Efficacy of the glucagon-like peptide-1 agonist exenatide in the treatment of short bowel syndrome

Efficacy and Safety of Liraglutide in Patients With an Ileal Pouch-Anal Anastomosis and Chronic High Bowel Frequency: A Placebo-Controlled, Crossover, Proof-of-Concept Study

INTRODUCTION

After colectomy with ileoanal pouch anastomosis (IPAA), many patients develop high bowel frequency (BF) refractory to antimotility agents, despite normal IPAA morphology. Low circulating levels of glucagon-like protein-1 (GLP-1), a modulator of gastroduodenal motility, have been reported after colectomy.

METHODS

Double-blind crossover study of 8 IPAA patients with refractory high BF treated with daily administration of the GLP-1 receptor agonist liraglutide or placebo.

RESULTS

Liraglutide, but not placebo, reduced daily BF by more than 35% ( P < 0.03).

DISCUSSION

Larger randomized controlled studies are warranted to delineate the treatment potential of GLP-1 receptor agonists in IPAA patients suffering from noninflammatory high BF.

Emerging uses of glucagon-like peptide 1 (GLP-1) receptor agonists following ileal resection: literature review and case examples

Following ileal resection, the combination of severe bile acid (BA) malabsorption, rapid small bowel transit and unrestricted upper gastrointestinal (GI) secretion results in severe diarrhoea that can prove refractory to pharmacological therapies. While established therapies, including BA sequestrants and antidiarrhoeal drugs seek to ameliorate symptoms, they do not target the underlying pathophysiological mechanisms in this patient group. Their use can also be limited by both intolerance and adverse effects. The novel use of glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) in these patients may allow restoration of the physiological negative feedback mechanisms lost in ileal resection and reduce diarrhoea by prolonging small bowel transit time, limiting upper GI secretions and perhaps by inhibiting hepatic BA synthesis. While recent evidence supports the use of GLP-1 RAs as a safe and effective therapy for bile acid diarrhoea (BAD), it remains uncertain whether those with severe BAD and subsequent short bowel syndrome secondary to extensive ileal resection will benefit. Here, we present three cases of severe diarrhoea secondary to extensive ileal resection in which the use of the GLP-1 RA, liraglutide, was well tolerated and resulted in an objective improvement in diarrhoeal symptoms. We further provide a narrative review of the emerging evidence base supporting the use of GLP therapies in this challenging condition.

Effects of Treatment with Liraglutide Early after Surgical Intervention on Clinical Outcomes in Patients with Short Bowel Syndrome: A Pilot Observational "Real-Life" Study

Liraglutide, a glucagon-like peptide-1 agonist, has been shown to have beneficial effects on fecal output in short bowel syndrome (SBS) by small human studies. Its potential effects early after gut resection are not known. In this pilot observational study, we described the 1- and 6-month liraglutide effects in 19 adult patients with a new SBS diagnosis within 1 month after surgical resection. Stomal/fecal and urinary outcomes, serum/urinary electrolytes, and body composition were assessed. Both within-group differences and between-group comparisons with 20 SBS patients refusing liraglutide treatment were evaluated. The main liraglutide-related side effect was mild nausea, except in one patient, who experienced severe nausea/vomiting. The median ostomy/fecal output was significantly reduced by -550 mL/day after 6 months of treatment (vs. -200 mL/day in untreated, p = 0.04). The number of patients reaching a ≥20% output reduction was 10/19 (52.6%) treated vs. 3/20 (15.0%) untreated patients (p = 0.013) at 1 month and 12/19 (63.2%) vs. 6/20 (30.0%) (p = 0.038) at 6 months, respectively. Participants with a clinically relevant output reduction at 6 months had a significantly lower baseline weight and BMI. Energy parenteral supply significantly decreased, while infused volumes, oral energy, and fluid intakes slightly decreased, though not significantly. This pilot study supports liraglutide benefits in ostomy/fecal output early after surgical gut resection in SBS patients, particularly in those with lower baseline weight values.

Intestinal adaptation and rehabilitation

Massive intestinal resection is a regrettably necessary but life-saving intervention for progressive or fulminant necrotizing enterocolitis (NEC). However, the resultant short bowel syndrome (SBS) poses its own array of challenges and complications. Within hours of such an abrupt loss of intestinal length, the intestine begins to adapt. Our ability to understand this process of intestinal adaptation has proven critical in our ability to clinically treat the challenging problem of short bowel syndrome. This review first highlights key data relating to intestinal adaptation including structural and functional changes, biochemical regulation, and other factors affecting the magnitude of intestinal adaptation responses. We then focus on intestinal rehabilitation as it relates to strategies to enhance intestinal adaptation while meeting nutritional needs and preventing complications of parenteral nutrition.

Short bowel syndrome: Complications and management

Short bowel syndrome (SBS) occurs when a patient loses bowel length or function significantly enough to cause malabsorption, oftentimes requiring lifelong parenteral support. In adults, this occurs most commonly in the setting of massive intestinal resection, whereas congenital anomalies and necrotizing enterocolitis predominate in children. Many patients with SBS develop long-term clinical complications over time related to their altered intestinal anatomy and physiology or to various treatment interventions such as parenteral nutrition and the central venous catheter through which it is administered. Identifying, preventing, and treating these complications can be challenging. This review will focus on the diagnosis, treatment, and prevention of several complications that can occur in this patient population, including diarrhea, fluid and electrolyte imbalance, vitamin and trace element derangements, metabolic bone disease, biliary disorders, small intestinal bacterial overgrowth, d-lactic acidosis, and complications of central venous catheters.

Treatment of short bowel syndrome: Breaking the therapeutic ceiling?

