scholarly journals Unravelling methanogenesis in ruminants, horses and kangaroos: the links between gut anatomy, microbial biofilms and host immunity

2018 ◽  
Vol 58 (7) ◽  
pp. 1175 ◽  
Author(s):  
R. A. Leng
Keyword(s):  
Gut Microbiota ◽  
Close Association ◽  
Methanogenic Archaea ◽  
H2 Production ◽  
Gas Production ◽  
Gas Pressure ◽  
Lymphoid Cells ◽  
Lymphoid Tissues ◽  
Microbial Biofilms ◽  
Kinetics Of

The present essay aims to resolve the question as to why macropod marsupials (e.g. kangaroos and wallabies, hereinafter termed ‘macropods) and horses produce much less methane (CH4) than do ruminants when digesting the same feed. In herbivores, gases produced during fermentation of fibrous feeds do not pose a major problem in regions of the gut that have mechanisms to eliminate them (e.g. eructation in the rumen and flatus in the lower bowel). In contrast, gas pressure build-up in the tubiform forestomach of macropods or in the enlarged tubiform caecum of equids would be potentially damaging. It is hypothesised that, to prevent this problem, evolution has favoured development of controls over gut microbiota that enable enteric gas production (H2 and CH4) to be differently regulated in the forestomach of macropods and the caecum of all three species, from the forestomach of ruminants. The hypothesised regulation depends on interactions between their gut anatomy and host-tissue immune responses that have evolved to modify the species composition of their gut microbiota which, importantly, are mainly in biofilms. Obligatory H2 production during forage fermentation is, thus, captured in CH4 in the ruminant where ruminal gases are readily released by eructation, or in acetate in the macropod forestomach and equid caecum–colon where a build-up in gas pressure could potentially damage these organs. So as to maintain appropriate gut microbiota in different species, it is hypothesised that blind sacs at the cranial end of the haustral anatomy of the macropod forestomach and the equid caecum are sites of release of protobiofilm particles that develop in close association with the mucosal lymphoid tissues. These tissues release immune secretions such as antimicrobial peptides, immunoglobulins, innate lymphoid cells and mucin that eliminate or suppress methanogenic Archaea and support the growth of acetogenic microbiota. The present review draws on microbiological studies of the mammalian gut as well as other microbial environments. Hypotheses are advanced to account for published findings relating to the gut anatomy of herbivores and humans, the kinetics of digesta in ruminants, macropods and equids, and also the composition of biofilm microbiota in the human gut as well as aquatic and other environments where the microbiota exist in biofilms.

scholarly journals Development of a simultaneous bioreactor system for characterization of gas production kinetics of methanogenic archaea at high pressure

2019 ◽  
Vol 19 (7) ◽  
pp. 537-544 ◽  
Author(s):  
Patricia Anna Pappenreiter ◽  
Sara Zwirtmayr ◽  
Lisa‐Maria Mauerhofer ◽  
Simon Karl‐Maria Rasso Rittmann ◽  
Christian Paulik
Keyword(s):  
High Pressure ◽  
Methanogenic Archaea ◽  
Gas Production ◽  
Production Kinetics ◽  
Bioreactor System ◽  
Kinetics Of

scholarly journals The role of gut microbiota in programming the immune phenotype

2013 ◽  
Vol 4 (3) ◽  
pp. 203-214 ◽  
Author(s):  
M. Weng ◽  
W. A. Walker
Keyword(s):  
Gut Microbiota ◽  
Lymphoid Cells ◽  
Premature Delivery ◽  
First Year ◽  
Lymphoid Tissues ◽  
Intestinal Colonization ◽  
Immune Phenotype ◽  
Gut Colonization ◽  
First Year Of Life

The human fetus lives in a germ-free intrauterine environment and enters the outside world containing microorganisms from several sources, resulting in gut colonization. Full-term, vaginally born infants are completely colonized with a diverse array of bacterial families in clusters (Phyla) and species (>1000) by the first year of life. Colonizing bacteria communicating with the gut epithelium and underlying lymphoid tissues (‘bacterial–epithelial crosstalk’) result in a functional immune phenotype and no expression of disease (immune homeostasis). Appropriate colonization is influenced by the prebiotic effect of breast milk oligosaccharides. Adequate colonization results in an innate and adaptive mucosal immune phenotype via communication between molecular patterns on colonizing bacteria and pattern-recognition receptors (e.g., toll-like receptors) on epithelial and lymphoid cells. This ontogeny affects the immune system's capacity to develop oral tolerance to innocuous bacteria and benign antigens. Inadequate intestinal colonization with premature delivery, delivery by Cesarean section and excessive use of perinatal antibiotics results in the absence of adequate bacterial–epithelial crosstalk and an increased incidence of immune-mediated diseases [e.g., asthma, allergy in general and necrotizing enterocolitis (NEC)]. Fortunately, infants with inadequate intestinal colonization can be restored to a bacterial balance with the intake of probiotics. This has been shown to prevent debilitating diseases such as NEC. Thus, understanding the role of gut microbiota in programming of the immune phenotype may be important in preventing disease expression in later childhood and adulthood.

