Morphological adaptation with preserved proliferation/transporter content in the colon of patients with short bowel syndrome

Sustained elimination of parenteral support in adult patients with under 60 cm of small intestine: A case series

Patients with short bowel syndrome (SBS) are often managed by expert multidisciplinary teams. One of the main goals in the management of SBS is the weaning of parenteral support (PS). Weaning of PS removes the risks associated with long-term central line placement and eliminates the need for intestinal transplant. Whereas several papers detail the ongoing care and management of patients with SBS who are dependent on PS, there are few reports discussing the successful weaning of PS in this patient population. We present five case studies examining weaning of PS in adult patients with <60-cm small bowel and partial or full colon who were enrolled in a multidisciplinary adult intestinal rehabilitation program. The case studies demonstrate weaning can occur >2 years after initial assessment and enrollment in an expert program. The ability of the program to focus on individualized care and frequent patient communication is key to PS weaning in patients with SBS.

Muscle hypertrophy and neuroplasticity in the small bowel in short bowel syndrome

Short bowel syndrome (SBS) is a severe, life-threatening condition and one of the leading causes of intestinal failure in children. Here we were interested in changes in muscle layers and especially in the myenteric plexus of the enteric nervous system (ENS) of the small bowel in the context of intestinal adaptation. Twelve rats underwent a massive resection of the small intestine to induce SBS. Sham laparotomy without small bowel transection was performed in 10 rats. Two weeks after surgery, the remaining jejunum and ileum were harvested and studied. Samples of human small bowel were obtained from patients who underwent resection of small bowel segments due to a medical indication. Morphological changes in the muscle layers and the expression of nestin, a marker for neuronal plasticity, were studied. Following SBS, muscle tissue increases significantly in both parts of the small bowel, i.e., jejunum and ileum. The leading pathophysiological mechanism of these changes is hypertrophy. Additionally, we observed an increased nestin expression in the myenteric plexus in the remaining bowel with SBS. Our human data also showed that in patients with SBS, the proportion of stem cells in the myenteric plexus had risen by more than twofold. Our findings suggest that the ENS is tightly connected to changes in intestinal muscle layers and is critically involved in the process of intestinal adaptation to SBS.

Hyperphagia is prominent in adult patients with short bowel syndrome: A role for the colon?

RATIONALE

Short Bowel Syndrome (SBS) is the major cause of chronic intestinal failure (IF) and requires parenteral nutrition (PN). After bowel resection, some patients develop spontaneous intestinal adaptations and hyperphagia. Since promoting oral energy intake contributes to PN weaning, this study aims to characterize hyperphagia in patients with SBS and identify its determinants.

METHODS

This observational retrospective study included adult patients with SBS who were followed at an expert PN center between 2006 and 2019, with at least 2 separate nutritional assessments. Exclusion criteria were: active neoplasia, alternative treatment for IF or appetite-affecting medication. Resting energy expenditure (REE) was calculated for each patient using the Harris-Benedict equation. Food Intake Ratio (FIR) was calculated by dividing the highest caloric oral intake by REE and hyperphagia was defined as FIR >1.5.

RESULTS

Among the 59 patients with SBS included in this study, 82.6% had a FIR >1.5, including 15.5% with a FIR >3. Protein supplied approximately 16% of total energy intake while fat and carbohydrates provided 36% and 48%, respectively. The FIR was independent of gender and whether patients received oral nutrition alone (n = 28) or combined with PN (n = 31). The FIR was also not associated with residual small bowel length, nor the proportion of preserved colon. However, it was negatively correlated with the body mass index (BMI) of these patients (r = -0.533, p < 0.001), whether they had PN support or not. Patients with either a jejuno-colonic (n = 31) or a jejuno-ileal anastomosis (n = 9), had a significantly higher FIR compared to those with an end-jejunostomy (n = 18) (p < 0.05). However, no difference was found in the proportion of calories provided by protein, fat and carbohydrate between the 3 patients groups divided according to the SBS anatomical type.

CONCLUSION

A large majority of patients with SBS exhibited a hyperphagia regardless of PN dependence or bowel length, which was inversely correlated with BMI. The presence of the colon in continuity, thus in contact with the nutritional flow, seems to favor a higher oral intake which is beneficial for the nutritional autonomy of patients. This raises the question of a role of colonic microbiota and hormones in this behavior. Finally, this study also revealed an unexpected discrepancy between recommended energy intakes from protein, fat and carbohydrate and the actual intake of patients with SBS.

An Overview of Short-Bowel Syndrome in Pediatric Patients: Focus on Clinical Management and Prevention of Complications

Short-bowel syndrome (SBS) in pediatric age is defined as a malabsorptive state, resulting from congenital malformations, significant small intestine surgical resection or disease-associated loss of absorption. SBS is the leading cause of intestinal failure in children and the underlying cause in 50% of patients on home parental nutrition. It is a life-altering and life-threatening disease due to the inability of the residual intestinal function to maintain nutritional homeostasis of protein, fluid, electrolyte or micronutrient without parenteral or enteral supplementation. The use of parenteral nutrition (PN) has improved medical care in SBS, decreasing mortality and improving the overall prognosis. However, the long-term use of PN is associated with the incidence of many complications, including liver disease and catheter-associated malfunction and bloodstream infections (CRBSIs). This manuscript is a narrative review of the current available evidence on the management of SBS in the pediatric population, focusing on prognostic factors and outcome. The literature review showed that in recent years, the standardization of management has demonstrated to improve the quality of life in these complex patients. Moreover, the development of knowledge in clinical practice has led to a reduction in mortality and morbidity. Diagnostic and therapeutic decisions should be made by a multidisciplinary team that includes neonatologists, pediatric surgeons, gastroenterologists, pediatricians, nutritionists and nurses. A significant improvement in prognosis can occur through the careful monitoring of nutritional status, avoiding dependence on PN and favoring an early introduction of enteral nutrition, and through the prevention, diagnosis and aggressive treatment of CRSBIs and SIBO. Multicenter initiatives, such as research consortium or data registries, are mandatory in order to personalize the management of these patients, improve their quality of life and reduce the cost of care.