Short bowel syndrome (SBS) is the most common cause of chronic intestinal failure, requiring home parenteral support (intravenous fluid, parenteral nutrition, or parenteral nutrition with intravenous fluid) to compensate for severe malabsorption. The loss of mucosal absorptive area after extensive intestinal resection is accompanied by an accelerated transit and hypersecretion. Changes in physiology and clinical outcomes differ between patients with SBS with or without the distal ileum and/or colon-in-continuity. This narrative review summarizes the treatments used in SBS, with a focus on novel approaches with intestinotrophic agents. During the early postoperative years, spontaneous adaptation occurs and can be induced or accelerated with conventional therapies, which include dietary and fluid modifications and antidiarrheal and antisecretory drugs. Based on the proadaptive role of enterohormones (eg, glucagon-like peptide [GLP]-2), analogues have been developed to allow enhanced or hyperadaptation after a period of stabilization. Teduglutide is the first GLP-2 analogue developed and commercialized with proadaptive effects resulting in reduced parenteral support needs; however, the potential for weaning of parenteral support is variable. Whether early treatment with enterohormones or accelerated hyperadaptation would further improve absorption and outcomes remains to be shown. Longer-acting GLP-2 analogues are currently being investigated. Encouraging reports with GLP-1 agonists require confirmation in randomized trials, and dual GLP-1 and GLP-2 analogues have yet to be clinically investigated. Future studies will prove whether the timing and/or combinations of different enterohormones will be able to break the ceiling of intestinal rehabilitation in SBS.

Type 2 Diabetes and the Microbiome

Diabetes represents one of the most significant, and rapidly escalating, global healthcare crises we face today. Diabetes already affects one-tenth of the world's adults-more than 537 million people, numbers that have tripled since 2000 and are estimated to reach 643 million by 2030. Type 2 diabetes (T2D), the most prevalent form, is a complex disease with numerous contributing factors, including genetics, epigenetics, diet, lifestyle, medication use, and socioeconomic factors. In addition, the gut microbiome has emerged as a significant potential contributing factor in T2D development and progression. Gut microbes and their metabolites strongly influence host metabolism and immune function, and are now known to contribute to vitamin biosynthesis, gut hormone production, satiety, maintenance of gut barrier integrity, and protection against pathogens, as well as digestion and nutrient absorption. In turn, gut microbes are influenced by diet and lifestyle factors such as alcohol and medication use, including antibiotic use and the consumption of probiotics and prebiotics. Here we review current evidence regarding changes in microbial populations in T2D and the mechanisms by which gut microbes influence glucose metabolism and insulin resistance, including inflammation, gut permeability, and bile acid production. We also explore the interrelationships between gut microbes and different T2D medications and other interventions, including prebiotics, probiotics, and bariatric surgery. Lastly, we explore the particular role of the small bowel in digestion and metabolism and the importance of studying small bowel microbes directly in our search to find metabolically relevant biomarkers and therapeutic targets for T2D.

Glucagon-like peptide-2 analogues for Crohn’s disease patients with short bowel syndrome and intestinal failure

Short bowel syndrome (SBS) with intestinal failure (IF) is a rare but severe complication of Crohn’s disease (CD), which is the most frequent benign condition that leads to SBS after repeated surgical resections, even in the era of biologics and small molecules. Glucagon-like peptide-2 analogues have been deeply studied recently for the treatment of SBS-IF. These drugs have a significant intestinotrophic effect and the potential to reduce the chronic dependence of SBS-IF patients on parenteral support or nutrition. Teduglutide has been approved for the treatment of SBS-IF, and apraglutide is currently in clinical development. The use of these drugs was examined with a focus on their use in CD patients.

Novel Therapeutic Approaches for Mitigating Complications in Short Bowel Syndrome

Short bowel syndrome (SBS) is a particularly serious condition in which the small intestine does not absorb sufficient nutrients for biological needs, resulting in severe illness and potentially death if not treated. Given the important role of the gut in many signaling cascades throughout the body, SBS results in disruption of many pathways and imbalances in various hormones. Due to the inability to meet sufficient nutritional needs, an intravenous form of nutrition, total parental nutrition (TPN), is administered. However, TPN presents difficulties such as severe liver injury and altered signaling secondary to the continued lack of luminal contents. This manuscript aims to summarize relevant studies into the systemic effects of TPN on systems such as the gut-brain, gut-lung, and gut-liver axis, as well as present novel therapeutics currently under use or investigation as mitigation strategies for TPN induced injury.

Therapeutic peptides: current applications and future directions

Peptide drug development has made great progress in the last decade thanks to new production, modification, and analytic technologies. Peptides have been produced and modified using both chemical and biological methods, together with novel design and delivery strategies, which have helped to overcome the inherent drawbacks of peptides and have allowed the continued advancement of this field. A wide variety of natural and modified peptides have been obtained and studied, covering multiple therapeutic areas. This review summarizes the efforts and achievements in peptide drug discovery, production, and modification, and their current applications. We also discuss the value and challenges associated with future developments in therapeutic peptides.

Complementary and antagonistic effects of combined glucagon-like peptide-2 and glucagon-like peptide-1 receptor agonist administration on parameters relevant to short bowel syndrome

BACKGROUND

Short Bowel Syndrome (SBS) is characterized by debilitating malabsorption requiring parenteral nutrition. The intestinotrophic glucagon-like peptide-2 receptor agonist, h[Gly2]GLP2, is currently used to treat patients with SBS. Recent evidence suggests that GLP-1 receptor agonists such as Exendin-4 (Ex4) may also be beneficial in SBS given their ability to increase intestinal growth and delay gastric emptying (GE).

METHODS

Intestinal growth, body weight (BW), food intake (FI), GE, gastrointestinal (GI) transit, intestinal permeability, and glucose tolerance were investigated in male and female C57/BL6 mice following vehicle, h[Gly2]GLP2 or Ex4 treatment, alone or in combination at "low", "medium", and "high" doses (0.1, 0.5, 1.0 and 0.01, 0.05, 0.1 μg/g, respectively).