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 Preserving Porphyra umbilicalis and Saccharina latissima as Silages for Ruminant Feeding

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1957
Author(s):  
Margarita Novoa-Garrido ◽  
Carlos Navarro Marcos ◽  
María Dolores Carro Travieso ◽  
Eduarda Molina Alcaide ◽  
Mogens Larsen ◽  
...  
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Volatile Fatty Acids ◽  
Gas Production ◽  
Saccharina Latissima ◽  
Porphyra Umbilicalis ◽  
In Vitro Gas Production ◽  
Ruminal Degradability ◽  
Kinetics Of

The study analyzed the characteristics, chemical composition, and in vitro gas production kinetics of Porphyra umbilicalis and Saccharina latissima silages. Each seaweed was ensiled in vacuum bags (three bags/silage) following a 2 × 3 factorial design, with two pre-treatments (unwilted or pre-wilted) and three silage types: unwashed seaweed ensiled without additive; seaweed washed and ensiled without additive; and seaweed washed and ensiled with 4 g of formic acid (FAC) per kg seaweed. Silages were kept for 3 months in darkness at 20 °C. Pre-wilting prevented (p < 0.001) effluent formation and reduced (p ≤ 0.038) the production of NH3-N and volatile fatty acids for both seaweeds. Both pre-wilting and washing increased (p < 0.05) the ruminal degradability of P. umbilicalis silages but not of S. latissima silages. The pH of the FAC-treated silages was below 4.0, but ranged from 4.54 to 6.23 in non FAC-treated silages. DL-lactate concentrations were low (≤23.0 g/kg dry matter) and acetate was the predominant fermentation product, indicating a non-lactic fermentation. The estimated ruminal degradability of the P. umbilicalis and S. latissima silages was as average, 59.9 and 86.1% of that for high-quality rye-grass silages, respectively, indicating a medium-low nutritional value of these seaweed silages for ruminants.

scholarly journals Delineating spatiotemporal and hierarchical development of human fetal innate lymphoid cells

Cell Research ◽  
2021 ◽  
Author(s):  
Chen Liu ◽  
Yandong Gong ◽  
Han Zhang ◽  
Hua Yang ◽  
Yang Zeng ◽  
...  
Keyword(s):  
Single Cell ◽  
Progenitor Cells ◽  
Fetal Liver ◽  
Innate Lymphoid Cells ◽  
Lymphoid Cells ◽  
Lymphoid Tissues ◽  
Hematopoietic Stem ◽  
Molecular Features ◽  
Lymphoid Progenitors ◽  
B Lineage

AbstractWhereas the critical roles of innate lymphoid cells (ILCs) in adult are increasingly appreciated, their developmental hierarchy in early human fetus remains largely elusive. In this study, we sorted human hematopoietic stem/progenitor cells, lymphoid progenitors, putative ILC progenitor/precursors and mature ILCs in the fetal hematopoietic, lymphoid and non-lymphoid tissues, from 8 to 12 post-conception weeks, for single-cell RNA-sequencing, followed by computational analysis and functional validation at bulk and single-cell levels. We delineated the early phase of ILC lineage commitment from hematopoietic stem/progenitor cells, which mainly occurred in fetal liver and intestine. We further unveiled interleukin-3 receptor as a surface marker for the lymphoid progenitors in fetal liver with T, B, ILC and myeloid potentials, while IL-3RA– lymphoid progenitors were predominantly B-lineage committed. Notably, we determined the heterogeneity and tissue distribution of each ILC subpopulation, revealing the proliferating characteristics shared by the precursors of each ILC subtype. Additionally, a novel unconventional ILC2 subpopulation (CRTH2– CCR9+ ILC2) was identified in fetal thymus. Taken together, our study illuminates the precise cellular and molecular features underlying the stepwise formation of human fetal ILC hierarchy with remarkable spatiotemporal heterogeneity.

scholarly journals THE EFFECT OF EPITHELIAL REMNANT AND WHOLE ORGAN GRAFTS OF THYMUS ON THE RECOVERY OF THYMECTOMIZED IRRADIATED MICE

1969 ◽  
Vol 129 (6) ◽  
pp. 1235-1246 ◽  
Author(s):  
Esther F. Hays
Keyword(s):  
Direct Action ◽  
Lymphoid Cells ◽  
Lymphoid Tissues ◽  
Functional Development ◽  
Reticular Cells ◽  
Microscopic Morphology ◽  
Two Parameters ◽  
A Minor ◽  
Cellular Components

Work has been presented which suggests that thymus epithelial reticular cells are not effective in restoring the microscopic morphology of lymphoid tissues and their immunologic capacities. They function in recruiting precursors of thymus lymphocytes from the host animals to produce an organ which, after it becomes architecturally normal, can reconstitute the defective host. Intact thymus grafts in situ from 10–14 days, but not for shorter periods of time, have been shown to result in a return toward normal of these two parameters. Evidence is offered to show that few dividing cellular components in the lymphoid tissue originate from the thymus remnant grafts, and that a minor cellular component is contributed by the intact grafts. These data support the concept that the structural and functional development of the lymphatic tissue in thymectomized animals is dependent on thymus lymphoid cells and/or their products, and that the epithelial-reticular cells do not have a direct action in peripheral lymphoid reconstitution.