Anatomical and physiological considerations in short bowel syndrome: Emphasis on intestinal adaptation and the role of enterohormones

Short bowel syndrome (SBS)-associated intestinal failure (IF) is a complex, life-threatening condition that requires complex care of multiple factors impacting the patient's long-term prognosis. Various etiologies result in SBS-IF, with three primary anatomical subtypes occurring following intestinal resection. Depending on the extent and segment(s) of the intestine resected, malabsorption can be nutrient specific or sweeping; however, such issues and the associated prognosis for the patient can be predicted with analysis of the residual intestine, along with baseline nutrient and fluid deficits and extent of malabsorption. The provision of parenteral nutrition/intravenous (PN-IV) fluids and antisymptomatic agents is fundamental; however, optimal management should focus on intestinal rehabilitation, wherein intestinal adaptation is prioritized and PN-IV fluids are weaned over time. Key strategies to maximize intestinal adaptation include hyperphagic consumption of an individualized SBS diet and the appropriate use of trophic agents, such as a glucagon-like peptide 2 analog.

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.

The Role of a Colon-in-Continuity in Short Bowel Syndrome

Short bowel syndrome (SBS) is a rare gastrointestinal condition that is defined as having less than 200 cm of remaining small intestine. SBS results from extensive surgical resection and is associated with a high risk for intestinal failure (IF) with a need for parenteral support (PS). Depending on the region of intestinal resection, three different main anatomy types can be distinguished from each other. In this review, we synthesize the current knowledge on the role of the colon in the setting of SBS-IF with a colon-in-continuity (SBS-IF-CiC), e.g., by enhancing the degree of intestinal adaptation, energy salvage, and the role of the microbiota. In addition, the effect of the disease-modifying treatment with glucagon-like peptide-2 (GLP-2) analogs in SBS-IF-CiC and how it differs from patients without a colon will be discussed. Overall, the findings explained in this review highlight the importance of preservation of the colon in SBS-IF.

Fecal microbiota transplantation in a rodent model of short bowel syndrome: A therapeutic approach?

Extensive intestinal resection leads to Short Bowel Syndrome (SBS), the main cause of chronic intestinal failure. Colon preservation is crucial for spontaneous adaptation, to improve absorption and reduce parenteral nutrition dependence. Fecal microbiota transplantation (FMT), a promising approach in pathologies with dysbiosis as the one observed in SBS patients, was assessed in SBS rats with jejuno-colonic anastomosis. The evolution of weight and food intake, the lenght of intestinal villi and crypts and the composition of fecal microbiota of Sham and SBS rats, transplanted or not with high fat diet rat microbiota, were analyzed. All SBS rats lost weight, increased their food intake and exhibited jejunal and colonic hyperplasia. Microbiota composition of SBS rats, transplanted or not, was largely enriched with Lactobacillaceae, and α- and β-diversity were significantly different from Sham. The FMT altered microbiota composition and α- and β-diversity in Sham but not SBS rats. FMT from high fat diet rats was successfully engrafted in Sham, but failed to take hold in SBS rats, probably because of the specific luminal environment in colon of SBS subjects favoring aero-tolerant over anaerobic bacteria. Finally, the level of food intake in SBS rats was positively correlated with their Lactobacillaceae abundance. Microbiota transfer must be optimized and adapted to this specific SBS environment.

Concise review on short bowel syndrome: Etiology, pathophysiology, and management

Adults have approximately 20 feet of small intestine, which is the primary site for absorbing essential nutrients and water. Resection of the intestine for any medical reason may result in short bowel syndrome (SBS), leading to loss of major absorptive surface area and resulting in various malabsorption and motility disorders. The mainstay of treatment is personalized close dietary management. Here we present SBS with its pathophysiology and different nutritional management options available. The central perspective of this paper is to provide a concise review of SBS and the treatment options available, along with how proper nutrition can solve major dietary issues in SBS and help patients recover faster.

Short Bowel Syndrome in Adults

Short bowel syndrome (SBS) is a rare disorder characterized by severe intestinal dysfunction leading to malabsorption of macronutrients and micronutrients that often results in permanent need of parenteral nutrition support. Patients can develop SBS because of massive intestinal resection or loss of intestinal function and consequently experience significant morbidity and increased healthcare utilization. The remaining anatomy and length of bowel after intestinal resection have important prognostic and therapeutic implications. Because patients with SBS constitute a heterogenous group, management is complex and multifaceted, involving nutrition support, fluid and electrolyte management, and pharmacologic therapies in particular to control diarrhea. Surgical interventions including intestinal transplantation may be considered in selected individuals. Successful care of these patients is best accomplished by a multidisciplinary team that is experienced in the management of this syndrome.

Enterohormone therapy for short bowel syndrome

PURPOSE OF REVIEW

Short bowel syndrome (SBS) patients are at risk to develop intestinal failure when the decreased absorption of macronutrients, water, and electrolytes necessitates parenteral support for survival. The adverse effects of SBS and parenteral support negatively affect the quality of life (QoL) of SBS-intestinal failure patients. However, spontaneous intestinal adaptation along with disease-modifying therapies allow reducing parenteral support, thereby improving QoL.

RECENT FINDINGS

During the first years following extensive surgery, spontaneous structural and functional intestinal changes take place which stimulate a more efficient nutrient and fluid absorption in the remaining bowel. Given their potential role in the ileal braking mechanism, enterohormones, such as glucagon-like peptide (GLP)-2, GLP-1, and peptide YY (PYY), promote an accelerated adaptation or hyperadaptation. While the exact role of GLP-1 and PYY in SBS is still being explored, GLP-2 analogs have clearly shown to be effective in improving outcome in SBS.

