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Space Environmental Factor Impacts upon Murine Colon Microbiota and Mucosal Homeostasis.

Ritchie LE, Taddeo SS, Weeks BR, Lima F, Bloomfield SA, Azcarate-Peril MA, Zwart SR, Smith SM, Turner ND - PLoS ONE (2015)

Bottom Line: Spaceflight increased Clostridiales and decreased Lactobacillales, and similar trends were observed in the experiment using a ground-based model of microgravity, suggesting altered gravity may affect colonic microbiota.Although we noted no differences in colon epithelial injury or inflammation, spaceflight elevated TGFβ gene expression.Microbiota and mucosal characterization in these models is a first step in understanding the impact of the space environment on intestinal health.

View Article: PubMed Central - PubMed

Affiliation: Intercollegiate Faculty of Genetics, Texas A&M University, College Station, Texas, United States of America.

ABSTRACT
Astronaut intestinal health may be impacted by microgravity, radiation, and diet. The aim of this study was to characterize how high and low linear energy transfer (LET) radiation, microgravity, and elevated dietary iron affect colon microbiota (determined by 16S rDNA pyrosequencing) and colon function. Three independent experiments were conducted to achieve these goals: 1) fractionated low LET γ radiation (137Cs, 3 Gy, RAD), high Fe diet (IRON) (650 mg/kg diet), and a combination of low LET γ radiation and high Fe diet (IRON+RAD) in male Sprague-Dawley rats; 2) high LET 38Si particle exposure (0.050 Gy), 1/6 G partial weight bearing (PWB), and a combination of high LET38Si particle exposure and PWB in female BalbC/ByJ mice; and 3) 13 d spaceflight in female C57BL/6 mice. Low LET radiation, IRON and spaceflight increased Bacteroidetes and decreased Firmicutes. RAD and IRON+RAD increased Lactobacillales and lowered Clostridiales compared to the control (CON) and IRON treatments. Low LET radiation, IRON, and spaceflight did not significantly affect diversity or richness, or elevate pathogenic genera. Spaceflight increased Clostridiales and decreased Lactobacillales, and similar trends were observed in the experiment using a ground-based model of microgravity, suggesting altered gravity may affect colonic microbiota. Although we noted no differences in colon epithelial injury or inflammation, spaceflight elevated TGFβ gene expression. Microbiota and mucosal characterization in these models is a first step in understanding the impact of the space environment on intestinal health.

No MeSH data available.


Related in: MedlinePlus

Principal coordinate analysis (PCoA) plot of samples from ground and flight mice.Flight mice data points clustered relatively tightly within the bottom right quadrant, whereas ground controls are distributed throughout the remainder of the plot. The PCoA analysis illustrates the differences in bacterial populations in the feces of flight mice compared to ground controls.
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pone.0125792.g003: Principal coordinate analysis (PCoA) plot of samples from ground and flight mice.Flight mice data points clustered relatively tightly within the bottom right quadrant, whereas ground controls are distributed throughout the remainder of the plot. The PCoA analysis illustrates the differences in bacterial populations in the feces of flight mice compared to ground controls.

Mentions: We observed a tendency for reduced species richness and diversity in flight mice relative to the ground control mice, these differences were not significant (Table 1). Unifrac and principal coordinate analysis (PCoA) of all sequences for each sample, represented as a discrete data point without overlap, revealed distinct clustering of samples collected from ground and flight mice (Fig 3), yet we observed no significant differences in OTUs at the phylum level (S4 Table). Flight mice had a numerically higher proportion Bacteroidetes (8%) and lower proportion of Firmicutes (14%) compared to ground mice (Fig 4). Ground mice had a numerically higher proportion of Erysipelotrichales compared to flight mice. Flight mice had a numerically higher proportion of Clostridiales (60%) and numerically lower proportion of Lactobacillales (62%) compared to ground mice (Fig 4).


Space Environmental Factor Impacts upon Murine Colon Microbiota and Mucosal Homeostasis.

Ritchie LE, Taddeo SS, Weeks BR, Lima F, Bloomfield SA, Azcarate-Peril MA, Zwart SR, Smith SM, Turner ND - PLoS ONE (2015)

Principal coordinate analysis (PCoA) plot of samples from ground and flight mice.Flight mice data points clustered relatively tightly within the bottom right quadrant, whereas ground controls are distributed throughout the remainder of the plot. The PCoA analysis illustrates the differences in bacterial populations in the feces of flight mice compared to ground controls.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4470690&req=5

pone.0125792.g003: Principal coordinate analysis (PCoA) plot of samples from ground and flight mice.Flight mice data points clustered relatively tightly within the bottom right quadrant, whereas ground controls are distributed throughout the remainder of the plot. The PCoA analysis illustrates the differences in bacterial populations in the feces of flight mice compared to ground controls.
Mentions: We observed a tendency for reduced species richness and diversity in flight mice relative to the ground control mice, these differences were not significant (Table 1). Unifrac and principal coordinate analysis (PCoA) of all sequences for each sample, represented as a discrete data point without overlap, revealed distinct clustering of samples collected from ground and flight mice (Fig 3), yet we observed no significant differences in OTUs at the phylum level (S4 Table). Flight mice had a numerically higher proportion Bacteroidetes (8%) and lower proportion of Firmicutes (14%) compared to ground mice (Fig 4). Ground mice had a numerically higher proportion of Erysipelotrichales compared to flight mice. Flight mice had a numerically higher proportion of Clostridiales (60%) and numerically lower proportion of Lactobacillales (62%) compared to ground mice (Fig 4).

Bottom Line: Spaceflight increased Clostridiales and decreased Lactobacillales, and similar trends were observed in the experiment using a ground-based model of microgravity, suggesting altered gravity may affect colonic microbiota.Although we noted no differences in colon epithelial injury or inflammation, spaceflight elevated TGFβ gene expression.Microbiota and mucosal characterization in these models is a first step in understanding the impact of the space environment on intestinal health.

View Article: PubMed Central - PubMed

Affiliation: Intercollegiate Faculty of Genetics, Texas A&M University, College Station, Texas, United States of America.

ABSTRACT
Astronaut intestinal health may be impacted by microgravity, radiation, and diet. The aim of this study was to characterize how high and low linear energy transfer (LET) radiation, microgravity, and elevated dietary iron affect colon microbiota (determined by 16S rDNA pyrosequencing) and colon function. Three independent experiments were conducted to achieve these goals: 1) fractionated low LET γ radiation (137Cs, 3 Gy, RAD), high Fe diet (IRON) (650 mg/kg diet), and a combination of low LET γ radiation and high Fe diet (IRON+RAD) in male Sprague-Dawley rats; 2) high LET 38Si particle exposure (0.050 Gy), 1/6 G partial weight bearing (PWB), and a combination of high LET38Si particle exposure and PWB in female BalbC/ByJ mice; and 3) 13 d spaceflight in female C57BL/6 mice. Low LET radiation, IRON and spaceflight increased Bacteroidetes and decreased Firmicutes. RAD and IRON+RAD increased Lactobacillales and lowered Clostridiales compared to the control (CON) and IRON treatments. Low LET radiation, IRON, and spaceflight did not significantly affect diversity or richness, or elevate pathogenic genera. Spaceflight increased Clostridiales and decreased Lactobacillales, and similar trends were observed in the experiment using a ground-based model of microgravity, suggesting altered gravity may affect colonic microbiota. Although we noted no differences in colon epithelial injury or inflammation, spaceflight elevated TGFβ gene expression. Microbiota and mucosal characterization in these models is a first step in understanding the impact of the space environment on intestinal health.

No MeSH data available.


Related in: MedlinePlus