Oligosaccharides Research Articles

Self-assembly of cyclodextrin complexes: detection, obstacles and benefits.

Cyclodextrins (CDs) are cyclic oligosaccharides that form water-soluble inclusion complexes of lipophilic molecules. They are commonly used as pharmaceutical excipients. Recently it has been observed that CDs and CD complexes self-assemble in aqueous solutions to form transient clusters, nanoparticles and small microparticles. The critical aggregation concentration (cac) of the natural αCD, βCD and γCD in pure aqueous solutions is about 25, 8 and 9 mg/ml, respectively. The cac of 2-hydroxypropyl-β-cyclodextrin (HPβCD), that consists of a mixture of isomers, in pure aqueous solutions is significantly higher or about 118 mg/ml. Formation of guest/ CD complexes can increase or decrease the cac value. Due to the transient nature of the CD clusters and nanoparticles they can be difficult to detect and their presence is frequently ignored. However, formation of such particulate matter in aqueous CD solutions can lead to erroneous analytical results and product rejections during drug manufacturing. On the other hand, they have also given rise to formation of novel drug delivery systems with exceptional properties.

Key genes involved in utilization of highly abundant HMO in breastmilk are present in B. infantis EVC001 allowing for superior colonization of the breastfed infant gut compared to other commercial probiotic strains

Purpose: Breast milk contains a high concentration of complex glycans known as human milk oligosaccharides (HMO). HMO influence the composition of the intestinal microbiome of breastfed infants by serving as growth substrates to select strains of bifidobacteria. More than 200 individual HMO structures have been identified in breastmilk. However, lacto-N-tetraose (LNT), lacto-N-neotetraose (LNnT), and 2’-Fucosyllactose (2’FL) in FUT2+ mothers, are disproportionally abundant. The biological role for their abundance in the context of bacterial colonization of the infant gut has not been determined. In a previous study, Bifidobacterium …

Quantum chemical and experimental exploration of biological activity and inhibitory potential of new acylated oligosaccharides from Pistacia integerrima J. L. Stewart ex Brandis

The new biologically active integrisides A (1) and B (2) have been isolated from the methanolic extract of Pistacia integerrima J. L. Stewart ex Brandis. The antibacterial activity of both the integrisides were tested against four pathogenic bacterial strains, two Gram-positive (Staphylococcus aureus, Streptococcus pyogenes) and two Gram-negative (Escherichia coli, Pseudomonas aeruginosa) as well as four fungal strains (Microsporum canis, Aspergillus clavatus, Candida albicans and Candida glabrata). Both the isolated compounds showed significant results analogous with Imipenam and Miconazole standard drugs. Carbonic anhydrase-II inhibition of integriside A (1) and B (2) with IC50 value 1.56 µM and 2.85 µM respectively, as compared to standard drug acetazolamide (1.57 µM). Cholinesterase activity was carried out with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) IC50 values of integriside A (1) (8.6, 4.8) and B (2) (0.91, 2.5) were found as compared with standard galanthamine (0.05, 0.92) and Eserine (0.6, 8.7). Here, various molecular descriptors, frontier molecular orbitals (FMO), electron affinity (E.A), ionization potential (IP), molecular electrostatic potential (MEP), and Hirshfeld analysis were carried out to understand the active sites and biological active nature of the integrisides A (1) and B (2). The energy gap, MEP, Hirshfeld analysis, and reactivity descriptors values demonstrate that the integriside A (1) and B (2) retain decent reactivity, which is in good agreement with current experimental and quantum chemical studies.

Bioethanol production from the comparison between optimization of sorghum stalk and sugarcane leaf for sugar production by chemical pretreatment and enzymatic degradation

This work reports the comparison of optimized pretreatment models on total sugar (TS) production from sugarcane leaf (SL) with sorghum stalk (SS) utilization to decompose the lignocellulosic biomass into oligosaccharide (OS). The accumulation variables were examined in the pretreatment model, including pretreatment time (1–3 days), concentrations of sodium hydroxide (NaOH) from 1 to 2% (w/v), and heating temperatures from 30 to 40 °C. TS productions were optimized by using response surface methodology (RSM) on central composite design (CCD) models. These models indicated excellent determination coefficients (R2) ranged from 0.9820 to 0.9900 and are significant. Process optimization showed that the highest TS yield was achieved of 32.612 g/L and 38.977 g/L for NaOH pretreatment at condition (2)% (w/v) NaOH at the temperature of 40 °C for 3 days. After pretreatment, the biomass was degraded using a cellulase enzyme to form the fermentable sugar for ethanol production by Saccharomyces cerevisiae TISTR5020. The maximum bioethanol yield of 8.374 ± 1.813 g/L was achieved at 2 days of fermentation time when compared with bioethanol yield (5.234 ± 0.907 g/L) of 4 days fermentation time.

