Host???microbe interactions in vivo in the human small intestine; the effects of lactobacillus plantarumWCFS1 using functional transcriptomics and proteomics

2006 ◽  
Vol 18 (1) ◽  
pp. A67-A68
Author(s):  
FJ Troost ◽  
RJM Brummer
Keyword(s):  
Small Intestine ◽  
Human Small Intestine ◽  
Microbe Interactions ◽  
Host Microbe Interactions

scholarly journals Measurement of rapidly available glucose (RAG) in plant foods: a potential in vitro predictor of the glycaemic response

1996 ◽  
Vol 75 (3) ◽  
pp. 327-337 ◽  
Author(s):  
Hans N Englyst ◽  
Jan Veenstra ◽  
Geoffrey J Hudson
Keyword(s):  
Small Intestine ◽  
Direct Calculation ◽  
Simple Calculation ◽  
Glycaemic Index ◽  
Equal Weight ◽  
Glycaemic Response ◽  
Human Small Intestine ◽  
Reference Amount

AbstractThe glycaemic index (GI) is an in vivo measurement based on the glycaemicresponse to carbohydrate-containing foods, and allows foods to be ranked on the basis of the rate of digestion and absorption of the carbohydrates that they contain. GI values are normalizedto a reference amount of available carbohydrate and do not reflect the amounts of carbohydrate normally present in foods; for example, a food with a low content of carbohydrates will have a high GI value if that carbohydrate is digested and absorbed rapidly in the human small intestine. This is potentially confusing for a person wishing to control his or her blood glucoselevels by the choice of foods. The rate and extent of starch digestion in vitro has been measured using a technique that classifies starch into three major fractions: rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). In addition, thistechnique gives a value for rapidly available glucose (RAG), which includes RDS, free glucose and the glucose moiety of sucrose. When the values for thirty-nine foods were expressed on the basis ofthe available carbohydrate content of these foods, highly significant (P<0·001) positive correlations were observed between GI and both RDS and RAG. The measurement of RAGin vitro provides values for direct calculation of the amount of glucose likely to be rapidly absorbed in the human small intestine and,thus, to influence blood glucose and insulin levels. These values can be used to compare foods, as eaten,on an equal-weight basis. Food-table RAG values would allow simple calculation of the total amount of RAG provided by single foods, by whole meals and by whole diets. Studies are planned in which RAG and the glycaemic response in man will be measured for identical food products.

scholarly journals Polymers in the gut compress the colonic mucus hydrogel

2016 ◽  
Vol 113 (26) ◽  
pp. 7041-7046 ◽  
Author(s):  
Sujit S. Datta ◽  
Asher Preska Steinberg ◽  
Rustem F. Ismagilov
Keyword(s):  
Thermodynamic Model ◽  
Ex Vivo ◽  
Polymer Concentration ◽  
Dietary Fibers ◽  
Physical Damage ◽  
Gut Microbes ◽  
Specific Pathogen ◽  
Microbe Interactions ◽  
Host Microbe Interactions

Colonic mucus is a key biological hydrogel that protects the gut from infection and physical damage and mediates host–microbe interactions and drug delivery. However, little is known about how its structure is influenced by materials it comes into contact with regularly. For example, the gut abounds in polymers such as dietary fibers or administered therapeutics, yet whether such polymers interact with the mucus hydrogel, and if so, how, remains unclear. Although several biological processes have been identified as potential regulators of mucus structure, the polymeric composition of the gut environment has been ignored. Here, we demonstrate that gut polymers do in fact regulate mucus hydrogel structure, and that polymer–mucus interactions can be described using a thermodynamic model based on Flory–Huggins solution theory. We found that both dietary and therapeutic polymers dramatically compressed murine colonic mucus ex vivo and in vivo. This behavior depended strongly on both polymer concentration and molecular weight, in agreement with the predictions of our thermodynamic model. Moreover, exposure to polymer-rich luminal fluid from germ-free mice strongly compressed the mucus hydrogel, whereas exposure to luminal fluid from specific-pathogen-free mice—whose microbiota degrade gut polymers—did not; this suggests that gut microbes modulate mucus structure by degrading polymers. These findings highlight the role of mucus as a responsive biomaterial, and reveal a mechanism of mucus restructuring that must be integrated into the design and interpretation of studies involving therapeutic polymers, dietary fibers, and fiber-degrading gut microbes.

scholarly journals Longitudinal In Vivo Assessment of Host-Microbe Interactions in a Murine Model of Pulmonary Aspergillosis

iScience ◽  
2019 ◽  
Vol 20 ◽  
pp. 184-194 ◽  
Author(s):  
Shweta Saini ◽  
Jennifer Poelmans ◽  
Hannelie Korf ◽  
James L. Dooley ◽  
Sayuan Liang ◽  
...  
Keyword(s):  
Murine Model ◽  
Pulmonary Aspergillosis ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
In Vivo Assessment

scholarly journals A New C-Type Lectin Similar to the Human Immunoreceptor DC-SIGN Mediates Symbiont Acquisition by a Marine Nematode

2006 ◽  
Vol 72 (4) ◽  
pp. 2950-2956 ◽  
Author(s):  
Silvia Bulgheresi ◽  
Irma Schabussova ◽  
Tie Chen ◽  
Nicholas P. Mullin ◽  
Rick M. Maizels ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Marine Nematode ◽  
Mannose Binding Protein ◽  
Mannose Binding ◽  
Marine Symbiosis ◽  
Microbe Interactions ◽  
Sulfur Oxidizing ◽  
Host Microbe Interactions ◽  
Symbiont Acquisition

