Publications by authors named "Rita Hickey"

Infants rely on their developing immune system and the protective components of breast milk to defend against bacterial and viral pathogens, as well as immune disorders such as food allergies, prior to the introduction of solid foods. When breastfeeding is not feasible, fortified infant formula will most frequently be offered, usually based on a cow's milk-based substitute. The current study aimed to explore the immunomodulatory effects of combinations of commercially available human milk oligosaccharides (HMOs).

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In ovo stimulation has been studied intensively as an alternative to antibiotic use in poultry production. We investigated the potential use of a probiotic in combination with a phytobiotic as a prophybiotic for in ovo stimulation and reported its beneficial effects on the gut microbiome of broiler chickens. The current study further investigates the gene expression in the immune-related organs of these chickens to understand the tissue-specific immunomodulatory effects of the treatments.

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Campylobacter and Salmonella are the two most prominent foodborne zoonotic pathogens reported in the European Union. As poultry is one of the major sources of these pathogens, it is imperative to mitigate the colonization of these pathogens in poultry. Many strains of lactic acid bacteria (LAB) have demonstrated anti-Salmonella and anti-Campylobacter characteristics to varying degrees and spectrums which are attributed to the production of various metabolites.

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Probiotics and phytobiotics have demonstrated effective improvement of gut health in broiler chickens when individually administered in-ovo. However, their combined use in-ovo, has not been studied to date. We coined the term "prophybiotic" (probiotic + phytobiotic) for such a combination.

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The ability of gut commensals to adhere to the intestinal epithelium can play a key role in influencing the composition of the gut microbiota. Bifidobacteria are associated with a multitude of health benefits and are one of the most widely used probiotics for humans. Enhanced bifidobacterial adhesion may increase host-microbe, microbe-nutrient, and/or microbe-microbe interactions, thereby enabling consolidated health benefits to the host.

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A number of bacterial species are found in high abundance in the faeces of healthy breast-fed infants, an occurrence that is understood to be, at least in part, due to the ability of these bacteria to metabolize human milk oligosaccharides (HMOs). HMOs are the third most abundant component of human milk after lactose and lipids, and represent complex sugars which possess unique structural diversity and are resistant to infant gastrointestinal digestion. Thus, these sugars reach the infant distal intestine intact, thereby serving as a fermentable substrate for specific intestinal microbes, including Firmicutes, Proteobacteria, and especially infant-associated Bifidobacterium spp.

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Synbiotics have been intensively studied recently to improve gut health of humans and animals. The success of synergistic synbiotics depends on the compatibility of the prebiotic and probiotic components. Certain plant extracts possess both antimicrobial and prebiotic properties representing a potential use in combination with probiotics to improve the gut health.

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Bifidobacteria 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.

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Food carbohydrates are macronutrients that are found in fruits, grains, vegetables, and milk products. These organic compounds are present in foods in the form of sugars, starches, and fibers and are composed of carbon, hydrogen, and oxygen. These wide ranging macromolecules can be classified according to their chemical structure into three major groups: low molecular weight mono- and disaccharides, intermediate molecular weight oligosaccharides, and high molecular weight polysaccharides.

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Human 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.

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Evidence that whey proteins and peptides have health benefits beyond basic infant nutrition has increased dramatically in recent years. Previously, we demonstrated that a whey-derived immunoglobulin G-enriched powder (IGEP) enhanced adhesion of subsp. ATCC 15697 () to HT-29 cells.

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A bovine colostrum fraction (BCF) was recently shown to enhance the adherence of several commensal organisms to intestinal epithelial cells through modulating the epithelial cell surface. In this study, the main components of the BCF were examined to investigate the active component/s responsible for driving the changes in the intestinal cells. The adherence of various bifidobacteria to HT-29 cells was increased when the intestinal cells were pre-incubated with immunoglobulin G (IgG).

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Bifidobacteria are known to inhibit, compete with and displace the adhesion of pathogens to human intestinal cells. Previously, we demonstrated that goat milk oligosaccharides (GMO) increased the attachment of subsp. ATCC 15697 to intestinal cells in vitro.

