Bifidobacterial utilization of human milk oligosaccharides

A promising strategy to improve health is the rational manipulation of one's beneficial microbiota via dietary interventions. This is observed in nature where specific bifidobacteria utilize human milk oligosaccharides (HMOs) that are encountered within the breast-fed infant colon. Bifidobacterium longum subsp. infantis is regarded as the archetypical HMO consumer associated with the developing neonate. This review summarizes the known molecular mechanisms underlying HMO utilization, as determined for bifidobacterial commensals. In addition, future directions of HMO research are discussed with an emphasis on physiological, ecological and clinical approaches to understand bifidobacterial utilization of this intriguing substrate.     

母乳低聚糖的检测方法研究进展

母乳低聚糖(HMOS)在母乳中的含量仅次于乳糖和脂肪,其生理功能受到越来越多的重视。在对母乳低聚糖的研究中,关键问题之一是灵敏和可定量的检测方法。由于母乳低聚糖属于复杂的混合物,结构多样,且没有内在的发色团,使得对其进行结构分辨和定量检测都存在不小的难度。本文拟对母乳低聚糖检测方法的研究进展进行综述。     

助智牛奶的研制

以保持良好记忆和脑部健康为原则,在牛奶中加入对记忆功能有调节作用的二十二碳六烯酸(DHA)、花生四烯酸(AA)、牛磺酸、锌,并同时调整稳定剂用量和工艺过程,使产品在功能及口感上实现最优化。     

大豆低聚糖在乳酸菌饮料中的应用研究

采用单因素及正交试验设计研究国产大豆低聚糖在乳酸菌饮料中的应用,得出在乳酸菌饮料中大豆低聚糖的添加量在低于4.0%时,不影响乳酸菌饮料的口感和质量,并具有保健意义,大豆低聚糖损失率低于10.0%。乳酸菌饮料最佳配方为,果汁4.0%、发酵脱脂乳6.0%、蔗糖12.0%、柠檬酸0.20%、大豆低聚糖4.0%、稳定剂(PGA∶CMC=1∶1)0.30%、L-Vc0.05%、香料0.10%、色素适量、水73.35%。     

Milk oligosaccharides: Structural and technological aspects

This review focuses on the more recent scientific information on composition and structural aspects of human and bovine milk oligosaccharides (OS). Advances in high performance liquid chromatography and capillary electrophoresis techniques have been at the forefront in making available efficient analytical methods for OS quantification. More sophisticated tools are available to assist with structural characterisation of milk OS. Furthermore, the review deals with existing and emerging technologies that have a potential for use in large scale fractionation/enrichment of OS, leading to the production of fractions rich in milk OS for use as physiologically active health promoting ingredients in functional dairy foods.     

Hydrolysis of soya milk oligosaccharides by Bifidobacterium longum CRL 849

 The reduction of soya milk oligosaccharides by Bifidobacterium longum CRL 849 was studied. The utilization of stachyose was concomitant with the use of sucrose. Maximum hydrolysis of stachyose (49.3%) occurred during the first 7 h of incubation at 37  °C, while a 79.3% decrease in the concentration of sucrose was observed after 9 h. No raffinose was detected after hydrolysis of the stachyose. Cell population decreased after 8 h of incubation because of the low pH attained (pH 4.7). l(+)-Lactate concentration was higher than acetate (molar ratio 6.7 : 1) at 6 h followed by a slow increase in acetate formation. Ethanol was detected in small amounts at the end of the incubation time (24 h). Received: 29 December 1997     

Comparative aspects of milk proteins.

The current status of knowledge of the major proteins of milks of various species is evaluated. Most of the non-bovine milk proteins are homologous with the recognized families of those of Bos taurus, alpha S1-caseins, alpha S2-caseins, beta-caseins, kappa-caseins, beta-lactoglobulins, and alpha-lactalbumins, each family representing a separate genetic locus specific to the mammary gland. No prominent milk protein not homologous to one of these families has yet been discovered in milk of any species. Genetic polymorphism resulting from substitutions in the polypeptide chains and various degrees of post-translational phosphorylation, glycosylation, and proteolysis have been identified in milk proteins of several species. Total protein production ranges among species from about 0.5 to 10 g/d per kg0.75 maternal weight. Proportions of the several proteins vary greatly among species, but few accurate analytical data are available except for total casein and total whey protein contents.     