SUMMARY

Whereas spontaneous intestinal adaptation improves the nutritional status of SBS patients to a certain extent, GLP-2 analogs can further decrease parenteral support needs through hyperadaptation. There are, however, other promising candidates on the horizon that - alone or in combination - could possibly establish additional disease-modifying effects.

Early Bowel Lengthening Procedures: Bi-Institutional Experience and Review of the Literature

Early bowel lengthening procedure (EBLP) has been defined as any bowel lengthening procedure performed before six months of age. The purpose of this paper is to compare our experience with literature on this subject to identify common indications. A bi-institutional retrospective analysis was performed. Diagnosis, type of surgery, age at procedure and outcomes were analysed. Eleven EBLP were performed in Manchester and Florence from 2006 to 2021. The median age at surgery was 126 days (102–180), pre-operative median short bowel (SB) length was 28 cm (17–49) with a post-operative median increase of 81%. Furthermore, a PubMed/Embase search was undertaken regarding bowel lengthening procedures performed in the last 40 years. Sixty-one EBLP were identified. The median age was 60 days (1–90). Serial transverse enteroplasty (STEP) was the most frequent procedure used, with a median increased bowel length of 57%. This study confirms that no clear consensus on indication or timing to perform early SB lengthening is reported. According to the gathered data, EBLP should be considered only in cases of actual necessity and performed in a qualified intestinal failure centre.

[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.

Imaging as predictor of clinical response to teduglutide in adult patients with short bowel syndrome with chronic intestinal failure

BACKGROUND

Teduglutide (TED) is a glucagon-like peptide 2 analogue approved in patients with short bowel syndrome with chronic intestinal failure. Bowel epithelial hyperplasia has been reported after TED treatment.

OBJECTIVE

The aim of this study was to describe small bowel modifications at imaging in patients with SBS-CIF receiving TED and to assess their predictive value for clinical response.

METHODS

Monocentric retrospective study including patients with SBS-CIF treated with TED from 2009 to 2018 with available computed tomography (CT) scans at baseline and during follow-up (≥12 mo). Small bowel (SB) wall thickness was measured as the average of 3 measurements on different SB segments. Clinical response to TED was defined as a ≥20% reduction of weekly parenteral support (PS) volume at 12 mo.

RESULTS

Thirty-one patients [20 male (65%), median age 51 y (IQR: 37-59)] were included. Baseline weekly PS volume was a median 7500 mL (IQR: 3500-15,000). After a median (IQR) follow-up of 16 mo (14-27), 26 of 31 patients (84%) had a clinical response. During follow-up, patients underwent 1 (n = 18/31, 58%), 2 (10/31, 32%), or 3 (3/31 10%) CT scans. Median SB wall thickness was 4.0 mm (IQR: 2.8-4.7) and 8.5 mm (IQR: 6.1-9.8) at baseline and after treatment, respectively [paired P < 0.001, median +122% increase (IQR: +65% to +172%)]. Patients with a clinical response had a trend toward a higher SB wall thickness increase [median +133% (IQR: +70% to +176%) compared with +90% (IQR: +52% to +93%), P = 0.061]. All patients with a ≥95% SB wall thickness increase (n = 18) had a clinical response, whereas only 8 of 13 (62%) patients with a <95% SB thickness increase did (P = 0.008).

CONCLUSIONS

Teduglutide induces a significant SB wall thickness increase that can be depicted by imaging <6 mo after treatment initiation, and the degree of such increase may be associated with clinical response. Bowel imaging in response to pharmacologic treatments may represent an important outcome to follow.

Short bowel syndrome: treatment options

Introduction Short bowel syndrome (SBS) refers to the malabsorptive state that occurs following extensive intestinal resection and is associated with several complications.

Methods The research for this review was conducted in the Pubmed database. Relevant scientific articles dated between 1991 and 2015 and written in Portuguese, Spanish or English were selected.

Results Several therapies, including nutritional support, pharmacological options and surgical procedures have been used in these patients.

Conclusions Over the last decades new surgical and pharmacological approaches emerged, increasing survival and quality of life (QoL) in patients with SBS. All SBS patients ought to have an individualized and multidisciplinary care that promotes intestinal rehabilitation.

Short Bowel Syndrome: A Paradigm for Intestinal Adaptation to Nutrition?

Short bowel syndrome (SBS) is a rare disease that results from extensive resection of the intestine. When the remaining absorption surface of the intestine cannot absorb enough macronutrients, micronutrients, and water, SBS results in intestinal failure (IF). Patients with SBS who suffer from IF require parenteral nutrition for survival, but long-term parenteral nutrition may lead to complications such as catheter sepsis and metabolic diseases. Spontaneous intestinal adaptation occurs weeks to months after resection, resulting in hyperplasia of the remnant gut, modification of gut hormone levels, dysbiosis, and hyperphagia. Oral nutrition and presence of the colon are two major positive drivers for this adaptation. This review aims to summarize the current knowledge of the mechanisms underlying spontaneous intestinal adaptation, particularly in response to modifications of luminal content, including nutrients. In the future, dietary manipulations could be used to treat SBS.

Intestinal plasticity in response to nutrition and gastrointestinal surgery

The plasticity of a material corresponds to its capacity to change its feature under the effect of an external action. Intestinal plasticity could be defined as the ability of the intestine to modify its size or thickness and intestinal cells to modulate their absorption and secretion functions in response to external or internal cues/signals. This review will focus on intestinal adaptation mechanisms in response to diet and nutritional status. These physiological mechanisms allow a fine and rapid adaptation of the gut to promote absorption of ingested food, but they can also lead to obesity in response to overnutrition. This plasticity could thus become a therapeutic target to treat not only undernutrition but also obesity. How the intestine adapts in response to 2 types of surgical remodeling of the digestive tract-extensive bowel resection leading to intestinal failure and surgical treatment of pathological obesity (ie, bariatric surgeries)-will also be reviewed.

