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- ItemSoft breakdown in MgO dielectric layers(Institute of Electrical and Electronics Engineers (IEEE), 2009-07-24) Miranda, Enrique; O'Connor, Éamon; Hughes, Gregory; Casey, P.; Cherkaoui, Karim; Monaghan, Scott; Long, Rathnait D.; O'Connell, Dan; Hurley, Paul K.; Generalitat de Catalunya; Ministerio de Ciencia y Tecnología; Science Foundation IrelandIn this work, we report on the occurrence of the soft breakdown (SBD) failure mode in 20 nm-thick films of magnesium oxide (MgO) grown on Si substrates. To our knowledge, this is the first observation of this failure mechanism in a high-kappa gate dielectric with such a large oxide thickness. We show that the I-V characteristics follow the power-law dependence typical of SBD conduction in a wider voltage range than that reported for SiO 2 . We pay special attention to the relationship between the magnitude of the current and the normalized differential conductance, and analyze the role played by the injection polarity and substrate type.
- ItemFactors associated with staffing provision and medical equipment acquisition in Irish general practice(Irish Medical Organisation, 2012-11) Bourke, Jane; Bradley, C. P.GPs form an integral part of Irish primary care provision. However, current information concerning general practice structure, staffing and development in Ireland is quite limited. This report provides a profile of General Practice in Ireland in 2010 drawing on a national survey of practices using a standardised questionnaire. On average, there are 2.7 GPs per practice, although one in four practices remains single-handed. The majority of practices employ nursing 485(80.7%) and clerical 549(91.3%) support. A high proportion of practices have the following items of equipment: ECG machine 496(82.5%), 24 hour blood pressure monitor 481(80.1%), spirometer 383(63.8%), cryotherapy equipment 505(84%), minor surgery equipment 453(74.3%) and foetal monitor 484(80.5%). Using chi square analysis, we find statistically significant positive relationships between nursing support and possession of each of the six items of medical equipment (X2 = 81.57, p<0.01; X2 = 105.4, p<0.01; X2 = 38.5, p<0.01; X2 = 16.6, p<0.01; X2 = 39.5, p<0.01; X2 = 19.5, p<0.01)and between practice size and possession of each item of medical equipment (X2 = 26.3, p<0.01; X2 = 45, p<0.01; X2 = 16.5, p<0.01; X2 = 44.4, p<0.01; X2 = 13.8, p<0.01; X2 = 14.7, p<0.01).
- ItemBacterial toxins: Offensive, defensive, or something else altogether?(Public Library of Science, 2017-09-21) Rudkin, Justine K.; McLoughlin, Rachel M.; Preston, Andrew; Massey, Ruth C.The secretion of proteins that damage host tissue is well established as integral to the infectious processes of many bacterial pathogens. However, recent advances in our understanding of the activity of toxins suggest that the attributes we have assigned to them from early in vitro experimentation have misled us into thinking of them as merely destructive tools. Here, we will discuss the multifarious ways in which toxins contribute to the lifestyle of bacteria and, by considering their activity from an evolutionary perspective, demonstrate how this extends far beyond their ability to destroy host tissue.
- ItemConstans II, Cherson or Bosporus, and the reform of the copper coinage under Constantine IV(Royal Numismatic Society, 2019-12) Woods, DavidIt is argued that an unusually heavy copper type of Constans II which has traditionally been dated to about 658/9 and attributed to either Cherson or Bosporus was probably a halffollis struck in Constantinople just before the accession of Constantine IV in 668 and his reform of the copper coinage.