Comparative aspects of milk fat synthesis

This general review attempts to capture the interest of nonspecialists, especially those whose main interest is the dairy cow, in the extraordinary diversity of milk fats synthesized and secreted by different mammalian species. The review compares differences in the gross proportions of fats in the milk of various species and discusses different strategies for providing the suckling young with sufficient energy as fat. Despite the constancy of the gross chemical composition of the milk fat globule and its membrane produced by mammals, there are striking differences among species in the fatty acid composition of milk triacylglycerols (triglycerides). The origins of the short-, medium-, and long-chain fatty acids of milk triacylglycerols are reviewed with emphasis on differences between ruminants and nonruminants. Because there appears to be less difference among mammals in the mechanisms of fatty acid desaturation, chain elongation, and esterification by the mammary gland, these topics are only briefly reviewed.     

人乳中低聚糖的含量及其常用分析方法的研究进展

人乳低聚糖（human milk oligosaccharides,HMOs）是母乳中的一类重要组分,迄今为止已经确定了200多种结构不同的HMOs。HMOs能在肠道微生物的作用下产生短链脂肪酸,对婴儿健康产生有益影响,这是母乳与配方粉的主要区别之一。研究表明,不同种类的肠道微生物利用不同机制来识别和消化不同结构的HMOs,维持肠道菌群平衡。同时,HMOs还具有缓解过敏症状,预防坏死性小肠结肠炎等多种功能。本文对HMOs的结构、种类与含量、与婴儿肠道菌群的互作及其免疫调节功能进行了综述。HMOs可促进婴儿肠道菌群的定植与生长,并通过多种方式直接或间接调节婴儿免疫功能。本文为HMOs在婴幼儿食品中的应用提供理论支持,对其未来研发方向提供新思路。

     

Permeate from cheese whey ultrafiltration is a source of milk oligosaccharides

Previously undescribed oligosaccharides in bovine cheese whey permeate were characterized by a combination of nanoelectrospray Fourier transform ion cyclotron resonance (nESI-FTICR) mass spectrometry and matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance (MALDI-FTICR) mass spectrometry. Oligosaccharide composition was elucidated by collision-induced dissociation within the ICR cell. In addition to sialyllactose (the most abundant oligosaccharide in bovine colostrum), we identified 14 other oligosaccharides, half of which have the same composition of human milk oligosaccharides. These oligosaccharides could potentially be used as additives in infant formula and products for the pharmaceutical industry. Because whey permeate is a by-product from the production of whey protein concentrate (WPC) and is readily available, it is an attractive source of oligosaccharides for potential application in human nutrition.     

不同阶段母乳中10种游离低聚糖的检测及含量分析

目的检测不同阶段母乳中10种游离母乳低聚糖(human milk oligosaccharides,HMOS)的含量,并比较其在不同阶段母乳中的变化。方法分别采集产后0~7 d(初乳)、产后8~15 d(过渡乳)、产后16~180 d(成熟乳)的母乳,采用荧光标记HMOS,通过超高效液相色谱-荧光检测法和标准曲线定量10种HMOS。采用Person相关比较不同泌乳时间与HMOS含量的相关性,3个泌乳阶段的组间差异采用单因素方差分析。结果在选定的色谱条件下,10种HMOS可完全分离并定量。10种HMOS中,2'岩藻糖乳糖(2'FL)、3'唾液酸乳糖(3'SL)、6'唾液酸乳糖(6'SL)、乳糖-N-四糖(LNT)、乳糖-N-新四糖(LNn T)、乳糖-N-五糖I(LNFP-I)与泌乳时间存在负相关关系,3'岩藻糖乳糖(3'FL)与泌乳时间存在正相关关系,上述7种HMOS在不同阶段母乳中差异有统计学意义(P0.05),而α-四糖(P_I)、乳糖-N-五糖V(LNFP-V)、乳糖-N-新五糖(LNnFP-V)与泌乳时间无明显相关关系,在不同阶段母乳中含量差异无统计学意义(P0.05)。结论不同阶段母乳中HMOS的含量不同。10种HMOS中,7种HMOS与泌乳时间具有相关关系并且在不同泌乳阶段差异有统计学意义(P0.05)。     

