Search

Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.

ScopeCost-effective microbial biosynthesis of 2′-fucosyllactose (2′-FL) allows its application in infant formula. The specific effects of 2′-FL on the gastrointestinal immune barrier are still largely unknown.Methods/resultsHere, we quantified and compared the effects of HMOs isolated from human milk, 2′-FL/lactose (Lac), and 2′-FL on the expression of the mucus associated genes MUC2, TFF3, RETLB and the Golgi sulfotransferases, CHST5, and GAL3ST5, in human goblet cells. We also determined whether these compounds have protective effects on A23187-induced barrier disruption of human T84 gut epithelial cells in vitro. The impact of isolated HMOs and 2′-FL/Lac on the mRNA expression of the mucus-related genes was minor while pure 2′-FL significantly induced GAL3ST2 and CHST5. Isolated HMOs, 2′-FL/Lac and 2′-FL all prevented A23187-induced barrier disruption in human T84 cells.ConclusionOur findings indicate that 2′-FL modulates the secretory function of goblet cells and protects gut epithelial cells.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 6'-sialyllactose (6'-SL) sodium salt as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 6'-SL, but it also contains d-lactose, 6'-sialyllactulose, sialic acid, N-acetyl-d-glucosamine and a small fraction of other related oligosaccharides. The NF is produced by fermentation with two genetically modified strains of Escherichia coli BL21 (DE3), the production strain and the optional degradation strain. The information provided on the identity, manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF to a variety of foods, including infant formula and follow-on formula, food for special medical purposes and food supplements. The target population is the general population. In some scenarios at the maximum use levels, the estimated intakes per kg body weight were higher than the high average natural intake of 6'-SL from human milk. However, given the intrinsic nature of human milk oligosaccharides (HMOs), the wide range of intakes from human milk, and considering that infants are naturally exposed to similar amounts of these substances, the Panel considers that the consumption of the NF at the proposed conditions of use does not raise safety concerns. The intake of 6'-SL in breastfed infants on a body weight basis is also expected to be safe for other population groups. The intake of other carbohydrate-type compounds structurally related to 6'-SL is also considered of no safety concern. Food supplements are not intended to be used if other foods with added 6'-SL or human milk are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use. (C) 2022 Wiley-VCH Verlag GmbH & Co. KgaA on behalf of the European Food Safety Authority.

Breastfeeding (BF) is the gold standard in infant nutrition; knowing how it influences brain connectivity would help understand the mechanisms involved, which would help close the nutritional gap between infant formulas and breast milk. We analyzed potential long-term differences depending on the diet with an experimental infant formula (EF), compared to a standard infant formula (SF) or breastfeeding (BF) during the first 18 months of life on children's hypothalamic functional connectivity (FC) assessed at 6 years old. A total of 62 children participating in the COGNIS randomized clinical trial (Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT02094547) were included in this study. They were randomized to receive an SF (n = 22) or a bioactive nutrient-enriched EF (n = 20). BF children were also included as a control study group (BF: n = 20). Brain function was evaluated using functional magnetic resonance imaging (fMRI) and mean glucose levels were collected through a 24-h continuous glucose monitoring (CGM) device at 6 years old. Furthermore, nutrient intake was also analyzed during the first 18 months of life and at 6 years old through 3-day dietary intake records. Groups fed with EF and BF showed lower FC between the medial hypothalamus (MH) and the anterior cingulate cortex (ACC) in comparison with SF-fed children. Moreover, the BF children group showed lower FC between the MH and the left putamen extending to the middle insula, and higher FC between the MH and the inferior frontal gyrus (IFG) compared to the EF-fed children group. These areas are key regions within the salience network, which is involved in processing salience stimuli, eating motivation, and hedonic-driven desire to consume food. Indeed, current higher connectivity found on the MH-IFG network in the BF group was associated with lower simple sugars acceptable macronutrient distribution ranges (AMDRs) at 6 months of age. Regarding linoleic acid intake at 12 months old, a negative association with this network (MH-IFG) only in the BF group was found. In addition, BF children showed lower mean glucose levels compared to SF-fed children at 6 years old. Our results may point out a possible relationship between diet during the first 18 months of life and inclined proclivity for hedonic eating later in life., Randox Laboratories, S.L. Contract University of Granada General Foundation, Spanish Government 3349, Contract University of Granada General Foundation 3349, European Commission CIEN-IDI-20141206, Junta de Andalucia Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades 4003, Fundacion Carolina, Madrid, Spain 633595 404

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 3-fucosyllactose (3-FL) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 3-FL, but it also contains d-lactose, l-fucose, d-glucose and d-galactose, and a small fraction of other related saccharides. The NF is produced by fermentation with a genetically modified strain of Escherichia coli BL21 (DE3). The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF to a variety of foods, including infant formula and follow-on formula, food for infants and young children, food for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of 3-FL from both proposed and combined (authorised and proposed) uses at their respective maximum use levels in all population categories does not exceed the highest intake level of 3-FL from human milk in infants on a body weight basis. The intake of 3-FL in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to 3-FL is also considered of no safety concern. Food supplements are not intended to be used if other foods with added 3-FL or human milk are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on lacto-N-tetraose (LNT) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a powdered mixture mainly composed of the human-identical milk oligosaccharide (HiMO) LNT, but it also contains d-lactose, lacto-N-triose II and para-lacto-N-hexaose, and a small fraction of other related saccharides. The NF is produced by fermentation with two genetically modified strains of Escherichia coli BL21 (DE3), the production strain and the optional degradation strain. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF to a variety of foods, including infant and follow-on formula, food for infants and young children, food for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of LNT from the NF at the maximum proposed use levels does not exceed the intake level of naturally occurring LNT in breastfed infants on a body weight basis. The intake of LNT in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to LNT is also considered of no safety concern. Food supplements are not intended to be used if other foods with added LNT or human milk are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use.

