The core objective of the Food Biosciences Department is to engage in advanced research and technology development in support of the Irish Agri-Food industry sector. Activities fall into three research areas: Food for Health; Cheese Microbiology and Biochemistry and Milk and Product Quality.

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Food Biosciences

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  • Bioinformatic approaches for studying the microbiome of fermented food

    Walsh, Liam H.; Coakley, Mairéad; Walsh, Aaron M.; O’Toole, Paul W.; Cotter, Paul; European Union; Science Foundation Ireland; Department of Agriculture, Food and the Marine; Enterprise Ireland; 818368; et al. (Informa UK Limited, 2022-10-26)
    High-throughput DNA sequencing-based approaches continue to revolutionise our understanding of microbial ecosystems, including those associated with fermented foods. Metagenomic and metatranscriptomic approaches are state-of-the-art biological profiling methods and are employed to investigate a wide variety of characteristics of microbial communities, such as taxonomic membership, gene content and the range and level at which these genes are expressed. Individual groups and consortia of researchers are utilising these approaches to produce increasingly large and complex datasets, representing vast populations of microorganisms. There is a corresponding requirement for the development and application of appropriate bioinformatic tools and pipelines to interpret this data. This review critically analyses the tools and pipelines that have been used or that could be applied to the analysis of metagenomic and metatranscriptomic data from fermented foods. In addition, we critically analyse a number of studies of fermented foods in which these tools have previously been applied, to highlight the insights that these approaches can provide.
  • Deficiency of essential dietary n-3 PUFA disrupts the caecal microbiome and metabolome in mice

    Robertson, Ruairi C.; Seira Oriach, Clara; Murphy, Kiera; Moloney, Gerard M.; Cryan, John F.; Dinan, Timothy G.; Ross, R. P.; Stanton, Catherine; Science Foundation Ireland; Health Research Board of Ireland; et al. (Cambridge University Press (CUP), 2017-11-27)
    n-3 PUFA are lipids that play crucial roles in immune-regulation, cardio-protection and neurodevelopment. However, little is known about the role that these essential dietary fats play in modulating caecal microbiota composition and the subsequent production of functional metabolites. To investigate this, female C57BL/6 mice were assigned to one of three diets (control (CON), n-3 supplemented (n3+) or n-3 deficient (n3−)) during gestation, following which their male offspring were continued on the same diets for 12 weeks. Caecal content of mothers and offspring were collected for 16S sequencing and metabolic phenotyping. n3− male offspring displayed significantly less % fat mass than n3+ and CON. n-3 Status also induced a number of changes to gut microbiota composition such that n3− offspring had greater abundance of Tenericutes, Anaeroplasma and Coriobacteriaceae. Metabolomics analysis revealed an increase in caecal metabolites involved in energy metabolism in n3+ including α-ketoglutaric acid, malic acid and fumaric acid. n3− animals displayed significantly reduced acetate, butyrate and total caecal SCFA production. These results demonstrate that dietary n-3 PUFA regulate gut microbiota homoeostasis whereby n-3 deficiency may induce a state of disturbance. Further studies are warranted to examine whether these microbial and metabolic disturbances are causally related to changes in metabolic health outcomes.
  • Bifidobacterium breve with α-linolenic acid alters the composition, distribution and transcription factor activity associated with metabolism and absorption of fat

    Patterson, Elaine; Wall, Rebecca; Lisai, Sara; Ross, R. Paul; Dinan, Timothy G.; Cryan, John F.; Fitzgerald, Gerald F.; Banni, Sebastiano; Quigley, Eamonn M.; Shanahan, Fergus; et al. (Springer Science and Business Media LLC, 2017-03-07)
    This study focused on the mechanisms that fatty acid conjugating strains - Bifidobacterium breve NCIMB 702258 and Bifidobacterium breve DPC 6330 - influence lipid metabolism when ingested with α-linolenic acid (ALA) enriched diet. Four groups of BALB/c mice received ALA enriched diet (3% (w/w)) either alone or in combination with B. breve NCIMB 702258 or B. breve DPC 6330 (109 CFU/day) or unsupplemented control diet for six weeks. The overall n-3 PUFA score was increased in all groups receiving the ALA enriched diet. Hepatic peroxisomal beta oxidation increased following supplementation of the ALA enriched diet with B. breve (P < 0.05) and so the ability of the strains to produce c9t11 conjugated linoleic acid (CLA) was identified in adipose tissue. Furthermore, a strain specific effect of B. breve NCIMB 702258 was found on the endocannabinoid system (ECS). Liver triglycerides (TAG) were reduced following ALA supplementation, compared with unsupplemented controls (P < 0.01) while intervention with B. breve further reduced liver TAG (P < 0.01), compared with the ALA enriched control. These data indicate that the interactions of the gut microbiota with fatty acid metabolism directly affect host health by modulating n-3 PUFA score and the ECS.
  • Draft Genome Sequences of 25 Listeria monocytogenes Isolates Associated with Human Clinical Listeriosis in Ireland