Determination of lactulose and soya oligosaccharides in infant formula milk feeds

A paper chromatography technique is described for the separation and quantification of minor sugars in infant formula milks. The precision and reliability of the technique are described. Infant milk feeds of various types were analysed and found to contain up to 11.4 mmol/l of the non-absorbed sugar lactulose. Soya derived feeds may contain a significant residue of non-absorbable oligosaccharides.     

Novel aspects of health promoting compounds in meat

Meat is an integral part of the human diet. Besides essential amino acids and nutritive factors of high quality and availability, meat provides often overlooked components of importance for human health. These are amino acids and bioactive compounds that may be very important in i) preventing muscle wasting diseases, such as in sarcopenia, ii) reducing food and caloric intake to prevent metabolic syndrome, iii) blood pressure homeostasis via ACE-inhibitory components from connective tissue, and iv) maintaining functional gut environment through meat-derived nucleotides and nucleosides. In addition, meat could be an important source of phytanic acid, conjugated linoleic acids and antioxidants. Further, it becomes increasingly apparent that design of in vitro meat will be possible, and that this development may lead to improved health benefits from commercially viable and sustainable meat products.     

母乳低聚糖的结构与功能研究进展

母乳低聚糖(human milk oligosaccharides, HMOs)是人乳中仅次于乳糖和脂肪的第三大营养物质,是母乳的独特成分,在婴幼儿生长发育中起到重要作用。每种母乳低聚糖可能具有不同的功能。本文阐述了母乳低聚糖结构组成、功能作用机理以及应用现状,为婴幼儿配方食品的设计、开发提供理论支持。     

人乳寡糖体外合成研究进展

人乳寡糖的益生作用被确定之后,其合成方法的研究也受到越来越多的重视。本文将人乳寡糖(HMOs)的合成方法分为化学法和生物法,详细阐述了每种合成方法的研究进展,并分析了其优劣势。通过对人乳寡糖合成方法的深入了解,将为实现人乳寡糖的工业化生产奠定坚实的基础。     

In vitro fermentability of human milk oligosaccharides by several strains of bifidobacteria

This study was conducted to investigate the catabolism and fermentation of human milk oligosaccharides (HMO) by individual strains of bifidobacteria. Oligosaccharides were isolated from a pooled sample of human milk using solid-phase extraction, and then added to a growth medium as the sole source of fermentable carbohydrate. Of five strains of bifidobacteria tested (Bifidobacterium longum biovar infantis, Bifidobacterium bifidum, Bifidobacterium longum biovar longum, Bifidobacterium breve, and Bifidobacterium adolescentis), B. longum bv. infantis grew better, achieving triple the cell density then the other strains. B. bifidum did not reach a high cell density, yet generated free sialic acid, fucose and N-acetylglucosamine in the media, suggesting some capacity for HMO degradation. Thin layer chromatography profiles of spent fermentation broth suggests substantial degradation of oligosaccharides by B. longum bv. infantis, moderate degradation by B. bifidum and little degradation by other strains. While all strains were able to individually ferment two monosaccharide constituents of HMO, glucose and galactose, only B. longum bv. infantis and B. breve were able to ferment glucosamine, fucose and sialic acid. These results suggest that as a potential prebiotic, HMO may selectively promote the growth of certain bifidobacteria strains, and their catabolism may result in free monosaccharides in the colonic lumen.