- ItemMobilome and resistome reconstruction from genomes belonging to members of the Bifidobacterium genus(MDPI, 2019-12) Mancino, Walter; Lugli, Gabriele A.; van Sinderen, Douwe; Ventura, Marco; Turroni, Francesca; Horizon 2020 Framework Programme; Science Foundation IrelandSpecific members of the genus Bifidobacterium are among the first colonizers of the human/animal gut, where they act as important intestinal commensals associated with host health. As part of the gut microbiota, bifidobacteria may be exposed to antibiotics, used in particular for intrapartum prophylaxis, especially to prevent Streptococcus infections, or in the very early stages of life after the birth. In the current study, we reconstructed the in silico resistome of the Bifidobacterium genus, analyzing a database composed of 625 bifidobacterial genomes, including partial assembled strains with less than 100 genomic sequences. Furthermore, we screened bifidobacterial genomes for mobile genetic elements, such as transposases and prophage-like elements, in order to investigate the correlation between the bifido-mobilome and the bifido-resistome, also identifying genetic insertion hotspots that appear to be prone to horizontal gene transfer (HGT) events. These insertion hotspots were shown to be widely distributed among analyzed bifidobacterial genomes, and suggest the acquisition of antibiotic resistance genes through HGT events. These data were further corroborated by growth experiments directed to evaluate bacitracin A resistance in Bifidobacterium spp., a property that was predicted by in silico analyses to be part of the HGT-acquired resistome.
- ItemBifidobacterium breve UCC2003 exopolysaccharide modulates the early life Microbiota by acting as a potential dietary substrate(MDPI, 2020) Püngel, Deborah; Treveil, Agatha; Dalby, Matthew J.; Caim, Shabhonam; Colquhoun, Ian J.; Booth, Catherine; Ketskemety, Jennifer; Korcsmaros, Tamas; van Sinderen, Douwe; Lawson, Melissa A. E.; Hall, Lindsay J.; Wellcome Trust; H2020 Marie Skłodowska-Curie Actions; Science Foundation IrelandBACKGROUND: Bifidobacterium represents an important early life microbiota member. Specific bifidobacterial components, exopolysaccharides (EPS), positively modulate host responses, with purified EPS also suggested to impact microbe-microbe interactions by acting as a nutrient substrate. Thus, we determined the longitudinal effects of bifidobacterial EPS on microbial communities and metabolite profiles using an infant model colon system. METHODS: Differential gene expression and growth characteristics were determined for each strain; Bifidobacterium breve UCC2003 and corresponding isogenic EPS-deletion mutant (B. breve UCC2003del). Model colon vessels were inoculated with B. breve and microbiome dynamics monitored using 16S rRNA sequencing and metabolomics (NMR). RESULTS: Transcriptomics of EPS mutant vs. B. breve UCC2003 highlighted discrete differential gene expression (e.g., eps biosynthetic cluster), though overall growth dynamics between strains were unaffected. The EPS-positive vessel had significant shifts in microbiome and metabolite profiles until study end (405 h); with increases of Tyzzerella and Faecalibacterium, and short-chain fatty acids, with further correlations between taxa and metabolites which were not observed within the EPS-negative vessel. CONCLUSIONS: These data indicate that B. breve UCC2003 EPS is potentially metabolized by infant microbiota members, leading to differential microbial metabolism and altered metabolite by-products. Overall, these findings may allow development of EPS-specific strategies to promote infant health.