RESULTS

Only the h[Gly2]GLP2 low/Ex4 high-dose combination increased small intestinal (SI) weight, in an additive manner, compared to vehicle and both mono-agonists (P<0.01-0.001), via increases in villus height (P<0.01) and SI length (P<0.05), respectively. This combination had no effects on BW, FI and fat, liver, spleen, heart and kidney weights, but reduced GI transit (P<0.001) compared to low-dose h[Gly2]GLP2 mono-treatment, and abrogated the inhibitory effects of high-dose Ex4 on GE (P<0.01) and of low-dose h[Gly2]GLP2 on intestinal permeability (P<0.05). Ex4-induced improvements in glucose homeostasis were maintained upon combination with h[Gly2]GLP2 (P<0.001).

CONCLUSIONS

These findings suggest that combining specific doses of GLP-2-based therapies and GLP-1 receptor agonists additively improves SI growth and GI transit without detrimental effects on BW, FI, GE, and glucose homeostasis, and may therefore be a useful approach to the treatment of patients with SBS. This article is protected by copyright. All rights reserved.

Dapiglutide, a novel dual GLP-1 and GLP-2 receptor agonist, attenuates intestinal insufficiency in a murine model of short bowel

BACKGROUND

Extensive intestinal resection may lead to short bowel (SB) syndrome, resulting in intestinal insufficiency or intestinal failure (IF). Intestinal insufficiency and IF involve deficiency of the proglucagon-derived hormones glucagon-like peptide-1 (GLP-1) and GLP-2. Two major problems of SB are epithelial surface loss and accelerated transit. Standard treatment now targets intestinal adaptation with a GLP-2 analogue to enlarge absorptive surface area. It is possible that additional benefit can be gained from a combination of GLP-1 and GLP-2 activity, with the aim to enlarge intestinal surface area and slow intestinal transit.

METHODS

The GLP-1- and GLP-2-specific effects of the novel dual GLP-1 receptor (GLP-1R) and GLP-2 receptor (GLP-2R) agonist dapiglutide (rINN) were characterized in rodents. Furthermore, in a murine SB model of intestinal insufficiency with 40% ileocecal resection, the influence of dapiglutide on intestinal growth, body weight, food intake, volume status, and stool water content was tested against vehicle and sham-operated male mice.

RESULTS

Dapiglutide significantly improves oral glucose tolerance, reduces intestinal transit time, and promotes intestinal growth. In the SB mouse model, dapiglutide promotes body weight recovery, despite unchanged intake of liquid diet. Dapiglutide promotes significant intestinal growth, as indicated by significantly increased villus height as well as intestinal length. Furthermore, dapiglutide reduces stool water losses, resulting in reduced plasma aldosterone.

CONCLUSION

Dapiglutide possesses specific and potent GLP-1R and GLP-2R agonist effects in rodents. In the murine SB model, combined unimolecular GLP-1R and GLP-2R stimulation with dapiglutide potently attenuates intestinal insufficiency and potentially also IF.

[Short bowel syndrome: From intestinal insufficiency to intestinal adaptation]

The short bowel syndrome results from an extensive intestinal resection. When intestinal function is below the minimum necessary for the absorption of macronutrients, water and electrolytes, short small bowel syndrome is responsible for chronic intestinal failure. The management is then parenteral nutrition. The evolution of the short bowel syndrome is schematically divided into three successive periods: (a) Immediate postoperative period lasting 3 to 6 weeks; (b) adaptive period lasting about 2 years and (c) stabilization period. However, the development of hyperphagia, spontaneous intestinal adaptation allowing an increase in the absorption surface area and in secretion of enterohormones and a modification of the microbiota occur spontaneously, improving intestinal absorption and decreasing dependence on parenteral nutrition. This review summarizes the main positive and negative pathophysiological consequences of extensive intestinal resection and the nutritional and drug management of short bowel syndrome in adults.

Chronic intestinal failure and short bowel syndrome in Crohn’s disease

Chronic intestinal failure (CIF) is a rare but feared complication of Crohn’s disease. Depending on the remaining length of the small intestine, the affected intestinal segment, and the residual bowel function, CIF can result in a wide spectrum of symptoms, from single micronutrient malabsorption to complete intestinal failure. Management of CIF has improved significantly in recent years. Advances in home-based parenteral nutrition, in particular, have translated into increased survival and improved quality of life. Nevertheless, 60% of patients are permanently reliant on parenteral nutrition. Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy. The outcomes of patients with CIF could be greatly improved by more effective prevention, understanding, and treatment. In complex cases, the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation, nutritional support, and an improved quality of life. Here, we summarize current literature on CIF and short bowel syndrome, encompassing epidemiology, pathophysiology, and advances in surgical and medical management, and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.

The safety of available treatment options for short bowel syndrome and unmet needs

INTRODUCTION

Short bowel syndrome (SBS) is a rare, highly disabling, life-threatening condition due to extensive intestinal resections, characterized by diarrhea, malabsorption, and malnutrition. SBS is the main cause of intestinal failure (SBS-IF). The primary therapy for SBS-IF is intravenous supplementation (IVS) of nutrients. The pharmacological therapy aims to improve the remnant bowel function, leading to the decrease of IVS requirement.

AREAS COVERED

This review provides a safety perspective and discusses unmet clinical needs on pharmacotherapy for SBS, ranging from symptomatic agents traditionally used off-label to manage hypersecretion and diarrhea, to curative drugs with selective intestinotrophic properties. Real-world evidence on symptomatic drugs is lacking. Data on teduglutide - the first-in-class glucagon-like peptide-2 (GLP-2) receptor agonist approved in SBS - are mainly derived from clinical trials, with several unsettled safety issues, including the risk of malignancies.