Multi-step purification method of water-soluble oligosaccharides produced from hardwood and softwood

Abstract Pressurized hot water pretreatment was performed on softwood (SW) and hardwood (HW) chips following the same conditions (1 h at 170 °C) in order to partly hydrolyse hemicelluloses. The complete characterization of these sugar enriched autohydrolysates (AH) being rather complex, two different purification methods were conducted. Nanofiltration (NF) 1kDa membrane and ultrafiltration (UF) 3 and 5kDa membranes were used to separate oligosaccharides (OS) from undesired compounds and for their molar mass fractionation. Granulated activated charcoal (GAC) adsorption was also used for hydrolysates detoxification. The chemical nature of OS and side charge groups vary significantly depending of the fractions obtained, e. g. xylans' chain length is positively correlated with the degree of acetylation. UF at 5kDa allows for the total separation of galactoglucomannans (GGMs) from xylans, in SW AH, however, this result was not achieved with HW. From the acid soluble lignin (ASL) removal point of view, membrane filtration from 1kDa is more efficient than activated carbon treatment concerning HW AH, on the contrary to SW AH. Regarding the lignin to OS ratio, for both species, GAC leads to a better sugar purity.

Pretreatment of Hazelnut Shells as a Key Strategy for the Solubilization and Valorization of Hemicelluloses into Bioactive Compounds

Hazelnut industries generate a large amount of byproducts. Among them, waste hazelnut shells (which account for about 50% of the nut weight), are potential raw materials to produce value added products. Hydrothermal pretreatment enables the solubilization of hemicelluloses, while cellulose and lignin remain in the solid phase almost unaltered, allowing their subsequent processing for an integral valorization of the feedstock. When the reaction was performed at the optimal temperature (210 °C), hemicelluloses were mainly converted into soluble substituted oligosaccharides (OS). Further membrane processing of the liquid phase from hydrothermal pretreatment enabled the refining of the OS, which accounted for up to 90.87 wt% of the nonvolatile solutes (NVC) in the refined solution, which also contained 5 g of natural bound phenolics/100 g NVC. The target products showed a dose-dependent antioxidant activity, conferred by the phenolic components. Substituted OS were made up of xylose backbones with a wide degree of polymerization distribution, and showed structures highly substituted by acetyl and uronic groups. The data included in this study provide the basis for assessing the large-scale manufacture of substituted oligosaccharides with bound phenolics as bioactive components of functional use in foods, cosmetics, or pharmaceuticals.

Total Glycosides of Cistanche deserticola Promote Neurological Function Recovery by Inducing Neurovascular Regeneration via Nrf-2/Keap-1 Pathway in MCAO/R Rats

BackgroundThe traditional Chinese medicine Cistanche deserticola has been reported to be valid for cardiovascular and cerebrovascular diseases. However, its active components for the protection of ischemic stroke are not clear. We aimed to explore the active components of C. deserticola against ischemic stroke as well as its potential mechanisms.MethodsWe investigated the brain protective effects of extracts from C. deserticola, total glycosides (TGs), polysaccharides (PSs), and oligosaccharides (OSs) in a rat model of middle cerebral artery occlusion-reperfusion (MCAO/R). 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining was used to assess the cerebral infarction volume, and Evans blue assay was adopted to assess the blood-brain barrier (BBB) permeability. Then, the expressions CD31, α-SMA, PDGFRβ, SYN, PSD95, MAP-2, ZO-1, claudin-5, occludin, Keap-1, and Nrf-2 were analyzed using western blotting or immunofluorescence, and the activities MDA, SOD, CAT, and GSH-Px were analyzed using kits.ResultsTGs treatment remarkably decreased neurological deficit scores and infarction volumes, promoted angiogenesis and neural remodeling, and effectively maintained blood-brain-barrier integrity compared with the model group. Furthermore, TGs significantly decreased MDA levels and increased antioxidant activities (SOD, CAT, and GSH-Px) in brains. Meanwhile, TGs remarkably downregulated Keap-1 expression and facilitated Nrf-2 nuclear translocation. On the contrary, no protective effects were observed for PSs and OSs groups.ConclusionTGs are the main active components of C. deserticola against MCAO/R-induced cerebral injury, and protection is mainly via the Nrf-2/Keap-1 pathway.