Digestive enzyme expression in the large intestine of children with short bowel syndrome in a late stage of adaptation

BACKGROUND AND AIMS

Intestinal adaptation in short bowel syndrome (SBS) includes morphologic processes and functional mechanisms. This study investigated whether digestive enzyme expression in the duodenum and colon is upregulated in SBS patients.

METHOD

Sucrase-isomaltase (SI), lactase-phlorizin hydrolase (LPH), and neutral Aminopeptidase N (ApN) were analyzed in duodenal and colonic biopsies from nine SBS patients in a late stage of adaptation as well as healthy and disease controls by immunoelectron microscopy (IEM), Western blots, and enzyme activities. Furthermore, proliferation rates and intestinal microbiota were analyzed in the mucosal specimen.

RESULTS

We found significantly increased amounts of SI, LPH, and ApN in colonocytes in most SBS patients with large variation and strongest effect for SI and ApN. Digestive enzyme expression was only partially elevated in duodenal enterocytes due to a low proliferation level measured by Ki-67 staining. Microbiome analysis revealed high amounts of Lactobacillus resp. low amounts of Proteobacteria in SBS patients with preservation of colon and ileocecal valve. Colonic expression was associated with a better clinical course in single cases.

CONCLUSION

In SBS patients disaccharidases and peptidases can be upregulated in the colon. Stimulation of this colonic intestinalization process by drugs, nutrients, and pre- or probiotics might offer better therapeutic approaches.

Reconnection surgery in adult post-operative short bowel syndrome < 100 cm: is colonic continuity sufficient to achieve enteral autonomy without autologous gastrointestinal reconstruction? Report from a single center and systematic review of literature

A systematic bibliographic research concerning patients operated on for SBS was performed: inclusion criteria were adult age, reconnection surgery and SBS < 100 cm. Autologous gastrointestinal reconstruction represented an exclusion criteria. The outcomes of interest were the rate of total parenteral nutrition (TPN) independence and the length of follow-up (minimum 1 year) after surgery. We reviewed our experience from 2003 to 2013 with minimum 1-year follow-up, dealing with reconnection surgery in 13 adults affected by < 100 cm SBS after massive small bowel resection: autologous gastrointestinal reconstruction was not feasible. Three (out of 5168 screened papers) non randomized controlled trials with 116 adult patients were analysed showing weaning from TPN (40%, 50% and 90% respectively) after reconnection surgery without autologous gastrointestinal reconstruction. Among our 13 adults, mean age was 54.1 years (53.8 % ASA III): 69.2 % had a high stomal output (> 500 cc/day) and TPN dependence was 100%. We performed a jejuno-colonic anastomosis (SBS type II) in 53.8%, in 46.1% of cases without ileo-cecal valve, leaving a mean residual small bowel length of 75.7 cm. In-hospital mortality was 0%. After a minimum period of 1 year of intestinal rehabilitation, all our patients (100%) went back to oral intake and 69.2% were off TPN (9 patients). No one was listed for transplantation. A residual small bowel length of minimum 75 cm, even if reconnected to part of the colon, seems able to produce a TPN independence without autologous gastrointestinal reconstruction after a minimum period of 1 year of intestinal rehabilitation.

Short Bowel Syndrome as the Leading Cause of Intestinal Failure in Early Life: Some Insights into the Management

Intestinal failure (IF) is the critical reduction of the gut mass or its function below the minimum needed to absorb nutrients and fluids required for adequate growth in children. Severe IF requires parenteral nutrition (PN). Pediatric IF is most commonly due to congenital or neonatal intestinal diseases or malformations divided into 3 groups: 1) reduced intestinal length and consequently reduced absorptive surface, such as in short bowel syndrome (SBS) or extensive aganglionosis; 2) abnormal development of the intestinal mucosa such as congenital diseases of enterocyte development; 3) extensive motility dysfunction such as chronic intestinal pseudo-obstruction syndromes. The leading cause of IF in childhood is the SBS. In clinical practice the degree of IF may be indirectly measured by the level of PN required for normal or catch up growth. Other indicators such as serum citrulline have not proven to be highly reliable prognostic factors in children. The last decades have allowed the development of highly sophisticated nutrient solutions consisting of optimal combinations of macronutrients and micronutrients as well as guidelines, promoting PN as a safe and efficient feeding technique. However, IF that requires long-term PN may be associated with various complications including infections, growth failure, metabolic disorders, and bone disease. IF Associated Liver Disease may be a limiting factor. However, changes in the global management of IF pediatric patients, especially since the setup of intestinal rehabilitation centres did change the prognosis thus limiting "nutritional failure" which is considered as a major indication for intestinal transplantation (ITx) or combined liver-ITx.

Emerging treatments for short bowel syndrome in adult patients

Short bowel syndrome (SBS) is the major cause of chronic intestinal failure (IF), defined as 'the reduction of gut function below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth'. Areas covered: Spontaneous intestinal adaptation, including increased hormonal secretion, development of hyperphagia and gut microbiota dysbiosis, occurs 2 years after resection, improving intestinal absorption and decreasing PN dependency. Hormonal treatments, promoting intestinal hyperadaptation, have been proposed in patients with SBS with chronic IF. Clinical studies showed teduglutide to increase urine production and reduce the need for parenteral support volume in these patients. According to the latest ESPEN Guidelines, if a growth factor treatment is considered, the GPL2 analog, teduglutide, should be the first-choice treatment. Expert opinion: These therapies underline the importance of patient monitoring at home and the complexity for HPN adaptation. A multidisciplinary approach should be a gold standard.

