Etiology and prognosis of pediatric short bowel syndrome

Clinical challenges of short bowel syndrome and the path forward for organoid-based regenerative medicine

Short bowel syndrome (SBS) is a rare condition, the main symptom of which is malabsorption following extensive resection of the small intestine. Treatment for SBS is mainly supportive, consisting of supplementation, prevention and treatment of complications, and promotion of intestinal adaptation. While development of parenteral nutrition and drugs promoting intestinal adaptation has improved clinical outcomes, the prognosis of patients with SBS remains poor. Intestinal transplantation is the only curative therapy but its outcome is unsatisfactory. In the absence of definitive therapy, novel treatment is urgently needed. With the advent of intestinal organoids, research on the intestine has developed remarkably in recent years. Concepts such as the "tissue-engineered small intestine" and "small intestinalized colon," which create a functional small intestine by combining organoids with other technologies, are potentially novel regenerative therapeutic approaches for SBS. Although they are still under development and there are substantial issues to be resolved, the problems that have prevented establishment of the complex function and structure of the small intestine are gradually being overcome. This review discusses the current treatments for SBS, the fundamentals of the intestine and organoids, the current status of these new technologies, and future perspectives.

Featuring molecular regulation of bile acid homeostasis in pediatric short bowel syndrome

BACKGROUND

Disturbed bile acid homeostasis may foster development of short bowel syndrome (SBS) associated liver disease during and after weaning off parenteral nutrition (PN). Our aim was to study hepatic molecular regulation of bile acid homeostasis in relation to serum and fecal bile acid profiles in pediatric SBS.

METHODS

Liver histopathology and mRNA expression of genes regulating synthesis, uptake and export of bile acids, and cellular receptors involved in bile acid signaling were measured in SBS patients (n = 33, median age 3.2 years). Simultaneously, serum (n = 24) and fecal (n = 10) bile acid profiles were assessed. Sixteen patients were currently on PN. Results of patients were compared to healthy control subjects.

RESULTS

Nine of ten (90 %) patients with histological cholestasis received current PN, while portal inflammation was present in 60 % (6/10) of patients with cholestasis compared to 13 % (3/23) without cholestasis (P = 0.01). In all SBS patients, hepatic synthesis and uptake of bile acids was increased. Patients on current PN showed widespread repression of hepatic FXR target genes, including downregulated canalicular (BSEP, MDR3) and basolateral (MRP3) bile acid exporters. Serum and fecal primary bile acids were increased both during and after weaning off PN.

CONCLUSIONS

Bile acid homeostasis in SBS is characterized by interrupted enterohepatic circulation promoting increased hepatic synthesis and conservation of bile acids. In PN dependent SBS patients with hepatic cholestasis and inflammation, the molecular fingerprint of downregulated hepatocyte canalicular and basolateral bile acid export with simultaneously increased synthesis and uptake of bile acids could favor their accumulation in hepatocytes and predispose to liver disease.

A survival analysis of cuffed tunneled silicon central venous catheters in children affected by short bowel syndrome: A lesson from the past

BACKGROUND

Tunneled central venous catheters (CVC) are crucial in the management of children affected by short bowel syndrome (SBS). This work aims to investigate the outcomes of tunneled CVC and to identify factors influencing their survival.

METHODS

All the children diagnosed with SBS and undergone a procedure of insertion of a tunneled CVC from 2010 to 2019 were included. Demographic data and surgical information about the procedures were collected. Regression models and Kaplan-Meier analysis were performed to estimate the survival.

RESULTS

Eighteen patients, eight males (44%), with a median length of residual bowel measuring 72 cm (IQR 50-102 cm), were enrolled. Thirty-nine Broviac CVCs were inserted with a mean number of 2.2 CVCs per patient and 13365 line-days. The overall incidence of complications was 3.2/1000 line-days, and the incidence of central line associated bloodstream infections (CLABSI) was 1.1/1000 line-days. No episode of catheter thrombosis was reported. The median survival was 269 days (IQR 82-1814 days). The survival was negatively influenced by a younger age at insertion (R2 = 0.29; p < 0.001), 2.7 Fr diameter (median survival 76 days; p < 0.001) and the occurrence of complications (median survival 169 days; p = 0.002). The length of residual bowel was a mild risk factor for anticipated removal (OR 1.1; CI95 1.0-1.1; p = 0.05).

CONCLUSION

CVC-related complications negatively influenced the survival of the line. An elder age at insertion together with a larger CVC diameter increased the survival of the line, while a shorter residual bowel was associated with an anticipated removal due to complications.

