scholarly journals Long-term iron deficiency and iron supplementation exacerbate acute DSS-induced colitis and are associated with significant dysbiosis

2019 ◽  
Author(s):  
Awad Mahalhal ◽  
Michael D. Burkitt ◽  
Carrie A. Duckworth ◽  
Georgina L. Hold ◽  
Barry J. Campbell ◽  
...  
Keyword(s):  
Iron Supplementation ◽  
Sodium Sulphate ◽  
Oral Iron ◽  
Dietary Iron ◽  
Chronic Colitis ◽  
Acute Colitis ◽  
Long Term Changes ◽  
Gastrointestinal Side Effects ◽  
The Impact

AbstractPatients taking oral iron supplementation often suffer from gastrointestinal side effects. We have previously shown that acute alterations in oral iron exacerbate dextran sodium sulphate (DSS) induced colitis and are associated with dysbiosis. As patients take iron supplementation for long periods, we asked whether this too would influence colitis and the microbiome. We assessed the impact of long-term changes in dietary iron, by feeding chow containing 100ppm, 200ppm and 400ppm (reflecting a deficient, normal or supplemented diet, respectively) for up to 9 weeks to female wild-type C57BL/6 (WT) mice in presence or absence of chronic colitis, or acute colitis induced after 8 weeks, induced by DSS. Assessment was made based on (i) clinical and histological severity of colitis, and (ii) faecal microbial diversity, as assessed by sequencing the V4 region of16SrRNA. In mice with long term changes to their dietary iron, reduced iron intake (100ppm iron diet) was associated with increased weight loss and histology scoring in the acute colitis model. Chronic colitis was not influenced by altering dietary iron however there was a clear change in the faecal microbiome in the 100 and 400ppm iron DSS-treated groups and in controls consuming the 400ppm iron diet. Proteobacteria levels increased significantly at day-63 compared to baseline and Bacteroidetes levels decreased in the 400ppm iron DSS group at day-63 compared to baseline; mirroring our previously published work in acute colitis. Long term dietary iron alterations clearly affects gut microbiota signatures but do not appear to exacerbate chronic colitis. However, acute colitis is exacerbated by changes in dietary iron. More work is needed to understand the impact of iron supplementation of the pathologenesis of IBD and rise that possiblity that the change in the microbiome, in patients with colitis, is a consequence of the increase in luminal iron and not simply the presence of colitis.

scholarly journals Long-Term Iron Deficiency and Dietary Iron Excess Exacerbate Acute Dextran Sodium Sulphate-Induced Colitis and Are Associated with Significant Dysbiosis

2021 ◽  
Vol 22 (7) ◽  
pp. 3646
Author(s):  
Awad Mahalhal ◽  
Michael D. Burkitt ◽  
Carrie A. Duckworth ◽  
Georgina L. Hold ◽  
Barry J. Campbell ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Iron Supplementation ◽  
Sodium Sulphate ◽  
Dietary Iron ◽  
Chronic Colitis ◽  
Dextran Sodium Sulphate ◽  
Acute Colitis ◽  
Long Term Changes ◽  
The Impact

Background: Oral iron supplementation causes gastrointestinal side effects. Short-term alterations in dietary iron exacerbate inflammation and alter the gut microbiota, in murine models of colitis. Patients typically take supplements for months. We investigated the impact of long-term changes in dietary iron on colitis and the microbiome in mice. Methods: We fed mice chow containing differing levels of iron, reflecting deficient (100 ppm), normal (200 ppm), and supplemented (400 ppm) intake for up to 9 weeks, both in absence and presence of dextran sodium sulphate (DSS)-induced chronic colitis. We also induced acute colitis in mice taking these diets for 8 weeks. Impact was assessed (i) clinically and histologically, and (ii) by sequencing the V4 region of 16S rRNA. Results: In mice with long-term changes, the iron-deficient diet was associated with greater weight loss and histological inflammation in the acute colitis model. Chronic colitis was not influenced by altering dietary iron however there was a change in the microbiome in DSS-treated mice consuming 100 ppm and 400 ppm iron diets, and control mice consuming the 400 ppm iron diet. Proteobacteria levels increased significantly, and Bacteroidetes levels decreased, in the 400 ppm iron DSS group at day-63 compared to baseline. Conclusions: Long-term dietary iron alterations affect gut microbiota signatures but do not exacerbate chronic colitis, however acute colitis is exacerbated by such dietary changes. More work is needed to understand the impact of iron supplementation on IBD. The change in the microbiome, in patients with colitis, may arise from the increased luminal iron and not simply from colitis.

scholarly journals Oral Iron Supplementation—Gastrointestinal Side Effects and the Impact on the Gut Microbiota

2021 ◽  
Vol 12 (2) ◽  
pp. 491-502
Author(s):  
Sarah R. Bloor ◽  
Rudolph Schutte ◽  
Anthony R. Hobson
Keyword(s):  
Side Effects ◽  
Gut Microbiota ◽  
Iron Supplementation ◽  
Methanogenic Archaea ◽  
Intravenous Iron ◽  
Oral Iron ◽  
Intestinal Lumen ◽  
Gastrointestinal Side Effects ◽  
Potential Link ◽  
The Impact