Starch Tolerance and the Short Bowel

Short bowel syndrome with intestinal failure is a rare disease with a massive impairment in quality of life, requiring a multidisciplinary team approach to medical, surgical, and nutritional therapy. Current pharmacological and surgical therapeutic options are limited; an important cornerstone is enteral and parenteral nutrition. The changed physiology of carbohydrate digestion plays a major role in the adaptation process and can be a target for specific enteral nutrition interventions. An important prognostic factor is the preservation of at least portions of the colon in continuity with small bowel. This strategy has to include an evaluation of the anatomical situation and small bowel absorptive capacity, adaptation processes, and luminal microbiota including its fermentative properties. Starch is probably the most important complex carbohydrate in short bowel syndrome nutrition, because it is absorbed or fermented almost completely. Benefits of supplementation with complex carbohydrates include improved adaptive processes, positive trophic effects on the mucosa and its hormonal response, longer transit time, and possibly a faster time to wean from parenteral nutrition, but supplementation advice needs to weigh carefully the risks and benefits, especially considering bacterial overgrowth, osmotic load, and D-lactate acidosis.

Impact of gastrointestinal disease states on oral drug absorption – implications for formulation design – a PEARRL review

Objectives

Drug product performance in patients with gastrointestinal (GI) diseases can be altered compared to healthy subjects due to pathophysiological changes. In this review, relevant differences in patients with inflammatory bowel diseases, coeliac disease, irritable bowel syndrome and short bowel syndrome are discussed and possible in vitro and in silico tools to predict drug product performance in this patient population are assessed.

Key findings

Drug product performance was altered in patients with GI diseases compared to healthy subjects, as assessed in a limited number of studies for some drugs. Underlying causes can be observed pathophysiological alterations such as the differences in GI transit time, the composition of the GI fluids and GI permeability. Additionally, alterations in the abundance of metabolising enzymes and transporter systems were observed. The effect of the GI diseases on each parameter is not always evident as it may depend on the location and the state of the disease. The impact of the pathophysiological change on drug bioavailability depends on the physicochemical characteristics of the drug, the pharmaceutical formulation and drug metabolism. In vitro and in silico methods to predict drug product performance in patients with GI diseases are currently limited but could be a useful tool to improve drug therapy.

Summary

Development of suitable in vitro dissolution and in silico models for patients with GI diseases can improve their drug therapy. The likeliness of the models to provide accurate predictions depends on the knowledge of pathophysiological alterations, and thus, further assessment of physiological differences is essential.

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.

Impact of Antibiotics on Necrotizing Enterocolitis and Antibiotic-Associated Diarrhea

Antibiotic treatment alters the composition and metabolic function of the intestinal microbiota. These alterations may contribute to the pathogenesis of necrotizing enterocolitis (NEC) and antibiotic-associated diarrhea (AAD). Recent studies are beginning to unravel the contribution of specific groups of microbes and their metabolic pathways to these diseases. Probiotics or other microbiota-targeted therapies may provide effect strategies to prevent and treat NEC and AAD.

Bacteria isolated from lung modulate asthma susceptibility in mice

Asthma is a chronic, non-curable, multifactorial disease with increasing incidence in industrial countries. This study evaluates the direct contribution of lung microbial components in allergic asthma in mice. Germ-Free and Specific-Pathogen-Free mice display similar susceptibilities to House Dust Mice-induced allergic asthma, indicating that the absence of bacteria confers no protection or increased risk to aeroallergens. In early life, allergic asthma changes the pattern of lung microbiota, and lung bacteria reciprocally modulate aeroallergen responsiveness. Primo-colonizing cultivable strains were screened for their immunoregulatory properties following their isolation from neonatal lungs. Intranasal inoculation of lung bacteria influenced the outcome of allergic asthma development: the strain CNCM I 4970 exacerbated some asthma features whereas the pro-Th1 strain CNCM I 4969 had protective effects. Thus, we confirm that appropriate bacterial lung stimuli during early life are critical for susceptibility to allergic asthma in young adults.

Protective Actions of Epithelial 5-Hydroxytryptamine 4 Receptors in Normal and Inflamed Colon

BACKGROUND & AIMS

The 5-hydroxytryptamine receptor 4 (5-HT₄R or HTR₄) is expressed in the colonic epithelium but little is known about its functions there. We examined whether activation of colonic epithelial 5-HT₄R protects colons of mice from inflammation.

METHODS

The 5-HT₄R agonist tegaserod (1 mg/kg), the 5-HT₄R antagonist GR113808 (1 mg/kg), or vehicle (control) were delivered by enema to wild-type or 5-HT₄R knockout mice at the onset of, or during, active colitis, induced by administration of dextran sodium sulfate or trinitrobenzene sulfonic acid. Inflammation was measured using the colitis disease activity index and by histologic analysis of intestinal tissues. Epithelial proliferation, wound healing, and resistance to oxidative stress-induced apoptosis were assessed, as was colonic motility.

RESULTS

Rectal administration of tegaserod reduced the severity of colitis compared with mice given vehicle, and accelerated recovery from active colitis. Rectal tegaserod did not improve colitis in 5-HT₄R knockout mice, and intraperitoneally administered tegaserod did not protect wild-type mice from colitis. Tegaserod increased proliferation of crypt epithelial cells. Stimulation of 5-HT₄R increased Caco-2 cell migration and reduced oxidative stress-induced apoptosis; these actions were blocked by co-administration of the 5-HT₄R antagonist GR113808. In noninflamed colons of wild-type mice not receiving tegaserod, inhibition of 5-HT₄Rs resulted in signs of colitis within 3 days. In these mice, epithelial proliferation decreased and bacterial translocation to the liver and spleen was detected. Daily administration of tegaserod increased motility in inflamed colons of guinea pigs and mice, whereas administration of GR113808 disrupted motility in animals without colitis.

CONCLUSIONS

5-HT₄R activation maintains motility in healthy colons of mice and guinea pigs, and reduces inflammation in colons of mice with colitis. Agonists might be developed as treatments for patients with inflammatory bowel diseases.