Human milk (HM) is the gold standard for the nutrition of infants. An important component of HM is human milk oligosaccharides (hMOs), which play an important role in gut microbiota colonization and gut immune barrier establishment, and thereby contribute to the maturation of the immune system in early life. Guiding these processes is important as disturbances have life-long health effects and can lead to the development of allergic diseases. Unfortunately, not all infants can be exclusively fed with HM. These infants are routinely fed with infant formulas that contain hMO analogs and other non-digestible carbohydrates (NDCs) to mimic the effects of hMOs. Currently, the hMO analogs 2'-fucosyllactose (2'-FL), galacto-oligosaccharides (GOS), fructo-oligosaccharides (FOS), and pectins are added to infant formulas; however, these NDCs cannot mimic all hMO functions and therefore new NDCs and NDC mixtures need to become available for specific groups of neonates like preterm and disease-prone neonates. In this review, we discuss human data on the beneficial effects of infant formula supplements such as the specific hMO analog 2'-FL and NDCs as well as their mechanism of effects like stimulation of microbiota development, maturation of different parts of the gut immune barrier and anti-pathogenic effects. Insights into the structure-specific mechanisms by which hMOs and NDCs exert their beneficial functions might contribute to the development of new tailored NDCs and NDC mixtures. We also describe the needs for new in vitro systems that can be used for research on hMOs and NDCs. The current data suggest that "tailored infant formulas" for infants of different ages and healthy statuses are needed to ensure a healthy development of the microbiota and the gut immune system of infants.

Galacto-oligosaccharides (GOS) are used in infant formula to replace the health effects of human milk oligosaccharides, which appear to be dependent upon the structure of the individual oligosaccharides present. However, a comprehensive overview of the structure-specific effects is still limited as a result of the high structural complexity of GOS. In this study, porous graphitic carbon (PGC) was used as the stationary phase during ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS). This approach resulted in the recognition of more than 100 different GOS structures in one single run, including reducing and non-reducing GOS isomers. Using nuclear magnetic resonance-validated structures of GOS trisaccharides, we discovered MS fragmentation rules to distinguish reducing isomers with a mono- and disubstituted terminal glucose by UHPLC-PGC-MS. UHPLC-PGC-MS enabled effective recognition of structural features of individual GOS components in complex GOS preparations and during, e.g., biological conversion reactions. Hence, this study lays the groundwork for future research into structure-specific health effects of GOS.

Resumen del póster presentado al International Scientific Association for Probiotics and Prebiotics Annual Meeting (ISAPP), celebrado en Sitges. Barcelona (España) del 15 al 17 de junio de 2022., Carbohydrates entering the complex microbial ecosystem resident in the human gut can be fermented to different degrees by the bacterial species present. Whilst insoluble carbohydrates may be fermented to a low degree, they may still be classed dietary fibres. More extensively fermented carbohydrates frequently display a selectivity towards particular microbial groups; if the end result of this process is an improvement in host health, then we would consider those carbohydrates to be prebiotics. It is a complex task to identify the structural basis of the fermentation selectivity underlying a prebiotic effect. Individuals vary in terms of the diversity of their gut microbiome and in the response of this microbiome to any given carbohydrate. The task is further complicated by the use of varying microbiology techniques across studies. Some generic understanding can be identified: It is clear that low molecular weight carbohydrates of a wide range of structure are very readily metabolised by bifidobacteria and are frequently seen to select for this genus in in vitro studies.. This selectivity is explained by the widespread presence of exo-glycosidase and sugar transport system genes in bifidobacterial genomes. Metabolism of higher molecular weight carbohydrates is dependant of organisms possessing the relevant polysaccharide utilisation genes like the bacteroides, rendering them highly adept at polysaccharide metabolism. To understand the fate of any given carbohydrate in the gut microbiome, however, the presence of cross-feeding networks must be taken into account. We know of some such cross feeding networks likely to operate in the gut but there is much to learn. ILSI Europe has commissioned an expert group to produce an authoritative view of the state of the art in terms of our understanding of structure function relationships in fermented carbohydrates. This presentation will highlight our current understanding of structure function relationships and point to the gaps in knowledge and the questions that arise in this area.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 2 '-fucosyllactose (2'-FL) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 2'-FL, but it also contains D-lactose, L-fucose, 3-fucosyllactose, difucosyllactose, D-glucose and D-galactose. The NF is produced by fermentation with a genetically modified strain (APC199) of Corynebacterium glutamicum ATCC 13032. 2'-FL, when chemically synthesised or produced by fermentation with derivative strains of Escherichia coli K-12 DH1 or E. coli BL21 (DE3), is already authorised and included in the EU list of NFs. This application refers to a change in the production process and specifications, while target population, conditions of use and consequently, the anticipated intake remain unchanged. The information provided on the identity, production process, composition and specifications of the NF does not raise safety concerns. The intake of other carbohydrate-type compounds structurally related to 2'-FL is also considered of no safety concern. In line with other milk oligosaccharides that are natural components of human milk, the safety assessment of this NF is mainly based on the comparison between the intake of breastfed infants and the estimated intake as NF. Given that the NF would be consumed at the same extent as the already authorised 2'-FL, the Panel considers that the consumption of the NF at the proposed uses and use levels does not raise safety concerns. The Panel concludes that the NF is safe under the proposed conditions of use.(c) 2022 Wiley-VCH Verlag GmbH & Co. KgaA on behalf of the European Food Safety Authority.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 3'-sialyllactose (3'-SL) sodium salt as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 3'-SL, but it also contains d-lactose, 3'-sialyllactulose, sialic acid, N-acetyl-d-glucosamine and a small fraction of other related oligosaccharides. The NF is produced by fermentation with two genetically modified strains of Escherichia coli BL21 (DE3), the production strain and the optional degradation strain. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF to a variety of foods, including infant formula and follow-on formula, food for infants and young children, food for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of 3'-SL from both proposed and combined (authorised and proposed) uses at their respective maximum use levels in all population categories does not exceed the highest intake level of 3'-SL from human milk in infants on a body weight basis. The intake of 3'-SL in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to 3'-SL is also considered of no safety concern. Food supplements are not intended to be used if other foods with added 3'-SL or human milk are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use.

