Biological and Physiological Actions of Regulatory Gut Peptides in the Gastrointestinal Tract

The gastrointestinal tract is the largest endocrine organ in the body, with its component cells dispersed along its length rather than being clustered in glands. More than 20 gut peptides integrate gastrointestinal function by regulating the actions of the epithelium, muscles, and nerves; they also affect the growth and development of the gut and have a major role in appetite control. They mostly work in an autocrine or paracrine manner. Gastrointestinal hormones include the gastrin–cholecystokinin family, the secretin superfamily, preproglucagon derivatives, the motilin–ghrelin family, the pancreatic polypeptide-fold family, and various other gut peptides. Gastrointestinal and other diseases may cause abnormalities of these gut peptides, for example: (1) achlorhydria (from atrophic gastritis or drug-induced) causes elevation of circulating gastrin; (2) malabsorptive conditions are associated with a decrease in the amount of peptides produced in the affected region, and a compensatory elevation of other peptides; and (3) obesity is associated with orexigenic (appetite-stimulating) and less satiating hormonal changes, and the beneficial effects of bariatric surgery are partly explained through alterations in gut hormones.

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Targeting the gastrointestinal tract to treat type 2 diabetes

Journal of Endocrinology ◽

10.1530/joe-16-0056 ◽

2016 ◽

Vol 230 (3) ◽

pp. R95-R113 ◽

Cited By ~ 17

Author(s):

Paige V Bauer ◽

Frank A Duca

Keyword(s):

Type 2 Diabetes ◽

Gastrointestinal Tract ◽

Nutrient Sensing ◽

Gut Peptides ◽

Glucose Levels ◽

Social Burden ◽

Lower Glucose ◽

Glucagon Like Peptide 1 ◽

Diabetes And Obesity

The rising global rates of type 2 diabetes and obesity present a significant economic and social burden, underscoring the importance for effective and safe therapeutic options. The success of glucagon-like-peptide-1 receptor agonists in the treatment of type 2 diabetes, along with the potent glucose-lowering effects of bariatric surgery, highlight the gastrointestinal tract as a potential target for diabetes treatment. Furthermore, recent evidence suggests that the gut plays a prominent role in the ability of metformin to lower glucose levels. As such, the current review highlights some of the current and potential pathways in the gut that could be targeted to improve glucose homeostasis, such as changes in nutrient sensing, gut peptides, gut microbiota and bile acids. A better understanding of these pathways will lay the groundwork for novel gut-targeted antidiabetic therapies, some of which have already shown initial promise.

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Hormones and the gastrointestinal tract

Oxford Textbook of Medicine ◽

10.1093/med/9780199204854.003.1509 ◽

2010 ◽

pp. 2316-2325

Author(s):

A.E. Bishop ◽

P.J. Hammond ◽

J.M. Polak ◽

S.R. Bloom

Keyword(s):

Gastrointestinal Tract ◽

Growth And Development ◽

The Body ◽

Gastrointestinal Function ◽

Gut Peptides ◽

Appetite Control ◽

Endocrine Organ ◽

Different Types

The gastrointestinal tract is the largest endocrine organ in the body, with its component cells dispersed along its length rather than being clustered in glands. Gut peptides integrate gastrointestinal function by regulating the actions of the epithelium, muscles, and nerves, affect the growth and development of the gut and—as has emerged comparatively recently—they also have a major role in appetite control. There is little evidence that many gut peptides act as hormones in a classical endocrine fashion: many are autocrine, regulating the function of the cell secreting them, or paracrine, influencing the behaviour of neighbouring cells of different types....

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Minireview: Gut Peptides Regulating Satiety

Endocrinology ◽

10.1210/en.2004-0089 ◽

2004 ◽

Vol 145 (6) ◽

pp. 2660-2665 ◽

Cited By ~ 111

Author(s):

Maralyn R. Druce ◽

Caroline J. Small ◽

Stephen R. Bloom

Keyword(s):

Body Weight ◽

Gastrointestinal Tract ◽

Peptide Yy ◽

Gut Hormones ◽

Premature Death ◽

Gut Peptides ◽

The United Kingdom ◽

Glucagon Like Peptide ◽

Low Levels ◽

Glucagon Like Peptide 1

Abstract The gastrointestinal tract and the pancreas release hormones regulating satiety and body weight. Ghrelin stimulates appetite, and glucagon-like peptide-1, oxyntomodulin, peptide YY, cholecystokinin, and pancreatic polypeptide inhibit appetite. These gut hormones act to markedly alter food intake in humans and rodents. Obesity is the current major cause of premature death in the United Kingdom, killing almost 1000 people per week. Worldwide, its prevalence is accelerating. There is currently no effective answer to the pandemic of obesity, but replacement of the low levels of peptide YY observed in the obese may represent an effective antiobesity therapy.

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Mechanisms of weight loss after obesity surgery

Endocrine Reviews ◽

10.1210/endrev/bnab022 ◽

2021 ◽

Author(s):

Elina Akalestou ◽

Alexander D Miras ◽

Guy A Rutter ◽

Carel W le Roux

Keyword(s):

Bariatric Surgery ◽

Weight Loss ◽

Gastrointestinal Tract ◽

Energy Expenditure ◽

Obesity Surgery ◽

Control Release ◽

Gut Peptides ◽

Appetite Control ◽

Metabolic Outcomes ◽

Weight Loss Interventions

Abstract Obesity surgery remains the most effective treatment for obesity and its complications. Weight loss was initially attributed to decreased energy absorption from the gut but have since been linked to reduced appetitive behaviour and potentially increased energy expenditure. Implicated mechanisms associating rearrangement of the gastrointestinal tract with these metabolic outcomes include central appetite control, release of gut peptides, change in microbiota and bile acids. However, the exact combination and timing of signals remain largely unknown. In this review, we survey recent research investigating these mechanisms, and seek to provide insights on unanswered questions over how weight loss is achieved following bariatric surgery which may eventually lead to safer, nonsurgical weight-loss interventions or combinations of medications with surgery.

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Habitat Association of Klebsiella Species

Infection Control ◽

10.1017/s0195941700062603 ◽

1985 ◽

Vol 6 (2) ◽

pp. 52-58 ◽

Cited By ~ 111

Author(s):

Susan T. Bagley

Keyword(s):

Drinking Water ◽

Gastrointestinal Tract ◽

Surface Waters ◽

Industrial Effluents ◽

Opportunistic Pathogen ◽

Habitat Associations ◽

Habitat Association ◽

Klebsiella Species ◽

Almost All ◽

Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

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