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.

Microbial perturbations and modulation in conditions associated with malnutrition and malabsorption

The intestinal microbiota is a complex ecosystem, which can be considered an accessory organ. It involves complex microbe-microbe and host-microbe interactions with indispensable functions for the human host with regard to the intestinal epithelium and barrier function, the innate and adaptive immune system, and its large metabolic capacity. Saccharolytic fermentation results in the production of short chain fatty acids, which exert an array of beneficial effects, while proteolytic fermentation leads to an increase in potentially harmful metabolites. In addition, numerous other microbial metabolites are being produced with various intestinal as well as extra-intestinal effects. Their generation depends on the composition of the microbiota as well as the availability of substrates, which both vary along the GI tract. Diet impacts the intestinal microbiota composition and activity in early infancy as well as in adults. Microbial perturbations have been demonstrated in subjects with under-nutrition and/or malabsorption. The bidirectional interactions between the microbiome, nutrient availability and GI function, can contribute to a vicious circle, further impairing health outcome in conditions associated with malnutrition and/or malabsorption. Integrated multivariate approaches are needed to further unravel the complex interaction between microbiome, diet and host factors, as well as possible modulation thereof by prebiotics or probiotics. The present overview will briefly outline the composition and function of the intestinal microbiota, its association with nutrient intake and availability, and will address the role of the intestinal microbiota in malnutrition and malabsorption.

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.

Copper and magnesium deficiencies in patients with short bowel syndrome receiving parenteral nutrition or oral feeding

BACKGROUND

Patients with short bowel syndrome have significant fluid and electrolytes loss.

OBJECTIVE

Evaluate the mineral and electrolyte status in short bowel syndrome patients receiving intermittent parenteral nutrition or oral feeding.

METHODS

Twenty two adults with short bowel syndrome, of whom 11 were parenteral nutrition dependent (PN group), and the 11 remaining had been weaned off parenteral nutrition for at least 1 year and received all nutrients by oral feeding (OF group). The study also included 14 healthy volunteers paired by age and gender (control group). Food ingestion, anthropometry, serum or plasma levels of sodium, potassium, phosphorus, magnesium, calcium, zinc, iron and copper were evaluated. PN group subjects were evaluated before starting a new parenteral nutrition cycle.

RESULTS

The levels of sodium, potassium, phosphorus, calcium and zinc were similar between the groups. The magnesium value was lower in the PN group (1.0 ± 0.4 mEq /L) than other groups. Furthermore, this electrolyte was lower in the OF group (1.4 ± 0.3 mEq /L) when compared to the Control group (1.8 ± 0.1 mEq/L). Lower values of copper (69±24 vs 73±26 vs 109±16 µg/dL) were documented, respectively, for the PN and OF groups when compared to the control group.

CONCLUSION

Hypomagnesemia and hypocupremia are electrolyte disturbances commonly observed in short bowel syndrome. Patients with massive intestinal resection require monitoring and supplementation in order to prevent magnesium and copper deficiencies.

Disruptions of the intestinal microbiome in necrotizing enterocolitis, short bowel syndrome, and Hirschsprung's associated enterocolitis

Next generation sequencing techniques are currently revealing novel insight into the microbiome of the human gut. This new area of research seems especially relevant for neonatal diseases, because the development of the intestinal microbiome already starts in the perinatal period and preterm infants with a still immature gut associated immune system may be harmed by a dysproportional microbial colonization. For most gastrointestinal diseases requiring pediatric surgery there is very limited information about the role of the intestinal microbiome. This review aims to summarize the current knowledge and outline future perspectives for important pathologies like necrotizing enterocolitis (NEC) of the newborn, short bowel syndrome (SBS), and Hirschsprung’s disease associated enterocolitis (HAEC). Only studies applying next generation sequencing techniques to analyze the diversity of the intestinal microbiome were included. In NEC patients intestinal dysbiosis could already be detected prior to any clinical evidence of the disease resulting in a reduction of the bacterial diversity. In SBS patients the diversity seems to be reduced compared to controls. In children with Hirschsprung’s disease the intestinal microbiome differs between those with and without episodes of enterocolitis. One common finding for all three diseases seems to be an overabundance of Proteobacteria. However, most human studies are based on fecal samples and experimental data question whether fecal samples actually represent the microbiome at the site of the diseased bowel and whether the luminal (transient) microbiome compares to the mucosal (resident) microbiome. In conclusion current studies already allow a preliminary understanding of the potential role of the intestinal microbiome in pediatric surgical diseases. Future investigations could clarify the interface between the intestinal epithelium, its immunological competence and mucosal microbiome. Advances in this field may have an impact on the understanding and non-operative treatment of such diseases in infancy.

Short bowel syndrome in children: surgical and medical perspectives

The main cause of intestinal failure in children is due to short bowel syndrome (SBS) resulting from congenital or acquired intestinal lesions. From the first lengthening procedure introduced by Bianchi, the last three decades have seen lengthening procedures established as fundamental components of multidisciplinary intestinal rehabilitation programs. Debate on indications and timing of the procedures is still open leaving SBS surgical treatment a great challenge. However, enteral autonomy is possible only with an individualized approach remembering that each SBS patient is unique. Current literature on autologous gastrointestinal reconstruction technique was reviewed aiming to assess a comprehensive pathway in SBS non-transplant management.

