Intestinal adaptation following resection

Posttranscriptional Regulation of Intestinal Mucosal Growth and Adaptation by Noncoding RNAs in Critical Surgical Disorders

The human intestinal epithelium has an impressive ability to respond to insults and its homeostasis is maintained by well-regulated mechanisms under various pathophysiological conditions. Nonetheless, acute injury and inhibited regeneration of the intestinal epithelium occur commonly in critically ill surgical patients, leading to the translocation of luminal toxic substances and bacteria to the bloodstream. Effective therapies for the preservation of intestinal epithelial integrity and for the prevention of mucosal hemorrhage and gut barrier dysfunction are limited, primarily because of a poor understanding of the mechanisms underlying mucosal disruption. Noncoding RNAs (ncRNAs), which include microRNAs (miRNAs), long ncRNAs (lncRNAs), circular RNAs (circRNAs), and small vault RNAs (vtRNAs), modulate a wide array of biological functions and have been identified as orchestrators of intestinal epithelial homeostasis. Here, we feature the roles of many important ncRNAs in controlling intestinal mucosal growth, barrier function, and repair after injury-particularly in the context of postoperative recovery from bowel surgery. We review recent literature surrounding the relationships between lncRNAs, microRNAs, and RNA-binding proteins and how their interactions impact cell survival, proliferation, migration, and cell-to-cell interactions in the intestinal epithelium. With advancing knowledge of ncRNA biology and growing recognition of the importance of ncRNAs in maintaining the intestinal epithelial integrity, ncRNAs provide novel therapeutic targets for treatments to preserve the gut epithelium in individuals suffering from critical surgical disorders.

Emerging drugs for the treatment of short bowel syndrome

INTRODUCTION

SBS is a rare and disabling condition. The standard management is based on diet optimization with parenteral supplementation. In addition, glucagon-like peptide-2 (GLP-2)analogs, have shown promising results as disease-modifying therapies for SBS.

AREAS COVERED

Short bowel syndrome (SBS) is defined as a reduction in functional intestinal length to less than 200 cm, leading to intestinal failure (IF) leading to malnutrition and parenteral support dependency. This review discusses the current management of SBS-CIFpatients, the place of GLP-2 analog treatment in terms of efficacy, safety and availability, and the new perspectives opened by the use of enterohormones.

EXPERT OPINION

Clinical trials and real-world experience demonstrated that Teduglutide   reduces dependence on parenteral support and has a place in the management of patients with SBS-CIF.  The use of Teduglutide should be discussed in patients stabilized after resection and its introduction requires the advice of an expert center capable of assessing the benefit-risk ratio. The complex, individualized management of SBS-C IF requires theexpertise of a specialized IF center which a multidisciplinary approach. The arrival of new treatments will call for new therapeutic strategies, and the question of how to introduce and monitor them will represent a new therapeutic challenge.

Nutritional Outcomes of Bowel Lengthening Procedure in Patients with Short Bowel Syndrome

BACKGROUND

Although parenteral nutrition (PN) significantly improves mortality rates in pediatric short bowel syndrome (SBS), long-term PN has many possible complications and impacts quality of life. Bowel lengthening procedures (BLPs) increase the contact surface of food and the intestinal mucosa and enable the better absorption of nutrients and liquids, possibly leading to a PN decrease.

METHODS

We retrospectively reviewed the data of patients with short bowel syndrome who underwent BLPs in the period from January 2016 to January 2022. Overall, eight patients, four male, five born prematurely, underwent BLPs.

RESULTS

There was a significant decrease in the percentage of total caloric intake provided via PN and PN volume after the BLPs. The more evident results were seen 6 months after the procedure and at the last follow-up, which was, on average, 31 months after the procedure. Two patients were weaned off PN after their BLPs. Patients remained well nourished during the follow-up.

CONCLUSIONS

The BLP led to a significant decrease in PN needs and an increase in the food intake; however, significant changes happened more than 6 months after the procedure.

