51
|
Milan AM, Cameron-Smith D. Digestion and Postprandial Metabolism in the Elderly. ADVANCES IN FOOD AND NUTRITION RESEARCH 2015; 76:79-124. [PMID: 26602572 DOI: 10.1016/bs.afnr.2015.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The elderly are an increasing segment of the population. Despite the rapid gains in medical knowledge and treatments, older adults are more likely to experience chronic illnesses that decrease quality of life and accelerate mortality. Nutrition is a key modifiable lifestyle factor which greatly impacts chronic disease risk. Yet despite the importance of nutrition, relatively little is known of the impact of advancing age on the gastrointestinal function, the digestive responses, and the post-meal metabolic adaptations that occur in response to ingested food. Knowledge of the age-related differences in digestion and metabolism in the elderly is essential to the development of appropriate nutritional recommendations for the maintenance of optimal health and prevention of disease.
Collapse
Affiliation(s)
- Amber M Milan
- Liggins Institute, University of Auckland, Auckland, New Zealand
| | | |
Collapse
|
52
|
de Oliveira Belém M, Cirilo CP, de Santi-Rampazzo AP, Schoffen JPF, Comar JF, Natali MRM, de Almeida Araújo EJ. Intestinal morphology adjustments caused by dietary restriction improves the nutritional status during the aging process of rats. Exp Gerontol 2015; 69:85-93. [DOI: 10.1016/j.exger.2015.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 12/27/2022]
|
53
|
Davitt CJ, Lavelle EC. Delivery strategies to enhance oral vaccination against enteric infections. Adv Drug Deliv Rev 2015; 91:52-69. [PMID: 25817337 DOI: 10.1016/j.addr.2015.03.007] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/25/2015] [Accepted: 03/12/2015] [Indexed: 01/22/2023]
Abstract
While the majority of human pathogens infect the body through mucosal sites, most licensed vaccines are injectable. In fact the only mucosal vaccine that has been widely used globally for infant and childhood vaccination programs is the oral polio vaccine (OPV) developed by Albert Sabin in the 1950s. While oral vaccines against Cholera, rotavirus and Salmonella typhi have also been licensed, the development of additional non-living oral vaccines against these and other enteric pathogens has been slow and challenging. Mucosal vaccines can elicit protective immunity at the gut mucosa, in part via antigen-specific secretory immunoglobulin A (SIgA). However, despite their advantages over the injectable route, oral vaccines face many hurdles. A key challenge lies in design of delivery strategies that can protect antigens from degradation in the stomach and intestine, incorporate appropriate immune-stimulatory adjuvants and control release at the appropriate gastrointestinal site. A number of systems including micro and nanoparticles, lipid-based strategies and enteric capsules have significant potential either alone or in advanced combined formulations to enhance intestinal immune responses. In this review we will outline the opportunities, challenges and potential delivery solutions to facilitate the development of improved oral vaccines for infectious enteric diseases.
Collapse
|
54
|
The Gut-Associated Lymphoid Tissues in the Small Intestine, Not the Large Intestine, Play a Major Role in Oral Prion Disease Pathogenesis. J Virol 2015; 89:9532-47. [PMID: 26157121 PMCID: PMC4542385 DOI: 10.1128/jvi.01544-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/01/2015] [Indexed: 01/09/2023] Open
Abstract
UNLABELLED Prion diseases are infectious neurodegenerative disorders characterized by accumulations of abnormally folded cellular prion protein in affected tissues. Many natural prion diseases are acquired orally, and following exposure, the early replication of some prion isolates upon follicular dendritic cells (FDC) within gut-associated lymphoid tissues (GALT) is important for the efficient spread of disease to the brain (neuroinvasion). Prion detection within large intestinal GALT biopsy specimens has been used to estimate human and animal disease prevalence. However, the relative contributions of the small and large intestinal GALT to oral prion pathogenesis were unknown. To address this issue, we created mice that specifically lacked FDC-containing GALT only in the small intestine. Our data show that oral prion disease susceptibility was dramatically reduced in mice lacking small intestinal GALT. Although these mice had FDC-containing GALT throughout their large intestines, these tissues were not early sites of prion accumulation or neuroinvasion. We also determined whether pathology specifically within the large intestine might influence prion pathogenesis. Congruent infection with the nematode parasite Trichuris muris in the large intestine around the time of oral prion exposure did not affect disease pathogenesis. Together, these data demonstrate that the small intestinal GALT are the major early sites of prion accumulation and neuroinvasion after oral exposure. This has important implications for our understanding of the factors that influence the risk of infection and the preclinical diagnosis of disease. IMPORTANCE Many natural prion diseases are acquired orally. After exposure, the accumulation of some prion diseases in the gut-associated lymphoid tissues (GALT) is important for efficient spread of disease to the brain. However, the relative contributions of GALT in the small and large intestines to oral prion pathogenesis were unknown. We show that the small intestinal GALT are the essential early sites of prion accumulation. Furthermore, congruent infection with a large intestinal helminth (worm) around the time of oral prion exposure did not affect disease pathogenesis. This is important for our understanding of the factors that influence the risk of prion infection and the preclinical diagnosis of disease. The detection of prions within large intestinal GALT biopsy specimens has been used to estimate human and animal disease prevalence. However, our data suggest that using these biopsy specimens may miss individuals in the early stages of oral prion infection and significantly underestimate the disease prevalence.