Iron deficiency anaemia (IDA) is a worldwide healthcare problem affecting approximately 25% of the global population. The most common IDA treatment is oral iron supplementation, which has been associated with gastrointestinal (GI) side effects such as constipation and bloating. These can result in treatment non-adherence and the persistence of IDA. Intravenous iron does not cause GI side effects, which may be due to the lack of exposure to the intestinal lumen. Luminal iron can cause changes to the gut microbiota, aiding the promotion of pathogenic species and decreasing beneficial protective species. Iron is vital for methanogenic archaea, which rely on iron for growth and metabolism. Increased intestinal methane has been associated with slowing of intestinal transit, constipation, and bloating. Here we explore the literature to understand a potential link between iron and methanogenesis as a novel way to understand the mechanism of oral iron supplementation induced GI side effects.

scholarly journals Analyzing the market position of fish species subject to the impact of long-term changes: a case study of French fisheries in the Bay of Biscay

2008 ◽  
Vol 21 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Pascal Le Floc'h ◽  
Jean-Charles Poulard ◽  
Olivier Thébaud ◽  
Fabian Blanchard ◽  
Julien Bihel ◽  
...  
Keyword(s):  
Fish Species ◽  
Bay Of Biscay ◽  
Market Position ◽  
Long Term Changes ◽  
The Impact

Long-term changes in fish community and the impact of exotic fish, between the Nakdong River and Upo Wetlands

2011 ◽  
Vol 34 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Hyun-Bin Jo ◽  
Min-Ho Jang ◽  
Kwang-Seuk Jeong ◽  
Yun-O Do ◽  
Gea-Jae Joo ◽  
...  
Keyword(s):  
Fish Community ◽  
Nakdong River ◽  
Exotic Fish ◽  
Long Term Changes ◽  
The Nakdong River ◽  
The Impact

scholarly journals Physics of Space Weather Phenomena: A Review

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 286
Author(s):  
Ashok Kumar Singh ◽  
Asheesh Bhargawa ◽  
Devendraa Siingh ◽  
Ram Pal Singh
Keyword(s):  
Space Weather ◽  
Modern Society ◽  
Major Elements ◽  
Space Environment ◽  
Time Data ◽  
Physical Relation ◽  
Long Term Changes ◽  
The Impact ◽  
Present Understanding

In the last few decades, solar activity has been diminishing, and so space weather studies need to be revisited with more attention. The physical processes involved in dealing with various space weather parameters have presented a challenge to the scientific community, with a threat of having a serious impact on modern society and humankind. In the present paper, we have reviewed various aspects of space weather and its present understanding. The Sun and the Earth are the two major elements of space weather, so the solar and the terrestrial perspectives are discussed in detail. A variety of space weather effects and their societal as well as anthropogenic aspects are discussed. The impact of space weather on the terrestrial climate is discussed briefly. A few tools (models) to explain the dynamical space environment and its effects, incorporating real-time data for forecasting space weather, are also summarized. The physical relation of the Earth’s changing climate with various long-term changes in the space environment have provided clues to the short-term/long-term changes. A summary and some unanswered questions are presented in the final section.

scholarly journals Historical Aerial Surveys Map Long-Term Changes of Forest Cover and Structure in the Central Congo Basin

2020 ◽  
Vol 12 (4) ◽  
pp. 638 ◽  
Author(s):  
Koen Hufkens ◽  
Thalès de Haulleville ◽  
Elizabeth Kearsley ◽  
Kim Jacobsen ◽  
Hans Beeckman ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Forest Cover ◽  
Congo Basin ◽  
Spatial And Temporal Patterns ◽  
Smallholder Farming ◽  
Aboveground Carbon ◽  
Decadal Scale ◽  
Long Term Changes ◽  
The Impact

Given the impact of tropical forest disturbances on atmospheric carbon emissions, biodiversity, and ecosystem productivity, accurate long-term reporting of Land-Use and Land-Cover (LULC) change in the pre-satellite era (<1972) is an imperative. Here, we used a combination of historical (1958) aerial photography and contemporary remote sensing data to map long-term changes in the extent and structure of the tropical forest surrounding Yangambi (DR Congo) in the central Congo Basin. Our study leveraged structure-from-motion and a convolutional neural network-based LULC classifier, using synthetic landscape-based image augmentation to map historical forest cover across a large orthomosaic (~93,431 ha) geo-referenced to ~4.7 ± 4.3 m at submeter resolution. A comparison with contemporary LULC data showed a shift from previously highly regular industrial deforestation of large areas to discrete smallholder farming clearing, increasing landscape fragmentation and providing opportunties for substantial forest regrowth. We estimated aboveground carbon gains through reforestation to range from 811 to 1592 Gg C, partially offsetting historical deforestation (2416 Gg C), in our study area. Efforts to quantify long-term canopy texture changes and their link to aboveground carbon had limited to no success. Our analysis provides methods and insights into key spatial and temporal patterns of deforestation and reforestation at a multi-decadal scale, providing a historical context for past and ongoing forest research in the area.

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