Oligosaccharide concentrations in colostrum, transition milk, and mature milk of primi- and multiparous Holstein cows during the first week of lactation

The objective of this study was to characterize the oligosaccharide (OS) profile of colostrum and transition milk from primiparous (Pp, n = 10) and multiparous (Mp, n = 10) Holstein cows. The experiment was conducted on a commercial dairy farm, where cows were assigned to the study at calving. Colostrum (milking 1) was collected at 5.3 ± 0.7 h after parturition, followed by collection of milkings 2 through 6, milkings 8, 10, 12, and 14 at 0500 and 1600 h each day. Samples were analyzed for OS concentrations using liquid chromatography-mass spectrometry and for IgG and milk components. Concentration of IgG was highest in colostrum and milking 2. Colostral IgG concentration was less in Pp cows than in Mp cows (82.1 ± 3.1 vs. 106.1 ± 16.2 mg/mL). Colostrum and milkings 2 and 3 had 3'-sialyllactose and 6'-sialyllactose concentrations greater than those of mature milk (milkings 8+). For colostrum and milking 2, 6'-sialyllactosamine concentrations were higher than all other milkings, while disialyllactose was only higher in colostrum. In addition, 3'-sialyllactose was the most abundant OS in colostrum and milkings 2 and 3 compared with all other OS. A parity difference was observed for 6'-sialyllactosamine, with Mp having a higher concentration over the first 7 d in milk than Pp (46.4 ± 8.7 vs. 16.9 ± 3.2 μg/mL). Similar results were observed between milkings for OS yields. Parity differences were detected for 3'-sialyllactose, 6'-sialyllactose, and 6'-sialyllactosamine yield, with Mp yield being greater than Pp over the first 7 d in milk. These findings demonstrate that colostrum and transition milk contain elevated concentrations of certain OS compared with mature milk and suggest further research should be conducted regarding the potential benefits of OS in colostrum and transition milk when fed to newborn calves.

Alginate Oligosaccharides Affect Mechanical Properties and Antifungal Activity of Alginate Buccal Films with Posaconazole.

Sodium alginate and its oligosaccharides through potential antifungal properties might improve the activity of antifungal drugs enhancing their efficacy and potentially reducing the frequency of application. Mucoadhesive buccal films are oral dosage forms designed for maintaining both local or systemic drug effects and seem to be a very promising alternative to conventional oral formulations. Hence, in this study, mucoadhesive buccal films based on the alginate and its oligosaccharide oligomer composed predominantly of mannuronic acid for the administration of posaconazole-antifungal drug from the azole group were developed. As the polymer gelation method, a relatively new freeze-thaw technique was chosen. All prepared formulations were examined for pharmaceutical tests, swelling, mechanical, and mucoadhesive properties. In addition, the influence of sodium alginate (ALG) and alginate oligosaccharides (OLG) on POS antifungal activity on Candida species was performed. It was observed that film formulation containing 1% ALG and 1% OLG (F2) was characterized by optimal mucoadhesive and swelling properties and prolonged drug release up to 5 h. Additionally, it was shown that OLG affected the growth reduction of all tested Candida spp. The obtained data has opened the way for future research for developing OLG-based dosage forms, which might increase the activity of antifungal drugs.

NUP62: the target of an anti-sperm auto-monoclonal antibody during testicular development.