Collapse
|
55
|
Rémond D, Shahar DR, Gille D, Pinto P, Kachal J, Peyron MA, Dos Santos CN, Walther B, Bordoni A, Dupont D, Tomás-Cobos L, Vergères G. Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrition. Oncotarget 2015; 6:13858-98. [PMID: 26091351 PMCID: PMC4546438 DOI: 10.18632/oncotarget.4030] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 12/11/2022] Open
Abstract
Although the prevalence of malnutrition in the old age is increasing worldwide a synthetic understanding of the impact of aging on the intake, digestion, and absorption of nutrients is still lacking. This review article aims at filling the gap in knowledge between the functional decline of the aging gastrointestinal tract (GIT) and the consequences of malnutrition on the health status of elderly. Changes in the aging GIT include the mechanical disintegration of food, gastrointestinal motor function, food transit, chemical food digestion, and functionality of the intestinal wall. These alterations progressively decrease the ability of the GIT to provide the aging organism with adequate levels of nutrients, what contributes to the development of malnutrition. Malnutrition, in turn, increases the risks for the development of a range of pathologies associated with most organ systems, in particular the nervous-, muscoskeletal-, cardiovascular-, immune-, and skin systems. In addition to psychological, economics, and societal factors, dietary solutions preventing malnutrition should thus propose dietary guidelines and food products that integrate knowledge on the functionality of the aging GIT and the nutritional status of the elderly. Achieving this goal will request the identification, validation, and correlative analysis of biomarkers of food intake, nutrient bioavailability, and malnutrition.
Collapse
Affiliation(s)
- Didier Rémond
- UMR 1019, UNH, CRNH Auvergne, INRA, 63000 Clermont-Ferrand, France
- Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, 63000 Clermont-Ferrand, France
| | - Danit R. Shahar
- Department of Public Health, The S. Daniel Abraham International Center for Health and Nutrition, Ben-Gurion University of the Negev, 84105 Beer-Sheva, Israel
| | - Doreen Gille
- Institute for Food Sciences IFS, Agroscope, Federal Department of Economic Affairs, Education and Research EAER, 3003 Berne, Switzerland
| | - Paula Pinto
- Escola Superior Agrária, Insituto Politécnico de Santarém, 2001-904 Santarem, Portugal
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | | | - Marie-Agnès Peyron
- UMR 1019, UNH, CRNH Auvergne, INRA, 63000 Clermont-Ferrand, France
- Clermont Université, Université d'Auvergne, Unité de Nutrition Humaine, BP 10448, 63000 Clermont-Ferrand, France
| | - Claudia Nunes Dos Santos
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
- Instituto de Biologia Experimental e Tecnológica, 2780-157 Oeiras, Portugal
| | - Barbara Walther
- Institute for Food Sciences IFS, Agroscope, Federal Department of Economic Affairs, Education and Research EAER, 3003 Berne, Switzerland
| | - Alessandra Bordoni
- Department of Agri-Food Sciences and Technologies, University of Bologna, 47521 Cesena, Italy
| | - Didier Dupont
- UMR 1253, Science et Technologie du Lait & de l'Œuf, INRA, 35000 Rennes, France
| | | | - Guy Vergères
- Institute for Food Sciences IFS, Agroscope, Federal Department of Economic Affairs, Education and Research EAER, 3003 Berne, Switzerland
| |
Collapse
|
56
|
Visualization of the entire differentiation process of murine M cells: suppression of their maturation in cecal patches. Mucosal Immunol 2015; 8:650-60. [PMID: 25336168 DOI: 10.1038/mi.2014.99] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 09/21/2014] [Indexed: 02/04/2023]
Abstract