EXPERT OPINION

Defining the long-term safety of drugs used for SBS is a priority; a unified list of commonly used drugs with consolidated proof of effectiveness is needed to harmonize the symptomatic pharmacological approach to SBS. GLP-2 receptor agonists are a promising curative pharmaco-therapeutic approach, although long-term safety and effectiveness deserve further real-world assessment. Pharmacovigilance and global data sharing are crucial to support safe prescribing in SBS.

Proteomic biomarkers in short bowel syndrome : are we ready to use them in clinical activity?

Introduction: Short bowel syndrome (SBS) is a clinical condition that can affect childhood and adult patients. Biomarker research is expected to be a new frontier in the clinical application, helpful for patients and health-care systems.Areas covered: SBS is usually a consequence of a massive intestinal resection that leads to an intestinal failure because of the reduction of absorptive surface, bacterial overgrowth, and faster intestinal transit. This new condition requires a multidisciplinary expertise to achieve again digestive autonomy. Parental nutrition (PN) supports nutritional status in SBS patients while the new guidelines on intestinal transplantation confirm its strict indication only for patients at actual risk of death on PN. A PubMed literature review from the 1980s up to date was performed, highlighting proteomic biomarkers and growth factor therapies that have shown so far promising results in SBS patients.Expert opinion: Apart from a few specific biomarkers and growth factors, the discovery of specific molecular events is currently under investigation of the proteomic analysis and could potentially represent fundamental, future changes in prevention, diagnosis, therapeutic management, and experimental practices in SBS.

Sitagliptin, a dipeptidyl peptidase-4 inhibitor, in patients with short bowel syndrome and colon in continuity: an open-label pilot study

OBJECTIVE

Patients with short bowel syndrome (SBS) and colon in continuity have better adaptation potential compared with patients with jejunostomy. Adaptation may involve enhanced postprandial secretion of the enteroendocrine hormones glucagon-like peptide (GLP)-1 and GLP-2 which are normally degraded by dipeptidyl peptidase (DPP)-4. Nevertheless, some patients with SBS with colon in continuity suffer from high-volume faecal excretions and have been shown to benefit from treatment with GLP-2. Therefore, we aimed to evaluate efficacy of sitagliptin, a DPP-4 inhibitor, on reducing faecal excretions in this patient group.

DESIGN

In an open-label, case series, proof-of-concept pilot study, 100 mg oral sitagliptin was given two times per day for 8 weeks to patients with SBS with ≥50% colon in continuity with or without the need for parenteral support (PS). To assess intestinal function, metabolic balance studies were done at baseline and following 8 weeks of treatment.

RESULTS

Of the 10 patients planned for enrolment, 8 patients were included; 7 patients completed the study. Although postprandial endogenous GLP-2 concentrations increased by 49 hours×pmol/L (39, 105; p=0.018) (median (min, max)), sitagliptin did not significantly reduce median faecal wet weight (-174 g/day (-1510, 675; p=0.176)) or increase intestinal wet weight absorption. However, heterogeneity in the treatment effect was observed: intestinal wet weight absorption increased in all four patients with intestinal failure. One patient achieved a reduction in PS by 500 mL per administration day.

CONCLUSION

Following this negative, small pilot study, larger, placebo-controlled, studies are needed to establish the therapeutic potential of DPP-4 inhibition in patients with SBS.

GLP-1 and Intestinal Diseases

Accumulating evidence implicates glucagon-like peptide-1 (GLP-1) to have, beyond glucose maintenance, a beneficial role in the gastrointestinal tract. Here, we review emerging data investigating GLP-1 as a novel treatment for intestinal diseases, including inflammatory bowel diseases, short-bowel syndrome, intestinal toxicities and coeliac disease. Possible beneficial mechanisms for these diseases include GLP-1′s influence on gastric emptying, its anti-inflammatory properties and its intestinotrophic effect. The current knowledge basis derives from the available GLP-1 agonist treatments in experimental animals and small clinical trials. However, new novel strategies including dual GLP-1/GLP-2 agonists are also in development for the treatment of intestinal diseases.

The Long Road to the Development of Effective Therapies for the Short Gut Syndrome: A Personal Perspective

The ability to provide parenteral support represents a revolutionary change in medical therapy for patients with temporary and inadequate intestinal absorptive capacity or for patients with chronic intestinal failure due to digestive diseases. Nevertheless, due to the rarity of intestinal failure, a de facto policy of "discrimination by organ failure treatment" exists in many countries whereby this problem is under-recognized and under-treated. With the increasing recognition of the pathophysiological consequences of intestinal resection and the occurrence of new pro-adaptive treatments for patients suffering from short bowel syndrome, this review reflects on the history of developments in this area and discusses current practice and future directions of the field.

Duodenocolostomy as Treatment of Ileus in Short Bowel Syndrome: A Case Report

Patient: Male, 68

Final Diagnosis: Short bowel syndrome • small bowel obstruction

Symptoms: Inablility to sustain oral nutrition

Medication: —

Clinical Procedure: Duodenocolostomy

Specialty: Surgery

Novel GLP-1/GLP-2 co-agonists display marked effects on gut volume and improves glycemic control in mice

AIM

Analogues of several gastrointestinal peptide hormones have been developed into effective medicines for treatment of diseases such as type 2 diabetes mellitus (T2DM), obesity and short bowel syndrome (SBS). In this study, we aimed to explore whether the combination of glucagon-like peptide-1 (GLP-1) and glucagon-like peptide-2 (GLP-2) into a potent co-agonist could provide additional benefits compared to existing monotherapies.

METHODS

A short-acting (GUB09-123) and a half-life extended (GUB09-145) GLP-1/GLP-2 co-agonist were generated using solid-phase peptide synthesis and tested for effects on food intake, body weight, glucose homeostasis, and gut proliferation in lean mice and in diabetic db/db mice.