    O’Callaghan, Amy; Hilliard, Amber; Morgan, Ciara A.; Culligan, Eamonn P.; Leong, Dara; DeLappe, Niall; Hill, Colin; Jordan, Kieran; Cormican, Martin; Gahan, Cormac G. M.; et al. (American Society for Microbiology, 2017-05-11)
    Listeria monocytogenes is a Gram-positive opportunistic pathogen that is the causative agent of listeriosis. Here, we report the draft genome sequences of 25 L. monocytogenes strains isolated from patients with clinical listeriosis in the Republic of Ireland between 2013 and 2015.
  • Impact of intrapartum antimicrobial prophylaxis upon the intestinal microbiota and the prevalence of antibiotic resistance genes in vaginally delivered full-term neonates

    Nogacka, Alicja; Salazar, Nuria; Suárez, Marta; Milani, Christian; Arboleya, Silvia; Solís, Gonzalo; Fernández, Nuria; Alaez, Lidia; Hernández-Barranco, Ana M.; de los Reyes-Gavilán, Clara G.; et al. (Springer Science and Business Media LLC, 2017-08-08)
    Background: Disturbances in the early establishment of the intestinal microbiota may produce important implications for the infant’s health and for the risk of disease later on. Different perinatal conditions may be affecting the development of the gut microbiota. Some of them, such as delivery mode or feeding habits, have been extensively assessed whereas others remain to be studied, being critical to identify their impact on the microbiota and, if any, to minimize it. Antibiotics are among the drugs most frequently used in early life, the use of intrapartum antimicrobial prophylaxis (IAP), present in over 30% of deliveries, being the most frequent source of exposure. However, our knowledge on the effects of IAP on the microbiota establishment is still limited. The aim of the present work was to evaluate the impact of IAP investigating a cohort of 40 full-term vaginally delivered infants born after an uncomplicated pregnancy, 18 of which were born from mothers receiving IAP. Results: Fecal samples were collected at 2, 10, 30, and 90 days of age. We analyzed the composition of the fecal microbiota during the first 3 months of life by 16S rRNA gene sequencing and quantified fecal short chain fatty acids by gas chromatography. The presence of genes for resistance to antibiotics was determined by PCR in the samples from 1-month-old infants. Our results showed an altered pattern of intestinal microbiota establishment in IAP infants during the first weeks of life, with lower relative proportions of Actinobacteria and Bacteroidetes and increased of Preoteobacteria and Firmicutes. A delay in the increase on the levels of acetate was observed in IAP infants. The analyses of specific antibiotic resistance genes showed a higher occurrence of some β-lactamase coding genes in infants whose mothers received IAP. Conclusions: Our results indicate an effect of IAP on the establishing early microbiota during the first months of life, which represent a key moment for the development of the microbiota-induced host homeostasis. Understanding the impact of IAP in the gut microbiota development is essential for developing treatments to minimize it, favoring a proper gut microbiota development in IAP-exposed neonates.
  • Intervention strategies for cesarean section–induced alterations in the microbiota-gut-brain axis

    Moya-Pérez, Angela; Luczynski, Pauline; Renes, Ingrid B.; Wang, Shugui; Borre, Yuliya; Anthony Ryan, C.; Knol, Jan; STANTON, CATHERINE; Dinan, Timothy G.; Cryan, John F.; et al. (Oxford University Press (OUP), 2017-04-01)
    Microbial colonization of the gastrointestinal tract is an essential process that modulates host physiology and immunity. Recently, researchers have begun to understand how and when these microorganisms colonize the gut and the early-life factors that impact their natural ecological establishment. The vertical transmission of maternal microbes to the offspring is a critical factor for host immune and metabolic development. Increasing evidence also points to a role in the wiring of the gut-brain axis. This process may be altered by various factors such as mode of delivery, gestational age at birth, the use of antibiotics in early life, infant feeding, and hygiene practices. In fact, these early exposures that impact the intestinal microbiota have been associated with the development of diseases such as obesity, type 1 diabetes, asthma, allergies, and even neurodevelopmental disorders. The present review summarizes the impact of cesarean birth on the gut microbiome and the health status of the developing infant and discusses possible preventative and restorative strategies to compensate for early-life microbial perturbations.
  • Human gut homeostasis and regeneration: the role of the gut microbiota and its metabolites