- ItemThe impact of primer design on amplicon-based metagenomic profiling accuracy: detailed insights into bifidobacterial community structure(MDPI, 2020-01) Mancabelli, Leonardo; Milani, Christian; Lugli, Gabriele A.; Fontana, Federico; Turroni, Francesca; van Sinderen, Douwe; Ventura, Marco; Horizon 2020; Science Foundation IrelandNext Generation Sequencing (NGS) technologies have overcome the limitations of cultivation-dependent approaches and allowed detailed study of bacterial populations that inhabit the human body. The consortium of bacteria residing in the human intestinal tract, also known as the gut microbiota, impacts several physiological processes important for preservation of the health status of the host. The most widespread microbiota profiling method is based on amplification and sequencing of a variable portion of the 16S rRNA gene as a universal taxonomic marker among members of the Bacteria domain. Despite its popularity and obvious advantages, this 16S rRNA gene-based approach comes with some important limitations. In particular, the choice of the primer pair for amplification plays a major role in defining the accuracy of the reconstructed bacterial profiles. In the current study, we performed an in silico PCR using all currently described 16S rRNA gene-targeting primer pairs (PP) in order to assess their efficiency. Our results show that V3, V4, V5, and V6 were the optimal regions on which to design 16S rRNA metagenomic primers. In detail, PP39 (Probio_Uni/Probio_Rev), PP41 (341F/534R), and PP72 (970F/1050R) were the most suitable primer pairs with an amplification efficiency of >98.5%. Furthermore, the Bifidobacterium genus was examined as a test case for accurate evaluation of intra-genus performances at subspecies level. Intriguingly, the in silico analysis revealed that primer pair PP55 (527f/1406r) was unable to amplify the targeted region of any member of this bacterial genus, while several other primer pairs seem to rather inefficiently amplify the target region of the main bifidobacterial taxa. These results highlight that selection of a 16S rRNA gene-based PP should be done with utmost care in order to avoid biases in microbiota profiling results.
- ItemThe infant gut microbiome as a microbial organ influencing host well-being(Springer Nature, 2020-02) Turroni, Francesca; Milani, Christian; Duranti, Sabrina; Lugli, Gabriele A.; Bernasconi, Sergio; Margolles, Abelardo; Di Pierro, Francesco; van Sinderen, Douwe; Ventura, Marco; Horizon 2020 Framework Programme; Science Foundation Ireland; Fondazione CariparmaInitial establishment of the human gut microbiota is generally believed to occur immediately following birth, involving key gut commensals such as bifidobacteria that are acquired from the mother. The subsequent development of this early gut microbiota is driven and modulated by specific dietary compounds present in human milk that support selective colonization. This represents a very intriguing example of host-microbe co-evolution, where both partners are believed to benefit. In recent years, various publications have focused on dissecting microbial infant gut communities and their interaction with their human host, being a determining factor in host physiology and metabolic activities. Such studies have highlighted a reduction of microbial diversity and/or an aberrant microbiota composition, sometimes referred to as dysbiosis, which may manifest itself during the early stage of life, i.e., in infants, or later stages of life. There are growing experimental data that may explain how the early human gut microbiota affects risk factors related to adult health conditions. This concept has fueled the development of various nutritional strategies, many of which are based on probiotics and/or prebiotics, to shape the infant microbiota. In this review, we will present the current state of the art regarding the infant gut microbiota and the role of key commensal microorganisms like bifidobacteria in the establishment of the first microbial communities in the human gut.
- ItemBifidobacterium breve UCC2003 induces a distinct global transcriptomic program in neonatal murine intestinal epithelial cells(Elsevier, 2020-07) Kiu, Raymond; Treveil, Agatha; Harnisch, Lukas C.; Caim, Shabhonam; Leclaire, Charlotte; van Sinderen, Douwe; Korcsmaros, Tamas; Hall, Lindsay J.; Norwich Bioscience Institutes (NBI) Computing infrastructure for Science (CiS) group; Wellcome Trust; Gut Microbes and Health; Genomics for Food security; Norwich Research Park Biosciences; Science Foundation IrelandThe underlying health-driving mechanisms of Bifidobacterium during early life are not well understood, particularly how this microbiota member may modulate the intestinal barrier via programming of intestinal epithelial cells (IECs). We investigated the impact of Bifidobacterium breve UCC2003 on the transcriptome of neonatal murine IECs. Small IECs from two-week-old neonatal mice administered B. breve UCC2003 or PBS (control) were subjected to global RNA sequencing, and differentially expressed genes, pathways, and affected cell types were determined. We observed extensive regulation of the IEC transcriptome with ∼4,000 genes significantly up-regulated, including key genes linked with epithelial barrier function. Enrichment of cell differentiation pathways was observed, along with an overrepresentation of stem cell marker genes, indicating an increase in the regenerative potential of the epithelial layer. In conclusion, B. breve UCC2003 plays a central role in driving intestinal epithelium homeostatic development during early life and suggests future avenues for next-stage clinical studies.
