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The ecology and immunology of the gastrointestinal tract in health and critical illness.

https://arctichealth.org/en/permalink/ahliterature225839
Source
J Hosp Infect. 1991 Sep;19 Suppl C:7-17
Publication Type
Article
Date
Sep-1991
Author
J C Marshall
Author Affiliation
Department of Surgery, University of Toronto, Canada.
Source
J Hosp Infect. 1991 Sep;19 Suppl C:7-17
Date
Sep-1991
Language
English
Publication Type
Article
Keywords
Critical Illness
Cross Infection - immunology
Digestive System - immunology - microbiology
Gastric Acid
Gram-Positive Bacteria - growth & development
Humans
Immunoglobulin A, Secretory - immunology
Lymphoid Tissue - immunology
Abstract
Interactions between the indigenous flora of the gastrointestinal tract and immunologically competent cells in the gut mucosa, gut-associated lymphoid tissues and liver play an important role in normal immune homeostasis. The microbial flora of the normal gut is complex, yet remarkably constant over time. The relative sterility of the upper gut is maintained by multiple factors including gastric acid, bile salts, normal motility and mucosal IgA, while the lower gut is densely colonized with a complex flora. An intact Gram-negative flora is a prerequisite for normal immunological maturation. On the other hand, overgrowth of the gut, particularly by Gram-negative bacteria or fungi, facilitates the translocation of bacteria into the host, and results in suppression of T-cell responses and altered hepatic Kupffer cell function. Bacterial overgrowth and the consequences of the interactions of this potentially pathogenic flora with the gut immune system may contribute to the septic state in critical illness, and to the syndrome of multiple organ failure.
PubMed ID
1684198 View in PubMed
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The gut as a potential trigger of exercise-induced inflammatory responses.

https://arctichealth.org/en/permalink/ahliterature203749
Source
Can J Physiol Pharmacol. 1998 May;76(5):479-84
Publication Type
Article
Date
May-1998
Author
J C Marshall
Author Affiliation
Department of Surgery, University of Toronto, Ontario, Canada. jmarshall@torhosp.toronto.on.ca
Source
Can J Physiol Pharmacol. 1998 May;76(5):479-84
Date
May-1998
Language
English
Publication Type
Article
Keywords
Animals
Cytokines - metabolism
Digestive System - immunology - microbiology
Endotoxins - metabolism
Exercise - physiology
Host-Parasite Interactions
Humans
Inflammation - etiology - physiopathology
Ischemia - etiology - immunology
Liver - immunology
Systemic Inflammatory Response Syndrome - etiology - immunology
Abstract
Multiple lines of evidence support the hypothesis that ischemia-induced impairment of normal gut barrier function, with loss of the normal tonic counterinflammatory influence of the gut immune system, contributes to the expression of uncontrolled inflammation in critically ill victims of trauma and overwhelming infection. The clinical syndrome known as the systemic inflammatory response syndrome (SIRS), which embodies uncontrolled inflammation in trauma and sepsis, is reproduced in its entirety by vigourous exercise, raising the possibility that the gut may also play a role in exercise-induced inflammation. Both strenuous exercise and systemic sepsis result in impairment of the normal gut barrier to luminal microorganisms, and result in elevated circulating levels of bacterial endotoxin. Under normal circumstances, the immune tissues of the gut-liver axis inhibit the expression of a host response to foodstuffs in the gut lumen, or to the indigenous microbial flora of the gut wall. This influence is an active, energy-requiring process. Both strenuous exercise and critical illness are associated with gut ischemia, providing a common biologic basis for the initiation of a dysregulated inflammatory response. Although direct evidence supporting or refuting the hypothesis that the gut can serve as a trigger for systemic inflammation following strenuous exercise is sparse, the similarities in the clinical manifestations of SIRS and exercise, and the promising results of prophylactic or therapeutic gut-directed strategies in critical illness, suggest that similar approaches may provide benefit for individuals engaged in extreme physical exercise.