    Arenas-Gómez, Claudia Marcela; Garcia-Gutierrez, Enriqueta; Escobar, Juan S.; Cotter, Paul D.; Marie Skłodowska-Curie grant; Science Foundation Ireland; Department of Agriculture, Food and the Marine; Enterprise Ireland; European Commission; 847402; et al. (Informa UK Limited, 2022-11-11)
    The healthy human gut is a balanced ecosystem where host cells and representatives of the gut microbiota interact and communicate in a bidirectional manner at the gut epithelium. As a result of these interactions, many local and systemic processes necessary for host functionality, and ultimately health, take place. Impairment of the integrity of the gut epithelium diminishes its ability to act as an effective gut barrier, can contribute to conditions associated to inflammation processes and can have other negative consequences. Pathogens and pathobionts have been linked with damage of the integrity of the gut epithelium, but other components of the gut microbiota and some of their metabolites can contribute to its repair and regeneration. Here, we review what is known about the effect of bacterial metabolites on the gut epithelium and, more specifically, on the regulation of repair by intestinal stem cells and the regulation of the immune system in the gut. Additionally, we explore the potential therapeutic use of targeted modulation of the gut microbiota to maintain and improve gut homeostasis as a mean to improve health outcomes.
  • The potential of non-starter lactic acid bacteria from Cheddar cheese to colonise the gut

    Leeuwendaal, N.; STANTON, CATHERINE; O'Toole, P.W.; Beresford, Tom P.; Teagasc Walsh Fellowship; Science Foundation Ireland; JPI Food Processing for Health; 2014073 (Elsevier, 2021-08-31)
    This study was undertaken to assess the potential of Non-Starter Lactic Acid Bacteria (NSLAB) from Cheddar cheese to survive gastric transit and display probiotic-related traits including bile salt hydrolase activity, the ability to adhere to the gut epithelium and inhibition of enteropathogen binding. Populations of NSLAB, up to 107 CFU/g per cheese were recovered following exposure of cheese to Simulated Stomach Duodenum Passage (SSDP) conditions. A total of 240 isolates were randomly selected from twelve Cheddar cheeses and assessed for probiotic traits. Two strains Lactobacillus paracasei DPC 7150 and Lactobacillus rhamnosus DPC 7102 showed the most probiotic potential. The Lb. paracasei and Lb. rhamnosus strains displayed adhesion rates of 64% and 79%, respectively and inhibited binding of pathogenic Escherichia coli by >20%. This research demonstrates that Cheddar cheese harbours potentially beneficial bacteria, a large portion of which can survive simulated digestion and potentially exhibit health beneficial effects once ingested.
  • High-Pressure Processing on Whole and Peeled Potatoes: Influence on Polyphenol Oxidase, Antioxidants, and Glycaemic Indices

    Tsikrika, Konstantina; Muldoon, Aine; O'Brien, Nora, M.; Rai, Dilip; Department of Agriculture, Food and the Marine; 17/F/299 (Multidisciplinary Digital Publishing Institute, 2021-10-13)
    Polyphenol oxidase (PPO) inactivation in five whole and peeled Irish potato cultivars was investigated using high-pressure processing (HPP) at 400 MPa and 600 MPa for 3 min. PPO activity was significantly lower in most of the HPP-treated samples, while the highest PPO inactivation was observed after HPP at 600 MPa. No significant (p > 0.05) changes were observed on the total phenolic content and antioxidant activity of all the HPP-treated potatoes. Regarding individual phenolic acids, chlorogenic acid was decreased significantly (p < 0.05) in all studied varieties with a concomitant increase (p < 0.05) in caffeic and quinic acid. Similarly, ferulic acid was also increased (p < 0.05) in all studied varieties after the HPP treatment, while there was a variation in rutin and 4-coumaric acid levels depending on the cultivar and the sample type. Anthocyanins in the coloured whole potato varieties (i.e., Kerr’s Pink and Rooster), tentatively identified as pelargonidin-O-ferulorylrutinoside-O-hexoside and pelargonidin-O-rutinoside-O-hexoside, also exhibited significantly (p < 0.05) higher levels in the HPP-treated samples as opposed to those untreated. Glycaemic indices of the potatoes treated with HPP did not differ with the corresponding untreated cultivars.
  • Migration of Cefquinome Antibiotic Residues from Milk to Dairy Products