Comparison of four in vitro gas production methods to study rumen fermentation kinetics of starch rich feeds

1997 ◽  
Vol 1997 ◽  
pp. 196-196
Author(s):  
S. Fakhri ◽  
A. R. Moss ◽  
D.I. Givens ◽  
E. Owen
Keyword(s):  
Rumen Fermentation ◽  
Gas Production ◽  
Production Methods ◽  
Fermentation Kinetics ◽  
In Vitro Gas Production ◽  
Production Techniques ◽  
Kinetics Of

Recently, the automatic in vitro gas production techniques (e.g. Cone. 1994; Theodorou et al., 1994) have been developed to study rumen fermentation kinetics. Many approaches have been taken. This work investigates the suitability of different methods for estimating the rumen fermentation of two starch rich feedstuffs.

scholarly journals Numerical Modeling of Water and Gas Transport in Compacted GMZ Bentonite under Constant Volume Condition

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Jiang-Feng Liu ◽  
Xu-Lou Cao ◽  
Hong-Yang Ni ◽  
Kai Zhang ◽  
Zhi-Xiao Ma ◽  
...  
Keyword(s):  
Gas Transport ◽  
Water Saturation ◽  
Underground Water ◽  
Gas Production ◽  
Gas Pressure ◽  
Constant Volume ◽  
Gmz Bentonite ◽  
Gas Migration ◽  
Sealing Ability ◽  
High Level

During deep geological disposal of high-level and long-lived radioactive waste, underground water erosion into buffer materials, such as bentonite, and gas production around the canister are unavoidable. Therefore, understanding water and gas migration into buffer materials is important when it comes to determining the sealing ability of engineered barriers in deep geological repositories. The main aim of our study is to provide insights into the water/gas transport in a compacted bentonite sample under constant volume conditions. The results of our study indicate that water saturation is obtained after 450 hours, which is similar to experimental results. Gas migration testing shows that the degree of water saturation in the samples is very sensitive to the gas pressure. As soon as 2 MPa or higher gas pressure was applied, the water saturation degree decreased quickly. Laboratory experiments indicate that gas breakthrough occurs at 4 MPa, with water being expelled from the downstream side. This indicates that gas pressure has a significant effect on the sealing ability of Gaomizozi (GMZ) bentonite.

scholarly journals Comparative metagenomic analysis following treatment with vancomycin in C57BL/6 and BALB/c mice to elucidate host immunity and behavior

2020 ◽  
Author(s):  
Pratikshya Ray ◽  
Debasmita Das ◽  
Uday Pandey ◽  
Palok Aich
Keyword(s):  
Gut Microbiota ◽  
Normal Level ◽  
Significant Rise ◽  
Host Immunity ◽  
Behavioral Changes ◽  
Metagenomic Analysis ◽  
Initial Increase ◽  
Host Behavior ◽  
And Behavior ◽  
Kinetics Of

AbstractThe gut is the largest reservoir of the resident microbiota. The microbiota can affect the host behavior and immunity. While the consequence of treatment with antibiotics on the gut microbiota can be destructive but can be utilized as a tool to understand the host immunity and behavior. The magnitude of perturbation and time needed for the restoration of gut microbiota can depend on the immune bias of the host. In the current study, we therefore, observed the perturbation and restoration kinetics of gut microbiota following treatment with vancomycin and its effect on the host physiology in both Th1-(C57BL/6) and Th2-(BALB/c) biased mice. A comparative metagenomic analysis revealed that the treatment with vancomycin caused a significant decrease in the abundance of Firmicutes and Bacteroidetes phyla and an initial increase in Proteobacteria. Increase in Proteobacteria decreased with continued treatment with vancomycin to result into a significant rise in Verrucomicrobia phylum. We established the patterns of gut microbiota alteration and its effect on a) the behavior of mice, b) expression of key brain molecules and b) immunity related genes. We followed the gut microbiome restoration for a period of two months following withdrawal of treatment with vancomycin. Maximum restoration (>70%) of gut microbiota happened by the 15th day of withdrawal. BALB/c mice showed a more efficient restoration of gut microbiota compared to C57BL/6 mice. The results, in general, revealed that along with the restoration of major gut microbes, important physiological and behavioral changes of both mice strains returned to the normal level.

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