Optimizing transition from pediatric to adult care in short bowel syndrome and intestinal failure

As the majority of children with short bowel syndrome (SBS) and intestinal failure (IF) are now surviving into adulthood, there is a paradigm shift from short-term management to long-term outcomes and a growing need to focus on healthcare transition (HCT). It is imperative that adolescents and young adults with SBS and IF receive disease education, empowerment, and support as they navigate the transition from pediatric to adult care. Furthermore, both pediatric and adult healthcare providers who manage these patients should be aware of the challenges faced by this population, barriers to their HCT, and strategies to overcome them. This article reviews the literature on HCT in children with chronic illnesses, discusses barriers to HCT in SBS/IF, identifies the important constituents of the transition process in SBS/IF, and provides recommendations for the successful and smooth transition of the pediatric patient to the adult healthcare environment. Structured and multicomponent HCT programs should become the standard of care to ensure uninterrupted high-quality care across the life span for patients with SBS/IF.

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.

An Engineered Living Intestinal Muscle Patch Produces Macroscopic Contractions that can Mix and Break Down Artificial Intestinal Contents

The intestinal muscle layers execute various gut wall movements to achieve controlled propulsion and mixing of intestinal content. Engineering intestinal muscle layers with complex contractile function is critical for developing bioartificial intestinal tissue to treat patients with short bowel syndrome. Here, the first demonstration of a living intestinal muscle patch capable of generating three distinct motility patterns and displaying multiple digesta manipulations is reported. Assessment of contractility, cellular morphology, and transcriptome profile reveals that successful generation of the contracting muscle patch relies on both biological factors in a serum-free medium and environmental cues from an elastic electrospun gelatin scaffold. By comparing gene-expression patterns among samples, it is shown that biological factors from the medium strongly affect ion-transport activities, while the scaffold unexpectedly regulates cell-cell communication. Analysis of ligandreceptor interactome identifies scaffold-driven changes in intercellular communication, and 78% of the upregulated ligand-receptor interactions are involved in the development and function of enteric neurons. The discoveries highlight the importance of combining biomolecular and biomaterial approaches for tissue engineering. The living intestinal muscle patch represents a pivotal advancement for building functional replacement intestinal tissue. It offers a more physiological model for studying GI motility and for preclinical drug discovery.

Combined procedures for surgical short bowel syndrome: experience from two European centres

BACKGROUND

Autologous gastrointestinal reconstructive surgery (AGIR) has become a key component of intestinal rehabilitation programs. However, the best surgical option for short bowel syndrome (SBS) remains unknown. This paper presents our experience using combined procedures as primary treatment.

METHODS

We collected data on SBS patients who underwent surgery from 2008 to 2021 in two tertiary European Centres. Combined procedures were defined as more than one technique used on the same patient. Charts were reviewed for demographics, type of procedures, complications, and outcomes. Data are presented as median and IQR. Wilcoxon signed rank was used for all paired analyses.

RESULTS

Twenty-one children (12 females) underwent combined procedures. Preoperative median small bowel length was 20 cm (IQR: 15-35 cm); after lengthening, it was 35.5 cm (IQR: 30.75-50.50 cm) (P < 0.001). Combined procedures were simultaneous in 15 patients and sequential in 6. At a median of 9.2 years (IQR: 7.55-9.78 years) follow-up, complications were three bowel obstructions after strictures of anastomosis and two wound infections. Two patients achieved enteral autonomy, and others followed a weaning home parenteral nutrition regimen with a median of 4 nights off (IQR: 3-4 nights) starting with a median of 7 nights (IQR: 7-7 nights).

CONCLUSIONS

Combined AGIR techniques are practical and safe in SBS treatment when tailored to meet patients' needs, combining lengthening, tailoring, and reducing transit time procedures. Therefore, combined AGIR may be considered a resource in intestinal rehabilitation units' armamentarium.

Pharmacokinetics, Safety, and Tolerability of Glepaglutide, a Long-Acting GLP-2 Analog, in Subjects with Renal Impairment

BACKGROUND

Glepaglutide is a novel, ready-to-use, long-acting, glucagon-like peptide-2 (GLP-2) analog intended for the treatment of patients with short bowel syndrome (SBS). This study investigated the impact of renal function on the pharmacokinetics and safety of glepaglutide.

METHODS

In this 3-site, non-randomized, open-label study, 16 subjects were enrolled: 4 with severe renal impairment (eGFR 15 to < 30 mL/min/1.73 m²), 4 with end stage renal disease (ESRD) not on dialysis (eGFR < 15 mL/min/1.73 m²), and 8 matching controls with normal renal function (eGFR ≥ 90 mL/min/1.73 m²). Blood samples were collected over a 14-day period following a single subcutaneous (SC) dose of glepaglutide 10 mg. Safety and tolerability were assessed throughout the study. The primary pharmacokinetic parameters were area under the curve between dosing and 168 h (AUC_0-168 h) and the maximum plasma concentration (C_max).