- ItemBarriers and waste in the research grant application process in higher education through a lean six sigma lens(Polska Akademia Nauk, 2020-09) Dempsey, Mary; Brennan, Attracta; McAvoy, JohnHigher education institutions (HEIs) typically generate income from two main sources; student fees and research income. In contrast, the predominant waste streams in HEIs tend to include; (1) assignment/examination mark submission process, (2) photocopying process and (3) the funding application process. Unintended internal process complexities and barriers typically aggravate the challenges already inherent, in the research grant application process. Although Lean Six Sigma (LSS) has been adopted by a number of HEIs in Ireland, very few have adopted an integrated LSS approach for waste reduction in the research grant application process. To identify barriers and waste in the research grant application process within an Irish HEI in an EU environment, the authors used an online survey deployed to 240 academics and researchers. The survey response rate was 13%. The participating HEI in this pilot study generated an annual income (including student fees and research income) exceeding (sic)240 million for the academic year 2017/2018. Using an LSS lens, this paper identified the primary waste in the research grant application process from an academic and researcher perspective to be; editing and revising applications, liaising and communicating with collaborators and waiting for information. Organised thematically, the main barriers were strategic thinking, collaborator identification and co-Ordination, eligibility, process, time and support & mentoring. The results from this study can be used to inform the next stage of the research where empirical studies will be carried out in other HEIs to develop a practical roadmap for the implementation of LSS as an operational excellence improvement methodology in the research grant application process.
- ItemEnvisioning emerging frontiers on human gut microbiota and its applications(Wiley, 2020-09) Ventura, Marco; Milani, Christian; Turroni, Francesca; van Sinderen, Douwe; European Commission; Fondazione Cariparma; Science Foundation Ireland; GenProbioThe human gut microbiota is involved in multiple health-influencing host interactions during the host's entire life span. Microbes colonize the infant gut instantaneously after birth and subsequently the founding and interactive progress of this early gut microbiota is considered to be driven and modulated by different host- and microbe-associated forces. A rising number of studies propose that the composition of the human gut microbiota in the early stages of life impact on the human health conditions at later stages of life. This notion has powered research aimed at detailed investigations of the infant gut microbiota composition. Nevertheless, the molecular mechanisms supporting the gut microbiome functionality and the interaction of the early gut microbes with the human host remain largely unknown.
- ItemHuman milk oligosaccharides: shaping the infant gut microbiota and supporting health(Elsevier, 2020-09) Walsh, Clodagh; Lane, Jonathan A.; van Sinderen, Douwe; Hickey, Rita M.; H and H Group; Science Foundation IrelandHuman milk oligosaccharides (HMO) are complex sugars which are found in breast milk at significant concentrations and with unique structural diversity. These sugars are the fourth most abundant component of human milk after water, lipids, and lactose and yet provide no direct nutritional value to the infant. Recent research has highlighted that HMOs have various functional roles to play in infant development. These sugars act as prebiotics by promoting growth of beneficial intestinal bacteria thereby generating short-chain fatty acids which are critical for gut health. HMOs also directly modulate host-epithelial immune responses and can selectively reduce binding of pathogenic bacteria and viruses to the gut epithelium preventing the emergence of a disease. This review covers current knowledge related to the functional biology of HMOs and their associated impact on infant gut health.