    Di Rocco, Melissa; Scollard, Jonathan; Sayers, Riona; Furey, Ambrose; Danaher, Martin; Jordan, Kieran; Lourenco, Antonio; Department of Agriculture, Food, and the Marine; 13/F/484 (Multidisciplinary Digital Publishing Institute, 2021-11-19)
    The aim of this study was to investigate the distribution of cefquinome in different dairy products during the processing of naturally contaminated milk or spiked milk. The analysis of cefquinome residues in milk, skimmed milk, buttermilk, whey, cream, butter, curd, and cheese samples was performed using a water:acetonitrile solvent extraction and C18 dispersive solid-phase extraction (d-SPE) clean-up, followed by ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS) determination. The target concentration of cefquinome was achieved in the spiked milk (100 µg kg−1). During its processing, the antibiotic migrated primarily with the skimmed milk as opposed to cream (ratios of 3.6:1 and 2.8:1 for experiments A and B, respectively), and with the buttermilk during butter manufacture (ratios of 6.9:1 and 4.6:1), but was equal in the curd and whey during the manufacture of cheese. In the milk collected from treated animals, the measured concentration of cefquinome was considerably high (approx. 5000 µg kg−1). The results obtained from the dairy products were similar to those obtained in the spiked study (ratios of 8.2:1 and 3.1:1 for experiments A and B, respectively, during the separation of skimmed milk and cream; 6.0:1 and 5.0:1 for A and B, respectively, during the separation of buttermilk and butter). However, during cheesemaking, cefquinome migrated with the whey after cutting the curd, with ratios of 0.54:1 and 0.44:1 for experiments A and B, respectively. The difference in the migration of cefquinome between curd and whey in spiked and animal studies is probably due to the different concentration levels in the two different experiments. The results of this study showed that, in dairy products manufactured from milk containing cefquinome residues, the drug migrated primarily with the high-water-containing fractions.
  • Rehydration Properties of Whey Protein Isolate Powders Containing Nanoparticulated Proteins

    Guralnick, Jacob R.; Panthi, Ram R.; Cenini, Valeria L.; Mishra, Vinay S. N.; O’Hagan, Barry M. G.; Crowley, Shane V.; O’Mahony, James A.; Irish Department of Agriculture, Food and the Marine; Department of Agriculture, Environment and Rural Affairs in Northern Ireland; DAIRYDRY 15-F-679 (Multidisciplinary Digital Publishing Institute, 2021-10-27)
    The rehydration properties of original whey protein isolate (WPIC) powder and spray-dried WPI prepared from either unheated (WPIUH) or nanoparticulated WPI solutions were investigated. Nanoparticulation of whey proteins was achieved by subjecting reconstituted WPIC solutions (10% protein, w/w, pH 7.0) to heat treatment at 90 °C for 30 s with no added calcium (WPIH) or with 2.5 mM added calcium (WPIHCa). Powder surface nanostructure and elemental composition were investigated using atomic force microscopy and X-ray photoelectron spectroscopy, followed by dynamic visualisation of wetting and dissolution characteristics using environmental scanning electron microscopy. The surface of powder particles for both WPIUH and WPIC samples generally appeared smooth, while WPIH and WPIHCa displayed micro-wrinkles with more significant deposition of nitrogen and calcium elements. WPIH and WPIHCa exhibited lower wettability and solubility performance than WPIUH and WPIC during microscopic observation. This study demonstrated that heat-induced aggregation of whey proteins, in the presence or absence of added calcium, before drying increases aggregate size, alters the powder surface properties, consequently impairing their wetting characteristics. This study also developed a fundamental understanding of WPI powder obtained from nanoparticulated whey proteins, which could be applied for the development of functional whey-based ingredients in food formulations, such as nanospacers to modulate protein–protein interactions in dairy concentrates.
  • Changes to the Oligosaccharide Profile of Bovine Milk at the Onset of Lactation