RESULTS

There was no clinically relevant difference between subjects with severe renal impairment/ESRD and normal renal function with respect to total exposure (AUC_0-168 h) and peak plasma concentrations (C_max) of glepaglutide following a single SC dose. A single SC dose of glepaglutide 10 mg appeared safe and well tolerated in subjects with normal renal function and subjects with severe renal impairment or ESRD. No serious adverse events were reported, and no safety issues were identified.

CONCLUSIONS

No difference in glepaglutide pharmacokinetics was seen between renal impaired and normal subjects. Based on this trial, dose adjustment appears not to be warranted in SBS patients with renal impairment.

TRIAL REGISTRATION

The trial is registered at http://www.

CLINICALTRIALS

gov (NCT04178447) and has the EudraCT number: 2019-001466-15.

Factors influencing enteral autonomy after autologous gastrointestinal reconstructive surgery: A two-centre UK perspective

BACKGROUND AND AIMS

The implementation of multidisciplinary care and improvements in parenteral nutrition (PN) in patients with short bowel syndrome (SBS) have led to better outcomes and higher survivability. Autologous gastrointestinal reconstructive (AGIR) surgery can reduce the duration on PN and lead to earlier enteral autonomy (EA). Our aim was to investigate the effect of SBS aetiology and other predictors on the achievement of enteral autonomy following AGIR surgery.

METHODS

Retrospective review of all patients undergoing AGIR surgery in two tertiary paediatric surgical units, between 2010 and 2021. Continuous data is presented as median (range).

RESULTS

Twenty-seven patients underwent 29 AGIR procedures (20 serial transverse enteroplasties (STEP), 9 longitudinal intestinal lengthening and tailoring (LILT)) at an age of 6.6 months (1.5 - 104.5). EA rate was 44% at 13.6 months after surgery (1 - 32.8). AGIR procedures achieved an increase in small bowel length of 70% (pre-operative 46.5 vs 77 cm, p = 0.003). No difference was found between STEP and LILT (p = 0.84). Percentage of expected small bowel length (based on the child's weight) was a strong predictor of EA (bowel length >15% - EA 80% vs bowel length ≤15% - EA 17%, p = 0.008). A diagnosis of gastroschisis showed a negative non-significant correlation with the ability to achieve EA (25% vs 60%, p = 0.12). Overall survival rate was 96%.

CONCLUSION

AGIR surgery is an important tool in the multidisciplinary management of children with SBS. Percentage of expected small length and aetiology of SBS are likely predictors of achievement of EA in patients undergoing AGIR surgery.

LEVEL OF EVIDENCE

IV: Retrospective Case-Series.

Histopathological liver steatosis linked with high parenteral glucose and amino acid supply in infants with short bowel syndrome

BACKGROUND

Steatosis is a common feature of intestinal failure-associated liver disease (IFALD) in adult and older pediatric patients receiving long-term parenteral nutrition (PN). There are limited clinical data concerning steatosis in infants with short bowel syndrome (SBS). We investigated early histopathological steatosis and its association to PN.

METHODS

In this retrospective study, 31 patients with SBS had a diagnostic liver biopsy taken at the median age of 5 (IQR 3-8) months. Follow-up biopsy was available for 24 patients at the median age of 29 (IQR 14-52) months. We evaluated the biopsies for steatosis and other histopathological signs of IFALD and compared results with patient characteristics, PN composition, and liver biochemistry.

RESULTS

Diagnostic biopsies revealed steatosis in 8 (26%) patients. At the age of 3 months, patients with steatosis had received higher amounts of parenteral glucose: median 15.1 (IQR 12.4-17.2) vs 12.3 (8.7-14.4) g/kg/d (P = 0.04), amino acids: 2.9 (2.5-3.4) vs 2.2 (1.6-2.7) g/kg/d (P = 0.03), and energy: 87 (80-98) vs 73 (54-79) kcal/kg/d (P = 0.01) than those without steatosis. We detected no significant differences in parenteral lipid intake between the groups. Steatosis also associated with increased serum bile acid (P = 0.02), alanine aminotransferase (P = 0.0002), and aspartate aminotransferase (P = 0.001) levels.

CONCLUSIONS

In this cohort, high parenteral glucose, amino acid, and energy provision associated with liver steatosis in infants with SBS. We recommend monitoring of bile acid and transaminase levels while aiming for PN with balanced macronutrient supply according to current recommendations to protect the liver from steatosis.

Initial blood cultures in pediatric patients with central line infections and short bowel syndrome can direct a treatment plan that can reduce hospital length of stay

BACKGROUND

Children with short bowel syndrome requiring parenteral nutrition are at high risk of recurrent central line-associated bloodstream infections requiring inpatient admission. Predicting responses to treatment at admission could help revise our current treatment algorithm and reduce the length of stay.

