菌属构成比明显降低（P<0.05），梭状芽孢杆菌属和志贺氏菌属构成比明显增加（P<0.05）。 结论 FPIP组与健康对照组相比，肠道菌群多样性下降，丰富度升高；在菌群组成结构上某些细菌菌属存在差异。提示在FPIP的发生发展过程中，肠道微生物群在属水平上的构成改变可能起到了重要作用。     

儿童急性淋巴细胞白血病化疗前后肠道菌群变化特点北大核心CSCD

目的探索儿童急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)患儿初诊时肠道菌群的变化及化疗对肠道菌群的影响。方法采集40例初诊ALL患儿化疗前、化疗后2周、化疗后1个月和化疗后2个月及10例健康对照组儿童的粪便样本,进行16S rDNA测序及分析,比较ALL组与健康对照组及ALL患儿化疗前后的肠道菌群差异。结果与化疗前及健康对照组相比,ALL患儿化疗后1个月及2个月时肠道菌群丰度显著下降(P<0.05)。与健康对照组比较,ALL患儿化疗前后肠道菌群多样性均明显降低(P<0.05)。门水平上,放线菌门的相对丰度在ALL患儿化疗后2周、1个月及2个月时较健康对照组显著降低(P<0.05),变形菌门的相对丰度在ALL患儿化疗后1个月及2个月时较健康对照组显著升高(P<0.05)。属水平上,双歧杆菌属的相对丰度在ALL患儿化疗后2周、1个月及2个月时均较健康对照组显著降低(P<0.05);克雷伯菌属的相对丰度在ALL患儿化疗后1个月及2个月时较健康对照组显著升高,并且在化疗后1个月时较化疗前显著升高(P<0.05);Faecalibacterium相对丰度在ALL患儿化疗前后均较健康对照组显著降低,并且在化疗后2周及1个月时较化疗前显著降低(P<0.05)。肠球菌属相对丰度在ALL患儿化疗后1个月及2个月较健康对照组及化疗前均明显升高(P<0.05)。结论ALL患儿肠道菌群多样性明显低于健康儿童。化疗导致肠道菌群丰度显著降低,并可致部分有益菌(双歧杆菌属、Faecalibacterium)丰度下降、病原菌(克雷伯菌属、肠球菌属)丰度增加。     

局灶性癫痫患儿治疗前后肠道菌群的变化及意义北大核心CSCD

目的研究局灶性癫痫患儿与健康儿童肠道菌群是否不同,以及癫痫患儿治疗前后肠道菌群的变化。方法招募未经治疗的初诊局灶性癫痫患儿10例为病例组,且均用单药奥卡西平治疗。收集患儿临床资料,以及治疗前和治疗3个月后的粪便标本;另招募相同年龄段的健康儿童14例为对照组。提取粪便标本中细菌总DNA,进行16S rDNA测序,并行生物信息学分析。结果病例组经奥卡西平治疗3个月后癫痫发作频率减少>50%。门水平方面,治疗前组放线菌门丰度高于治疗后组和对照组(P<0.05);属水平方面,治疗前组埃希菌/志贺菌属、链球菌属、柯林斯菌属和巨单胞菌属丰度高于对照组(P<0.05),经治疗后其丰度降低(P<0.05)。结论与健康儿童相比,局灶性癫痫患儿的肠道菌群存在显著差异;奥卡西平可以显著改善癫痫症状,重塑癫痫患儿的肠道菌群。     

Analysis of intestinal flora development in breast-fed and formula-fed infants by using molecular identification and detection methods

BACKGROUND: An obvious difference between breast-fed and formula-fed newborn infants is the development of the intestinal flora, considered to be of importance for protection against harmful micro-organisms and for the maturation of the intestinal immune system. In this study, novel molecular identification methods were used to verify the data obtained by traditional culture methods and to validate the culture independent fluorescent in situ hybridization (FISH) technique. METHODS: From each of six breast-fed and six formula-fed newborn infants, six fecal samples were obtained during the first 20 days of life. The microbial compositions of the samples were analyzed by culturing on specific media and by FISH, by using specific 16S rRNA-targeted oligonucleotide probes. The colonies growing on the media were identified by random amplified polymorphic DNA pattern analysis and by polymerase chain reaction amplification and subsequent analysis of the 16S rRNA gene. RESULTS: Molecular identification of the colonies showed that the selective media are insufficiently selective and unsuitable for quantitative analyses. Qualitative information from the culturing results combined with the data obtained by the FISH technique revealed initial colonization in all infants of a complex (adult-like) flora. After this initial colonization, a selection of bacterial strains began in all infants, in which Bifidobacterium strains played an important role. In all breast-fed infants, bifidobacteria become dominant, whereas in most formula-fed infants similar amounts of Bacteroides and bifidobacteria (approximately 40%) were found. The minor components of the fecal samples from breast-fed infants were mainly lactobacilli and streptococci; samples from formula-fed infants often contained staphylococci, Escherichia coli, and clostridia. CONCLUSIONS: This study confirms the differences in development of intestinal flora between breast-fed and formula-fed infants. The results obtained from the FISH technique were consistent. Although the repertoire of probes for this study was not yet complete, the FISH technique will probably become the method of reference for future studies designed to develop breast-fed-like intestinal flora in formula-fed infants.     

Supplementation of a bovine milk formula with an oligosaccharide mixture increases counts of faecal bifidobacteria in preterm infants

BACKGROUND: The establishment of a balanced intestinal microflora which may protect against infection is desirable for the preterm infant. OBJECTIVE: To investigate the effect of a preterm formula milk supplement consisting of oligosaccharides in similar proportions to human milk on the faecal flora and stool characteristics of preterm infants. STUDY DESIGN: To resemble the effect of human milk, an oligosaccharide mixture consisting of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides was used to supplement a standard preterm formula at a concentration of 10 g/l. This supplemented formula was studied in 15 preterm infants, and the results were compared with those found in 15 infants fed a formula supplemented with maltodextrin as placebo. A group fed fortified mother's milk was investigated as a reference group (n = 12). On four days during a 28 day feeding period (1, 7, 14, and 28), the faecal flora was investigated, and stool characteristics, growth, and possible side effects were recorded. RESULTS: During the study period, the number of bifidobacteria in the group fed the oligosaccharide supplemented formula increased to the upper range of bifidobacteria counts in the reference group. The difference between the supplemented and non-supplemented groups was highly significant (p = 0.0008). The stool characteristics were also influenced by the supplement: the stool frequency after 28 days was significantly lower in the control group than in the oligosaccharide supplemented group (p = 0.0079) and the reference group (p < 0.0001). Over the study period, the stool consistency in the control group became harder, but remained fairly stable in the other two groups. There was no effect of the different diets on the incidence of side effects (crying, regurgitation, vomiting) or on weight gain or length gain. CONCLUSION: Supplementing preterm formula with a mixture of galacto- and fructo-oligosaccharides at a concentration of 10 g/l stimulates the growth of bifidobacteria in the intestine and results in stool characteristics similar to those found in preterm infants fed human milk. Therefore prebiotic mixtures such as the one studied may help to improve intestinal tolerance to enteral feeding in preterm infants.