Use of teduglutide in adults with short bowel syndrome-associated intestinal failure

Short bowel syndrome (SBS) is a rare gastrointestinal disorder associated with intestinal failure (SBS-IF) and poor health-related outcomes. Patients with SBS-IF are unable to absorb sufficient nutrients or fluids to maintain significantly metabolic homeostasis via oral or enteral intake alone and require long-term intravenous supplementation (IVS), consisting of partial or total parenteral nutrition, fluids, electrolytes, or a combination of these. The goal of medical and surgical treatment for patients with SBS-IF is to maximize intestinal remnant absorptive capacity so that the need for IVS support may eventually be reduced or eliminated. Daily subcutaneous administration of the glucagon-like peptide 2 analog, teduglutide, has been shown to be clinically effective in reducing IVS dependence and potentially improving the health-related quality of life of patients with SBS-IF. The management of patients with SBS-IF is complex and requires close monitoring. This narrative review discusses the use of teduglutide for patients with SBS-IF in clinical practice. The screening of patient eligibility for teduglutide treatment, initiation, monitoring of efficacy and safety of treatment, adapting or weaning off IVS, and the healthcare setting needed for SBS-IF management are described, taking into consideration data from clinical trials, observational studies, and clinical experience.

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.

Cutoffs and Characteristics of Abnormal Bowel Dilatation in Pediatric Short Bowel Syndrome

OBJECTIVES

Although excessive intestinal dilatation associates with worsened outcomes in pediatric short bowel syndrome (SBS), little is known about the natural history and definition of pathological dilatation. We addressed fore-, mid-, and hind-gut dilatation in children with SBS, who had not undergone autologous intestinal reconstructive (AIR) surgery, in relation to controls.

METHODS

SBS children without history of AIR surgery (n = 59) and age-matched controls without any disclosed intestinal pathology (n = 140) were included. Maximum diameter of duodenum, small bowel (SB), and colon were measured in each intestinal contrast series during 2002 to 2020 and expressed as diameter ratio (DR) to L5 vertebrae height. Predictive ability of DR for weaning off parenteral nutrition (PN) was analyzed with Cox proportional hazards regression models using multiple cutoffs.

RESULTS

Duodenum (DDR), SB (SBDR), and colon (CDR) DR were 53%, 183%, and 23% higher in SBS patients compared to controls ( P < 0.01 for all). The maximal DDR and SBDR measured during follow-up is associated with current PN dependence and young age. DDR correlated with SBDR ( r = 0.586, P < 0.01). Patients with maximal DDR less than 1.5, which was also the 99th percentile for controls, were 2.5-fold more likely to wean off PN ( P = 0.005), whereas SBDR and CDR were not predictive for PN duration.

CONCLUSIONS

All segments of remaining bowel, especially SB, dilate above normal levels in children with SBS. In SBS children without AIR surgery, PN dependence and young age is associated with duodenal and small intestinal dilatation, while duodenal dilatation also predicted prolonged PN.

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.

Effects of Teduglutide on Diarrhea in Pediatric Patients with Short Bowel Syndrome-Associated Intestinal Failure

OBJECTIVES

This post-hoc analysis evaluated the effect of teduglutide treatment on diarrhea in patients with short bowel syndrome-associated intestinal failure (SBS-IF).

METHODS

Data from 2 open-label, multicenter, phase 3 pediatric SBS-IF clinical trials of teduglutide (NCT01952080 and NCT02682381) were pooled where possible. The primary objective was to evaluate the change in stool consistency, frequency, and volume from baseline to weeks 12 and 24 of treatment in patients who received any teduglutide dose from both studies ("total teduglutide"). Safety assessments included gastrointestinal adverse event reporting.

RESULTS

Overall, 101 patients were analyzed. Among the total teduglutide group (n = 87), there were significant changes from baseline to weeks 12 and 24 in mean (standard error) Bristol Stool Form Scale (BSFS) score [-1.8 (0.26; P < 0.0001) and -2.2 (0.27; P < 0.0001), respectively], parenteral nutrition and/or intravenous fluid (PN/IV) volume [-16.9 (1.7; P < 0.0001) and -20.1 (2.3; P < 0.0001) mL/kg/day, respectively], and enteral nutrition volume [9.2 (1.7; P < 0.0001) and 9.6 (2.3; P = 0.0002) mL/kg/day, respectively]. Among patients in the standard of care group (n = 14) there were numerical changes in BSFS score, and enteral nutrition volume at weeks 12 and 24; significant changes in PN/IV volume [-6.9 (1.5) mL/kg/day; P = 0.0041] were observed at 24 weeks, but not at 12 weeks.

