Determination of sweetener specificity of horse gut-expressed sweet taste receptor T1R2-T1R3 and its significance for energy provision and hydration.

Studies carried out in several species have demonstrated that detection of low-calorie sweeteners in the lumen of the intestine, by the sweet receptor, T1R2-T1R3, initiates a signaling pathway leading to enhanced expression and activity of intestinal Na/glucose cotransporter 1, SGLT1. This results in an increased gut capacity to absorb glucose, sodium chloride and water, the basis for oral rehydration therapy. Horses express T1R2, T1R3 and downstream signaling elements in the intestinal tissue.

Alterations of mucosa-attached microbiome and epithelial cell numbers in the cystic fibrosis small intestine with implications for intestinal disease.

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Defective CFTR leads to accumulation of dehydrated viscous mucus within the small intestine, luminal acidification and altered intestinal motility, resulting in blockage. These changes promote gut microbial dysbiosis, adversely influencing the normal proliferation and differentiation of intestinal epithelial cells.

Non-nutritive sweetener activation of the pig sweet taste receptor T1R2-T1R3 in vitro mirrors sweetener stimulation of the gut-expressed receptor in vivo.

The perception of sweet is mediated by the sweet taste receptor T1R2-T1R3 expressed in taste cells of the lingual epithelium. This receptor is also expressed in intestinal enteroendocrine cells and is required for sensing luminal sugars and sweeteners to regulate expression of intestinal Na-glucose cotransporter 1 (SGLT1). There are some notable differences amongst species in the ability to detect certain non-nutritive (artificial) sweeteners.

The Effect of Milk Replacer Composition on the Intestinal Microbiota of Pre-ruminant Dairy Calves.

The impact of dietary composition and prebiotics, in promoting the growth of beneficial groups of gut bacteria, is increasingly apparent. Using Illumina MiSeq sequencing of bacterial 16S rRNA genes, this study has aimed to characterize and compare the establishment of the gastrointestinal microbiota in dairy calves given two different commercial milk replacer (MR) diets. MR1 and MR2 contain different levels of macronutrients such as protein and fat.

Glucagon-Like Peptide-2 and the Enteric Nervous System Are Components of Cell-Cell Communication Pathway Regulating Intestinal Na/Glucose Co-transport.

The Na/glucose cotransporter 1, SGLT1 is the major route for transport of dietary glucose from the lumen of the intestine into absorptive enterocytes. Sensing of dietary sugars and artificial sweeteners by the sweet taste receptor, T1R2-T1R3, expressed in the enteroendocrine L-cell regulates SGLT1 expression in neighboring absorptive enterocytes. However, the mechanism by which sugar sensing by the enteroendocrine cell is communicated to the absorptive enterocytes is not known.

Host selectively contributes to shaping intestinal microbiota of carnivorous and omnivorous fish.

Fish production is increasingly important to global food security. A major factor in maintaining health, productivity and welfare of farmed fish is the establishment and promotion of a stable and beneficial intestinal microbiota. Understanding the effects of factors such as host and environment on gut microbial community structure is essential for developing strategies for stimulating the establishment of a health-promoting gut-microbiota.

Deregulation of transcription factors controlling intestinal epithelial cell differentiation; a predisposing factor for reduced enteroendocrine cell number in morbidly obese individuals.

Morbidly obese patients exhibit impaired secretion of gut hormones that may contribute to the development of obesity. After bariatric surgery there is a dramatic increase in gut hormone release. In this study, gastric and duodenal tissues were endoscopically collected from lean, and morbidly obese subjects before and 3 months after laparoscopic sleeve gastrectomy (LSG).

Composition and diversity of mucosa-associated microbiota along the entire length of the pig gastrointestinal tract; dietary influences.

Mucosa-associated microbial populations of the gastrointestinal tract are in intimate contact with the outer mucus layer. This proximity offers these populations a higher potential, than lumenal microbiota, in exerting effects on the host. Functional characteristics of the microbiota and influences of host-physiology shape the composition and activity of the mucosa-associated bacterial community.

Low calorie sweeteners and gut microbiota.

Studies dating back to 1980s, using bacterial cultures, have reported associations between low calorie sweeteners (LCS) and alterations in bacterial composition, raising the potential that LCS might exert effects on the host via interactions with gut microbiota. However, the results of a few recent studies carried out in this area have produced controversies. There is evidence that human fecal samples, used in most human microbiome studies, may provide a poor representation of microbial contents of the proximal intestine.

Bacterial sensing underlies artificial sweetener-induced growth of gut Lactobacillus.

Disruption in stable establishment of commensal gut microbiota by early weaning is an important factor in susceptibility of young animals to enteric disorders. The artificial sweetener SUCRAM [consisting of neohesperidin dihydrochalcone (NHDC) and saccharin] included in piglets' feed reduces incidence of enteric disease. Pyrosequencing of pig caecal 16S rRNA gene amplicons identified 25 major families encompassing seven bacterial classes with Bacteroidia, Clostridia and Bacilli dominating the microbiota.

Characterization of butyrate transport across the luminal membranes of equine large intestine.

The diet of the horse, pasture forage (grass), is fermented by the equine colonic microbiota to short-chain fatty acids, notably acetate, propionate and butyrate. Short-chain fatty acids provide a major source of energy for the horse and contribute to many vital physiological processes. We aimed to determine both the mechanism of butyrate uptake across the luminal membrane of equine colon and the nature of the protein involved.

Role of nutrient-sensing taste 1 receptor (T1R) family members in gastrointestinal chemosensing.