Background Human-milk oligosaccharides (HMOs) are an abundant component of human milk that have health-related effects on breastfeeding infants. Since variation in HMO composition can be explained by maternal and environmental factors, understanding the diversity in HMOs across settings and identifying context-specific factors associated with HMO abundances is important. Objectives The aim was to describe the HMO profile of Bangladeshi women and to estimate the effect of maternal vitamin D supplementation on HMO composition. Methods In a cross-sectional analysis of data and samples from the Maternal Vitamin D for Infant Growth trial in Dhaka, Bangladesh (clinicaltrials.gov; NCT01924013), 192 participants were randomly selected including 96 from each of the placebo and highest-dose vitamin D supplementation groups. In mid-feed breast milk samples collected at a mean (±SD) postpartum age of 93 ± 7 d, absolute and relative abundances of 19 HMOs were analyzed by HPLC. “Secretors” were defined as participants with 2′fucosyllactose concentrations >350 nmol/mL. Associations between HMO concentrations and selected maternal or environmental factors were estimated by multivariable linear regression, adjusting for vitamin D group allocation and secretor status. HMO profiles of Bangladeshi women were compared with data from other international cohorts. Results Overall, 34% (65/192) of participants were nonsecretors. Secretor status was associated with the concentrations of total HMOs and 79% (15/19) of individual HMOs. Vitamin D supplementation did not affect the total or individual concentration of any measured HMO. 3-Fucosyllactose concentration was significantly higher in breast milk samples collected in December to February compared with samples collected in March to May. HMO composition was similar to other previously reported cohorts. Conclusions The HMO profile of Bangladeshi women is predominantly determined by secretor status. Context-specific HMO data may improve understanding of the effects of HMOs on the infant microbiome and health and guide the development of HMO-containing interventions., Human-milk oligosaccharide (HMO) profiles of Bangladeshi women are similar to those described in other countries. Vitamin D supplementation did not affect the Bangladeshi HMO profile.

The colonisation and development of the gut microbiota has been implicated in paediatric metabolic disorders via its powerful effect on host metabolic and immune homeostasis. Here we summarise the evidence from human studies on the early gut microbiota and paediatric overweight and obesity. Manipulation of the early gut microbiota may represent a promising target for countering the burgeoning metabolic disorders in the paediatric population, provided the assembly patterns of microbiota and their health consequences can be decoded. Therefore, in this review, we pay particular attention to the important ecological drivers affecting the community dynamics of the early gut microbiota. We then discuss the knowledge gaps in commonly studied exposures linking the gut microbiota to metabolic disorders, especially regarding maternal factors and antibiotic use. This review also attempts to give directions for future studies aiming to identify predictive and corrective measures for paediatric metabolic disorders based on the gut microbiota.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 3-fucosyllactose (3-FL) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 3-FL but also contains D-lactose and its monomers, L-fucose and a small fraction of other related saccharides. The NF is produced by fermentation with a genetically modified strain of Escherichia coli K-12. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and toddlers, foods for special medical purposes and food supplements. The target population is the general population, except for food supplements for which the target population is individuals above 1 year of age. The anticipated daily intake of 3-FL from the NF at the maximum proposed use levels is unlikely to exceed the intake level of breastfed infants on a body weight basis. The intake of 3-FL in breastfed infants on a body weight basis is expected to be safe also for other population groups. In infants below 1 year of age, a possible exceedance of a natural intake was observed, but the degree of this exceedance is not considered of safety concern in view of the wide range of 3-FL concentrations in human milk. Food supplements are not intended to be used if other foods with the added NF (as well as human milk for young children) are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use. (C) 2021 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Lactobacillus reuteri DSM 17938 supplementation reduces morbidities in very low birth weight infants (

Lactobacillus reuteri DSM 17938 supplementation reduces morbidities in very low birth weight infants (&lt, 1500 g), while the effect on extremely low birth weight infants (ELBW, &lt, 1000 g) is still questioned. In a randomised placebo-controlled trial (ClinicalTrials.gov ID NCT01603368), head growth, but not feeding tolerance or morbidities, improved in L. reuteri-supplemented preterm ELBW infants. Here, we investigate colonisation with the probiotic strain in preterm ELBW infants who received L. reuteri DSM 17938 or a placebo from birth to postmenstrual week (PMW) 36. Quantitative PCR was used on 582 faecal DNA samples collected from 132 ELBW infants at one, two, three, and four weeks, at PMW 36, and at two years of age. Human milk oligosaccharides were measured in 31 milk samples at two weeks postpartum. At least 86% of the ELBW infants in the L. reuteri group were colonised with the probiotic strain during the neonatal period, despite low gestational age, high antibiotic pressure, and independent of infant feeding mode. Higher concentrations of lacto-N-tetraose, sialyl-lacto-N-neotetraose c, and 6′-sialyllactose in mother’s milk weakly correlated with lower L. reuteri abundance. Within the L. reuteri group, higher L. reuteri abundance weakly correlated with a shorter time to reach full enteral feeding. Female sex and L. reuteri colonisation improved head growth from birth to four weeks of age. In conclusion, L. reuteri DSM 17938 supplementation leads to successful colonisation in ELBW infants.