RESULTS

Sub-chronic administration of GUB09-123 to lean mice significantly reduced food intake, improved glucose tolerance, and increased gut volume, superior to monotherapy with the GLP-2 analogue teduglutide. Chronic administration of GUB09-123 to diabetic mice significantly improved glycemic control and showed persistent effects on gastric emptying, superior to monotherapy with the GLP-1 analogue liraglutide. Due to the short-acting nature of the molecule, no effects on body weight were observed, whereas a marked and robust intestinotrophic effect on mainly the small intestine volume and surface area was obtained. In contrast to GUB09-123, sub-chronic administration of a half-life extended GUB09-145 to lean mice caused marked dose-dependent effects on body weight while maintaining its potent intestinotrophic effect.

CONCLUSION

Our data demonstrate that the GLP-1/GLP-2 co-agonists have effects on gut morphometry, showing a marked increase in intestinal volume and mucosal surface area. Furthermore, effects on glucose tolerance and long-term glycemic control are evident. Effects on body weight and gastric emptying are also observed depending on the pharmacokinetic properties of the molecule. We suggest that this novel co-agonistic approach could exemplify a novel concept for treatment of T2DM or SBS.

Effect of Liraglutide Treatment on Jejunostomy Output in Patients With Short Bowel Syndrome: An Open-Label Pilot Study

BACKGROUND

An impaired hormonal "ileo-colonic brake" may contribute to rapid gastric emptying, gastric hypersecretion, high ostomy losses, and the need for parenteral support in end-jejunostomy short bowel syndrome (SBS) patients with intestinal failure (IF). Liraglutide, a glucagon-like peptide 1 receptor agonist, may reduce gastric hypersecretion and dampen gastric emptying, thereby improving conditions for intestinal absorption.

MATERIALS AND METHODS

In an 8-week, open-label pilot study, liraglutide was given subcutaneously once daily to 8 end-jejunostomy patients, aged 63.4 ± 10.9 years (mean ± SD) and with small bowel lengths of 110 ± 66 cm. The 72-hour metabolic balance studies were performed before and at the end of treatment. Food intake was unrestricted. Oral fluid intake and parenteral support volume were kept constant. The primary end point was change in the ostomy wet weight output.

RESULTS

Liraglutide reduced ostomy wet weight output by 474 ± 563 g/d from 3249 ± 1352 to 2775 ± 1187 g/d (P = .049, Student t test). Intestinal wet weight absorption tended to increase by 464 ± 557 g/d (P = .05), as did urine production by 765 ± 759 g/d (P = .02). Intestinal energy absorption improved by 902 ± 882 kJ/d (P = .02).

CONCLUSION

Liraglutide reduced ostomy wet weight output in end-jejunostomy patients with SBS-IF and increased their intestinal wet weight and energy absorption. If larger, randomized, placebo-controlled studies confirm these effects, it adds to the hypothesis that many ileo-colonic brake hormones in conjunction may be involved in the process of intestinal adaptation. By identification of key hormones and addressing their potential synergistic effects, better treatments may be provided to patients with SBS-IF. This trial was registered at clinicaltrialsregister.eu as 2013-005499-16.

Growth factors and their use in short bowel

PURPOSE OF REVIEW

To examine the most recent literature on the clinical trials associated with the relevant growth factors that have been of interest in the treatment of short bowel.

RECENT FINDINGS

Short bowel is a rare but devastating condition that condemns patients to lifelong parenteral support. Historically, treatment options negating the need for parenteral support were limited. Therapeutic growth factor use is of interest, but the clinical trial data are inconclusive. The STEPS-2 trial was the first trial that showed a sustained positive effect of the growth factor glucagon-like peptide-2 (GLP-2). This led to a phase shift in the management of short bowel, with the US Food and Drug Administration approval of the GLP-2 analogue teduglutide in 2012. This review summarizes all the relevant clinical trials of growth factors in the treatment of short bowel.

SUMMARY

GLP-2 has shown that growth factors can revolutionize the treatment of short bowel. Data however are lacking with regards to the solitary use of other factors. This review highlights the need for further work using the factors in combination as well as considering their use in novel methods for example in the field of regenerative medicine.

Microbiota Is Involved in Post-resection Adaptation in Humans with Short Bowel Syndrome

Short bowel syndrome (SBS) is characterized by severe intestinal malabsorption following restrictive surgery. The objective of this study was to determine the functional contribution of SBS-microbiota after resection. It is well-known that SBS-microbiota displayed specific features with a prevalence of Lactobacillus, a low amount of some anaerobic microbes (Clostridium leptum) and an accumulation of fecal lactate in some patients. Patients with jejuno-colonic anastomosis were stratified according to the presence of lactate in their feces and, we observe that the lactate-producing bacteria were predominant in the sub-group of patients accumulating fecal lactate. One case of D-encephalopathy crisis occurred when the D-lactate isoform accumulated in the feces and plasma bicarbonate levels decreased. The fecal sample at the time of the encephalopathy was transferred to germ free rats (SBS-H rats). The SBS-H microbiota conserved some characteristics of the SBS donnor, predominated by lactate-producing bacteria (mainly Lactobacillus), a low level of lactate-consuming bacteria and undetectable C. leptum. However, lactate did not accumulate in feces of recipient rats and the D-encephalopathy was not reproduced in SBS-H rats. This suggests that the intact small bowel of the recipient rats protected them from lactate accumulation and that D-lactate encephalopathy can occur only in the absence of small intestine. After fecal transfer, we also show that gnotobiotic rats exhibited high levels of circulating GLP-1 and ghrelin, two hormones that are known to be induced in SBS patients. Therefore, the microbiota of SBS is a reservoir of biological signals involved in post-resection adaptation.

