• Analysis of Health Benefits Conferred by Lactobacillus Species from Kefir

      Cotter, Paul D.; Slattery, Conor; O'Toole, Paul W.; Department of Agriculture, Food and Marine; Science Foundation Ireland; APC Microbiome Ireland; Vistamilk; Enterprise Ireland; European Union; 818368 (MDPI, 2019-06-01)
      Lactobacilli are among the most common microorganisms found in kefir; a traditional fermented milk beverage produced locally in many locations around the world. Kefir has been associated with a wide range of purported health benefits; such as antimicrobial activity; cholesterol metabolism; immunomodulation; anti-oxidative effects; anti-diabetic effects; anti-allergenic effects; and tumor suppression. This review critically examines and assesses these claimed benefits and mechanisms with regard to particular Lactobacillus species and/or strains that have been derived from kefir; as well as detailing further potential avenues for experimentation.
    • Breast Milk, a Source of Beneficial Microbes and Associated Benefits for Infant Health

      Lyons, Katríona E.; Ryan, C. Anthony; Dempsey, Eugene M.; Ross, R Paul; STANTON, CATHERINE; Department of Agriculture, Food and the Marine; Science Foundation Ireland; 15F721 (MDPI AG, 2020-04-09)
      Human breast milk is considered the optimum feeding regime for newborn infants due to its ability to provide complete nutrition and many bioactive health factors. Breast feeding is associated with improved infant health and immune development, less incidences of gastrointestinal disease and lower mortality rates than formula fed infants. As well as providing fundamental nutrients to the growing infant, breast milk is a source of commensal bacteria which further enhance infant health by preventing pathogen adhesion and promoting gut colonisation of beneficial microbes. While breast milk was initially considered a sterile fluid and microbes isolated were considered contaminants, it is now widely accepted that breast milk is home to its own unique microbiome. The origins of bacteria in breast milk have been subject to much debate, however, the possibility of an entero-mammary pathway allowing for transfer of microbes from maternal gut to the mammary gland is one potential pathway. Human milk derived strains can be regarded as potential probiotics; therefore, many studies have focused on isolating strains from milk for subsequent use in infant health and nutrition markets. This review aims to discuss mammary gland development in preparation for lactation as well as explore the microbial composition and origins of the human milk microbiota with a focus on probiotic development.
    • Gut microbiota as a source of novel antimicrobials

      Garcia-Gutierrez, Enriqueta; Mayer, Melinda J.; Cotter, Paul D.; Narbad, Arjan; Teagasc; Science Foundation Ireland; Biotechnology and Biological Sciences Research Council; 2015066; SFI/12/RC/2273; SFI/11/PI/1137; et al. (Taylor & Francis, 2019-05-22)
      Bacteria, Archaea, Eukarya and viruses coexist in the human gut, and this coexistence is functionally balanced by symbiotic or antagonistic relationships. Antagonism is often characterized by the production of antimicrobials against other organisms occupying the same environmental niche. Indeed, close co-evolution in the gut has led to the development of specialized antimicrobials, which is attracting increased attention as these may serve as novel alternatives to antibiotics and thereby help to address the global problem of antimicrobial resistance. The gastrointestinal (GI) tract is especially suitable for finding novel antimicrobials due to the vast array of microbes that inhabit it, and a considerable number of antimicrobial producers of both wide and narrow spectrum have been described. In this review, we summarize some of the antimicrobial compounds that are produced by bacteria isolated from the gut environment, with a special focus on bacteriocins. We also evaluate the potential therapeutic application of these compounds to maintain homeostasis in the gut and the biocontrol of pathogenic bacteria.
    • Lactic Acid Bacteria and Bifidobacteria with Potential to Design Natural Biofunctional Health-Promoting Dairy Foods

      Linares, Daniel M.; Gomez, Carolina; Renes, Erica; Fresno, José M.; Tornadijo, María E.; Ross, R Paul; STANTON, CATHERINE; Science Foundation Ireland (Frontiers, 2017-05-18)
      Consumer interest in healthy lifestyle and health-promoting natural products is a major driving force for the increasing global demand of biofunctional dairy foods. A number of commercial sources sell synthetic formulations of bioactive substances for use as dietary supplements. However, the bioactive-enrichment of health-oriented foods by naturally occurring microorganisms during dairy fermentation is in increased demand. While participating in milk fermentation, lactic acid bacteria can be exploited in situ as microbial sources for naturally enriching dairy products with a broad range of bioactive components that may cover different health aspects. Several of these bioactive metabolites are industrially and economically important, as they are claimed to exert diverse health-promoting activities on the consumer, such as anti-hypertensive, anti-inflammatory, and anti-diabetic, anti-oxidative, immune-modulatory, anti-cholesterolemic, or microbiome modulation. This review aims at discussing the potential of these health-supporting bacteria as starter or adjunct cultures for the elaboration of dairy foods with a broad spectrum of new functional properties and added value.
    • Lactic Acid Bacteria and Bifidobacteria with Potential to Design Natural Biofunctional Health-Promoting Dairy Foods