METHODS

We conducted a retrospective study of all intestinal rehabilitation clinic patients admitted for central line-associated bloodstream infections at our academic hospital between January 2018 and June 2021. Demographic, blood culture, and treatment response data were analyzed.

RESULTS

There were 180 separate admissions for central line-associated bloodstream infections, involving 24 patients who met the inclusion and exclusion criteria. The average length of stay was 9.4 days, and 77.1% of the admissions exceeded the predicted length of stay. All patients were treated according to the standard protocols. In the initial blood cultures, 64.4%, 10.6%, and 25% grew a single bacterium, a single fungus, and multiple organisms, respectively. After treatment initiation, 73.3% of single bacterial infections did not show additional positive cultures. However, 78.9% and 48.9% of fungal and multiple organism infections, respectively, had multiple positive cultures, even after initiating treatment. All positive repeat cultures were treated with an ethanol lock for 24 hours in addition to continued treatment. The treatment preserved 90.5% of the catheters.

CONCLUSION

Patients experiencing short bowel syndrome admitted for central line-associated bloodstream infections with initial cultures growing fungi or multiple organisms frequently had multiple positive cultures, whereas those with a single bacterial organism did not. Discharging patients who grew a single bacterial organism and placing an initial ethanol lock on those with multiple or fungal organisms could reduce the average length of stay, even if some of these patients would require readmission for line removal.

Bowel Lengthening Procedures in Children with Short Bowel Syndrome: A Systematic Review

INTRODUCTION

 The aims of the study are to systematically assess and critically appraise the evidence concerning two surgical techniques to lengthen the bowel in children with short bowel syndrome (SBS), namely, the longitudinal intestinal lengthening and tailoring (LILT) and serial transverse enteroplasty (STEP), and to identify patient characteristics associated with a favorable outcome.

MATERIALS AND METHODS

 MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from inception till December 2019. No language restriction was used.

RESULTS

 In all, 2,390 articles were found, of which 40 were included, discussing 782 patients. The median age of the patients at the primary bowel lengthening procedure was 16 months (range: 1-84 months). Meta-analysis could not be performed due to the incomparability of the groups, due to heterogeneous definitions and outcome reporting. After STEP, 46% of patients weaned off parenteral nutrition (PN) versus 52% after LILT. Mortality was 7% for STEP and 26% for LILT. Patient characteristics predictive for success (weaning or survival) were discussed in nine studies showing differing results. Quality of reporting was considered poor to fair.

CONCLUSION

 LILT and STEP are both valuable treatment strategies used in the management of pediatric SBS. However, currently it is not possible to advise surgeons on accurate patient selection and to predict the result of either intervention. Homogenous, prospective, outcome reporting is necessary, for which an international network is needed.

Immunosuppression Regimens for Intestinal Transplantation in Children

Pediatric intestinal transplant serves as the only definitive treatment for children with irreversible intestinal failure. Successful intestinal transplant hinges upon appropriate management of immunosuppression. The indications for intestinal transplant have changed over time. Immunosuppression regimens can be divided into induction and maintenance phases along with treatment of acute rejection. Intestinal transplant induction now often includes antithymocyte globulin or basiliximab in addition to corticosteroids. Maintenance regimens continue to be dominated by tacrolimus, with additional agents used to either decrease goal tacrolimus levels to limit toxicity or as an adjunct in sensitized patients. Careful monitoring can help to limit serious complications, such as rejection, infection, and malignancy. Future work will aim to decrease variation in practice and identify methods to determine optimal immunosuppression for a particular patient. Furthermore, there is a need for non-invasive monitoring of the intestinal graft and functional assessments of immunosuppression.

Patient-level costing analysis of paediatric short bowel syndrome care in a specialist tertiary centre

PURPOSE

To undertake a pilot study estimating patient-level costs of care for paediatric short bowel syndrome (SBS) from the healthcare provider perspective.

METHODS

A pilot group of patients with anatomical SBS was selected at a single specialist tertiary centre in the United Kingdom. The Patient Level Information and Costing System (PLICS) was used to extract costing data for all hospital-based activities related to SBS, from the implementation of PLICS in 2016 to April 2021. Patient-specific and pooled data were reported descriptively in per patient-year terms.

RESULTS

Five patients had full PLICS data available for the 5-year study period and 2 patients had 4 years of data. The median cost for hospital care of SBS was £52,834 per patient-year (range £1804-£331,489). The key cost drivers were inpatient beds, pharmacy, and staffing costs, which made up > 60% of annual costs. In the first 3 years following index admission (n = 2), there was a steady decline in the annual cost of care to a level comparable with patients with established SBS.

CONCLUSION

Patient-level cost of care analysis for SBS is feasible using PLICS. Hospital-related costs vary widely between and within individual patients over time. Key drivers of cost are related to complications of SBS.