ABSTRACT Although thiotrophic symbioses have been intensively studied for the last three decades, nothing is known about the molecular mechanisms of symbiont acquisition. We used the symbiosis between the marine nematode Laxus oneistus and sulfur-oxidizing bacteria to study this process. In this association a monolayer of symbionts covers the whole cuticle of the nematode, except its anterior-most region. Here, we identify a novel Ca2+-dependent mannose-specific lectin that was exclusively secreted onto the posterior, bacterium-associated region of L. oneistus cuticle. A recombinant form of this lectin induced symbiont aggregation in seawater and was able to compete with the native lectin for symbiont binding in vivo. Surprisingly, the carbohydrate recognition domain of this mannose-binding protein was similar both structurally and functionally to a human dendritic cell-specific immunoreceptor. Our results provide a molecular link between bacterial symbionts and host-secreted mucus in a marine symbiosis and suggest conservation in the mechanisms of host-microbe interactions throughout the animal kingdom.

scholarly journals Identification of Erwinia amylovora Genes Induced during Infection of Immature Pear Tissue

2005 ◽  
Vol 187 (23) ◽  
pp. 8088-8103 ◽  
Author(s):  
Youfu Zhao ◽  
Sara E. Blumer ◽  
George W. Sundin
Keyword(s):  
Pseudomonas Syringae ◽  
Erwinia Amylovora ◽  
Sequence Similarity ◽  
Type Ii Secretion ◽  
Knockout Mutant ◽  
Technology System ◽  
Microbe Interactions ◽  
Host Microbe Interactions ◽  
Blight Disease

ABSTRACT The enterobacterium Erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. In this study, we used a modified in vivo expression technology system to identify E. amylovora genes that are activated during infection of immature pear tissue, a process that requires the major pathogenicity factors of this organism. We identified 394 unique pear fruit-induced (pfi) genes on the basis of sequence similarity to known genes and separated them into nine putative function groups including host-microbe interactions (3.8%), stress response (5.3%), regulation (11.9%), cell surface (8.9%), transport (13.5%), mobile elements (1.0%), metabolism (20.3%), nutrient acquisition and synthesis (15.5%), and unknown or hypothetical proteins (19.8%). Known virulence genes, including hrp/hrc components of the type III secretion system, the major effector gene dspE, type II secretion, levansucrase (lsc), and regulators of levansucrase and amylovoran biosynthesis, were upregulated during pear tissue infection. Known virulence factors previously identified in E. (Pectobacterium) carotovora and Pseudomonas syringae were identified for the first time in E. amylovora and included HecA hemagglutinin family adhesion, Peh polygalacturonase, new effector HopPtoCEA, and membrane-bound lytic murein transglycosylase MltEEA. An insertional mutation within hopPtoC EA did not result in reduced virulence; however, an mltE EA knockout mutant was reduced in virulence and growth in immature pears. This study suggests that E. amylovora utilizes a variety of strategies during plant infection and to overcome the stressful and poor nutritional environment of its plant hosts.

Absorption of Inorganic Phosphate in the Human Small Intestine

1979 ◽  
Vol 56 (5) ◽  
pp. 407-412 ◽  
Author(s):  
J. Walton ◽  
T. K. Gray
Keyword(s):  
Small Intestine ◽  
Inorganic Phosphate ◽  
Water Movement ◽  
Human Subjects ◽  
Sodium Concentration ◽  
Phosphate Concentration ◽  
Phosphate Absorption ◽  
Human Small Intestine ◽  
Intestinal Phosphate Absorption

1. Intestinal phosphate absorption in human subjects was studied by the technique of triple lumen intestinal perfusion in vivo. 2. Ileal phosphate absorption increased as the intraluminal phosphate concentration was increased. 3. Ileal rates of phosphate absorption were lower at any given intraluminal phosphate concentration than previously described jejunal rates. Acidification of the ileal lumen did not increase phosphate absorption. 4. Phosphate absorption was shown in the jejunum to be dependent on the intraluminal sodium concentration. 5. Phosphate absorption in the human small intestine consists of at least two components, one directly proportional to water movement and the second apparently independent of water movement.

scholarly journals Mechanically Resolved Imaging of Bacteria using Expansion Microscopy

2019 ◽  
Author(s):  
Youngbin Lim ◽  
Margarita Khariton ◽  
Keara M. Lane ◽  
Anthony L. Shiver ◽  
Katharine M. Ng ◽  
...  
Keyword(s):  
Cell Walls ◽  
Pathogenic Bacteria ◽  
Cell Envelope ◽  
Grand Challenge ◽  
Bacterial Cells ◽  
Spectral Separation ◽  
Microbe Interactions ◽  
Microscopy Method ◽  
Host Microbe Interactions

AbstractImaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many species adopt similar morphologies. While prior studies have relied on techniques involving spectral labeling, we have developed an expansion microscopy method (μExM) in which cells are physically expanded prior imaging and their expansion patterns depend on the structural and mechanical properties of their cell walls, which vary across species and conditions. We use this phenomenon as a quantitative and sensitive phenotypic imaging contrast orthogonal to spectral separation in order to resolve bacterial cells of different species or in distinct physiological states. Focusing on host-microbe interactions that are difficult to quantify through fluorescence alone, we demonstrate the ability of μExM to distinguish species within a dense community throughin vivoimaging of a model gut microbiota, and to sensitively detect cell-envelope damage caused by antibiotics or previously unrecognized cell-to-cell phenotypic heterogeneity among pathogenic bacteria as they infect macrophages.

Sign in / Sign up

Export Citation Format

Share Document