Galacto-oligosaccharides (GOS) and 2 '-fucosyllactose (2 '-FL) are non-digestible carbohydrates (NDCs) that are often added to infant formula to replace the functionalities of human milk oligosaccharides (HMOs). It is not known if combining GOS and 2 '-FL will affect their fermentation kinetics and subsequent immune-modulatory effects such as AhR-receptor stimulation. Here, we used an in vitro set-up for the fermentation of 2 '-FL and GOS, either individually or combined, by fecal microbiota of 8-week-old infants. We found that GOS was fermented two times faster by the infant fecal microbiota when combined with 2 '-FL, while the combination of GOS and 2 '-FL did not result in a complete degradation of 2 '-FL. Fermentation of both GOS and 2 '-FL increased the relative abundance of Bifidobacterium, which coincided with the production of acetate and lactate. Digesta of the fermentations influenced dendritic cell cytokine secretion differently under normal conditions and in the presence of the AhR-receptor blocker CH223191. We show that, combining GOS and 2 '-FL accelerates GOS fermentation by the infant fecal microbiota of 8-week-old infants. In addition, we show that the fermentation digesta of GOS and 2 '-FL, either fermented individually or combined, can attenuate DC cytokine responses in a similar and in an AhR-receptor dependent way.

Human milk contains a dynamic and complex site-specific microbiome, which is not assembled in an aleatory way, formed by organized microbial consortia and networks. Presence of some genera, such as Staphylococcus, Streptococcus, Corynebacterium, Cutibacterium (formerly known as Propionibacterium), Lactobacillus, Lactococcus and Bifidobacterium, has been detected by both culture-dependent and culture-independent approaches. DNA from some gut-associated strict anaerobes has also been repeatedly found and some studies have revealed the presence of cells and/or nucleic acids from viruses, archaea, fungi and protozoa in human milk. Colostrum and milk microbes are transmitted to the infant and, therefore, they are among the first colonizers of the human gut. Still, the significance of human milk microbes in infant gut colonization remains an open question. Clinical studies trying to elucidate the question are confounded by the profound impact of non-microbial human milk components to intestinal microecology. Modifications in the microbiota of human milk may have biological consequences for infant colonization, metabolism, immune and neuroendocrine development, and for mammary health. However, the factors driving differences in the composition of the human milk microbiome remain poorly known. In addition to colostrum and milk, breast tissue in lactating and non-lactating women may also contain a microbiota, with implications in the pathogenesis of breast cancer and in some of the adverse outcomes associated with breast implants. This and other open issues, such as the origin of the human milk microbiome, and the current limitations and future prospects are addressed in this review.

Human milk (HM) is the gold standard for the nutrition of infants. An important component of HM is human milk oligosaccharides (hMOs), which play an important role in gut microbiota colonization and gut immune barrier establishment, and thereby contribute to the maturation of the immune system in early life. Guiding these processes is important as disturbances have life-long health effects and can lead to the development of allergic diseases. Unfortunately, not all infants can be exclusively fed with HM. These infants are routinely fed with infant formulas that contain hMO analogs and other non-digestible carbohydrates (NDCs) to mimic the effects of hMOs. Currently, the hMO analogs 2'-fucosyllactose (2'-FL), galacto-oligosaccharides (GOS), fructo-oligosaccharides (FOS), and pectins are added to infant formulas; however, these NDCs cannot mimic all hMO functions and therefore new NDCs and NDC mixtures need to become available for specific groups of neonates like preterm and disease-prone neonates. In this review, we discuss human data on the beneficial effects of infant formula supplements such as the specific hMO analog 2'-FL and NDCs as well as their mechanism of effects like stimulation of microbiota development, maturation of different parts of the gut immune barrier and anti-pathogenic effects. Insights into the structure-specific mechanisms by which hMOs and NDCs exert their beneficial functions might contribute to the development of new tailored NDCs and NDC mixtures. We also describe the needs for new in vitro systems that can be used for research on hMOs and NDCs. The current data suggest that "tailored infant formulas" for infants of different ages and healthy statuses are needed to ensure a healthy development of the microbiota and the gut immune system of infants.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 3'-Sialyllactose (3'-SL) sodium salt as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human identical milk oligosaccharide (HiMO) 3'-SL but also containing D-lactose, sialic acid and a small fraction of other related oligosaccharides resulting in a fully characterised mixture of carbohydrates. The NF is produced by fermentation with a genetically modified strain of Escherichia coif K-12 DH1. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and toddlers, foods for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of 3'-SL from the NF at the maximum proposed use levels is unlikely to exceed the intake level of naturally occurring 3'-SL in breastfed infants on a body weight basis. The intake of 3'-SL in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to 3'-SL is also considered of no safety concern. Food supplements are not intended to be used if other foods with added NF (as well as breast milk, milk, fermented milk-based products and selected cheeses retaining milk sugar (e.g. curd cheese) for infants and young children) are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use for the proposed target populations. (C) 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 6'-Sialyllactose (6'-SL) sodium salt as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) 6'-SL but also contains D-lactose, sialic acid and a small fraction of other related oligosaccharides. The NF is produced by fermentation with a genetically modified strain of Escherichia coil K-12 DH1. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and toddlers, foods for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of 6'-SL from the NF at the maximum proposed use levels is unlikely to exceed the intake level of naturally occurring 6'-SL in breastfed infants on a body weight basis. The intake of 6'-SL in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to 6'-SL is also considered of no safety concern. Food supplements are not intended to be used if other foods with the added NF or breast milk are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use. (C) 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority. Non