- ItemFrom lab bench to formulated ingredient: characterization, production, and commercialization of human milk oligosaccharides(Elsevier, 2020-09) Walsh, Clodagh; Lane, Jonathan A.; van Sinderen, Douwe; Hickey, Rita M.; H & H Group; Science Foundation IrelandHuman milk oligosaccharides (HMOs) are known to positively influence infant health. Extensive variation exists in the levels, diversity, and complexity of oligosaccharides in the milk of a lactating mother. Until recently, limited availability of HMOs hampered their use in clinical applications. Most HMOs are unique to human milk, and have proven difficult and expensive to isolate and synthesize. Added to that, analysis of these complex glycans in milk samples requires state-of-the-art analytical instruments and associated technologies. The current review provides a critical overview of methods used in HMO analysis, and highlights the importance of understanding the factors which influence their composition and structural diversity. We also discuss recently employed strategies to overcome the availability of HMOs at industrial scale including microbial metabolic engineering and chemoenzymatic techniques. Finally, we examine how these recent advancements have opened up new avenues for future research and nutraceutical applications.
- ItemDietary fat intakes in Irish children: changes between 2005 and 2019(Cambridge University Press on behalf of The Nutrition Society, 2020-10-26) O'Connor, Aileen; Buffini, Maria; Nugent, Anne; Kehoe, Laura; Flynn, Albert; Walton, Janette; Kearney, John; McNulty, Breige; Department of Agriculture, Food and the Marine, IrelandObjective: To examine current dietary fat intakes and compliance in Irish children and to examine changes in intakes from 2005 to 2019. Design: Analyses were based on data from the Irish National Children’s Food Survey (NCFS) and the NSFS II, two cross-sectional studies that collected detailed food and beverage intake data through 7-day and 4-day weighed food diaries, respectively. Setting: NCFS and NCFS II, Republic of Ireland. Participants: A nationally representative sample of 594 (NCFS) and 600 (NCFS II) children aged 5–12 years. Current intakes from the NCFS II were compared with those previously reported in the NCFS (www.iuna.net). Results: Current intakes of total fat, SFA, MUFA, PUFA and trans fat as a percentage of total energy are 33·3, 14·0, 13·6, 5·6 and 0·5 %, respectively. Total fat, SFA and trans fat intakes since 2005 remained largely stable over time with all displaying minor decreases of <1 %. Adherence to SFA recommendations remains inadequate, with only 7 % of the population complying. Insufficient compliance with PUFA (71 %) and EPA and DHA (DHA; 16 %) recommendations was also noted. Conclusion: Children in Ireland continue to meet the total fat and trans fat target goals. Adherence to MUFA and PUFA recommendations has also significantly improved. However, deviations for some fats remain, in particular SFA. These findings are useful for the development of dietary strategies to improve compliance with current recommendations.
- ItemWhich factors are influencing artistic swimming performance?(Open Access Publishing Group, 2021) Ntomali, Stavroula; Adamakis, Manolis; Venetsanou, Fotini; Chairopoulou, Chrysoula; Psychountaki, MariaRhythmic ability (RA) plays an important role in sports in which music accompaniment is used, such as artistic swimming (AS). The aim of the present study was to investigate RA's relationship with the athletes’ overall performance in AS, as well as the independent scores of AS performance (i.e., Execution, Artistic Impression and Difficulty), taking into account their competitive category and experience. The sample consisted of 47 female artistic swimmers (age 15.8±3.3 years; athletic experience 6.6±3.3 years) divided into three competitive categories (Senior, Junior, and Comen). The High/Scope Rhythmic Competence Αnalysis Τest (Weikart, 1989) was used for the evaluation of RA of participants. Three official AS judges were used to assess athletes’ performance in the water routine session. Descriptive and inferential (i.e., two MANCOVAs) statistical analysis revealed that experience was a significant positive predictor of AS Performance and RA, indicating that as experience increased, athletes’ AS performance and RA also increased. In addition, results showed that athletes in the senior category scored higher in all variables in relation to junior and comen athletes; however, these differences were not statistically significant.