Regenerative medicine for childhood gastrointestinal diseases

Several paediatric gastrointestinal diseases result in life-shortening organ failure. For many of these conditions, current therapeutic options are suboptimal and may not offer a cure. Regenerative medicine is an inter-disciplinary field involving biologists, engineers, and clinicians that aims to produce cell and tissue-based therapies to overcome organ failure. Exciting advances in stem cell biology, materials science, and bioengineering bring engineered gastrointestinal cell and tissue therapies to the verge of clinical trial. In this review, we summarise the requirements for bioengineered therapies, the possible sources of the various cellular and non-cellular components, and the progress towards clinical translation of oesophageal and intestinal tissue engineering to date.

Fecal microbiome alterations in pediatric patients with short bowel syndrome receiving a rotating cycle of gastrointestinal prophylactic antibiotics

BACKGROUND

Pediatric patients with short bowel syndrome (SBS) are at risk of developing small intestinal bacterial overgrowth (SIBO). Prevention of SIBO using cyclic enteric antibiotics has been implemented to control the balance in microbial ecosystems, although its effectiveness has not been well studied.

PURPOSE

This study aimed to explore the change in the gut microbial composition in SBS patients during cyclic antibiotic phases and antibiotic-free period, and to compare the microbiota composition between healthy controls and SBS patients.

METHOD

SBS patients taking oral metronidazole alternating with trimethoprim-sulfamethoxazole (TMP-SMT) and antibiotic-free conditions as a '10-day cyclic protocol' were involved in fecal microbiome study using Illumina 16S sequencing.

RESULTS

When healthy control possessed the majority of Bacteroidetes spp. (54%) and Firmicutes spp. (33%), the microbial composition in SBS patients especially Firmicutes spp. and Proteobacteria spp. was prominently changed in each phase of treatment. In antibiotic-free period, SBS patients displayed 49% Firmicutes and 36% Proteobacteria. However, higher Proteobacteria than Firmicutes were detected at the commencement of metronidazole (58% versus 33%). Similarly, 56% Proteobacteria and 27% Firmicutes were found during TMP-SMT. Escherichia coli increased prominently during the antibiotic periods.

CONCLUSION

Prophylactic antibiotics change the gut microbiota composition in an unfavorable direction, especially when repeatedly used for a long period. This practice should be reconsidered.

LEVEL OF EVIDENCE

III.

Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory disease affecting premature infants. Intestinal microbial composition may play a key role in determining which infants are predisposed to NEC and when infants are at highest risk of developing NEC. It is unclear how to optimize antibiotic therapy in preterm infants to prevent NEC and how to optimize antibiotic regimens to treat neonates with NEC. This article discusses risk factors for NEC, how dysbiosis in preterm infants plays a role in the pathogenesis of NEC, and how probiotic and antibiotic therapy may be used to prevent and/or treat NEC and its sequelae.

Clinical Outcomes of Pediatric Chronic Intestinal Pseudo-Obstruction

Chronic intestinal pseudo-obstruction (CIPO) is an extremely rare condition with symptoms of recurrent intestinal obstruction without any lesions. The outcomes of pediatric CIPO and predictors for the outcomes have not yet been well established. We analyzed the clinical outcomes and associated factors for the outcomes of pediatric CIPO. We retrospectively reviewed 66 primary CIPO patients diagnosed between January 1985 and December 2017. We evaluated parenteral nutrition (PN) factors such as PN duration, PN use over 6 months, home PN, and mortality as outcomes. We selected onset age, presence of urologic symptoms, pathologic type, and involvement extent as predictors. The early-onset CIPO was found in 63.6%, and 21.2% of the patients presenting with urologic symptoms. Of the 66 patients, 47 and 11 had neuropathy and myopathy, respectively. The generalized involvement type accounted for 83.3% of the cases. At the last follow-up, 24.2% of the patients required home PN management. The mean duration of PN was 11.8 ± 21.0 months. The overall mortality rate of primary CIPO was 18.2%. PN factors were predicted by the urologic symptoms and extent of involvement. However, mortality was predicted by pathologic type. The onset age was not significantly associated with the outcomes. CIPO with urologic symptoms and generalized CIPO had poor PN outcomes. Myopathy is suggested as a predictor of mortality in children with primary CIPO.