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 3'-Sialyllactose (3'-SL) sodium salt as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human identical milk oligosaccharide (HiMO) 3'-SL but also containing D-lactose, sialic acid and a small fraction of other related oligosaccharides resulting in a fully characterised mixture of carbohydrates. The NF is produced by fermentation with a genetically modified strain of Escherichia coif K-12 DH1. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and toddlers, foods for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of 3'-SL from the NF at the maximum proposed use levels is unlikely to exceed the intake level of naturally occurring 3'-SL in breastfed infants on a body weight basis. The intake of 3'-SL in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to 3'-SL is also considered of no safety concern. Food supplements are not intended to be used if other foods with added NF (as well as breast milk, milk, fermented milk-based products and selected cheeses retaining milk sugar (e.g. curd cheese) for infants and young children) are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use for the proposed target populations. (C) 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the change in the production process and specifications of lacto-N-neotetraose (LNnT) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is mainly composed of the human-identical milk oligosaccharide (HiMO) LNnT but also contains lactose, lacto-N-triose II (LNT II), para-lacto-N-neo-hexaose (para-LNnH) and other related carbohydrates. The NF is produced by fermentation with two genetically modified strains of Escherichia coli BL21. LNnT when chemically synthesised or produced by microbial fermentation using another E. coli strain (K-12) is already authorised and included in the EU list of NFs. This application is limited to a change in the manufacturing process and specifications while target population, uses and use levels and consequently the anticipated intake do not change. The information provided on the manufacturing process, including the absence of DNA from the producing microorganisms, composition, identity and specifications of the NF do not raise safety concerns. Particularly, the proposed changes in the specifications are limited to a slightly higher ash content and limits for the presence of yeast and moulds, while specifications for methanol and LNnT fructose isomer have been removed. Food supplements are not intended to be used if other foods with the added NF or breast milk for young children are consumed on the same day. The Panel concludes that lacto-N-neotetraose (LNnT) as a NF when produced by fermentation with two genetically modified strains of E. coli BL21 is safe under the proposed conditions of use. (C) 2020 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on lacto-N-tetraose (LNT) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a powdered mixture mainly composed by LNT, but also containing D-lactose and other oligosaccharides such as para-lacto-N-hexaose-2 (para-LNH-2), lacto-N-triose II and a small fraction of other carbohydrates. It is produced by fermentation with a genetically modified strain of Escherichia coli K-12. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and toddlers, foods for special medical purposes and food supplements. The target population is the general population except for food supplements, for which the target population is individuals above 1 year of age. The intake of LNT from the NF at the proposed use levels is unlikely to exceed the intake level of naturally occurring LNT in breastfed infants on a body weight basis. The intake of other carbohydrate-type compounds structurally related to LNT is considered of no safety concern. The Panel concludes that the NF is safe under the proposed conditions of use for the proposed target populations. (c) 2019 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 2'-fucosyllactose/difucosyllactose (2'-FL/DFL) mixture as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a powdered mixture mainly composed of two oligosaccharides, 2'-FL and DFL, which are produced together by fermentation with a genetically modified strain of Escherichia coli K12. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and young children, foods for special medical purposes and food supplements. The target population is the general population except for food supplements, for which the target population is individuals above 1 year of age. Since the intake of 2'-FL and DFL from the NF at the proposed use levels is unlikely to exceed the intake level of naturally occurring 2'-FL and DFL in breastfed infants per kilogram body weight, the Panel concludes that the NF, a mixture of 2'-FL and DFL, is safe under the proposed conditions of use for the proposed target population. (C) 2019 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on 2'-fucosyllactose/difucosyllactose (2'-FL/DFL) mixture as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a powdered mixture mainly composed of two oligosaccharides, 2'-FL and DFL, which are produced together by fermentation with a genetically modified strain of Escherichia coli K12. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and young children, foods for special medical purposes and food supplements. The target population is the general population except for food supplements, for which the target population is individuals above 1 year of age. Since the intake of 2'-FL and DFL from the NF at the proposed use levels is unlikely to exceed the intake level of naturally occurring 2'-FL and DFL in breastfed infants per kilogram body weight, the Panel concludes that the NF, a mixture of 2'-FL and DFL, is safe under the proposed conditions of use for the proposed target population. (C) 2019 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Recent works provide evidence of the prebiotic potential of arabinoxylan-derived oligosaccharides (A)XOS. In this study, we developed a structural analysis for cereal-derived (A)XOS by negative ionization HILIC-MS/MS. Initially, we assessed twelve (A)XOS samples of known structures with different linkage positions and branching points by direct-infusion negative ESI-MSn. We subsequently developed the negative ion HILIC-MS/MS with a post-column addition of ammonium chloride. The selected (A)XOS represented both linear (arabinofuranosyl residue linked to the non-reducing end of xylooligosaccharide) and branched structures. Each (A)XOS sample produced a specific spectrum in negative ion ESI-MSn. By analyzing cross-ring fragment ions, we determined the linkage positions of linear (A)XOS. The presence or absence of diagnostic ions in the MS3 allowed us to detect different branches (O-2- or/and O-3-linked arabinofuranosyl with/or without O-4-linked xylopyranosyl at the non-reducing end). Furthermore, we could identify all analyzed samples by HILIC-MS/MS, based on the formed spectral library and chromatographic retention times.

Natural polysaccharides with health benefits are characterized by a large structural diversity and differ in building blocks, linkages, and lengths. They contribute to human health by functioning as anti-adhesives preventing pathogen adhesion, stimulate immune maturation and gut barrier function, and serve as fermentable substrates for gut bacteria. Examples of such beneficial carbohydrates include the human milk oligosaccharides (HMOs). Also, specific non-digestible carbohydrates (NDCs), such as galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS) are being produced with this purpose in mind, and are currently added to infant formula to stimulate the healthy development of the newborn. They mimic some functions of HMO, but not all. Therefore, many research efforts focus on identification and production of novel types of NDCs. In this review, we give an overview of the few NDCs currently available [GOS, FOS, polydextrose (PDX)], and outline the potential of alternative oligosaccharides, such as pectins, (arabino) xylo-oligosaccharides, and microbial exopolysaccharides (EPS). Moreover, state-of-the-art techniques to generate novel types of dietary glycans, including sialylated GOS (Sia-GOS) and galactosylated chitin, are presented as a way to obtain novel prebiotic NDCs that help shaping the infant microbiome.