PubMed ID
9839072 View in PubMed
Less detail
Source
Indian J Pediatr. 2001 Jul;68 Suppl 3:S8-18
Publication Type
Article
Date
Jul-2001
Author
B S Tomar
Author Affiliation
Institute of Pediatric Gastroenterology, S.M.S. Medical College, Jaipur. tomar-dr@jp1.dot.net.in
Source
Indian J Pediatr. 2001 Jul;68 Suppl 3:S8-18
Date
Jul-2001
Language
English
Publication Type
Article
Keywords
Anti-Bacterial Agents - therapeutic use
Bacterial Infections - microbiology - therapy
Child
Diarrhea - therapy
Digestive System - immunology - microbiology
Enterobacteriaceae - pathogenicity
Gastroenteritis - therapy - virology
Gastrointestinal Diseases - etiology - physiopathology - therapy
Helminthiasis - therapy
Humans
Intestinal Diseases, Parasitic - therapy
Abstract
Gastrointestinal infections are the significant cause of childhood morbidity and mortality worldwide. Gastrointestinal infections reflects the balance between the intrinsic virulence factors of the enteropathogens and host mechanisms which defend against enteric infections. Host defense factors include gastric acidity, intestinal motility, the normal indigenous intestinal microflora, mucous secretion, and specific mucosal and systemic immune mechanisms. Majority of GI infections are self limited so on one hand antibiotics are not needed and on the other hand the irrational use of antibiotics produces resistant strains. Acute diarrheal diseases which are one of the important intestinal infections, in majority of the cases are viral and have short course. Antibiotics are recommended only in specific cases and in immunocompromised individuals. Gastrointestinal disease is one of the most common manifestations of HIV infection. The gastrointestinal tract contains abundant quantities of lymphoid tissue and is likely to function as a reservoir of HIV infection, a site of profound immune dysregulation, and a target for opportunistic infections. In this situation specific antibiotics are indicated.
PubMed ID
11980461 View in PubMed
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Prevention of gut inflammation by Bifidobacterium in dextran sulfate-treated gnotobiotic mice associated with Bacteroides strains isolated from ulcerative colitis patients.

https://arctichealth.org/en/permalink/ahliterature186170
Source
Microbes Infect. 2003 Feb;5(2):115-22
Publication Type
Article
Date
Feb-2003
Author
Hiromi Setoyama
Akemi Imaoka
Hideki Ishikawa
Yoshinori Umesaki
Author Affiliation
Yakult Central Institute for Microbiological Research, Yaho 1796, Kunitachi-shi, Tokyo 186-8650, Japan.
Source
Microbes Infect. 2003 Feb;5(2):115-22
Date
Feb-2003
Language
English
Publication Type
Article
Keywords
Animals
Antibiosis
Bacteroides - growth & development - isolation & purification
Bacteroides Infections - microbiology
Bifidobacterium - growth & development
Cecum - immunology - microbiology - pathology
Colitis, Ulcerative - chemically induced - microbiology
Dextran Sulfate - administration & dosage
Digestive System - immunology - microbiology - pathology
Disease Models, Animal
Female
Germ-Free Life
Humans
Inflammation - prevention & control
Mice
Mice, Inbred BALB C
Abstract
Indigenous Bacteroides strains are closely associated with the occurrence and exacerbation of ulcerative colitis (UC). In this study, we aimed to clarify the effect of Bifidobacterium strains, another major member of colonic bacteria, on the development of gut inflammation using gnotobiotic mouse models associated with Bacteroides strains isolated from UC patients. Dextran sulfate (DSS) administration induced inflammation in the large intestine, in particular of the cecum, in the gnotobiotic mice associated with three strains of Bacteroides vulgatus, judging from the myeloperoxidase activity, occult blood score, and IgG leakage into the intestinal contents. However, the severity of the inflammation was greatly reduced in the gnotobiotic mice associated with both B. vulgatus and Bifidobacterium strains. The severity of the cecal inflammation was well correlated with the concentration of succinic acid in the cecum. Bacteriologically, the density of B. vulgatus strain A (BV-A) greatly decreased and the predominant strain changed from BV-A to BV-B on additional association with Bifidobacterium strains. Among gnotobiotic mice associated with a single B. vulgatus strain, the severity of cecal inflammation in BV-A-associated mice was greater than that in BV-B-associated mice. Each Bifidobacterium strain produced compound(s) more effectively inhibiting the growth of BV-A than BV-B in in vitro culture. Taken together, these results suggest that the severity of DSS-induced gut inflammation is closely associated with a particular B. vulgatus strain, and that Bifidobacterium strains may repress exacerbation of intestinal inflammation through growth inhibition of the B. vulgatus strain.