    Quinn, Erin M.; O'Callaghan, Tom F.; T. Tobin, John; Murphy, John Paul; Sugrue, Katie; Slattery, Helen; O'Donovan, Michael; Hickey, Rita M.; Teagasc (Multidisciplinary Digital Publishing Institute, 2020-12-01)
    Numerous bioactive components exist in human milk including free oligosaccharides, which represent some of the most important, and provide numerous health benefits to the neonate. Considering the demonstrated value of these compounds, much interest lies in characterising structurally similar oligosaccharides in the dairy industry. In this study, the impacts of days post-parturition and parity of the cows on the oligosaccharide and lactose profiles of their milk were evaluated. Colostrum and milk samples were obtained from 18 cows 1–5 days after parturition. Three distinct phases were identified using multivariate analysis: colostrum (day 0), transitional milk (days 1–2) and mature milk (days 3–5). LS-tetrasaccharide c, lacto-N-neotetraose, disialyllacto-N-tetraose, 3’-sial-N-acetyllactosamine, 3’-sialyllactose, lacto-N-neohexaose and disialyllactose were found to be highly affiliated with colostrum. Notably, levels of lactose were at their lowest concentration in the colostrum and substantially increased 1-day post-parturition. The cow’s parity was also shown to have a significant effect on the oligosaccharide profile, with first lactation cows containing more disialyllacto-N-tetraose, 6’-sialyllactose and LS-tetrasaccharide compared to cows in their second or third parity. Overall, this study identifies key changes in oligosaccharide and lactose content that clearly distinguish colostrum from transitional and mature milk and may facilitate the collection of specific streams with divergent biological functions.
  • Lactobacillus rhamnosus GG soluble mediators ameliorate early life stress-induced visceral hypersensitivity and changes in spinal cord gene expression

    McVey Neufeld, Karen-Anne; Strain, Conall R.; Pusceddu, Matteo M.; Waworuntu, Rosaline V.; Manurung, Sarmauli; Gross, Gabriele; M. Moloney, Gerry; Hoban, Alan E.; Murphy, Kiera; STANTON, CATHERINE; et al. (Portland Press Ltd., 2020-11-23)
    Visceral hypersensitivity is a hallmark of many functional and stress-related gastrointestinal disorders, and there is growing evidence that the gut microbiota may play a role in its pathophysiology. It has previously been shown that early life stress-induced visceral sensitivity is reduced by various probiotic strains of bacteria (including Lactobacillus rhamnosus GG (LGG)) alone or in combination with prebiotic fibres in rat models. However, the exact mechanisms underpinning such effects remain unresolved. Here, we investigated if soluble mediators derived from LGG can mimic the bacteria’s effects on visceral hypersensitivity and the microbiota–gut–brain axis. Rats were exposed to maternal separation (MS) from postnatal days 2–12. From weaning onwards both non-separated (NS) and MS offspring were provided drinking water with or without supplementation of standardized preparations of the LGG soluble mediators (LSM). Our results show that MS led to increased visceral sensitivity and exaggerated corticosterone plasma levels following restraint stress in adulthood, and both of these effects were ameliorated through LSM supplementation. Differential regulation of various genes in the spinal cord of MS versus NS rats was observed, 41 of which were reversed by LSM supplementation. At the microbiota composition level MS led to changes in beta diversity and abundance of specific bacteria including parabacteroides, which were ameliorated by LSM. These findings support probiotic soluble mediators as potential interventions in the reduction of symptoms of visceral hypersensitivity.
  • The gut microbiome influences the bioavailability of olanzapine in rats