Luminal nutrient sensing by G-protein-coupled receptors (GPCR) expressed on the apical domain of enteroendocrine cells activates intracellular pathways leading to secretion of gut hormones that control vital physiological processes such as digestion, absorption, food intake and glucose homeostasis. The taste 1 receptor (T1R) family of GPCR consists of three members: T1R1; T1R2; T1R3. Expression of T1R1, T1R2 and T1R3 at mRNA and protein levels has been demonstrated in the intestinal tissue of various species.

Dietary supplementation with lactose or artificial sweetener enhances swine gut Lactobacillus population abundance.

The commensal bacteria Lactobacillus are widely used as probiotic organisms conferring a heath benefit on the host. They have been implicated in promoting gut health via the stimulation of host immunity and anti-inflammatory responses, as well as protecting the intestinalmucosa against pathogen invasion. Lactobacilli grow by fermenting sugars and starches and produce lactic acid as their primary metabolic product.

Sensing of amino acids by the gut-expressed taste receptor T1R1-T1R3 stimulates CCK secretion.

CCK is secreted by endocrine cells of the proximal intestine in response to dietary components, including amino acids. CCK plays a variety of roles in digestive processes, including inhibition of food intake, consistent with a role in satiety. In the lingual epithelium, the sensing of a broad spectrum of L-amino acids is accomplished by the heteromeric amino acid (umami) taste receptor (T1R1-T1R3).

Expression of sweet receptor components in equine small intestine: relevance to intestinal glucose transport.

The heteromeric sweet taste receptor T1R2-T1R3 is expressed on the luminal membrane of certain populations of enteroendocrine cells. Sensing of sugars and other sweet compounds by this receptor activates a pathway in enteroendocrine cells, resulting in secretion of a number of gut hormones, including glucagon-like peptide 2 (GLP-2). This subsequently leads to upregulation in the expression of intestinal Na(+)/glucose cotransporter, SGLT1, and increased intestinal glucose absorption.

Alterations in microbiota and fermentation products in equine large intestine in response to dietary variation and intestinal disease.

We aimed to determine the effects of variations in dietary composition on equine gut microbiota and their fermentation products, and proposed that dietary modifications profoundly affect microbial ecosystems and their metabolites. Bacterial communities within the large intestine of three groups of horses were compared using oligonucleotide-RNA hybridisation methodology. Each group consisting of six horses was maintained on (1) a grass-only diet, (2) a concentrate diet (i.

Expression of Na+/glucose co-transporter 1 (SGLT1) in the intestine of piglets weaned to different concentrations of dietary carbohydrate.

Na+/glucose co-transporter 1 (SGLT1) transports dietary sugars from the lumen of the intestine into enterocytes. Regulation of this protein is essential for the provision of glucose to the body and, thus, is important for maintenance of glucose homeostasis. We have assessed expression of SGLT1 at mRNA, protein and functional levels in the intestinal tissue of 28 d old piglets weaned onto isoenergetic diets with differing concentrations of digestible carbohydrate (CHO).

Expression of Na+/glucose co-transporter 1 (SGLT1) is enhanced by supplementation of the diet of weaning piglets with artificial sweeteners.

In an intensive livestock production, a shorter suckling period allows more piglets to be born. However, this practice leads to a number of disorders including nutrient malabsorption, resulting in diarrhoea, malnutrition and dehydration. A number of strategies have been proposed to overcome weaning problems.

Adaptive response of equine intestinal Na+/glucose co-transporter (SGLT1) to an increase in dietary soluble carbohydrate.

Experimental and epidemiological evidence suggests that consumption of hydrolyzable carbohydrate, hCHO (grain), by horses is an important risk factor for colic, a common cause of equine mortality. It is unknown whether the small intestinal capacity to digest hCHO and/or to absorb monosaccharides is limiting, or even if horses can adapt to increased carbohydrate load. We investigated changes in the brush-border membrane carbohydrate digestive enzymes and glucose absorptive capacity of horse small intestine in response to increased hCHO.

T1R3 and gustducin in gut sense sugars to regulate expression of Na+-glucose cotransporter 1.

Dietary sugars are transported from the intestinal lumen into absorptive enterocytes by the sodium-dependent glucose transporter isoform 1 (SGLT1). Regulation of this protein is important for the provision of glucose to the body and avoidance of intestinal malabsorption. Although expression of SGLT1 is regulated by luminal monosaccharides, the luminal glucose sensor mediating this process was unknown.

Microarray analysis of butyrate regulated genes in colonic epithelial cells.

Butyrate is a naturally occurring product of colonic microbial fermentation of dietary carbohydrates that escape hydrolysis in the small intestine. Butyrate plays a significant role in the maintenance of colonic tissue homeostasis by regulating the expression of genes associated with the processes of proliferation, differentiation, and apoptosis. Using microarray analysis, we assessed changes in the expression of 19,400 genes in response to butyrate in a human colonic epithelial cell line.

Evaluation of glucose tolerance and intestinal luminal membrane glucose transporter function in horses with equine motor neuron disease.

Objective: To confirm whether the plasma glucose concentration curve obtained during oral glucose tolerance tests (OGTTs) in horses with equine motor neuron disease (EMND) is decreased, compared with that obtained in clinically normal horses, and determine whether that decrease is a result of defective glucose metabolism or intestinal glucose transport dysfunction.

Animals: 8 horses with EMND and 44 matched control horses.

Procedure: Electromyography and OGTTs were performed in all 8 affected horses and 10 control horses.

Glucose sensing in the intestinal epithelium.

Dietary sugars regulate expression of the intestinal Na+/glucose cotransporter, SGLT1, in many species. Using sheep intestine as a model, we showed that lumenal monosaccharides, both metabolisable and nonmetabolisable, regulate SGLT1 expression. This regulation occurs not only at the level of transcription, but also at the post-transcriptional level.