CONCLUSION

In this post-hoc analysis, short-term treatment with teduglutide was associated with improved stool consistency, as well as trends towards reductions in PN/IV requirements and advancements in enteral nutrition volume in children with SBS-IF. Further research assessing the impact of patient-level factors on stool characteristics when using teduglutide is warranted.

Absorption of an engineered medium-chain fatty acid analogue in two short bowel syndrome minipig models

BACKGROUND

Enteral drug therapy is challenging in short bowel syndrome with intestinal failure (SBS-IF) because of unpredictable absorption. SEFA-6179 is an enterally administered medium-chain fatty acid analogue under development for intestinal failure-associated liver disease. We investigate the pharmacokinetics of two SEFA-6179 formulations in two large-animal models of SBS-IF, including a new pseudojejunostomy model.

METHODS

Twenty Yucatan minipigs were obtained. Half underwent pre-resection pharmacokinetic study with single-dose SEFA-6179 administration. All minipigs then underwent 90% jejunoileal resection, with either a jejunoileal anastomosis or bypass of the intraperitoneal colon with anastomosis just proximal to the rectum (pseudojejunostomy). On postoperative day 3, a single-dose pharmacokinetic study was performed.

RESULTS

Both SBS-IF models were well tolerated. Compared with the jejunoileal anastomosis minipigs, pseudojejunostomy minipigs had a more severe malabsorptive phenotype with weight loss by postoperative day 4 (+0.1 vs -0.9 kg, P = 0.03) and liquid diarrhea (Bristol 5 vs Bristol 7, P = 0.0007). Compared with pre-resection minipigs, both jejunoileal and pseudojejunostomy minipigs had lower total plasma exposure of SEFA-6179 measured by area under the curve (jejunoileal: 37% less, P = 0.049; pseudojejunostomy: 74% less, P = 0.0001). Peak plasma concentration was also lower in the pseudojejunostomy group compared with pre-resection (65% less, P = 0.04), but not lower in the jejunoileal group (P = 0.47).

CONCLUSION

In two SBS-IF minipig models, SEFA-6179 had substantially decreased absorption compared with pre-resection minipigs. Dose optimization for different intestinal anatomy and function may be required. We describe a new SBS-IF pseudojejunostomy model that may improve the translation of preclinical research to patients with SBS-IF who have enterostomies.

New Mouse Models of Roux-en Y Gastric Bypass and One Anastomosis Gastric Bypass for Type 2 Diabetes

BACKGROUND

Current bariatric surgery models primarily utilize mice with obesity, overlooking those with type 2 diabetes (T2DM). These models have limitations in replicating clinical procedures accurately and achieving broad applicability. This study aimed to develop novel mouse models of Roux-en-Y gastric bypass (RYGB) and one anastomosis gastric bypass (OAGB) surgeries specifically designed for T2DM research, utilizing simplified surgical techniques closely resembling clinical procedures.

METHODS

Eight-week-old C57/Bl6 mice, except for the Blank-Control group, were induced with T2DM by combining a high-fat diet and streptozotocin injection. RYGB involved creating a 10% gastric pouch, a 4-cm biliopancreatic limb (BL), and a 4-cm Roux limb (RL). Similarly, OAGB maintained a 10% gastric pouch and a 4-cm BL. To assess the efficacy of these models, we measured the body weight and fasting blood glucose (FBG) and conducted intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test (ITT), and liver B-ultrasound, as well as a histopathological analysis of multiple organs 12 weeks post-operation.

RESULTS

The survival rates in the Blank-Control, T2DM-Sham, T2DM-RYGB, and T2DM-OAGB groups were 100% (6/6), 100% (6/6), 85.7% (6/7), and 100% (6/6), respectively. Both RYGB and OAGB surgeries similarly led to sustained weight loss, reduced the FBG levels, improved the IPGTT and ITT results, and alleviated the histopathological manifestations in multiple organs.

CONCLUSION

The innovative mouse models of RYGB and OAGB surgeries effectively improve T2DM. Both surgeries demonstrate comparable efficacy in ameliorating T2DM, even when utilizing a gastric pouch of the same size and the same length of BL in OAGB.