Endocrine regulation of gut maturation in early life in pigs

After birth, the newborn must adapt to the acute challenges of circulatory changes, active respiration, thermoregulation, microbial colonization, and enteral nutrition. Whereas these processes normally occur without clinical complications in neonates born at term, birth at a preterm state of gestation is associated with high morbidity and mortality. In commercial pig production, perinatal mortality is higher than in any other mammalian species. Asphyxia, hypothermia, hypoglycemia, sepsis, and gut dysmotility, represent some of the most common findings. The intestine is a particularly sensitive organ after birth, as it must adapt acutely to enteral nutrition and microbial colonization. Likewise, during the weaning phase, the intestine must adapt to new diet types. Both critical phases are associated with high morbidity. This review focuses on the endocrine changes occurring around birth and weaning. There are a number of endocrine adaptations in late gestation and early postnatal life that are under influence of development stage and environmental factors such as diet. The review discusses general endocrine changes in perinatal life but specifically focuses on the role of glucagon-like peptide-2. This gut-derived hormone plays a key role in development and function of the intestine in early life.

Management and Complications of Short Bowel Syndrome: an Updated Review

Short bowel syndrome (SBS) is defined as loss of bowel mass from surgical resection, congenital defects, or disease. Intestinal failure (IF) includes the subset of SBS unable to meet nutrition needs with enteral supplements and requires parenteral nutrition (PN). The parenteral treatment of SBS is now a half-century old. Recent pharmacologic treatment (GLP-2 analogues) has begun to make a significant impact in the care and ultimate management of these patients such that the possibility of reducing PN requirements in formerly PN-dependent patients is a now a real possibility. Finally, newer understanding and possible treatment for some of the complications related to IF have more recently evolved and will be an emphasis of this report. This review will focus on developments over the last 10 years with the goal of updating the reader to new advances in our understanding of the care and feeding of the SBS patient.

Enhanced Ghrelin Levels and Hypothalamic Orexigenic AgRP and NPY Neuropeptide Expression in Models of Jejuno-Colonic Short Bowel Syndrome

Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations.

Obesity and the microbiome

Obesity constitutes a significant and rapidly increasing public health challenge and is associated with significant co-morbidities and healthcare costs. Although undoubtedly multifactorial, research over the last decade has demonstrated that the microbes that colonize the human gut may contribute to the development of obesity through roles in polysaccharide breakdown, nutrient absorption, inflammatory responses and gut permeability. Studies have consistently shown that the Firmicutes to Bacteroidetes ratio, in particular, is increased in obesity and reduces with weight loss. In addition, we and others have shown that the methanogenic Archaea may also contribute to altered metabolism and weight gain in the host. However, much remains to be learned about the roles of different gut microbial populations in weight gain and obesity and the underlying mechanisms before we can begin to approach targeted treatments.

Promoting intestinal adaptation by nutrition and medication

The ultimate goal in the treatment of short bowel syndrome is to wean patients off parenteral nutrition, by promoting intestinal adaptation. Intestinal adaptation is the natural compensatory process that occurs after small bowel resection. Stimulating the remaining bowel with enteral nutrition can enhance this process. Additionally, medication can be used to either reduce factors that complicate the adaptation process or to stimulate intestinal adaptation, such as antisecretory drugs and several growth factors. The aim of this review was to provide an overview of the best nutritional strategies and medication that best promote intestinal adaptation.

GLP-1 based therapies: clinical implications for gastroenterologists

The gut-derived incretin hormone, glucagon-like peptide 1 (GLP-1) lowers postprandial blood glucose levels by stimulating insulin and inhibiting glucagon secretion. Two novel antihyperglycaemic drug classes augment these effects; GLP-1 receptor agonists and inhibitors of the GLP-1 degrading enzyme dipeptidyl peptidase 4. These so called GLP-1 based or incretin based drugs are increasingly used to treat type 2 diabetes, because of a low risk of hypoglycaemia and favourable effect on body weight, blood pressure and lipid profiles. Besides glucose control, GLP-1 functions as an enterogastrone, causing a wide range of GI responses. Studies have shown that endogenous GLP-1 and its derived therapies slow down digestion by affecting the stomach, intestines, exocrine pancreas, gallbladder and liver. Understanding the GI actions of GLP-1 based therapies is clinically relevant; because GI side effects are common and need to be recognised, and because these drugs may be used to treat GI disease.

Extensive Intestinal Resection Triggers Behavioral Adaptation, Intestinal Remodeling and Microbiota Transition in Short Bowel Syndrome

Extensive resection of small bowel often leads to short bowel syndrome (SBS). SBS patients develop clinical mal-absorption and dehydration relative to the reduction of absorptive area, acceleration of gastrointestinal transit time and modifications of the gastrointestinal intra-luminal environment. As a consequence of severe mal-absorption, patients require parenteral nutrition (PN). In adults, the overall adaptation following intestinal resection includes spontaneous and complex compensatory processes such as hyperphagia, mucosal remodeling of the remaining part of the intestine and major modifications of the microbiota. SBS patients, with colon in continuity, harbor a specific fecal microbiota that we called “lactobiota” because it is enriched in the Lactobacillus/Leuconostoc group and depleted in anaerobic micro-organisms (especially Clostridium and Bacteroides). In some patients, the lactobiota-driven fermentative activities lead to an accumulation of fecal d/l-lactates and an increased risk of d-encephalopathy. Better knowledge of clinical parameters and lactobiota characteristics has made it possible to stratify patients and define group at risk for d-encephalopathy crises.