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Oligosaccharides are the third most abundant component in human milk. It is widely accepted that they play several important protective, physiological, and biological roles, including selective growth stimulation of beneficial gut microbiota, inhibition of pathogen adhesion, and immune modulation. However, until recently, very few commercial products on the market have capitalized on these functions.

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We are beginning to see how the microbiota of the human gastrointestinal tract (GIT) can drive the development of new products to benefit human health and wellbeing. Despite the growing market for prebiotics and probiotics, there are currently no commercial products available that aid or increase the attachment of health-promoting bacteria to the gut mucosal surface. Components in milk have the potential to increase commensal adherence in the gut by priming the bacteria or the mucosal surface for colonization.

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Historically, honey is known for its anti-bacterial and anti-fungal activities and its use for treatment of wound infections. Although this practice has been in place for millennia, little information exists regarding which manuka honey components contribute to the protective nature of this product. Given that sugar accounts for over 80% of honey and up to 25% of this sugar is composed of oligosaccharides, we have investigated the anti-infective activity of manuka honey oligosaccharides against a range of pathogens.

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Immunoglobulin G (IgG) in bovine milk is credited with ensuring efficient passive immunity for newborn calves. Bovine milk IgG glycosylation may also have positive impacts on the health of nonbovine consumers of cow's milk. Milk IgG's glycosylation contributes to effector function and may also protect it from protease digestion, allowing IgG to reach the intestine for absorption.

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Nutritional intake may influence the intestinal epithelial glycome and in turn the available attachment sites for bacteria. In this study, we tested the hypothesis that bovine colostrum may influence the intestinal cell surface and in turn the attachment of commensal organisms. Human HT-29 intestinal cells were exposed to a bovine colostrum fraction (BCF) rich in free oligosaccharides.

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Bovine colostrum is a rich source of bioactive components which are important in the development of the intestine, in stimulating gut structure and function and in preparing the gut surface for subsequent colonization of microbes. What is not clear, however, is how colostrum may affect the repertoire of receptors and membrane proteins of the intestinal surface and the post-translational modifications associated with them. In the present work, we aimed to characterize the surface receptor and glycan profile of human HT-29 intestinal cells after exposure to a bovine colostrum fraction (BCF) by means of proteomic and glycomic analyses.

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Bifidobacteria play a vital role in human nutrition and health by shaping and maintaining the gut ecosystem. In order to exert a beneficial effect, a sufficient population of bifidobacteria must colonise the host. In this study, we developed a miniaturised high-throughput in vitro assay for assessing the colonising ability of bacterial strains in human cells.

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In recent years, the potential of glycosylated food components to positively influence health has received considerable attention. Milk is a rich source of biologically active glycoconjugates which are associated with antimicrobial, immunomodulatory, anti-adhesion, anti-inflammatory and prebiotic properties. Glycomacropeptide (GMP) is the C-terminal portion of kappa-casein that is released from whey during cheese-making by the action of chymosin.

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Bovine lactoferrin (LF) has been shown to prevent adhesion to and invasion of mammalian cell lines by pathogenic bacteria, with evidence for direct bacterial binding by the milk glycoprotein. However, the glycosylation pattern of LF changes over the lactation cycle. In this study, we aim to investigate the effect that this variation has on the milk glycoprotein's ability to interact with pathogens.

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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.

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The bovine milk fat globule membrane (MFGM) has many associated biological activities, many of which are linked with specific carbohydrate structures of MFGM glycoconjugates. Bovine buttermilk is a commercially viable source of MFGM and is an under-valued by-product of butter making. However, the changes in buttermilk glycosylation over the course of lactation have not been extensively investigated.

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Bifidobacteria are common and frequently dominant members of the gut microbiota of many animals, including mammals and insects. Carbohydrates are considered key carbon sources for the gut microbiota, imposing strong selective pressure on the complex microbial consortium of the gut. Despite its importance, the genetic traits that facilitate carbohydrate utilization by gut microbiota members are still poorly characterized.

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