Natural polysaccharides with health benefits are characterized by a large structural diversity and differ in building blocks, linkages, and lengths. They contribute to human health by functioning as anti-adhesives preventing pathogen adhesion, stimulate immune maturation and gut barrier function, and serve as fermentable substrates for gut bacteria. Examples of such beneficial carbohydrates include the human milk oligosaccharides (HMOs). Also, specific non-digestible carbohydrates (NDCs), such as galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS) are being produced with this purpose in mind, and are currently added to infant formula to stimulate the healthy development of the newborn. They mimic some functions of HMO, but not all. Therefore, many research efforts focus on identification and production of novel types of NDCs. In this review, we give an overview of the few NDCs currently available [GOS, FOS, polydextrose (PDX)], and outline the potential of alternative oligosaccharides, such as pectins, (arabino) xylo-oligosaccharides, and microbial exopolysaccharides (EPS). Moreover, state-of-the-art techniques to generate novel types of dietary glycans, including sialylated GOS (Sia-GOS) and galactosylated chitin, are presented as a way to obtain novel prebiotic NDCs that help shaping the infant microbiome.

Contains fulltext : 201327.pdf (Publisher’s version ) (Open Access) Gastrointestinal (GI) microbiota composition differs between breastfed and formula-fed infants. Today's infant formulas are often fortified with prebiotics to better mimic properties of human milk with respect to its effect on GI microbiota composition and function. We used Illumina HiSeq sequencing of PCR-amplified 16S rRNA gene fragments to investigate the composition of faecal microbiota in 2-12 week old infants receiving either breastmilk, infant formulas fortified with prebiotics, or mixed feeding. We compared these results with results from infants fed traditional formulas used in the Netherlands in 2002-2003, which contained no added prebiotics. We showed that today's formulas supplemented with either scGOS (0.24-0.50 g/100 ml) or scGOS and lcFOS (at a 9:1 ratio; total 0.6 g/100 ml) had a strong bifidogenic effect as compared to traditional formulas, and they also resulted in altered patterns of microbial colonisation within the developing infant gastrointestinal tract. We identified three microbial states (or developmental stages) in the first 12 weeks of life, with a gradual transition pattern towards a bifidobacteria dominated state. In infants receiving only fortified formulas, this transition towards the bifidobacteria dominated state was accelerated, whereas in infants receiving mixed feeding the transition was delayed, as compared to exclusively breastfed infants. 13 p.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on lacto-N-tetraose (LNT) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a powdered mixture mainly composed by LNT, but also containing D-lactose and other oligosaccharides such as para-lacto-N-hexaose-2 (para-LNH-2), lacto-N-triose II and a small fraction of other carbohydrates. It is produced by fermentation with a genetically modified strain of Escherichia coli K-12. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF in a variety of foods, including infant and follow-on formula, foods for infants and toddlers, foods for special medical purposes and food supplements. The target population is the general population except for food supplements, for which the target population is individuals above 1 year of age. The intake of LNT from the NF at the proposed use levels is unlikely to exceed the intake level of naturally occurring LNT in breastfed infants on a body weight basis. The intake of other carbohydrate-type compounds structurally related to LNT is considered of no safety concern. The Panel concludes that the NF is safe under the proposed conditions of use for the proposed target populations. (c) 2019 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Necrotising enterocolitis (NEC) is one of the most frequent and fatal intestinal disorders in preterm infants and has very limited treatment options. Breast-fed infants are at a 6–10-fold lower NEC risk than formula-fed infants, and we have previously shown that human milk oligosaccharides (HMO) improved survival and reduced pathology in a rat NEC model. The HMO disialyllacto-N-tetraose (DSLNT) was most effective, and sialylation was shown to be essential for its protective effect. Galacto-oligosaccharides (GOS), currently added to some infant formula, but not containing sialic acid, had no effect. In addition to DSLNT, our previous work also showed that the neutral HMO fraction, which contains high concentrations of 2′-fucosyllactose (2′FL), slightly improved pathology scores. Here, we assessed the in vivo efficacy of 2′FL, as well as of GOS that we enzymatically sialylated (Sia-GOS). Neonatal rats were randomised into the following study groups – dam-fed (DF), formula-fed (FF), FF containing pooled HMO (10 mg/ml), GOS (8 mg/ml), Sia-GOS (500 µm) or 2′FL (2 mg/ml) – and subjected to the established NEC protocol. The DF and HMO groups had the lowest pathology scores with mean values of 0·67 (sd 0·34) and 0·90 (sd 0·47), respectively. The FF group had significantly elevated pathology scores of 2·02 (sd 0·63). Although the addition of GOS to the formula had no protective effect and generated scores of 2·00 (sd 0·63), the addition of Sia-GOS or 2′FL significantly lowered pathology scores to 1·32 (sd 0·56) (Psd 0·51) (P

The establishment of the infant gut microbiota is a highly dynamic process dependent on extrinsic and intrinsic factors. We characterized the faecal microbiota of 4 breastfed infants and 4 formula-fed infants at 17 consecutive time points during the first 12 weeks of life. Microbiota composition was analysed by a combination of 16S rRNA gene sequencing and quantitative PCR (qPCR). In this dataset, individuality was a major driver of microbiota composition (P = 0.002) and was more pronounced in breastfed infants. A developmental signature could be distinguished, characterized by sequential colonisation of i) intrauterine/vaginal birth associated taxa, ii) skin derived taxa and other typical early colonisers such as Streptococcus and Enterobacteriaceae, iii) domination of Bifidobacteriaceae, and iv) the appearance of adultlike taxa, particularly species associated with Blautia, Eggerthella, and the potential pathobiont Clostridium difficile. Low abundance of potential pathogens was detected by 16S profiling and confirmed by qPCR. Incidence and dominance of skin and breast milk associated microbes were increased in the gut microbiome of breastfed infants compared to formula-fed infants. The approaches in this study indicate that microbiota development of breastfed and formula-fed infants proceeds according to similar developmental stages with microbiota signatures that include stage-specific species.

