Simulation of the Rat Intestinal Ecosystem using a Two-stage Continuous Culture System

Veilleux, B. G.; Rowland, Ian

doi:10.1099/00221287-123-1-103

Cited by 47 publications

(29 citation statements)

References 15 publications

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“…The colonic micro¯ora is involved in bowel motility, enterohepatic cycling of primary bile acids and possibly the metabolism of cholesterol, resulting in the production of faecal neutral sterols (Rafter, 1995). Species diversity and an array of microbial interactions lead to a high degree of homoeostasis and self-regulation in the colonic micro¯ora (Veilleux & Rowland, 1981). Stability of the micro¯ora effectively limits the capacity of invading micro-organisms, including pathogens, to colonise the gut, giving rise to what has been termed`colonisation resistance' (Hentges, 1992).…”

Section: Microbial Ecology Of the Human Gastrointestinal Tractmentioning

confidence: 99%

Perspectives on the role of the human gut microbiota and its modulation by pro- and prebiotics

et al. 2000

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One of the most topical areas of human nutrition is the role of the gut in health and disease. Specifically, this involves interactions between the resident microbiota and dietary ingredients that support their activities. Currently, it is accepted that the gut microflora contains pathogenic, benign and beneficial components. Some microbially induced disease states such as acute gastroenteritis and pseudomembranous colitis have a defined aetiological agent(s). Speculation on the role of microbiota components in disorders such as irritable bowel syndrome, bowel cancer, neonatal necrotising enterocolitis and ulcerative colitis are less well defined, but many studies are convincing. It is evident that the gut microflora composition can be altered through diet. Because of their perceived health-promoting status, bifidobacteria and lactobacilli are the commonest targets. Probiotics involve the use of live micro-organisms in food; prebiotics are carbohydrates selectively metabolized by desirable moieties of the indigenous flora; synbiotics combine the two approaches. Dietary intervention of the human gut microbiota is feasible and has been proven as efficacious in volunteer trials. The health bonuses of such approaches offer the potential to manage many gut disorders prophylactically. However, it is imperative that the best methodologies available are applied to this area of nutritional sciences. This will undoubtedly involve a genomic application to the research and is already under way through molecular tracking of microbiota changes to diet in controlled human trials.

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Section: Microbial Ecology Of the Human Gastrointestinal Tractmentioning

confidence: 99%

Perspectives on the role of the human gut microbiota and its modulation by pro- and prebiotics

et al. 2000

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“…Veilleux and Rowland (1981) and Freter et al (19838) also demonstrated similar population levels of bacteria in anaerobic C F cultures to those observed in the lower alimentary canal of conventional or gnotobiotic animals. Accordingly, the anaerobic C F culture system has been considered as an excellent in-vitro model for examining bacterial interactions in lower areas of the alimentary canal.…”

Section: Introductionmentioning

confidence: 53%

Potent Antagonism of Escherichia Coli, Bacteroides Ovatus, Fusobacterium Varium, and Enterococcus Faecalis, Alone or in Combination, for Enteropathogens in Anaerobic Continuous Flow Cultures

Ushijima

Ozaki

1986

Journal of Medical Microbiology

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Summary.Interactions between representative strains of four predominant resident bacteria of the human colon, Escherichia coli, Enterococcus faecalis, Bacteroides ovatus, and Fusobacterium varium, and strains of seven enteropathogens, Yersinia enterocolitica, Shigella JEexneri, Salmonella typhimurium, Vibrio parahaemolyticus, V. cholerae serogroup non 0 1, Staphylococcus aureus, and Clostridium perfringens, were examined in studies with an anaerobic continuous flow culture system and medium resembling the content of the mouse caecum (MCM). Potent unilateral antagonism attributable to synergic activities of the resident bacteria against the enteropathogens was evident.The four resident bacteria persisted at levels of c. lo6 cfu/ml or more in single and in any mixed cultures of the resident species. The seven enteropathogens also persisted in single cultures. In contrast, Y. enterocolitica was excluded in several days in mixed cultures with each of the four resident bacteria. Sh.JEexneri and Staph. aureus were excluded in the presence of E. coli alone. C. perfringens, V. parahaemolyticus and V. cholerae serogroup non 0 1 were excluded in the presence of E. coli with B. ovatus and, in some cases, with additional species. S. typhimurium was the most resistant; only c. 1 02-fold reduction of the population level was observed in mixed culture with all four of the resident species. When the amounts of some components in the medium, such as peptone and yeast extract, were increased, C. perfringens grew and persisted even in the presence of the four resident bacteria. Sh.Jexneri, in contrast decreased steadily, even in enriched media.

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“…In vitro models of the mammalian gut have been used in a number of studies (1,2,12,14,18,26,29). However, the potential of in vitro intestinal models has not yet been fully exploited in the area of colonization, probably because of the practical problems of running continuous-flow (CF) systems.…”

mentioning

confidence: 99%

“…To obtain a constant and diverse microflora comparable to the fecal flora of the rat, they found that a two-stage CF culture system with a low pH in the first stage and cell recycling between the two stages gave optimal conditions. Our porcine in vitro model was basically set up like the model described by Veilleux and Rowland (26), with the exception that we left out the cell recycling step, which would complicate the interpretation of the fate of test strains added to the system. An important aspect of these investigations was the evaluation of the extrapolation possibilities from the in vitro model to the in vivo situation.…”

mentioning

confidence: 99%

Use of norfloxacin to study colonization ability of Escherichia coli in in vivo and in vitro models of the porcine gut

Nielsen¹,

Schlundt²

1992

Antimicrob Agents Chemother

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The colonization resistance conveyed by the intestinal microbiota can prevent colonization of the intestinal system by new strains. In this study, this resistance was partly circumvented by use of the antimicrobial drug norfloxacin. The colonization abilities of two closely related Escherichia coli strains, which were resistant to nalidixic acid and rifampin, respectively, were investigated in minipigs and a two-stage continuous-flow in vitro gut model. Whereas both strains were unable to colonize the intact enteric system in vivo and in vitro, a 3-day norfloxacin treatment modified both systems to allow colonization by the nalidixic acid-resistant strain but not the rifampin-resistant strain. The results indicate the usefulness of norfloxacin to circumvent the normal colonization resistance while keeping a fairly normal microbiota in the gut. The results also indicate that it could be possible to construct in vitro gut models which could distinguish between strains with different gut colonization abilities. Both of these possibilities could come to be used in the study of the colonization and effects in the gut of new bacterial strains, i.e., genetically modified microorganisms.The enteric colonizing ability of bacteria is based on several factors, some of which are not yet fully understood. Two factors considered significant for the colonization ability of Escherichia coli are the adhesins (21) and the growth rate in the mucous layer (27), although there seems to be conflicting views on the relative importance of these factors.

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Simulation of the Rat Intestinal Ecosystem using a Two-stage Continuous Culture System

Cited by 47 publications

References 15 publications

Perspectives on the role of the human gut microbiota and its modulation by pro- and prebiotics

Perspectives on the role of the human gut microbiota and its modulation by pro- and prebiotics

Potent Antagonism of Escherichia Coli, Bacteroides Ovatus, Fusobacterium Varium, and Enterococcus Faecalis, Alone or in Combination, for Enteropathogens in Anaerobic Continuous Flow Cultures

Use of norfloxacin to study colonization ability of Escherichia coli in in vivo and in vitro models of the porcine gut

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