PubMed ID
12650769 View in PubMed
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Source
Am J Clin Nutr. 2001 Feb;73(2 Suppl):444S-450S
Publication Type
Article
Date
Feb-2001
Author
E. Isolauri
Y. Sütas
P. Kankaanpää
H. Arvilommi
S. Salminen
Author Affiliation
Department of Pediatrics, the University of Turku, Turku, Finland. erika.isolauri@utu.fi
Source
Am J Clin Nutr. 2001 Feb;73(2 Suppl):444S-450S
Date
Feb-2001
Language
English
Publication Type
Article
Keywords
Adjuvants, Immunologic - pharmacology
Antigens - physiology
Cytokines
Digestive System - immunology - microbiology
Humans
Hypersensitivity
Immune System - immunology - microbiology
Immunity, Mucosal
Immunoglobulin A - immunology
Inflammation - therapy
Intestines - immunology - microbiology
Lymphocytes
Permeability
Probiotics - pharmacology
Abstract
The gastrointestinal tract functions as a barrier against antigens from microorganisms and food. The generation of immunophysiologic regulation in the gut depends on the establishment of indigenous microflora. This has led to the introduction of novel therapeutic interventions based on the consumption of cultures of beneficial live microorganisms that act as probiotics. Among the possible mechanisms of probiotic therapy is promotion of a nonimmunologic gut defense barrier, which includes the normalization of increased intestinal permeability and altered gut microecology. Another possible mechanism of probiotic therapy is improvement of the intestine's immunologic barrier, particularly through intestinal immunoglobulin A responses and alleviation of intestinal inflammatory responses, which produce a gut-stabilizing effect. Many probiotic effects are mediated through immune regulation, particularly through balance control of proinflammatory and anti-inflammatory cytokines. These data show that probiotics can be used as innovative tools to alleviate intestinal inflammation, normalize gut mucosal dysfunction, and down-regulate hypersensitivity reactions. More recent data show that differences exist in the immunomodulatory effects of candidate probiotic bacteria. Moreover, distinct regulatory effects have been detected in healthy subjects and in patients with inflammatory diseases. These results suggest that specific immunomodulatory properties of probiotic bacteria should be characterized when developing clinical applications for extended target populations.
PubMed ID
11157355 View in PubMed
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[The current concepts of the influence of lactobacilli on the immune system of the human body]

https://arctichealth.org/en/permalink/ahliterature57617
Source
Fiziol Zh. 1997;43(3-4):106-15
Publication Type
Article
Date
1997
Author
O P Kostiuk
L I Chernyshova
A P Volokha
Source
Fiziol Zh. 1997;43(3-4):106-15
Date
1997
Language
Ukrainian
Publication Type
Article
Keywords
Animals
Digestive System - immunology - microbiology
English Abstract
Humans
Immune System - immunology - microbiology
Immunization
Intestinal Mucosa - immunology - microbiology
Lactobacillus - immunology
Abstract
The review summarizes experimental and clinical data about the influence of Lactobacillus on the immune system. A conclusion is made that the effect of Lactobacillus is a multifactor process. After entering the intestinal tract live microorganisms or biologically active substances produced by them may activate specific and nonspecific systems of microorganism protection. Experimental and clinical data about the action of Lactobacillus as adjuvants to the humoral immune response are presented. The mechanisms of anticancerogenic action of Lactobacillus and their cell wall components are analyzed in detail. The prospects for the use of Lactobacillus as probiotics in medicine are considered. The conclusion about positive value of the multifactor action of these microorganisms on the human immune system is made, since no negative effects are evoked by the discussed mechanisms of specific effect of Lactobacillus. This opens wide possibilities for the development of application schemes of probiotics from lactobacillus for the stimulation of several functions of the immune system, creation a new forms of antitumor drugs and combination of them with oral vaccines for improving their immunogenicity.
PubMed ID
9303793 View in PubMed
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7 records – page 1 of 1.