Enteral Feeding Interventions in the Prevention of Necrotizing Enterocolitis: A Systematic Review of Experimental and Clinical Studies

Necrotizing enterocolitis (NEC), which is characterized by severe intestinal inflammation and in advanced stages necrosis, is a gastrointestinal emergency in the neonate with high mortality and morbidity. Despite advancing medical care, effective prevention strategies remain sparse. Factors contributing to the complex pathogenesis of NEC include immaturity of the intestinal immune defense, barrier function, motility and local circulatory regulation and abnormal microbial colonization. Interestingly, enteral feeding is regarded as an important modifiable factor influencing NEC pathogenesis. Moreover, breast milk, which forms the currently most effective prevention strategy, contains many bioactive components that are known to support neonatal immune development and promote healthy gut colonization. This systematic review describes the effect of different enteral feeding interventions on the prevention of NEC incidence and severity and the effect on pathophysiological mechanisms of NEC, in both experimental NEC models and clinical NEC. Besides, pathophysiological mechanisms involved in human NEC development are briefly described to give context for the findings of altered pathophysiological mechanisms of NEC by enteral feeding interventions.

Compromised duodenal mucosal integrity in children with short bowel syndrome after adaptation to enteral autonomy

BACKGROUND

Intestinal adaptation has been extensively studied experimentally, but very limited data is available on human subjects. In this study we assessed intestinal adaption in humans with short bowel syndrome (SBS).

METHODS

We comparatively evaluated mucosal hyperplasia, inflammation, barrier function and nutrient transport using histology, immunohistochemistry and qPCR for selected 52 key genes in duodenal biopsies obtained from children with SBS after weaning off parenteral nutrition (n = 33), and matched controls without intestinal pathology (n = 12). Small bowel dilatation was assessed from contrast small bowel series.

RESULTS

Duodenal mucosa of SBS children showed increased histologic inflammation of lamina propria (p = 0.033) and mucosal mRNA expression of tumor necrosis factor (p = 0.027), transforming growth factor (TGF)-β2 (p = 0.006) and caveolin-1 (CAV1; p = 0.001). Villus height, crypt depth, enterocyte proliferation, apoptosis and expression of proliferation and nutrient transport genes remained unchanged. Pathologic small bowel dilatation reduced crypt depth (p = 0.045) and downregulated mRNA expression of interleukin (IL)-6 by three-fold (p = 0.008), while correlating negatively with IL6 (r = -0.609, p = 0.004). Loss of ileocecal valve (ICV) upregulated mRNA expression of toll-like receptor 4 (TLR4), TGF-β1, CAV1, several apoptosis regulating genes, and mRNA expression of zonulin (p < 0.05 for all).

CONCLUSIONS

Despite successful adaptation to enteral autonomy, duodenal mucosa of SBS children displayed histologic and molecular signs of abnormal inflammation and regulation of epithelial permeability, whereas no structural or molecular signs of adaptive hyperplasia or enhanced nutrient transport were observed. Excessive dilatation of the remaining small bowel paralleled impaired duodenal crypt homeostasis, while absence of ICV modified regulation of mucosal inflammation, regeneration and permeability.

LEVEL OF EVIDENCE

II.

In neonatal-onset surgical short bowel syndrome survival is high, and enteral autonomy is related to residual bowel length

BACKGROUND

In an era of improved management and treatment options, this study aims to describe the long-term outcomes and factors predictive of outcomes of neonatal-onset intestinal failure (IF) due to surgical short bowel syndrome (SBS).

METHODS

Retrospective, single-center cohort study of infants born between January 2011 and December 2018 with inclusion criteria: <44 weeks postmenstrual age at SBS diagnosis, <28 days on admission, parenteral nutrition dependence >60 days, and documented intestinal resection. Primary outcomes included survival and achievement of enteral autonomy (EA). Data analysis utilized Fisher.s exact test, Kruskal-Wallis test, survival analysis methods, Cox proportional hazards regression, linear regression and logistic regression.

RESULTS

Ninety-five patients (males 56%) were studied with median follow-up of 38 months (IQR 19, 59). Survival at last follow-up was 96%, and EA was achieved in 85%. Forty-eight patients had documented residual bowel length (RBL) with median length of 49 cm (IQR 36, 80). Survival in patients with RBL of <30cm (n = 8), 30-59cm (n = 19), and >60cm (n = 21) was 100%, 95%, and 95% respectively. Shorter RBL was associated with longer time to achieve EA (p = 0.007), but not with survival (p = 0.81). Delay in achieving EA was associated with absence of ileocecal valve (p = 0.002) and bloodstream infections (p < 0.001). Peak conjugated bilirubin correlated with increased mortality (p = 0.002).

CONCLUSION

Overall high rate of survival and achievement of EA was found in neonatal onset IF due to SBS. EA but not survival was correlated with RBL. Ileocecal valve, bloodstream infections, and conjugated bilirubin levels were the other predictive factors of outcomes.