In the first years after birth, the intestinal microbiota develops rapidly both in diversity and complexity while being relatively stable in healthy adults. Different life-style-related factors as well as medical practices have an influence on the early-life intestinal colonisation. We address the impact of some of these factors on the consecutive microbiota development and later health. An overview is presented of the microbial colonisation steps and the role of the host in that process. Moreover, new early biomarkers are discussed with examples that include the association of microbiota and atopic diseases, the correlation of colic and early development and the impact of the use of antibiotics in early life. Our understanding of the development and function of the intestinal microbiota is constantly improving but the long-term influence of early-life microbiota on later life health deserves careful clinical studies.

Human milk oligosaccharides are abundant in breast milk and are associated with various beneficial effects. In this study, a validated in vitro gut model was used to evaluate the prebiotic potential of 2′-fucosyllactose (2′-FL) on the activity and composition of microbiota from three 6-month-old formula-fed infants after weaning. 2′-FL was fermented along the entire length of the colon. In the distal colon, a specific decrease in lactate was observed accompanied with increased butyrate concentrations. 16S rRNA gene amplicon sequencing indicated shifts in the microbial composition at luminal and mucosal level, depending on donor and colon location. 2′-FL increased the relative abundance of Bifidobacterium adolescentis and of butyrate-producing bacteria, the latter only in the mucus. These data support the addition of 2′-FL to follow-on infant formulas and show that additional studies are needed to fully elucidate the mechanisms of action by which 2′-FL modulates the gut microbiota in older formula-fed infants.

Milk oligosaccharides have many associated bioactivities which can contribute to human health and offer protective properties to the host. Such bioactivities include anti-infective properties whereby oligosaccharides interact with bacterial cells and prevent adhesion to the host and subsequent colonization. Milk oligosaccharides have also been shown to alter the glycosylation of intestinal cells, leading to a reduction in pathogenic colonization. In addition, these sugars promote adhesion of commensal bacterial strains to host cells as well as possessing the ability to alter mucin expression in intestinal cells and improve barrier function. The ability of milk oligosaccharides to alter the transcriptome of both commensal bacterial strains and intestinal epithelial cells has also been revealed, indicating the potential of many cell types to detect the presence of milk oligosaccharides and respond accordingly at the genetic level. Interestingly, domestic animal milk may provide a bioactive source of oligosaccharides for formula supplementation with the aim of emulating the gold standard that is human milk. Overall, this review highlights the ability of milk oligosaccharides to promote health in a variety of ways, for example, through direct bacterial interactions, immunomodulatory activities, promotion of gut barrier function, and induction of protective transcriptional responses.

Adding prebiotics or probiotics to infant formula to improve the intestinal flora of formula-fed infants is considered to be a major innovation. Several companies have brought relevant formulations onto the market. However, comparative data on the effects of pre- and probiotics on the intestinal microflora of infants are not available. The present study aimed to compare the effects of infant formula containing a mixture of galacto- and fructo-oligosaccharides or viableBifidobacterium animalison the composition and metabolic activity of the intestinal microflora. Before birth, infants were randomised and double blindly allocated to one of three formulas. The prebiotic (GOS/FOS) group (n19) received regular infant formula supplemented with a mixture of galacto-oligosaccharides and fructo-oligosaccharides (6g/l). The probiotic (Bb-12) group (n19) received the same formula supplemented with 6·0×1010viable cells ofB. animalisper litre. The standard group (n19) received non-supplemented regular formula. A group of sixty-three breast-fed infants was included as a reference group. Faecal samples were taken at postnatal day 5 and 10, and week 4, 8, 12 and 16. Compared with the groups fed Bb-12 and standard formula, the GOS/FOS formula group showed higher faecal acetate ratio (69·7% (sem 2·7), 69·9% (sem 3·9) and 82·2% (sem 5·3);PP

BACKGROUND: Bifidobacteria constitute a specific group of commensal bacteria that commonly inhabit the mammalian gastrointestinal tract. Bifidobacterium breve UCC2003 was previously shown to utilize a variety of plant/diet/host-derived carbohydrates, including cellodextrin, starch and galactan, as well as the mucin and HMO-derived monosaccharide, sialic acid. In the current study, we investigated the ability of this strain to utilize parts of a host-derived source of carbohydrate, namely the mucin glycoprotein, when grown in co-culture with the mucin-degrading Bifidobacterium bifidum PRL2010. RESULTS: B. breve UCC2003 was shown to exhibit growth properties in a mucin-based medium, but only when grown in the presence of B. bifidum PRL2010, which is known to metabolize mucin. A combination of HPAEC-PAD and transcriptome analyses identified some of the possible monosaccharides and oligosaccharides which support this enhanced co-cultivation growth/viability phenotype. CONCLUSION: This study describes the potential existence of a gut commensal relationship between two bifidobacterial species. We demonstrate the in vitro ability of B. breve UCC2003 to cross-feed on sugars released by the mucin-degrading activity of B. bifidum PRL2010, thus advancing our knowledge on the metabolic adaptability which allows the former strain to colonize the (infant) gut by its extensive metabolic abilities to (co-)utilize available carbohydrate sources.