- ItemDynamic conceptual framework to investigate adoption of healthy diet through agent-based modelling(Emerald Publishing Ltd., 2021-02-17) Rahmani, Jamal; MirzayRazaz, Jalaledin; Kalantari, Naser; Garcia, Leandro M. T.; Shariatpanahi, Seyed Peyman; Bawadi, Hiba; Thompson, Jacqueline Y.; Ryan, Paul M.; Santos, Heitor O.; Haghighian Roudsari, ArezooPurpose: The purpose of this research is to develop a dynamic conceptual framework depicting factors related to the adoption of a healthy diet, which will underpin the development of an agent-based model (ABM) to uncover the dynamic interplay between these factors. Design/methodology/approach: The conceptual framework was developed in three steps using available empirical data from a semi-structured in-depth interview qualitative study, comprehensive systematic literature searches, existing theories and models and expert opinions from across the world. Findings: The conceptual framework explicitly presents intention as the key determinant of the tendency to adopt a healthy diet. Intention is determined by demographic, psychological and behavioural factors and individual dietary mindset factors and dynamically affected by social environment and the person's past behaviour. The relationship between intention and behaviour is dynamically moderated by perceived control factors (price and accessibility of healthy food and time). Originality/value: The conceptual framework developed in this study is well supported by evidence and experts' opinions. This conceptual framework will be used to design the ABM of this study, and it can be used in future investigations on the tendency to adopt healthy diet and food choices.
- ItemBroad purpose vector for site-directed insertional mutagenesis in Bifidobacterium breve(Frontiers Media S.A., 2021-03) Hoedt, Emily C.; Bottacini, Francesca; Cash, Nora; Bongers, Roger S.; van Limpt, Kees; Ben Amor, Kaouther; Knol, Jan; MacSharry, John; van Sinderen, Douwe; Nutricia Research Foundation; Science Foundation Ireland; Federation of European Microbiological SocietiesMembers of the genus Bifidobacterium are notoriously recalcitrant to genetic manipulation due to their extensive and variable repertoire of Restriction-Modification (R-M) systems. Non-replicating plasmids are currently employed to achieve insertional mutagenesis in Bifidobacterium. One of the limitations of using such insertion vectors is the presence within their sequence of various restriction sites, making them sensitive to the activity of endogenous restriction endonucleases encoded by the target strain. For this reason, vectors have been developed with the aim of methylating and protecting the vector using a methylase-positive Escherichia coli strain, in some cases containing a cloned bifidobacterial methylase. Here, we present a mutagenesis approach based on a modified and synthetically produced version of the suicide vector pORI28 (named pFREM28), where all known restriction sites targeted by Bifidobacterium breve R-M systems were removed by base substitution (thus preserving the codon usage). After validating the integrity of the erythromycin marker, the vector was successfully employed to target an alpha-galactosidase gene responsible for raffinose metabolism, an alcohol dehydrogenase gene responsible for mannitol utilization and a gene encoding a priming glycosyltransferase responsible for exopolysaccharides (EPS) production in B. breve. The advantage of using this modified approach is the reduction of the amount of time, effort and resources required to generate site-directed mutants in B. breve and a similar approach may be employed to target other (bifido)bacterial species.
- ItemDiscursive strategies of legitimization: The case of abortion in Ireland in 2018(Irish Association for Applied Linguistics, 2021-06-11) O'Donovan, Jennifer; Siller, BarbaraThe following article is based on a study on abortion discourse carried out in Ireland in 2018 prior to and after the Referendum to Repeal the Eighth Amendment to the Constitution allowing for legislation to be introduced regulating termination of pregnancy. Its main focus was to identify the strategies of legitimization employed by both online users and campaign bodies in the period directly before and after the historic referendum to create the possibility to legislate for abortion in Ireland. The study also aimed at examining how the discursive strategies engaged in creating identities on both a national level and also of the collective voter groups. The corpus included unregulated textual and regulated visual data collected between May and June 2018. The textual data derived from the Facebook pages of four prominent campaigning bodies from both sides of the referendum one month before and after the referendum while the visual data originated from photos taken of the campaign posters displayed in Ireland. Critical Discourse Analysis formed the conceptual framework of the study: the study employed Reyes’ (2011) model of strategies of legitimization in political discourse as well as the two visual analysis frameworks as proposed by Van Leeuwen (2008) and Ledin and Machin (2018). A mixed-method approach in the format of a triangulation design (Creswell & Plano Clark, 2007) was used, whereby qualitative textual and visual discourses were transformed into quantitative data for the purpose of analysis. The findings indicated that the strategy of emotion was the most utilized; this became apparent through the quantitatively high use of terms such as ‘rape’, ‘incest’ or ‘murder’, in order to provoke an emotional reaction in the message perceiver. The results also pointed to high instances of ‘othering’ strategies of the different groups participating in the discourse.