    Cussotto, Sofia; Walsh, Jacinta; Golubeva, Anna V.; Zhdanov, Alexander V.; Strain, Conall R.; Fouhy, Fiona; STANTON, CATHERINE; Dinan, Timothy G.; Hyland, Niall P.; Clarke, Gerard; et al. (Elsevier BV, 2021-03-11)
    Background: The role of the gut microbiome in the biotransformation of drugs has recently come under scrutiny. It remains unclear whether the gut microbiome directly influences the extent of drug absorbed after oral administration and thus potentially alters clinical pharmacokinetics. Methods: In this study, we evaluated whether changes in the gut microbiota of male Sprague Dawley rats, as a result of either antibiotic or probiotic administration, influenced the oral bioavailability of two commonly prescribed antipsychotics, olanzapine and risperidone. Findings: The bioavailability of olanzapine, was significantly increased (1.8-fold) in rats that had undergone antibiotic-induced depletion of gut microbiota, whereas the bioavailability of risperidone was unchanged. There was no direct effect of microbiota depletion on the expression of major CYP450 enzymes involved in the metabolism of either drug. However, the expression of UGT1A3 in the duodenum was significantly downregulated. The reduction in faecal enzymatic activity, observed during and after antibiotic administration, did not alter the ex vivo metabolism of olanzapine or risperidone. The relative abundance of Alistipes significantly correlated with the AUC of olanzapine but not risperidone. Interpretation: Alistipes may play a role in the observed alterations in olanzapine pharmacokinetics. The gut microbiome might be an important variable determining the systemic bioavailability of orally administered olanzapine. Additional research exploring the potential implication of the gut microbiota on the clinical pharmacokinetics of olanzapine in humans is warranted.
  • Shared and non-shared sIgA-coated and uncoated bacteria in intestine of mother-infant pairs

    Ding, Mengfan; Chen, Haiqin; Yu, Renqiang; Ross, R. Paul; STANTON, CATHERINE; Zhang, Hao; Yang, Bo; Chen, Wei; National Key R&D Program of China; National Natural Science Foundation of China; et al. (Research Square Platform LLC, 2022-04-20)
    Background The infant gut microbiota is critical for promoting and maintaining early life health. Bacteria coated by secretory immunoglobulin A (sIgA) may help commensal bacteria colonize the gastrointestinal tract. The study aimed to analyze the composition of sIgA-coated and sIgA-uncoated bacterial communities at genus level, and lactobacilli and bifidobacterial communities at species level in human breast milk (HBM), infant, and maternal feces. Results Eleven pregnant women were recruited successfully. HBM, infant feces during colostrum, transition, and mature stages, and maternal feces within the mature stage were collected. sIgA-coated and sIgAuncoated bacteria were separated with magnetic-activated cell sorting. Then 16S rRNA sequencing, bifidobacterial groEL gene sequencing, and lactobacilli groEL gene sequencing were performed to analyze the bacterial community. The richness of sIgA-coated bacteria was significantly higher than that of sIgA-uncoated bacteria in HBM. PCoA revealed that the compositions of sIgA-coated and sIgAuncoated bacteria were different among HBM, infant and maternal feces. The dominant sIgA-coated bacteria in those samples were Escherichia/shigella and the dominant sIgA-uncoated bacteria was Pseudomonas. Higher relative abundance of sIgA-uncoated Bifidobacterium was found in the three lactation stages in infant feces compared to the corresponding HBM, and a higher relative abundance of sIgA-uncoated Faecalibacterium was found in maternal feces compared to HBM and infant feces. For the bifidobacterial community, PCoA analysis revealed a significantly different Bifidobacterium composition only in the sIgA-uncoated segments of infant feces and maternal feces. sIgA-coated and sIgA-uncoated B. longum subsp. infantis and B. pseudocatenulatum was dominant in infant feces and maternal feces, respectively. Additionally, the relative abundance of sIgA-uncoated B. longum subsp. infantis was significantly higher in infant feces compared to that in maternal feces. For the Lactobacillus community, the composition was significantly different in infant and maternal feces, while at species level, L. paragasseri and L. mucosae were dominant in infant and maternal feces, respectively. Conclusion HBM, infant, and maternal feces showed distinct diversity and composition of both sIgA-coated and sIgAuncoated bacteria at genus level. Infant and maternal feces showed similar diversity and similar composition of Bifidobacterium at species level. The same Bifidobacterium species could be detected both in sIgA-coated and sIgA-uncoated form
  • Bifidobacterium longum counters the effects of obesity: Partial successful translation from rodent to human