Intestinal adaptation following resection

Intestinal adaptation is a natural compensatory process that occurs following extensive intestinal resection, whereby structural and functional changes in the intestine improve nutrient and fluid absorption in the remnant bowel. In animal studies, postresection structural adaptations include bowel lengthening and thickening and increases in villus height and crypt depth. Functional changes include increased nutrient transporter expression, accelerated crypt cell differentiation, and slowed transit time. In adult humans, data regarding adaptive changes are sparse, and the mechanisms underlying intestinal adaptation remain to be fully elucidated. Several factors influence the degree of intestinal adaptation that occurs post resection, including site and extent of resection, luminal stimulation with enteral nutrients, and intestinotrophic factors. Two intestinotrophic growth factors, the glucagon-like peptide 2 analog teduglutide and recombinant growth hormone (somatropin), are now approved for clinical use in patients with short bowel syndrome (SBS). Both agents enhance fluid absorption and decrease requirements for parenteral nutrition (PN) and/or intravenous fluid. Intestinal adaptation has been thought to be limited to the first 1-2 years following resection in humans. However, recent data suggest that a significant proportion of adult patients with SBS can achieve enteral autonomy, even after many years of PN dependence, particularly with trophic stimulation.

Dipeptidyl peptidase-4 inhibitor anagliptin facilitates restoration of dextran sulfate sodium-induced colitis

OBJECTIVE. Inflammatory bowel disease (IBD) is a chronic debilitating disease associated with severe damage to the intestinal mucosa. Glucagon-like peptide-2 (GLP-2) is a potent and specific gastrointestinal growth factor. GLP-2 released from enteroendocrine cells is inactivated by dipeptidyl peptidase-4 (DPP-4). The aim of this study was to examine whether the DPP-4 inhibitor anagliptin improves experimental murine colitis. MATERIAL AND METHODS. Male C57BL/6 mice aged 8 weeks were exposed to 1.5% dextran sulfate sodium (DSS) in drinking water for 7 days to induce experimental colitis. Anagliptin (0.1% in diet) was administrated from 2 days before the beginning of DSS to 7 days after the end of DSS. Changes in body weight and disease activity index were evaluated daily. Histological colitis severity, cellular proliferation and gene expression were determined in colonic tissues. RESULTS. Treatment with anagliptin clearly improved body weight loss and disease activity index in the recovery phase. Histological score in the DSS + anagliptin group at day 14 was significantly lower than that in the DSS alone group. Treatment with anagliptin increased the Ki67-positive rate at days 10 and 14, and tended to increase insulin-like growth factor-1 mRNA expression in the DSS + anagliptin group. CONCLUSION. In this model of experimental colitis, the DPP-4 inhibitor anagliptin facilitated the restoration of mucosal damage, thereby resulting in the acceleration of healing. These findings suggest a new and novel therapeutic approach for the treatment of IBD.

Gut microbial diversity is reduced and is associated with colonic inflammation in a piglet model of short bowel syndrome

BACKGROUND AND OBJECTIVES

Following small bowel resection (SBR), the luminal environment is altered, which contributes to clinical manifestations of short bowel syndrome (SBS) including malabsorption, mucosal inflammation and bacterial overgrowth. However, the impact of SBR on the colon has not been well-defined. The aims of this study were to characterize the colonic microbiota following SBR and to assess the impact of SBR on mucosal inflammation in the colon.

RESULTS

Analysis of the colonic microbiota demonstrated that there was a significant level of dysbiosis both two and six weeks post-SBR, particularly in the phylum Firmicutes, coupled with a decrease in overall bacterial diversity in the colon. This decrease in diversity was associated with an increase in colonic inflammation six weeks post-surgery.

METHODS

Female (4-week old) piglets (5-6/group) received a 75% SBR, a transection (sham) or no surgery. Compositional analysis of the colonic microbiota was performed by high-throughput sequencing, two- and six-weeks post-surgery. The gene expression of the pro-inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8, IL-18 and tumor necrosis factor (TNF)-α in the colonic mucosa was assessed by qRT-PCR and the number of macrophages and percentage inducible nitric oxide synthase (iNOS) staining in the colonic epithelium were quantified by immunohistochemistry.

CONCLUSIONS

SBR significantly decreased the diversity of the colonic microbiota and this was associated with an increase in colonic mucosal inflammation. This study supports the hypothesis that SBR has a significant impact on the colon and that this may play an important role in defining clinical outcome.

Long-term outcome after extensive intestinal resection for chronic radiation enteritis

INTRODUCTION

Management of chronic radiation enteritis is often controversial, particularly due to the risk of short bowel syndrome.

METHODS

One hundred and seven chronic radiation enteritis patients with short bowel syndrome were studied retrospectively between 1980 and 2009. Survival and home parenteral nutrition dependence rates were evaluated with univariate and multivariate analysis.

RESULTS

The survival probabilities were 93%, 67% and 44.5% at 1, 5 and 10 years, respectively. On multivariate analysis, survival was significantly decreased with residual neoplastic disease (HR=0.21 [0.11-0.38], p<0.001), an American Society of Anesthesiologists score >3 (HR=0.38 [0.20-0.73], p=0.004) and an age of chronic radiation enteritis diagnosis >60 years (HR=0.45 [0.22-0.89], p=0.02). The actuarial home parenteral nutrition dependence probabilities were 66%, 55% and 43% at 1, 2 and 3 years, respectively. On multivariate analysis, this dependence was significantly decreased when there was a residual small bowel length >100 cm (HR=0.35 [0.18-0.68], p=0.002), adaptive hyperphagia (HR=0.39 [0.17-0.87], p=0.02) and the absence of a definitive stoma (HR=0.48 [0.27-0.84], p=0.01).

CONCLUSION

The survival of patients with diffuse chronic radiation enteritis after extensive intestinal resection was good and was mainly influenced by underlying comorbidities. Almost two-thirds of patients were able to be weaned off home parenteral nutrition.

Faecal D/L lactate ratio is a metabolic signature of microbiota imbalance in patients with short bowel syndrome

Our objective was to understand the functional link between the composition of faecal microbiota and the clinical characteristics of adults with short bowel syndrome (SBS).