- ItemSea level rise will change estuarine tidal energy: A review(Elsevier Ltd., 2021-12-09) Khojasteh, Danial; Lewis, Matthew; Tavakoli, Sasan; Farzadkhoo, Maryam; Felder, Stefan; Iglesias, Gregorio; Glamore, William; Engineering and Physical Sciences Research Council; University of New South WalesClimate change induced sea level rise (SLR) is likely to impact estuarine hydrodynamics and associated processes, including tidal energy. In this study, a hierarchy of factors influencing the future of estuarine tidal energy resources is proposed based on their relevance to SLR. These include primary factors (e.g., tidal prism, tidal range, tidal current, tidal asymmetry), secondary factors (e.g., sediment transport), and tertiary factors (e.g., shifts in estuarine shape/landform). The existing uncertainty regarding SLR impacts on tidal energy resource is high, given the spatial variability of estuaries. SLR may cause tidal ranges or currents to strengthen or weaken, depending on estuarine shape and boundary conditions (e.g., presence or absence of levees and adjacent low-lying areas). To date, local site studies have not resulted in an overarching assessment of SLR effects on tidal energy resources and comparative studies encompassing different regions and estuary types are recommended in order to address the existing knowledge gaps and provide insights for policymakers and stakeholders. SLR implications to estuarine tidal energy resources may be particularly important as SLR-induced changes can alter the available resource within a renewable energy development's operational lifetime (-20-30 years for tidal stream devices and-120 years for tidal barrages). In this regard, broader environmental impacts, as well as technoeconomic assessments, are difficult to predict and long-term management decisions associated with harnessing the potential of tidal energy schemes within estuaries should be made with caution.
- ItemHuman milk oligosaccharide-sharing by a consortium of infant derived Bifidobacterium species(Nature Research, 2022-03) Walsh, Clodagh; Lane, Jonathan A.; van Sinderen, Douwe; Hickey, Rita M.; H and H Group; Science Foundation IrelandBifidobacteria are associated with a host of health benefits and are typically dominant in the gut microbiota of healthy, breast-fed infants. A key adaptation, facilitating the establishment of these species, is their ability to consume particular sugars, known as human milk oligosaccharides (HMO), which are abundantly found in breastmilk. In the current study, we aimed to characterise the co-operative metabolism of four commercial infant-derived bifidobacteria (Bifidobacterium bifidum R0071, Bifidobacterium breve M-16V, Bifidobacterium infantis R0033, and Bifidobacterium infantis M-63) when grown on HMO. Three different HMO substrates (2 '-fucosyllactose alone and oligosaccharides isolated from human milk representing non-secretor and secretor status) were employed. The four-strain combination resulted in increased bifidobacterial numbers (> 21%) in comparison to single strain cultivation. The relative abundance of B. breve increased by > 30% during co-cultivation with the other strains despite demonstrating limited ability to assimilate HMO in mono-culture. HPLC analysis revealed strain-level variations in HMO consumption. Metabolomics confirmed the production of formate, acetate, 1,2-propanediol, and lactate with an overall increase in such metabolites during co-cultivation. These results support the concept of positive co-operation between multiple bifidobacterial strains during HMO utilisation which may result in higher cell numbers and a potentially healthier balance of metabolites.