Etiology and Management of Pediatric Intestinal Failure: Focus on the Non-Digestive Causes

Background: Intestinal failure (IF) is defined as reduction in functioning gut mass below the minimal amount necessary for adequate digestion and absorption. In most cases, IF results from intrinsic diseases of the gastrointestinal tract (digestive IF) (DIF); few cases arise from digestive vascular components, gut annexed (liver and pancreas) and extra-digestive organs or from systemic diseases (non-digestive IF) (NDIF). The present review revised etiology and treatments of DIF and NDIF, with special focus on the pathophysiological mechanisms, whereby NDIF develops. Methods: We performed a comprehensive search of published literature from January 2010 to the present by selecting the following search strings: “intestinal failure” OR “home parenteral nutrition” OR “short bowel syndrome” OR “chronic pseudo-obstruction” OR “chronic intestinal pseudo-obstruction” OR “autoimmune enteropathy” OR “long-term parenteral nutrition”. Results: We collected overall 1656 patients with well-documented etiology of IF: 1419 with DIF (86%) and 237 with NDIF (14%), 55% males and 45% females. Among DIF cases, 66% had SBS and among NDIF cases 90% had malabsorption/maldigestion. Conclusions: The improved availability of diagnostic and therapeutic tools has increased prevalence and life expectancy of rare and severe diseases responsible for IF. The present review greatly expands the spectrum of knowledge on the pathophysiological mechanisms through which the diseases not strictly affecting the intestine can cause IF. In view of the rarity of the majority of pediatric IF diseases, the development of IF Registries is strongly required; in fact, through information flow within the network, the Registries could improve IF knowledge and management.

European Pediatric Surgeon' Association Survey on the Management of Short-Bowel Syndrome

INTRODUCTION

 The aim of this study was to assess the management of short-bowel syndrome (SBS) at the time of primary surgery, and the strategies used to facilitate enteral autonomy depending on the institutional expertise.

MATERIALS AND METHODS

 An online questionnaire was sent in 2019 to members of The European Pediatric Surgeons' Association.

RESULTS

 Among the 65 responding members (26 countries, 85% from university hospitals), 57% manage less than three new patients with SBS per year (group A), and 43% at least three patients (group B). The cut-off of three patients treated yearly used in our study was defined after statistical analysis of different cut-offs. A multidisciplinary intestinal rehabilitation program is significantly more frequent in group B than in group A (85 and 53%, respectively; p = 0.009). Considering the primary surgical management of multiple intestinal atresia and congenital ultra-short bowel with jejunal atresia, primary surgical strategies to optimize bowel length are more often used in group B than group A (p = 0.09 and p = 0.04, respectively). A minimum of one intestinal lengthening procedure every 2 to 3 years is significantly more frequent in group B than group A (95 and 45%, respectively; p = 0.0013). Among the strategies used to promote intestinal adaptation, group B (35%) uses significantly more often glucagon-like peptide 2 analogs than group A (10%) (p = 0.02).

CONCLUSION

 Based on our survey, a minimum number of SBS patients treated yearly is required to manage this challenging disease according to up-to-date medical and surgical strategies. However, whatever their level of expertise is in managing SBS, most of pediatric surgeons are involved in the primary surgery. Medical education programs about SBS should be more largely available to pediatric surgeons.

An overview of the current management of short-bowel syndrome in pediatric patients

Short-bowel syndrome (SBS) is defined as a state of malabsorption after resection or loss of a major portion of the bowel due to congenital or acquired factors. This article presents an overview on the recent management of pediatric SBS. The pediatric SBS population is very heterogeneous. The incidence of SBS is estimated to be 24.5 per 100,000 live births. The nutritional, medical, and surgical therapies available require a comprehensive evaluation. Thus, multidisciplinary intestinal rehabilitation programs (IRPs) are necessary for the management of these complex patients. The key points of focus in IRP management are hepato-protective strategies to minimize intestinal failure-associated liver disease; the aggressive prevention of catheter-related bloodstream infections; strategic nutritional supply to optimize the absorption of enteral calories; and the management and prevention of small bowel bacterial overgrowth, nephrocalcinosis, and metabolic bone disease. As the survival rate of children with SBS currently exceeds 90%, the application of small bowel transplantation has been evolving. The introduction of innovative treatments, such as combined therapy of intestinotrophic hormones, including glucagon-like peptide-2, may lead to further improvements in patients' quality of life.

Nutritional and pharmacological strategy in children with short bowel syndrome

Short bowel syndrome in neonates is a severe and life-threatening disease after a major loss of small bowel with or without large bowel. Intestinal adaptation, by which the organism tries to restore digestive and absorptive capacities, is entirely dependent on stimulation of the active enterocytes by enteral nutrition. This review summarizes recent knowledge about the pathophysiologic consequences after the loss of different intestinal parts and outlines the options for enteral nutrition and pharmacological therapies to support the adaptation process.