Incretins

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the known incretin hormones in humans, released predominantly from the enteroendocrine K and L cells within the gut. Their secretion is regulated by a complex of integrated mechanisms involving direct contact for the activation of different chemo-sensors on the brush boarder of K and L cells and several indirect neuro-immuno-hormonal loops. The biological actions of GIP and GLP-1 are fundamental determinants of islet function and blood glucose homeostasis in health and type 2 diabetes. Moreover, there is increasing recognition that GIP and GLP-1 also exert pleiotropic extra-glycaemic actions, which may represent therapeutic targets for human diseases. In this review, we summarise current knowledge of the biology of incretin hormones in health and metabolic disorders and highlight the therapeutic potential of incretin hormones in metabolic regulation.

Role of the Gut Microbiome in Obesity and Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) and obesity represent two of the biggest global health challenges of this century and are associated with significant comorbidities and healthcare costs. Although multiple factors undoubtedly contribute to the development and progression of DM and obesity, research over the last decade has demonstrated that the microbes that colonize the human gut may play key contributory roles. Gut microbes are now known to codevelop with the human host and are strongly influenced by mode of birth and early diet and nutrition, as well as environmental and other factors including antibiotic exposure. Gut microbes contribute to human health through roles in polysaccharide breakdown, nutrient absorption, inflammatory responses, gut permeability, and bile acid modification. Numerous studies have suggested that disruptions in the relative proportions of gut microbial populations may contribute to weight gain and insulin resistance, including alterations in Gammaproteobacteria and Verrucomicrobia and the ratios of Firmicutes to Bacteroidetes in weight gain and possible alterations in butyrate-producing bacteria such as Faecalibacterium prausnitzii in DM. In addition, it has been shown that the methanogenic Archaea may contribute to altered metabolism and weight gain in the host. However, the majority of studies are performed with stool or colonic samples and may not be representative of the metabolically active small intestine. Studies predominantly in rodent models are beginning to elucidate the mechanisms by which gut microbes contribute to DM and obesity, but much remains to be learned before we can begin to approach targeted treatments.

Gut hormones in the treatment of short-bowel syndrome and intestinal failure

PURPOSE OF REVIEW

The approval of teduglutide, a recombinant analog of human glucagon-like peptide (GLP) 2, by the US Food and Drug Administration (Gattex) and the European Medicines Agency (Revestive) has illustrated the potential of selected gut hormones as treatments in patients with short-bowel syndrome and intestinal failure. Gut hormones may improve the structural and functional intestinal adaptation following intestinal resection by decreasing a rapid gastric emptying and hypersecretion, by increasing the intestinal blood flow, and by promoting intestinal growth. This review summarizes the findings from phase 2 and 3 teduglutide studies, and pilot studies employing GLP-1 and agonists for this orphan condition.

RECENT FINDINGS

In a 3-week, phase 2, metabolic balance study, teduglutide increased the intestinal wet weight absorption by approximately 700 g/day and reduced fecal energy losses by approximately 0.8 MJ/day (∼200 Kcal/day). In two subsequent 24-week, phase 3 studies, teduglutide reduced the need for parenteral support in the same magnitude. Adverse events were mainly of gastrointestinal origin and consistent with the known mechanism of action of teduglutide. Pilot studies suggest that GLP-1 may be less potent. Synergistic effects may be seen by co-treatment with GLP-2.

SUMMARY

Gut hormones promote intestinal adaptation and absorption, decreasing fecal losses, thereby decreasing or even eliminating the need for parenteral support. This will aid the intestinal rehabilitation in these severely disabled short-bowel syndrome patients.

Handle energy resources with care

While politicians discuss rules to improve the efficacy of global energy consumption and to limit environmental pollution, the mammalian body has numerous mechanisms to efficiently use nutrient resources and appropriately extract energy. A new mechanism has recently been identified by the group of Fredrik Bäckhed in Cell Host & Microbe.

Gut motility and enteroendocrine secretion

The motility of the gastrointestinal (GI) tract is modulated by complex neural and hormonal networks; the latter include gut peptides released from enteroendocrine cells during both the interdigestive and postprandial periods. Conversely, it is increasingly recognised that GI motility is an important determinant of gut hormone secretion, in that the transit of luminal contents influences the degree of nutrient stimulation of enteroendocrine cells in different gut regions, as well as the overall length of gut exposed to nutrient. Of particular interest is the relationship between gallbladder emptying and enteroendocrine secretion. The inter-relationships between GI motility and enteroendocrine secretion are central to blood glucose homeostasis, where an understanding is fundamental to the development of novel strategies for the management of diabetes mellitus.

Key issues in addressing the clinical and humanistic burden of short bowel syndrome in the US

BACKGROUND

The purpose of this analysis was to provide a concise report of the literature on the burden of intestinal failure associated with short bowel syndrome (SBS-IF) in adults, focused on clinical and humanistic issues important to clinicians and payers.

SCOPE

A literature search was performed using the National Library of Medicine PubMed database ( http://www.ncbi.nlm.nih.gov/pubmed ) with the search term 'short bowel syndrome' limited to adult populations and English-language reports published from January 1, 1965, to January 18, 2013. Citations were assessed for relevance and excluded articles focused on single case studies, colon fermentation, absorption of medications with PN/IV, surgical technique, mesenteric artery complications/surgery, and transplantation focus. Additional hand searches were performed using the terms 'short bowel syndrome' AND 'cost', and 'home parenteral nutrition' AND 'cost', along with the exclusion criteria described above.

FINDINGS

Despite advances in management in recent decades, SBS-IF continues to carry a high burden of morbidity and mortality. In the absence of sufficient intestinal adaptation following resection, many patients remain dependent on long-term parenteral nutrition and/or intravenous fluids (PN/IV). Although potentially life saving, PN/IV is costly, invasive, and associated with numerous complications and deleterious effects on health and quality of life. Surgical interventions, especially intestinal transplantation, are costly and are associated with substantial morbidity and high mortality. New therapies, which show promise in promoting intestinal rehabilitation and reducing dependence on PN/IV therapy, are the subject of active research.