    Schellekens, Harriët; Torres-Fuentes, Cristina; van de Wouw, Marcel; Long-Smith, Caitriona M.; Mitchell, Avery; Strain, Conall; Berding, Kirsten; Bastiaanssen, Thomaz, F. S.; Rea, Kieran; Golubeva, Anna V.; et al. (Elsevier, 2021-01-31)
    BackgroundThe human gut microbiota has emerged as a key factor in the development of obesity. Certain probiotic strains have shown anti-obesity effects. The objective of this study was to investigate whether Bifidobacterium longum APC1472 has anti-obesity effects in high-fat diet (HFD)-induced obese mice and whether B. longum APC1472 supplementation reduces body-mass index (BMI) in healthy overweight/obese individuals as the primary outcome. B. longum APC1472 effects on waist-to-hip ratio (W/H ratio) and on obesity-associated plasma biomarkers were analysed as secondary outcomes. MethodsB. longum APC1472 was administered to HFD-fed C57BL/6 mice in drinking water for 16 weeks. In the human intervention trial, participants received B. longum APC1472 or placebo supplementation for 12 weeks, during which primary and secondary outcomes were measured at the beginning and end of the intervention. FindingsB. longum APC1472 supplementation was associated with decreased bodyweight, fat depots accumulation and increased glucose tolerance in HFD-fed mice. While, in healthy overweight/obese adults, the supplementation of B. longum APC1472 strain did not change primary outcomes of BMI (0.03, 95% CI [-0.4, 0.3]) or W/H ratio (0.003, 95% CI [-0.01, 0.01]), a positive effect on the secondary outcome of fasting blood glucose levels was found (-0.299, 95% CI [-0.44, -0.09]). InterpretationThis study shows a positive translational effect of B. longum APC1472 on fasting blood glucose from a preclinical mouse model of obesity to a human intervention study in otherwise healthy overweight and obese individuals. This highlights the promising potential of B. longum APC1472 to be developed as a valuable supplement in reducing specific markers of obesity. FundingThis research was funded in part by Science Foundation Ireland in the form of a Research Centre grant (SFI/12/RC/2273) to APC Microbiome Ireland and by a research grant from Cremo S.A.
  • Comparison of lactose free and traditional mozzarella cheese during shelf-life by aroma compounds and sensory analysis

    Condurso, Concetta; Tripodi, Gianluca; Merlino, Maria; Prestia, Ottavia; STANTON, CATHERINE; Verzera, Antonella; Italian Ministry for Education, University and Research; AIM 1823923-3 - CUP J44I18000190006 (Elsevier, 2021-04-30)
    Aroma compounds and sensory features of lactose free (LFM) and traditional (TM) Mozzarella cheese have been investigated during their labeled shelf-life. Acetoin and 2-heptanone characterized both types of cheese at the production time. During the shelf-life, a statistically significant increase in the amount of the volatiles coming from amino acid and fatty acid metabolism occurred in the LFM samples after 8 days of storage and, to a lesser extent, in TM cheese after 13 days of storage. As regard sensory analysis, milk odor and milk flavor descriptors characterized TM and LFM in the early stage of their shelf-life; bitter and acid taste and yoghurt odor descriptors characterized LFM after 8 days and TM after 13 days. The differences between the two cheese types can be attributed to the proteolytic activity of the lactase enzyme. As a result, the volatile aroma profile and the sensory quality should be taken into account for a proper shelf-life definition of Mozzarella cheese and a shorter shelf-life should be suggested for LFM than TM cheese.
  • Assessing the ability of nisin A and derivatives thereof to inhibit gram-negative bacteria from the genus Thermus

    Jonnala, Bhagya R. Yeluri; Feehily, Conor; O'Connor, Paula M.; Field, Des; Hill, Colin; Ross, R Paul; McSweeney, P.L.H.; Sheehan, Diarmuid (JJ); Cotter, Paul D; Teagasc Walsh Fellowship Programme; et al. (Elsevier, 2021-03-31)
    Nisin is a bacteriocin that is globally employed as a biopreservative in food systems to control gram-positive, and some gram-negative, bacteria. Here we tested the bioactivity of nisin A-producing Lactococcus lactis NZ9700 and producers of bioengineered variants thereof against representatives of the gram-negative genus Thermus, which has been associated with the pink discoloration defect in cheese. Starting with a total of 73 nisin variant-producing Lactococcus lactis, bioactivity against Thermus was assessed via agar diffusion assays, and 22 variants were found to have bioactivity greater than or equal to that of the nisin A-producing control. To determine to what extent this enhanced bioactivity was attributable to an increase in specific activity, minimum inhibitory concentrations were determined using the corresponding purified form of these 22 nisin A derivatives. From these experiments, nisin M17Q and M21F were identified as peptides with enhanced antimicrobial activity against the majority of Thermus target strains tested. In addition, several other peptide variants were found to exhibit enhanced specific activity against a subset of strains.
  • Improvements in sleep indices during exam stress due to consumption of a Bifidobacterium longum