Sixteen patients suffering from type II SBS were included in the study. They displayed a total oral intake of 2661±1005 Kcal/day with superior sugar absorption (83±12%) than protein (42±13%) or fat (39±26%). These patients displayed a marked dysbiosis in faecal microbiota, with a predominance of Lactobacillus/Leuconostoc group, while Clostridium and Bacteroides were under-represented. Each patient exhibited a diverse lactic acid bacteria composition (L. delbrueckii subsp. bulgaricus, L. crispatus, L. gasseri, L. johnsonii, L. reuteri, L. mucosae), displaying specific D and L-lactate production profiles in vitro. Of 16 patients, 9/16 (56%) accumulated lactates in their faecal samples, from 2 to 110 mM of D-lactate and from 2 to 80 mM of L-lactate. The presence of lactates in faeces (56% patients) was used to define the Lactate-accumulator group (LA), while absence of faecal lactates (44% patients) defines the Non lactate-accumulator group (NLA). The LA group had a lower plasma HCO3⁻ concentration (17.1±2.8 mM) than the NLA group (22.8±4.6 mM), indicating that LA and NLA groups are clinically relevant sub–types. Two patients, belonging to the LA group and who particularly accumulated faecal D-lactate, were at risk of D-encephalopathic reactions. Furthermore, all patients of the NLA group and those accumulating preferentially L isoform in the LA group had never developed D-acidosis. The D/L faecal lactate ratio seems to be the most relevant index for a higher D- encephalopathy risk, rather than D- and L-lactate faecal concentrations per se. Testing criteria that take into account HCO3⁻ value, total faecal lactate and the faecal D/L lactate ratio may become useful tools for identifying SBS patients at risk for D-encephalopathy.

Primocolonization is associated with colonic epithelial maturation during conventionalization

Interaction between the gut microbiota and the host starts immediately after birth with the progressive colonization of the sterile intestine. Our aim was to investigate the interactions taking place in the colonic epithelium after the first exposure to gut microbiota. Germ-free (GF) rats were inoculated with two different microbiotas: the first, obtained from suckling rats, was rich in primocolonizing bacteria and the second, obtained from adult rats, was representative of a mature microbiota. Once transferred into GF rats, these two microbiotas evolved such that they converged, and recapitulated the primocolonization pattern, mimicking the chronological scheme of implantation following birth. The two microbiotas induced common responses in the colonic epithelium: a transitory proliferative phase followed by a compensatory phase characterized by increases in the abundance of p21(Cip1) and p27(Kip1) and in the number of goblet cells. The effects of the two microbiotas diverged only through their effects on colonic transporters. Analyses of solute carriers and aquaporins revealed that functional maturation was more pronounced following exposure to adult microbiota than suckling microbiota. The colon matured in parallel with the evolution of the microbiota composition, and we therefore suggest a link between intestinal events regulating homeostasis of the colon and modulation of microbial composition.

Intestinal adaptation is stimulated by partial enteral nutrition supplemented with the prebiotic short-chain fructooligosaccharide in a neonatal intestinal failure piglet model

BACKGROUND

Butyrate has been shown to stimulate intestinal adaptation when added to parenteral nutrition (PN) following small bowel resection but is not available in current PN formulations. The authors hypothesized that pre- and probiotic administration may be a clinically feasible method to administer butyrate and stimulate intestinal adaptation.

METHODS AND MATERIALS

Neonatal piglets (48 hours old, n = 87) underwent placement of a jugular catheter and an 80% jejunoileal resection and were randomized to one of the following treatment groups: control (20% standard enteral nutrition/80% standard PN), control plus prebiotic (10 g/L short-chain fructooligosaccharides [scFOS]), control plus probiotic (1 × 10(9) CFU Lactobacillus rhamnosus GG [LGG]), or control plus synbiotic (scFOS + LGG). Animals received infusions for 24 hours, 3 days, or 7 days, and markers of intestinal adaptation were assessed.

RESULTS

Prebiotic treatment increased ileal mucosa weight compared with all other treatments (P = .017) and ileal protein compared with control (P = .049), regardless of day. Ileal villus length increased in the prebiotic and synbiotic group (P = .011), regardless of day, specifically due to an increase in epithelial proliferation (P = .003). In the 7-day prebiotic group, peptide transport was upregulated in the jejunum (P = .026), whereas glutamine transport was increased in both the jejunum and colon (P = .001 and .003, respectively).

CONCLUSIONS

Prebiotic and/or synbiotic supplementation resulted in enhanced structure and function throughout the residual intestine. Identification of a synergistic prebiotic and probiotic combination may enhance the promising results obtained with prebiotic treatment alone.

Insulin-like growth factor 1: common mediator of multiple enterotrophic hormones and growth factors

PURPOSE OF REVIEW

To summarize the recent evidence that insulin-like growth factor 1 (IGF1) mediates growth effects of multiple trophic factors and discuss clinical relevance.

RECENT FINDINGS

Recent reviews and original reports indicate benefits of growth hormone (GH) and long-acting glucagon-like peptide 2 (GLP2) analogs in short bowel syndrome and Crohn's disease. This review highlights the evidence that biomarkers of sustained small intestinal growth or mucosal healing and evaluation of intestinal epithelial stem cell biomarkers may improve clinical measures of intestinal growth or response to trophic hormones. Compelling evidence that IGF1 mediates growth effects of GH and GLP2 on intestine or linear growth in preclinical models of resection or Crohn's disease is presented, along with a concept that these hormones or IGF1 may enhance sustained growth if given early after bowel resection. Evidence that suppressor of cytokine signaling protein induction by GH or GLP2 in normal or inflamed intestine may limit IGF1-induced growth, but protect against risk of dysplasia or fibrosis, is reviewed. Whether IGF1 receptor mediates IGF1 action and potential roles of insulin receptors are addressed.

SUMMARY

IGF1 has a central role in mediating trophic hormone action in small intestine. Better understanding of benefits and risks of IGF1, receptors that mediate IGF1 action, and factors that limit undesirable growth are needed.