trans -Sialidase (TS) enzymes catalyze the transfer of sialyl (Sia) residues from Sia(α2-3)Gal(β1- x )-glycans (sialo-glycans) to Gal(β1- x )-glycans (asialo-glycans). Aiming to apply this concept for the sialylation of linear and branched (Gal) n Glc oligosaccharide mixtures (GOS) using bovine κ-casein-derived glycomacropeptide (GMP) as the sialic acid donor, a kinetic study has been carried out with three components of GOS, i.e., 3′-galactosyl-lactose (β3′-GL), 4′-galactosyl-lactose (β4′-GL), and 6′-galactosyl-lactose (β6′-GL). This prebiotic GOS is prepared from lactose by incubation with suitable β-galactosidases, whereas GMP is a side-stream product of the dairy industry. The trans -sialidase from Trypanosoma cruzi (TcTS) was expressed in Escherichia coli and purified. Its temperature and pH optima were determined to be 25°C and pH 5.0, respectively. GMP [sialic acid content, 3.6% (wt/wt); N -acetylneuraminic acid (Neu5Ac), >99%; (α2-3)-linked Neu5Ac, 59%] was found to be an efficient sialyl donor, and up to 95% of the (α2-3)-linked Neu5Ac could be transferred to lactose when a 10-fold excess of this acceptor substrate was used. The products of the TcTS-catalyzed sialylation of β3′-GL, β4′-GL, and β6′-GL, using GMP as the sialic acid donor, were purified, and their structures were elucidated by nuclear magnetic resonance spectroscopy. Monosialylated β3′-GL and β4′-GL contained Neu5Ac connected to the terminal Gal residue; however, in the case of β6′-GL, TcTS was shown to sialylate the 3 position of both the internal and terminal Gal moieties, yielding two different monosialylated products and a disialylated structure. Kinetic analyses showed that TcTS had higher affinity for the GL substrates than lactose, while the V max and k cat values were higher in the case of lactose.

A genomic DNA-based microarray was constructed containing over 6000 randomly cloned genomic fragments of approximately 1-2 kb from six mammalian intestinal Bifidobacterium spp. including B. adolescentis, B. animalis, B. bifidum, B. catenulatum, B. longum and B. pseudolongum. This Bifidobacterium Mixed-Species (BMS) microarray was used to differentiate between type strains and isolates belonging to a set of nine Bifidobacterium spp. Hierarchical clustering of genomic hybridization data confirmed the grouping of the Bifidobacterium spp. according to the 16S rRNA-based phylogenetic clusters. In addition, these genomic hybridization experiments revealed high homology between the type-strain B. animalis subsp. lactis LMG18314 and B. animalis subsp. animalis LMG10508 (79%) as well as between the type strains B. longum biotype longum LMG13197 and B. longum biotype infantis LMG8811 (72%) - nevertheless, discrimination between these species was possible due to the high resolution output of the BMS-array. In addition, it was shown that the BMS-array could be used for assigning unknown Bifidobacterium isolates to a species group. Finally, a set of 54 diagnostic clones for Bifidobacterium identification was selected and sequenced to advance the understanding of the species-related differences. Remarkably, a large fraction (31%) of these was predicted to encode proteins that belong to the bifidobacterial glycobiome and another 11% had functional homology with genes involved in the protection against foreign DNA. Overall, the BMS-microarray is a high-resolution diagnostic tool that is able to facilitate the detection of strain- and species-specific characteristics of bifidobacteria. © 2008 Elsevier B.V. All rights reserved.

After birth, development of a normal microbial community occurs gradually, and is affected by factors such as the composition of the maternal gut microbiota, the environment, and the host genome. Diet also has a direct influence, both on composition and activity of this community. This influence begins with the milk, when specific components exert their growth-promoting effect on a beneficial microbiota, thereby suppressing potential pathogens. For example, breast-fed infants compared with formula-fed babies usually have a microbial community dominated by bifidobacteria. When solid food is introduced (weaning), dramatic changes in microbial composition occur, so pathogens can gain access to the disturbed gastrointestinal (GI) ecosystem. However, use of specific dietary components can alter the composition and activity of the microbiota positively. Of all dietary components, fermentable carbohydrates seem to be most promising in terms of promoting proliferation of beneficial bacterial species. Carbohydrate fermentation results in the production of SCFA which are known for their trophic and health-promoting effects. Fermentation of proteins, on the other hand, is often associated with growth of potential pathogens, and results in production of detrimental substances including NH3and amines. In terms of the GI microbiota, lipids are often associated with the antimicrobial activity of medium-chain fatty acids and their derivatives. The present review aims to provide deeper insights into the composition and development of the neonatal GI microbiota, how this microbiota can be influenced by certain dietary components, and how this might ultimately lead to improvements in host health.

Human milk contains prebiotic oligosaccharides, which stimulate the growth of intestinal bifidobacteria and lactobacilli. It is unclear whether the prebiotic capacity of human milk contributes to the larger bile salt pool size and the more efficient fat absorption in infants fed human milk compared with formula. We determined the effect of prebiotic oligosaccharides on bile salt metabolism in rats. Rats were fed a control diet or an isocaloric diet containing a mixture of galactooligosaccharides (GOS), long-chain fructooligosaccharides (lcFOS), and acidified oligosaccharides (AOS) for 3 wk. We determined synthesis rate, pool size, and fractional turnover rate (FTR) of the primary bile salt cholate by using stable isotope dilution methodology. We quantified bile flow and biliary bile salt secretion rates through bile cannulation. Prebiotic intervention resulted in significant changes in fecal and colonic flora: the proportion of lactobacilli increased 344% ( P < 0.01) in colon content and 139% ( P < 0.01) in feces compared with the control group. The number of bifidobacteria also increased 366% ( P < 0.01) in colon content and 282% in feces after the prebiotic treatment. Furthermore, pH in both colon and feces decreased significantly with 1.0 and 0.5 pH point, respectively. However, despite this alteration of intestinal bacterial flora, no significant effect on relevant parameters of bile salt metabolism and cholate kinetics was found. The present data in rats do not support the hypothesis that prebiotics naturally present in human milk contribute to a larger bile salt pool size or altered bile salt pool kinetics.