    Moloney, Gerard M.; Long-Smith, Caitriona M.; Murphy, Amy; Dorland, Danielle; Hojabri, Sara Firuzeh; Ramirez, Loreto Olavarría; Marin, David Campos; Bastiaanssen, Thomaz, F. S.; Cusack, Anne-Marie; Berding, Kirsten; et al. (Elsevier, 2021-01-31)
    Targeting the gut microbiome as an effective therapeutic strategy for psychological disorders has shown promise in recent years. Variation in the composition of the microbiota and restoration of a stable microbiome using targeted interventions (psychobiotics) including Bifidobacteria have shown promise in pre-clinical studies, but more human data is required on the potential health benefits of these live microorganisms. Bifidobacterium including Bif. longum 1714 has been shown to dampen the effects of acute stress in humans. However, its effects over a period of prolonged stress have not been examined. A randomised, placebo-controlled, repeated measures, cross-over intervention study was conducted to examine the effects of a probiotic intervention on measures of stress, cognitive performance, and mood in healthy human volunteers. Twenty male students participated in this crossover study. Post-intervention assessments took place during the university exam period, which was used as a naturalistic chronic stressor. Self-reported measures of stress, depression, sleep quality, physical activity, gastrointestinal symptoms, cognition, and mood were assessed by questionnaire. In addition, tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered to all participants. Stress and depression scores increased in both placebo and probiotic treated groups during the exam period. While overall sleep quality and duration of sleep improved significantly in the probiotic treated group during exam stress compared with the placebo treated group, B. longum 1714, similar to placebo treatment, showed no efficacy in improving measures of working memory, visual memory, sustained attention or perception. Overall, while B. longum 1714 shows promise in improving sleep quality and duration, it did not alleviate symptoms of chronic stress, depression, or any measure of cognitive assessment. Thus, further mechanistic studies into the ability of B. longum 1714 to modulate sleep during prolonged periods of stress are now warranted.
  • The Prebiotic Effect of Australian Seaweeds on Commensal Bacteria and Short Chain Fatty Acid Production in a Simulated Gut Model

    Shannon, Emer; Conlon, Michael; Hayes, Maria (MDPI AG, 2022-05-23)
    Diet is known to affect the composition and metabolite production of the human gut microbial community, which in turn is linked with the health and immune status of the host. Whole seaweeds (WH) and their extracts contain prebiotic components such as polysaccharides (PS) and polyphenols (PP). In this study, the Australian seaweeds, Phyllospora comosa, Ecklonia radiata, Ulva ohnoi, and their PS and PP extracts were assessed for potential prebiotic activities using an in vitro gut model that included fresh human faecal inoculum. 16S rRNA sequencing post gut simulation treatment revealed that the abundance of several taxa of commensal bacteria within the phylum Firmicutes linked with short chain fatty acid (SCFA) production, and gut and immune function, including the lactic acid producing order Lactobacillales and the chief butyrate-producing genera Faecalibacteria, Roseburia, Blautia, and Butyricicoccus were significantly enhanced by the inclusion of WH, PS and PP extracts. After 24 h fermentation, the abundance of total Firmicutes ranged from 57.35–81.55% in the WH, PS and PP samples, which was significantly greater (p ≤ 0.01) than the inulin (INU) polysaccharide control (32.50%) and the epigallocatechingallate (EGCG) polyphenol control (67.13%); with the exception of P. comosa PP (57.35%), which was significantly greater than INU only. However, all WH, PS and PP samples also increased the abundance of the phylum Proteobacteria; while the abundance of the phylum Actinobacteria was decreased by WH and PS samples. After 24 h incubation, the total and individual SCFAs present, including butyric, acetic and propionic acids produced by bacteria fermented with E. radiata and U. ohnoi, were significantly greater than the SCFAs identified in the INU and EGCG controls. Most notably, total SCFAs in the E. radiata PS and U. ohnoi WH samples were 227.53 and 208.68 µmol/mL, respectively, compared to only 71.05 µmol/mL in INU and 7.76 µmol/mL in the EGCG samples. This study demonstrates that whole seaweeds and their extracts have potential as functional food ingredients to support normal gut and immune function.

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