The microfold (M) cell residing in the follicle-associated epithelium is a specialized epithelial cell that initiates mucosal immune responses by sampling luminal antigens. The differentiation process of M cells remains unclear due to limitations of analytical methods. Here we found that M cells were classified into two functionally different subtypes based on the expression of Glycoprotein 2 (GP2) by newly developed image cytometric analysis. GP2-high M cells actively took up luminal microbeads, whereas GP2-negative or low cells scarcely ingested them, even though both subsets equally expressed the other M-cell signature genes, suggesting that GP2-high M cells represent functionally mature M cells. Further, the GP2-high mature M cells were abundant in Peyer's patch but sparse in the cecal patch: this was most likely due to a decrease in the nuclear translocation of RelB, a downstream transcription factor for the receptor activator of nuclear factor-κB signaling. Given that murine cecum contains a protrusion of beneficial commensals, the restriction of M-cell activity might contribute to preventing the onset of any excessive immune response to the commensals through decelerating the M-cell-dependent uptake of microorganisms.
Collapse
|
57
|
Mabbott NA, Kobayashi A, Sehgal A, Bradford BM, Pattison M, Donaldson DS. Aging and the mucosal immune system in the intestine. Biogerontology 2015; 16:133-45. [PMID: 24705962 DOI: 10.1007/s10522-014-9498-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 03/24/2014] [Indexed: 02/07/2023]
Abstract
Bacterial and viral infections of the gastrointestinal tract are more common in the elderly and represent a major cause of morbidity and mortality. The mucosal immune system provides the first line of defence against pathogens acquired by ingestion and inhalation, but its function is adversely affected in the elderly. This aging-related decline in the immune function is termed immunosenescence and is associated with diminished abilities to generate protective immunity, reduced vaccine efficacy, increased incidence of cancer, inflammation and autoimmunity, and the impaired ability to generate tolerance to harmless antigens. In this review we describe our current understanding of the effects immunosenescence has on the innate and adaptive arms of the mucosal immune system in the intestine. Current estimates suggest that by the year 2050 up to 40% of the UK population will be over 65 years old, bringing with it important health challenges. A thorough understanding of the mechanisms that contribute to the development of immunosenescence is therefore crucial to help identify novel approaches to improve mucosal immunity in the elderly.
Collapse
Affiliation(s)
- Neil A Mabbott
- The Roslin Institute & Royal (Dick) School of Veterinary Sciences, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK,
| | | | | | | | | | | |
Collapse
|
58
|
Sato S, Kiyono H, Fujihashi K. Mucosal Immunosenescence in the Gastrointestinal Tract: A Mini-Review. Gerontology 2014; 61:336-42. [PMID: 25531743 DOI: 10.1159/000368897] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 10/07/2014] [Indexed: 01/15/2023] Open
Abstract
It has been shown that pathogen-specific secretory IgA (SIgA) antibody (Ab) is the major player at mucosal surfaces for host defense. However, alterations in the mucosal immune system occur in advanced aging, which results in a failure of induction of SIgA Abs for the protection from infectious diseases. Signs of mucosal senescence first appear in the gut immune system. Further, changes in the intestinal microbiota most likely influence mucosal immunity. To overcome the immunological aging decline in mucosal immunity, several adjuvant systems including mucosal dendritic cell targeting have been shown to be attractive and effective immunological strategies. Similarly, microfold (M) cells involved in the antigen (Ag) uptake are ideal targets for facilitating Ag-specific mucosal immune responses. However, the numbers of M cells are reduced in aged mice. In this regard, Spi-B, an essential transcription factor for the functional and structural differentiation of M cells, could be a potent strategy for the induction of effective mucosal immunity in aging.