      Linares, Daniel M.; Gomez, Carolina; Renes, Erica; Fresno, José M.; Tornadijo, María E.; Ross, R Paul; STANTON, CATHERINE; JPI Food Processing for Health; Science Foundation Ireland (Frontiers, 2017-05-18)
      Consumer interest in healthy lifestyle and health-promoting natural products is a major driving force for the increasing global demand of biofunctional dairy foods. A number of commercial sources sell synthetic formulations of bioactive substances for use as dietary supplements. However, the bioactive-enrichment of health-oriented foods by naturally occurring microorganisms during dairy fermentation is in increased demand. While participating in milk fermentation, lactic acid bacteria can be exploited in situ as microbial sources for naturally enriching dairy products with a broad range of bioactive components that may cover different health aspects. Several of these bioactive metabolites are industrially and economically important, as they are claimed to exert diverse health-promoting activities on the consumer, such as anti-hypertensive, anti-inflammatory, and anti-diabetic, anti-oxidative, immune-modulatory, anti-cholesterolemic, or microbiome modulation. This review aims at discussing the potential of these health-supporting bacteria as starter or adjunct cultures for the elaboration of dairy foods with a broad spectrum of new functional properties and added value.
    • The Potential Impact of Probiotics on the Gut Microbiome of Athletes

      Wosinska, Laura; Cotter, Paul D.; O’Sullivan, Orla; Guinane, Caitriona; Science Foundation Ireland; SFI/12/RC/2273 (MDPI AG, 2019-09-21)
      There is accumulating evidence that physical fitness influences the gut microbiome and as a result, promotes health. Indeed, exercise-induced alterations in the gut microbiome can influence health parameters crucial to athletic performance, specifically, immune function, lower susceptibility to infection, inflammatory response and tissue repair. Consequently, maintenance of a healthy gut microbiome is essential for an athlete’s health, training and performance. This review explores the effect of exercise on the microbiome while also investigating the effect of probiotics on various potential consequences associated with over-training in athletes, as well as their associated health benefits.
    • Production of multiple bacteriocins from a single locus by gastrointestinal strains of Lactobacillus salivarius

      O'Shea, Eileen F.; O'Connor, Paula M.; Raftis, Emma J.; O'Toole, Paul W.; STANTON, CATHERINE; Cotter, Paul D.; Ross, R Paul; Hill, Colin; Department of Agriculture, Food and the Marine, Ireland; Science Foundation Ireland; et al. (American Society for Microbiology, 07/10/2011)
      Bacteriocins produced by Lactobacillus salivarius isolates derived from gastrointestinal origin have previously demonstrated efficacy for in vivo protection against Listeria monocytogenes infection. In this study, comparative genomic analysis was employed to investigate the intraspecies diversity of seven L. salivarius isolates of human and porcine intestinal origin, based on the genome of the well characterised bacteriocin-producing strain L. salivarius UCC118. This revealed a highly conserved megaplasmid-encoded gene cluster in these strains involved in the regulation and secretion of two-component class IIb bacteriocins. However, considerable intraspecific variation was observed in the structural genes encoding the bacteriocin peptides. These ranged from close relatives of abp118 such as salivaricin P, which differs by 2 amino acids, to completely novel bacteriocins such as salivaricin T, which is characterized in this study. Salivaricin T inhibits closely related lactobacilli and bears little homology to previously characterized salivaricins. Interestingly, the two peptides responsible for salivaricin T activity, SalTα and SalTβ, share considerable identity with the component peptides of thermophilin 13, a bacteriocin produced by Streptococcus thermophilus. Furthermore, the salivaricin locus of strain DPC6488 also encodes an additional novel one-component class IId anti-listerial bacteriocin, salivaricin L. These findings suggest a high level of redundancy in the bacteriocins that can be produced by intestinal L. salivarius isolates using the same enzymatic production and export machinery. Such diversity may contribute to their ability to dominate and compete within the complex microbiota of the mammalian gut.
    • Subspecies diversity in bacteriocin production by intestinal Lactobacillus salivarius strains

      O'Shea, Eileen F.; O'Connor, Paula M.; Raftis, Emma J.; O'Toole, Paul W.; STANTON, CATHERINE; Cotter, Paul D.; Ross, R Paul; Hill, Colin; Department of Agriculture, Food and the Marine, Ireland; Science Foundation Ireland; et al. (Landes Bioscience, 2012-10)
      A recent comparative genomic hybridisation study in our laboratory revealed considerable plasticity within the bacteriocin locus of gastrointestinal strains of Lactobacillus salivarius. Most notably these analyses led to the identification of two novel unmodified bacteriocins salivaricin L and salivaricin T produced by the neonatal isolate L. salivarius DPC6488 with immunity, regulatory and export systems analogous to those of abp118, a two-component bacteriocin produced by the well characterized reference strain L. salivarius UCC118. In this addendum we discuss the intraspecific diversity of our seven bacteriocin-producing L. salivarius isolates on a genome-wide level, and more specifically, with respect to their salivaricin loci.