• Beneficial modulation of the gut microbiota

      Cotter, Paul D. (Elsevier, 2016-03-29)
      As the scientific community continues to develop an ever-greater understanding of the composition and function of the human gut microbiota, and the role of specific microbial populations in health and disease, attention has turned to the tools that are at our disposal with respect to altering these microbes in a beneficial way. The options available include the use of diet, probiotics/prebiotics, antimicrobials and, potentially, exercise. Here, our recent investigations of the relationship between protein, bacteriocin producing probiotics and exercise and the gut microbiota and, in turn, health will be described.
    • Beneficial modulation of the gut microbiota

      Cotter, Paul D. (Elsevier BV, 2016-04-01)
      As the scientific community continues to develop an ever-greater understanding of the composition and function of the human gut microbiota, and the role of specific microbial populations in health and disease, attention has turned to the tools that are at our disposal with respect to altering these microbes in a beneficial way. The options available include the use of diet, probiotics/prebiotics, antimicrobials and, potentially, exercise. Here, our recent investigations of the relationship between protein, bacteriocin producing probiotics and exercise and the gut microbiota and, in turn, health will be described.
    • Enduring Behavioral Effects Induced by Birth by Caesarean Section in the Mouse

      Morais, Livia H.; Golubeva, Anna V.; Moloney, Gerard M; Stanton, Catherine; Dinan, Timothy G.; Cryan, John F.; Science Foundation Ireland; European Union; Department of Agriculture, Food and the Marine; Science without Borders; et al. (2020-08-20)
      Birth by Caesarean (C)-section impacts early gut microbiota colonization and is associated with an increased risk of developing immune and metabolic disorders. Moreover, alterations of the microbiome have been shown to affect neurodevelopmental trajectories. However, the long-term effects of C-section on neurobehavioral processes remain unknown. Here, we demonstrated that birth by C-section results in marked but transient changes in microbiome composition in the mouse, in particular, the abundance of Bifidobacterium spp. was depleted in early life. Mice born by C-section had enduring social, cognitive, and anxiety deficits in early life and adulthood. Interestingly, we found that these specific behavioral alterations induced by the mode of birth were also partially corrected by co-housing with vaginally born mice. Finally, we showed that supplementation from birth with a Bifidobacterium breve strain, or with a dietary prebiotic mixture that stimulates the growth of bifidobacteria, reverses selective behavioral alterations in C-section mice. Taken together, our data link the gut microbiota to behavioral alterations in C-section-born mice and suggest the possibility of developing adjunctive microbiota-targeted therapies that may help to avert long-term negative consequences on behavior associated with C-section birth mode.
    • The gut microbiota and the liver. Pathophysiological and clinical implications

      Quigley, Eamonn M.M.; STANTON, CATHERINE; Murphy, Eileen F. (Elsevier BV, 2012-11-06)
      The term microbiota is used to describe the complete population of microorganisms that populate a certain location, such as the gut, and is preferred to the term flora as the former incorporates not just bacteria but also archaea, viruses, and other microorganisms, such as protozoa. Though the potential role of the microbiota (through such concepts as ‘‘the putrefactive principle associated with faeces’’ and ‘‘intestinal toxins’’) in the pathogenesis of systemic disorders has been recognized since antiquity, a firm scientific basis for a role for the gut microbiome in liver disease did not emerge until the middle of the last century with the recognition of the relationship between hepatic coma and the absorption of nitrogenous substances from the intestine [1]. This was followed by the description of abundant coliforms in the small intestine of cirrhotics [2] and the role of bacteria was clinched by trials demonstrating that antibiotics led to clinical improvement in hepatic encephalopathy (HE) [3]. Subsequently, these same gut-derived bacteria were implicated in another complication of chronic liver disease and portal hypertension, spontaneous bacterial peritonitis. Most recently, more credence has been given to a suggestion that has lingered in the background for decades, namely, that the gut microbiota might play a role in the pathogenesis or progression of certain liver diseases, including alcoholic liver disease [4], non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steato-hepatitis (NASH) [5], total parenteral nutrition (TPN)/intestinal failure-related liver disease (IFALD) [6], and primary sclerosing cholangitis (PSC) [7], either through the direct effects of bacteria or their products, via inflammatory mediators such as tumor necrosis factor a (TNF), whose release had been triggered by constituents of the microbiota, or, as in the case of primary sclerosing cholangitis (PSC), through cross-reactivity between microbial antigens and human tissue components (e.g., atypical anti-nuclear cytoplasmic antibodies (p-ANCA), in PSC, recognize both tubulin beta isoform 5 in human neutrophils, and the bacterial cell division protein FtsZ) [8]. Indeed, inflammatory mediators have also been implicated in the development and maintenance of the hyperdynamic circulation that is a feature of portal hypertension [9], in impairing liver function and contributing to haemostatic failure [10]. It is in these contexts that modulation of the microbiota has emerged as a potential therapeutic strategy in the management of liver disease
    • Potential Use of Biotherapeutic Bacteria to Target Colorectal Cancer-Associated Taxa

      Lawrence, Garreth W.; Begley, Máire; Cotter, Paul D.; Guinane, Caitriona M. (MDPI AG, 2020-01-30)
      The role of the gut microbiome in human health and disease is the focus of much attention. It has been widely agreed upon that our gut bacteria play a role in host immunity, nutrient absorption, digestion, metabolism, and other key drivers of health. Furthermore, certain microbial signatures and specific taxa have also been associated with the development of diseases, such as obesity; inflammatory bowel disease; and, indeed, colorectal cancer (CRC), which is the focus of this review. By extension, such taxa represent potential therapeutic targets. In particular, the emerging human pathogen Fusobacterium nucleatum represents an important agent in CRC development and its control within the gastrointestinal tract is desirable. This paper reviews the principal bacterial pathogens that have been associated with CRC to date and discusses the in vitro and human studies that have shown the potential use of biotherapeutic strains as a means of targeting CRC-associated bacteria.
    • Precision Nutrition and the Microbiome, Part I: Current State of the Science

      Mills, Susan; Stanton, Catherine; Lane, Jonathan; Smith, Graeme; Ross, R. (MDPI AG, 2019-04-24)
      The gut microbiota is a highly complex community which evolves and adapts to its host over a lifetime. It has been described as a virtual organ owing to the myriad of functions it performs, including the production of bioactive metabolites, regulation of immunity, energy homeostasis and protection against pathogens. These activities are dependent on the quantity and quality of the microbiota alongside its metabolic potential, which are dictated by a number of factors, including diet and host genetics. In this regard, the gut microbiome is malleable and varies significantly from host to host. These two features render the gut microbiome a candidate ‘organ’ for the possibility of precision microbiomics—the use of the gut microbiome as a biomarker to predict responsiveness to specific dietary constituents to generate precision diets and interventions for optimal health. With this in mind, this two-part review investigates the current state of the science in terms of the influence of diet and specific dietary components on the gut microbiota and subsequent consequences for health status, along with opportunities to modulate the microbiota for improved health and the potential of the microbiome as a biomarker to predict responsiveness to dietary components. In particular, in Part I, we examine the development of the microbiota from birth and its role in health. We investigate the consequences of poor-quality diet in relation to infection and inflammation and discuss diet-derived microbial metabolites which negatively impact health. We look at the role of diet in shaping the microbiome and the influence of specific dietary components, namely protein, fat and carbohydrates, on gut microbiota composition.