Ts4, an autosperm-monoclonal antibody (mAb), reacts with a specific oligosaccharide (OS) of glycoproteins containing bisecting N-acetylglucosamine residues. Ts4 reactivity was observed against epididymal spermatozoa, testicular germ cells, and the early embryo, but not against major organs in adult mice. In mature testis, Ts4 exhibits immunoreactivity with a germ cell-specific glycoprotein, TEX101, whereas the mAb immunoreacts with alpha-N-acetylglucosaminidase in the acrosomal region of cauda epididymal spermatozoa. Thus, Ts4 seems to react against different molecules throughout spermiogenesis via binding to its OS epitope. Since the Ts4-epitope OS is observed only in reproduction-related regions, the Ts4-reactive OS may play a role in the reproductive process. The aim of this study is to investigate the characteristics of the Ts4-reactive molecule(s) during testicular development. Ts4 reactivity was observed in testes from the prenatal period; however, its distribution changed according to the stage of maturation and was identical to that of the adult testes after 29-day-postpartum (dpp). Ts4 immunoreactivity was detected against a protein with 63 kDa in testis from 1 to 29 dpp. In contrast, Ts4 showed reactivity against some other glycoproteins after 29 dpp, including TEX101 at the 5-week-old stage and onward. To identify the Ts4-reactive 63 kDa molecule, we identified NUP62 as the target of Ts4 in 22 dpp testis using liquid chromatography-tandem mass spectrometry analysis. Because NUP62 has been known to play active roles in a variety of cellular processes including mitosis and cell migration, the bisecting GlcNAc recognized by Ts4 on NUP62 may play a role in regulating the early development of germ cells in male gonadal organs.

The Effect of Milk Replacer Composition on the Intestinal Microbiota of Pre-ruminant Dairy Calves.

The impact of dietary composition and prebiotics, in promoting the growth of beneficial groups of gut bacteria, is increasingly apparent. Using Illumina MiSeq sequencing of bacterial 16S rRNA genes, this study has aimed to characterize and compare the establishment of the gastrointestinal microbiota in dairy calves given two different commercial milk replacer (MR) diets. MR1 and MR2 contain different levels of macronutrients such as protein and fat. Moreover, differences in manufacturing methods infer that MR2 may contain a greater proportion of conjugated milk oligosaccharides (OS), while MR1 contains more free milk OS. A total of 10 dairy calves, five in each group, were assigned to one of the two MR diets. Freshly voided fecal samples were taken at 0, 7, 14, 28, and 49 days after first consumption of milk replacer. The relative abundance of two individual Bifidobacterium species, which are known to utilize milk OS, and Faecalibacterium prausnitzii were significantly higher at day 7 in the fecal microbiome of calves fed MR2 compared with MR1. These commensal bacteria are widely regarded as probiotic organisms that confer a health benefit on the host. Our findings suggest that the composition of bovine milk replacers can have significant effects on the establishment of the gut microbiota in pre-weaned (neonatal) dairy calves. Better understanding of milk composition-microbiota-host interactions in early life will inform targeted interventions to increase growth and reduce mortality in young animals.

Preferred conformations of lipooligosaccharides and oligosaccharides of Moraxella catarrhalis.

Moraxella catarrhalis (M. catarrhalis) is a pathogenic gram-negative bacterium that causes otitis media and sinusitis in children. Three major serotypes A, B and C are identified to account for approximately 95% of the clinical isolates. Understanding the conformational properties of different serotypes of M. catarrhalis provides insights into antigenic determinants. In this work, all-atom molecular dynamics simulations were conducted for M. catarrhalis lipooligosaccharide (LOS) bilayer systems and oligosaccharides (OS) in water solution to investigate the conformational similarities and differences of three serotypes. For up to 10 neutral monosaccharides in the core part, the conformational ensembles described by the pair-wise root mean square deviation distributions are similar among the three serotypes of either the LOS or OS. At the central β-($1\to4$)-linkage, anti-$\psi$ conformation in conjunction with the gauche-gauche (g-) conformation of the central trisubstituted glucosyl residue is observed as the dominant conformation to sustain the structural characteristics of M. catarrhalis three types, which is further supported by calculated transglycosidic ${}^3{J}_{C,H}\Big({\psi}_H\Big)$ of serotype A in comparison to experimental data. Interestingly, the conformational variability of three serotypes is more restricted for the OS in water solution than that in the LOS bilayer systems. The LOS-LOS interactions in the bilayer systems are responsible for the increased conformational diversity despite of tight packing. Solvent-accessible surface area analysis suggests that a trisaccharide attached to the β-($1\to 6$)-linked sugar in all three serotypes of LOS could be the common epitope and have the possibility to interact with antibodies.