Anti-TNF-α Therapy Exerts Intestinal Anti-inflammatory and Anti-apoptotic Effects After Massive Bowel Resection in a Rat

OBJECTIVES

The aim of this study was to examine the effect of massive small bowel resection on proinflammatory cytokine intestinal expression and the effect of anti-TNF-α antibodies (ATA) on intestinal inflammation, epithelial cell turnover, and intestinal adaptation after bowel resection in rats.

METHODS

Male Sprague-Dawley rats were divided into 4 experimental groups: Sham-rats underwent bowel transection; Sham-ATA rats underwent bowel transection and were treated with ATA; SBS-animals underwent 75% bowel resection; and SBS-ATA rats underwent bowel resection and were treated with ATA similarly to Group B. Parameters of intestinal adaptation, enterocyte proliferation, and apoptosis were determined at sacrifice. TNF-α and apoptosis-related gene and protein levels were determined by Illumina's Digital Gene Expression (DGE) analysis, Real Time PCR, Western blotting, and immunohistochemistry.

RESULTS

From 25 genes related to TNF-α signalling that were investigated, 8 genes in the jejunum and 10 genes in the ileum were found to be up-regulated in resected versus sham animals. SBS rats demonstrated a significant increase in tissue and plasma TNF-α, IL-6 levels, intestinal mucosal TNF-α related gene expression, and microscopic parameters of inflammation. Treatment of resected animals with ATA resulted in a significant decrease in TNF-α levels, intestinal mucosal TNF-α-related gene expression, decreased number of intraepithelial lymphocytes and macrophages, and lower apoptotic index compared with SBS animals.

CONCLUSIONS

In a rat model of SBS, ATA decreased plasma and tissue TNF-α levels, diminished mucosal inflammation, and inhibited cell apoptosis. Anti-apoptotic effects of ATA appear to be associated with an inhibited extrinsic apoptotic pathway.

Moving on: How to switch young people with chronic intestinal failure from pediatric to adult care. a position statement by italian society of gastroenterology and hepatology and nutrition (SIGENP) and italian society of artificial nutrition and metabolism (SINPE)

In 2019 the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) and the Italian Society of Artificial Nutrition and Metabolism (SINPE) created a joint panel of experts with the aim of preparing an official statement on transition in Chronic Intestinal Failure (CIF). The transition from pediatric to adult care has a key role in managing all chronic diseases and in optimizing the compliance to care. Thus SIGENP and SINPE, in light of the growing number of patients with IF who need long-term Parenteral Nutrition (PN) and multidisciplinary rehabilitation programs throughout adulthood, shared a common protocol to provide an accurate and timely process of transition from pediatric to adult centers for CIF. The main objectives of the transition process for CIF can be summarized as the so-called "acronym of the 5 M": 1)Motivate independent choices which are characteristics of the adult world; 2)Move towards adult goals (e.g. self-management of his pathology and sexual issues); 3)Maintain the habitual mode of care; 4) Minimize the difficulties involved in the transition process and 5)Modulate the length of the transition so as to fully share with the adult's team the children's peculiarities.

Multidisciplinary Management in Pediatric Ultrashort Bowel Syndrome

Pediatric intestinal failure (IF) remains a complex and devastating condition resulting in the inability of the gastrointestinal tract to absorb adequate fluids and nutrients to sustain life. The goal in the management of IF is to achieve enteral autonomy and when not possible to avoid and minimize the development of long-term complications. Survival rates for children with IF have continued to improve resulting in an increased population of children with more altered anatomy. While IF remains a rare disease, children with IF secondary to ultrashort bowel syndrome comprise an even smaller patient population. The goal of this article is to review the recent literature related to the impact of multidisciplinary intestinal rehabilitation programs (IRPs) on the management and outcomes of intestinal failure in children with ultrashort bowel syndrome and potential avenues to further improve the long-term outcomes of this patient population.

The Structure and Function of the Human Small Intestinal Microbiota: Current Understanding and Future Directions

Despite growing literature characterizing the fecal microbiome and its association with health and disease, few studies have analyzed the microbiome of the small intestine. Here, we examine what is known about the human small intestinal microbiota in terms of community structure and functional properties. We examine temporal dynamics of select bacterial populations in the small intestine, and the effects of dietary carbohydrates and fats on shaping these populations. We then evaluate dysbiosis in the small intestine in several human disease models, including small intestinal bacterial overgrowth, short-bowel syndrome, pouchitis, environmental enteric dysfunction, and irritable bowel syndrome. What is clear is that the bacterial biology, and mechanisms of bacteria-induced pathophysiology, are enormously broad and elegant in the small intestine. Studying the small intestinal microbiota is challenged by rapidly fluctuating environmental conditions in these intestinal segments, as well as the complexity of sample collection and bioinformatic analysis. Because the functionality of the digestive tract is determined primarily by the small intestine, efforts must be made to better characterize this unique and important microbial ecosystem.