Establishment of Defined Microbial Ecosystems in Germ-Free Rats

1972 ◽  
Vol 6 (3) ◽  
pp. 211-223 ◽  
Author(s):  
F.H.M. Mikx ◽  
J.S. van der Hoeven ◽  
K.G. König ◽  
A.J.M Plasschaert ◽  
B. Guggenheim
Keyword(s):  
Germ Free ◽  
Microbial Ecosystems

Establishment of Defined Microbial Ecosystems in Germ-Free Rats

1976 ◽  
Vol 10 (1) ◽  
pp. 49-58 ◽  
Author(s):  
F.H.M. Mikx ◽  
J.S. van der Hoeven ◽  
A.J.M. Plasschaert ◽  
J. C. Maltha
Keyword(s):  
Germ Free ◽  
Microbial Ecosystems

Staphylococcal bacteremia in a "Germ-free" unit

1976 ◽  
Vol 136 (11) ◽  
pp. 1238-1240 ◽  
Author(s):  
M. E. Plaut
Keyword(s):  
Germ Free

Fibrinolytic Activity of Lung and Spleen Extracts Observed in Conventional but not in Germ-Free Rats

1979 ◽  
Vol 42 (02) ◽  
pp. 726-733 ◽  
Author(s):  
Utako Okamoto ◽  
Jun-ichiro Yamamoto ◽  
Yoko Nagamatsu ◽  
Noboru Horie
Keyword(s):  
Serine Protease ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Iodoacetic Acid ◽  
Thrombin Inhibitor ◽  
Rat Tissues ◽  
Germ Free ◽  
Neutral Ph ◽  
Tissue Extracts

SummaryProtease-like activity which split plasminogen-free fibrin was demonstrated in 2 M KSCN extracts of the lung and spleen of conventional rats. The activity was virtually undetectable in tissue extracts from germ-free rats. The extracts from the conventional rat tissues split fibrin and fibrinogen remarkably at neutral pH, but not casein, when examined using fibrin, fibrinogen-agar and casein-agar plates. The fibrinolytic activity was inhibited by STI and DFP, indicating a serine protease nature. The activity was not inhibited by TLCK, t-AMCHA or dansyl-L-arginine-methylpiperidine amide (a selective synthetic thrombin inhibitor, OM189). It was neither activated nor inhibited by cysteine, KCN or iodoacetic acid. The results obtained indicate that the protease-like activity of the lung and spleen extracted with 2 M KSCN from conventional rats has properties which differ from those of trypsin, plasmin, plasminogen-activator, thrombin, and cathepsin A, B and C.

β-Glucuronidase activity in germ-free, monoassociated and conventional mice

2006 ◽  
Vol 18 (1) ◽  
Author(s):  
Maria E. Cardona ◽  
Elisabeth Norin ◽  
Tore Midtvedt
Keyword(s):  
Germ Free ◽  
Glucuronidase Activity

10 THE ROLE OF DIETARY L-SERINE IN THE REGULATION OF INTESTINAL MUCUS BARRIER DURING INFLAMMATION

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S42-S42
Author(s):  
Kohei Sugihara ◽  
Nobuhiko Kamada
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gut Microbiota ◽  
Control Diet ◽  
Bacterial Strains ◽  
Germ Free ◽  
Intestinal Mucus ◽  
Gnotobiotic Mice ◽  
Mucus Barrier

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

scholarly journals Glycosphingolipid patterns of the gastrointestinal tract and feces of germ-free and conventional rats.

1986 ◽  
Vol 261 (32) ◽  
pp. 15294-15300
Author(s):  
B E Gustafsson ◽  
K A Karlsson ◽  
G Larson ◽  
T Midtvedt ◽  
N Strömberg ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Germ Free
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