Oligosaccharides Preparation from Rice Bran Arabinoxylan by Two Different Commercial Endoxylanase Enzymes.

Xylooligosaccharides (XOS) and arabinoxylooligosaccharides (AXOS), potential prebiotics, can be produced from rice bran arabinoxylan (RBAX) using commercial endoxylanase enzymes. However, differences in rice bran cultivars and endoxylanase enzyme types may affect extracted oligosaccharides (OS) yields. This study investigated extracted OS structures derived from three different RBAX using two commercial endoxylanase enzymes. RBAX extracted from commercially defatted rice bran (CDRB) yielded the greatest OS amount (456.69 mg/g RBAX), followed by that of the San-Pah-Tawng1 (SPT1) cultivar (231.7 mg/g RBAX), and lastly, the Chai-Nat1 (CN1) cultivar (172.57 mg/g RBAX), as evidenced via Ultraflo L enzyme hydrolysis. Ultraflo Max enzyme hydrolysis produced a similar trend, however, OS amounts from all RBAX sources were remarkably lower (83.39 mg/g RBAX extracted from CDRB, 27.05 mg/g RBAX from SPT1 cultivar, and 21.53 mg/g RBAX from CN1 cultivar). Interestingly, 32-α-L-Araf-(1-4)-β-D-xylobiose (A3X) was the primary AXOS product in all RBAX hydrolysates prepared by Ultraflo Max. RBAX extracted from CDRB solubilized by Ultraflo L (45.67% weight of RBAX) had higher OS yields than that obtained via Ultraflo Max (8.3% weight of RBAX). Ultraflo L was therefore a suitable commercial enzyme for short-chain OS conversion from RBAX.

Stress Tolerance and Virulence-Related Roles of Lipopolysaccharide in Burkholderia glumae.

The lipopolysaccharide (LPS) composed of lipid A, core, and O-antigen is the fundamental constituent of the outer membrane in gram-negative bacteria. This study was conducted to investigate the roles of LPS in Burkholderia glumae, the phytopathogen causing bacterial panicle blight and seedling rot in rice. To study the roles of the core oligosaccharide (OS) and the O-antigen region, mutant strains targeting the waaC and the wbiFGHI genes were generated. The LPS profile was greatly affected by disruption of the waaC gene and slight reductions were observed in the O-antigen region following wbiFGHI deletions. The results indicated that disruption in the core OS biosynthesis-related gene, waaC, was associated with increased sensitivity to environmental stress conditions including acidic, osmotic, saline, and detergent stress, and to polymyxin B. Moreover, significant impairment in the swimming and swarming motility and attenuation of bacterial virulence to rice were also observed in the waaC-defective mutant. The motility and virulence of O-antigen mutants defective in any gene of the wbiFGHI operon, were not significantly different from the wild-type except in slight decrease in swimming and swarming motility with wbiH deletion. Altogether, the results of present study indicated that the LPS, particularly the core OS region, is required for tolerance to environmental stress and full virulence in B. glumae. To our knowledge, this is the first functional study of LPS in a plant pathogenic Burkholderia sp. and presents a step forward toward full understanding of B. glumae pathogenesis.

Neonatal Consumption of Oligosaccharides Greatly Increases L-Cell Density without Significant Consequence for Adult Eating Behavior.

Oligosaccharides (OS) are commonly added to infant formulas, however, their physiological impact, particularly on adult health programming, is poorly described. In adult animals, OS modify microbiota and stimulate colonic fermentation and enteroendocrine cell (EEC) activity. Since neonatal changes in microbiota and/or EEC density could be long-lasting and EEC-derived peptides do regulate short-term food intake, we hypothesized that neonatal OS consumption could modulate early EECs, with possible consequences for adult eating behavior. Suckling rats were supplemented with fructo-oligosaccharides (FOS), beta-galacto-oligosaccharides/inulin (GOS/In) mix, alpha-galacto-oligosaccharides (αGOS) at 3.2 g/kg, or a control solution (CTL) between postnatal day (PND) 5 and 14/15. Pups were either sacrificed at PND14/15 or weaned at PND21 onto standard chow. The effects on both microbiota and EEC were characterized at PND14/15, and eating behavior at adulthood. Very early OS supplementation drastically impacted the intestinal environment, endocrine lineage proliferation/differentiation particularly in the ileum, and the density of GLP-1 cells and production of satiety-related peptides (GLP-1 and PYY) in the neonatal period. However, it failed to induce any significant lasting changes on intestinal microbiota, enteropeptide secretion or eating behavior later in life. Overall, the results did not demonstrate any OS programming effect on satiety peptides secreted by L-cells or on food consumption, an observation which is a reassuring outlook from a human perspective.