CONCLUSIONS

Overall, the available literature suggests that although SBS-IF affects a relatively small population, the clinical and humanistic burden is significant, and there is an unmet need for effective therapeutic options that target the underlying problem of inadequate absorptive capacity of the remaining intestine. Consequently, many patients with SBS-IF remain dependent on long-term PN/IV support, adding to the burden imposed by the underlying disorder.

Intestinal Methanobrevibacter smithii but not total bacteria is related to diet-induced weight gain in rats

It is increasingly understood that gastrointestinal (GI) methanogens, including Methanobrevibacter smithii, influence host metabolism.

OBJECTIVE

Therefore, we compared M. smithii colonization and weight gain in a rat model under different dietary conditions.

DESIGN AND METHODS

Sprague-Dawley rats were inoculated with M. smithii or vehicle (N = 10/group), fed normal chow until day 112 postinoculation, high-fat chow until day 182, then normal chow until day 253. Thereafter, five rats from each group were fed high-fat and normal chow until euthanasia.

RESULTS

Both groups exhibited M. smithii colonization, which increased following inoculation only for the first 9 days. Change to high-fat chow correlated with significant increases in weight (P < 0.00001) and stool M. smithii (P < 0.01) in all rats, with stool M. smithi decreasing on return to normal chow. Rats switched back to high-fat on day 253 further increased weight (P < 0.001) and stool M. smithii (P = 0.039). Euthanasia revealed all animals had higher M. smithii, but not total bacteria, in the small intestine than in the colon. Rats switched back to high-fat chow had higher M. smithii levels in the duodenum, ileum, and cecum than those fed normal chow; total bacteria did not differ in any bowel segment. Rats which gained more weight had more bowel segments colonized, and the lowest weight recorded was in a rat on high-fat chow which had minimal M. smithii colonization.

CONCLUSIONS

We conclude that M. smithii colonization occurs in the small bowel as well as in the colon, and that the level and extent of M. smithii colonization is predictive of degree of weight gain in this animal model.

Acute effects of continuous infusions of glucagon-like peptide (GLP)-1, GLP-2 and the combination (GLP-1+GLP-2) on intestinal absorption in short bowel syndrome (SBS) patients. A placebo-controlled study

BACKGROUND AND AIMS

The ileocolonic brake is impaired in short bowel syndrome (SBS) patients with distal bowel resections. An attenuated meal-stimulated hormone secretion may cause gastric hypersecretion, rapid gastric and intestinal transit and a poor adaptation. Attempting to restore this ileocolonic brake, this study evaluated the acute effects of continuous intravenous administration of glucagon-like peptide (GLP) 1 and 2, alone or in combination, on gastrointestinal function in SBS patients.

METHODS

SBS patients were admitted 4 times for identical 72-h balance studies, where infusions (1 pmol/kg/min) of GLP-1, placebo (saline), GLP-2 and GLP-1+2 (1 pmol/kg/min of each), were provided. Patients filled out a VAS questionnaire regarding subjective symptoms during treatments. Bone mineral content, body-weight and -composition were measured using DEXA scans. Blood glucose, insulin, pro insulin C-peptide and GLP concentrations were measured in relation to a standardized breakfast.

RESULTS

Nine SBS patients (5 women/4 men, aged 52±11) were enrolled and completed the study; 7 had end-jejunostomies, 2 had 50% of colon-in-continuity. All treatments significantly reduced the fecal wet weight, energy, nitrogen, sodium and potassium losses compared to placebo. However, only GLP-2 containing treatments increased absolute absorption of wet weight and sodium. Only GLP-1+2 improved the hydrational status evaluated by DEXA increases in the fat mass and calculated total body weight. GLP-1 and GLP-1+2 reduced the post-prandial blood glucose levels. A tendency of nausea and reduced appetite was seen in relation to GLP-1 treatment, but this was ameliorated by the co-administration of GLP-2.

CONCLUSION

GLP-1 decreased diarrhea and fecal excretions in SBS patients, but it seems less potent than GLP-2. The combination of GLP-1+2 numerically provided additive effects on intestinal absorption compared to either peptide given alone. Larger, long-term studies should further assess the potential of the glucagon-like peptides or analogs, alone or in combination, in the treatment of SBS patients.

Review article: the management of long-term parenteral nutrition

BACKGROUND

Home parenteral nutrition (HPN) is currently the management of choice for patients with chronic intestinal failure.

AIM

To summarise the major issues in delivering long-term parenteral nutrition (>3 months) and assess outcome as per complications, mortality and quality of life. To assess the evidence for the therapeutic use of trophic factors such as teduglutide and to review evolving therapeutic options in the treatment of chronic intestinal failure.

METHODS

A literature search using PubMed and MEDLINE databases was performed.

RESULTS

Safe delivery of HPN relies upon individualised formulations of parenteral nutrition administered via carefully maintained central venous catheters by trained patients or carers, supported by a skilled multidisciplinary team. Early diagnosis and treatment of complications including catheter-associated blood stream infection (reported incidence 0.14-0.83 episodes/patient-year on HPN) and central venous thrombosis (reported incidence 0.03 episodes/patient-year) is important to minimise mortality and morbidity. There is a significant variation in the reported incidence of both hepatobiliary complications (19-75%) and advanced liver disease (0-50%). Five-year survival rates in large centres are reported between 60% and 78% with survival primarily related to underlying diagnosis. Long-term survival remains higher on HPN than with intestinal transplantation. The role of intestinal lengthening procedures is yet to be validated in adults.

CONCLUSIONS

Home parenteral nutrition delivered by skilled nutrition teams has low incidences of catheter-related complications. Most deaths relate to the underlying disease. Therapies such as teduglutide and small bowel transplantation appear promising, but home parenteral nutrition appears likely to remain the bedrock of management in the near term.