Collapse
Affiliation(s)
- Shintaro Sato
- Division of Mucosal Immunology, Department of Microbiology and Immunology, The University of Tokyo, Tokyo, Japan
| | | | | |
Collapse
|
59
|
Abstract
Most infectious diseases are caused by pathogenic infiltrations from the mucosal tract. Therefore, vaccines delivered to the mucosal tissues can mimic natural infections and provide protection at the first site of infection. Thus, mucosal, especially, oral delivery is becoming the most preferred mode of vaccination. However, oral vaccines have to overcome several barriers such as the extremely low pH of the stomach, the presence of proteolytic enzymes and bile salts as well as low permeability in the intestine. Several formulations based on nanoparticle strategies are currently being explored to prepare stable oral vaccine formulations. This review briefly discusses several molecular mechanisms involved in intestinal immune cell activation and various aspects of oral nanoparticle-based vaccine design that should be considered for improved mucosal and systemic immune responses.
Collapse
Affiliation(s)
- Nirmal Marasini
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia
| | | | | |
Collapse
|
60
|
Saffrey MJ. Aging of the mammalian gastrointestinal tract: a complex organ system. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9603. [PMID: 24352567 PMCID: PMC4082571 DOI: 10.1007/s11357-013-9603-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 11/25/2013] [Indexed: 05/23/2023]
Abstract
Gastrointestinal disorders are a major cause of morbidity in the elderly population. The gastrointestinal tract is the most complex organ system; its diverse cells perform a range of functions essential to life, not only secretion, digestion, absorption and excretion, but also, very importantly, defence. The gastrointestinal tract acts not only as a barrier to harmful materials and pathogens but also contains the vast number of beneficial bacterial populations that make up the microbiota. Communication between the cells of the gastrointestinal tract and the central nervous and endocrine systems modifies behaviour; the organisms of the microbiota also contribute to this brain-gut-enteric microbiota axis. Age-related physiological changes in the gut are not only common, but also variable, and likely to be influenced by external factors as well as intrinsic aging of the cells involved. The cellular and molecular changes exhibited by the aging gut cells also vary. Aging intestinal smooth muscle cells exhibit a number of changes in the signalling pathways that regulate contraction. There is some evidence for age-associated degeneration of neurons and glia of the enteric nervous system, although enteric neuronal losses are likely not to be nearly as extensive as previously believed. Aging enteric neurons have been shown to exhibit a senescence-associated phenotype. Epithelial stem cells exhibit increased mitochondrial mutation in aging that affects their progeny in the mucosal epithelium. Changes to the microbiota and intestinal immune system during aging are likely to contribute to wider aging of the organism and are increasingly important areas of analysis. How changes of the different cell types of the gut during aging affect the numerous cellular interactions that are essential for normal gut functions will be important areas for future aging research.
Collapse
Affiliation(s)
- M Jill Saffrey
- Department of Life Health and Chemical Sciences, Biomedical Research Network, The Open University, Milton Keynes, MK7 6AA, UK,
| |
Collapse
|
61
|
The impact of ageing on the intestinal epithelial barrier and immune system. Cell Immunol 2014; 289:112-8. [DOI: 10.1016/j.cellimm.2014.04.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 03/31/2014] [Accepted: 04/01/2014] [Indexed: 12/18/2022]
|
62
|
Microfold (M) cells: important immunosurveillance posts in the intestinal epithelium. Mucosal Immunol 2013; 6:666-77. [PMID: 23695511 PMCID: PMC3686595 DOI: 10.1038/mi.2013.30] [Citation(s) in RCA: 449] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The transcytosis of antigens across the gut epithelium by microfold cells (M cells) is important for the induction of efficient immune responses to some mucosal antigens in Peyer's patches. Recently, substantial progress has been made in our understanding of the factors that influence the development and function of M cells. This review highlights these important advances, with particular emphasis on: the host genes which control the functional maturation of M cells; how this knowledge has led to the rapid advance in our understanding of M-cell biology in the steady state and during aging; molecules expressed on M cells which appear to be used as "immunosurveillance" receptors to sample pathogenic microorganisms in the gut; how certain pathogens appear to exploit M cells to infect the host; and finally how this knowledge has been used to specifically target antigens to M cells to attempt to improve the efficacy of mucosal vaccines.
Collapse
|