Development and pre-clinical evaluation of a synthetic oligosaccharide-protein conjugate vaccine against Neisseria meningitidis serogroup C

Significant improvement has been made in the development of vaccines against Neisseria meningitidis infections since the introduction of polysaccharide-protein conjugate vaccines. Conventional bacterial capsular polysaccharide (PS) based conjugate vaccines require unique and expensive manufacturing facilities, complex production processes and extensive quality testing. Synthetic oligosaccharide (OS) based approach is one of the novel technologies that is being developed to simplify production of conjugate vaccines. OSs can be chemically synthesized to a desired length long enough to represent the antigenic epitopes which often present as a homogenous mixture. We prepared OSs corresponding to tetramer and octamer of N. meningitidis serogroup C (MenC) PS by organic synthesis. The MenC tetramer and octamer were further conjugated with tetanus toxoid to produce respective monovalent conjugates having the desired physico-chemical characteristics. The conjugates were evaluated in a mouse model for immunogenicity and compared with a licensed PS conjugate vaccine. Synthetic conjugates could induce anti-MenC PS IgG as well as serum bactericidal titers at levels comparable to those elicited by the licensed vaccine. The increase in length of synthetic oligomers from tetramer to octamer did not appear to increase immunogenicity. The results establish the pre-clinical proof of concept for a synthetic MenC oligosaccharide conjugate vaccine candidate.

Naturally Occurring Bioactive Oligosaccharides in Goat’s Milk-Infant Formula (P11-078-19)

ObjectivesHuman milk is rich in oligosaccharides (OS) that impart significant health benefits to the infant. When breast feeding is not possible, infant formula (IF) is used as an alternative. However, little is known about the presence of OS in IF and their potential health effects. This study was aimed at quantifying naturally occurring OS in a commercial goat’s milk IF and examining their prebiotic and anti-infection properties. MethodsOS were isolated from IF using molecular weight cut-off filters and HILIC-LC/MS system. Prebiotic activity of OS was assessed by co-incubating Bifidobacterium (BB12 and BB526) and Lactobacillus (LA4461 and LC2607) strains in growth media with or without OS anaerobically at 37°C for 24 hr and measuring OD600. Anti-adhesion potential of OS was determined by co-incubating E. coli NCTC 10418 and S. typhimurium, pre-incubated with or without OS for 2 hr at 37°C, with Caco-2 cells for 90 min. After PBS washes and cell lysis, supernatants were plated onto agars for measuring bacterial counts and calculating the anti-adhesion %. ResultsFourteen OS were quantified in goat’s milk IF, of which 5 were structurally similar to those reported in human milk. At concentrations similar to those in reconstituted IF, OS fractions were significantly effective in enhancing the growth of bifidobacteria and lactobacilli strains and preventing the adhesion of E. coli NCTC10418 (52.4%) and S. typhimurium (35%) to the Caco-2 cells. ConclusionsGoat’s milk IF contains several naturally occurring human milk-like OS that appear to promote the growth of beneficial gut microbes and protect against gut pathogens. Funding SourcesNo conflicts of interest were involved. Nuchev Pty Ltd. provided goat’s milk IF. Research costs were covered by RMIT University.

A genome-wide association study reveals specific transferases as candidate loci for bovine milk oligosaccharides synthesis

BackgroundHuman milk oligosaccharides (OS) play a key role in brain and gut microbiota development of the neonate, but the underlying biosynthetic steps of OS in the mammary gland are still largely unknown. As bovine milk contains OS with somewhat similar structures and functionalities there is increased interest in further understanding the genetic basis underlying the OS content of milk for eventual extraction and generation of value-added ingredients for infant formulas and nutraceuticals. The present study is the first to report on genetic parameter estimation as well as on a genome wide association study (GWAS) from the largest bovine milk OS dataset analyzed to date.ResultsIn total 15 different bovine milk OS were monitored. Heritabilities ranged from 0 to 0.68 in Danish Holstein and from 0 to 0.92 in Danish Jersey. The GWAS identified in total 1770 SNPs (FDR < 0.10) for five different OS in Danish Holstein and 6913 SNPs (FDR < 0.10) for 11 OS in Danish Jersey. In Danish Holstein, a major overlapping QTL was identified on BTA1 for LNH and LNT explaining 24% of the variation in these OS. The most significant SNPs were associated with B3GNT5, a gene encoding a glycosyltransferase involved in glycan synthesis. In Danish Jersey, a very strong QTL was detected for the OS with composition 2 Hex 1 HexNAc (isomer 1) on BTA11. The most significant SNP had –log10(P-value) of 52.88 (BOVINEHD1100030300) and was assigned to ABO, a gene encoding ABO blood group glycosyltransferases. This SNP has been reported to be a missense mutation and explains 56% of the OS variation. Other candidate genes of interest identified for milk OS were ALG3, B3GALNT2, LOC520336, PIGV, MAN1C1, ST6GALNAC6, GLT6D1, GALNT14, GALNT17, COLGALT2, LFNG and SIGLEC.ConclusionTo our knowledge, this is the first study documenting a solid breeding potential for bovine milk OS and a strong indication of specific candidate genes related to OS synthesis underlying this genetic influence. This new information has the potential to guide breeding strategies to achieve production of milk with higher diversity and concentration of OS and ultimately facilitate large-scale extraction of bovine milk OS.

Structures and Metabolic Properties of Bovine Milk Oligosaccharides and Their Potential in the Development of Novel Therapeutics.

Among the many bioactive components in human milk, the free oligosaccharides (OS) have been intensely studied in recent decades due to their unique ability to selectively modulate the infant gut microbiota, in addition to providing numerous other health benefits. In light of the demonstrated value of these compounds, recent studies have set out to characterize the structures and properties of the similar and more widely-available OS in the dairy industry. This mini review gives a brief overview of the common analytical techniques used to characterize bovine milk OS and highlights several recent, key studies that have identified valuable physiological and metabolic effects of these molecules in vivo. Although traditionally considered indigestible by human enzymes, evidence now suggests that milk OS are partially absorbed in the intestines and likely contribute to the development of molecular structures in the brain. Furthermore, aside from their prebiotic effects, these compounds show promise as therapeutics that could alleviate numerous metabolic abnormalities, including undernutrition, obesity, and excessive intestinal permeability. The need for novel treatments to address these and related health issues is motivating the development of scalable techniques to produce large quantities of milk OS for use as food ingredients. The safety and tolerability of high dosages of bovine milk OS have been demonstrated in two independent human studies, which potentially opens the door for further research aiming to utilize these molecules to alleviate common metabolic health issues.

OLIGOSACCHARIDES IN HUMAN MILK AND IN MILK FORMULAS FOR PRETERM INFANTS – VALUE FOR PRETERM INFANTS

Better long-term survival of very preterm infants depends on optimizing the methods of their nutritional support. Today it is widely recognized that mother’s breast milk is the optimal enteral food for this extremely vulnerable infant population, becausebreast milk feeding reduces their morbidity and mortality. The advantages of breast milkfeeding are related to the biologically active components of breast milk, especially oligosaccharides (OS),concentration of which is only less than amount of lactose and fat. Available experimental and clinical data suggest that the positive clinical effect of the OS can be mostly structure-specific, since the spectrum of human milk oligosaccharides (HMO) is quite wide and includes more than 200 known different compounds. The content of the OS in breast milk is individual and depends on many factors. Despite the emergence of the potential for industrial synthesis of several HMOs, there are currently no results of interventional clinical studies with the use of food products for preterm infants enriched with such OS. Instead, the available data prove positive clinical effects of enrichment of formulas and breast milkwith synthetic OS, which, by their biological properties, mimicHMO. The largest number of such scientific data exists with respect to a special complex of OS, consisting of short-chain galactooligosaccharides (scGOS) and long-chain fructooligosaccharides (lcFOS) in a ratio of 9:1 with the possible addition of galacturonic acid. The article presentscurrent data on functional biology of HMO, clinical effectiveness of the use of synthetic OS in preterm infants, as well as future challenges and opportunities associated with the clinical application of the OS.