Predictive Potential of Biomarkers of Intestinal Barrier Function for Therapeutic Management with Teduglutide in Patients with Short Bowel Syndrome

INTRODUCTION

The human intestinal tract reacts to extensive resection with spontaneous intestinal adaptation. We analyzed whether gene expression analyses or intestinal permeability (IP) testing could provide biomarkers to describe regulation mechanisms in the intestinal barrier in short bowel syndrome (SBS) patients during adaptive response or treatment with the glucagon-like peptide-2 analog teduglutide.

METHODS

Relevant regions of the GLP-2 receptor gene were sequenced. Gene expression analyses and immunohistochemistry were performed from mucosal biopsies. IP was assessed using a carbohydrate oral ingestion test.

RESULTS

The study includes 59 SBS patients and 19 controls. Increases in gene expression with teduglutide were received for sucrase-isomaltase, sodium/glucose cotransporter 1, and calcium/calmodulin serine protein kinase. Mannitol recovery was decreased in SBS but elevated with teduglutide (Δ 40%), showed a positive correlation with remnant small bowel and an inverse correlation with parenteral support.

CONCLUSIONS

Biomarkers predicting clinical and functional features in human SBS are very limited. Altered specific gene expression was shown for genes involved in nutrient transport but not for genes controlling tight junctions. However, mannitol recovery proved useful in describing the absorptive capacity of the gut during adaptation and treatment with teduglutide.

Circulating Apolipoprotein B-48 as a Biomarker of Parenteral Nutrition Dependence in Adult Patients with Short Bowel Syndrome

Short bowel syndrome (SBS) is a rare but serious condition that may lead to chronic intestinal failure. Citrulline concentrations are currently used to reflect the residual intestinal mass in patients with SBS, although this method has several limitations. In a cohort of patients with SBS, we quantified apolipoprotein B-48 (ApoB-48), which is exclusively synthesized by enterocytes and secreted associated with dietary lipids and investigated the relationship between ApoB-48 and clinical and biological data as well as PN dependence. A total of 51 adult patients were included, 36 of whom were PN-dependent. We found a robust positive correlation between circulating ApoB-48 and residual small bowel length, which was also found in the subgroup of patients with jejunocolic anastomosis. Fasting ApoB-48 levels were significantly lower in PN-dependent patients than in PN-weaned patients and negatively correlated with parenteral nutrition dependence. Our results suggest that ApoB-48 could be proposed as a marker of intestinal absorptive function and could be an interesting follow-up marker in patients with SBS.

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

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

Altered fecal microbiome and metabolome profiles in rat models of short bowel syndrome

Introduction

Short bowel syndrome (SBS) is featured by impaired nutrients and fluids absorption due to massive small intestine resection. Gut dysbiosis has been implicated in SBS, this study aimed to characterize the metagenomic and metabolomic profiles of SBS and identify potential therapeutic targets.

Methods

Fecal samples from SBS and Sham rats (n = 8 per group) were collected for high-throughput metagenomic sequencing. Fecal metabolomics was measured by untargeted liquid chromatography-mass spectrometry.

Results

We found that the species-level α-diversity significantly decreased in SBS rats, accompanied by altered microbiome compositions. The beneficial anaerobes from Firmicutes and Bacteroidetes were depleted while microorganisms from Lactobacillus, Escherichia, Enterococcus, and Streptococcus were enriched in faces from SBS rats. LEfSe analysis identified 17 microbial species and 38 KEGG modules that were remarkably distinct between SBS and Sham rats. In total, 1,577 metabolites with known chemical identity were detected from all samples, among them, 276 metabolites were down-regulated and 224 metabolites were up-regulated in SBS group. The typical signatures of SBS fecal metabolome comprised reduced short-chain fatty acids and products of amino acid metabolism (indole derivatives and p-cresol), as well as altered bile acid spectrum. We revealed 215 robust associations between representative differentially abundant microbial species and metabolites, the species with the same changing trend tended to have a similar correlation with some certain metabolites.

Conclusion

The fecal microbiome and metabolome significantly altered in SBS. Our findings may lay the foundation for developing new strategies to facilitate intestinal adaptation in SBS patients.

Decreased Expression of KLF4 Leading to Functional Deficit in Pediatric Patients with Intestinal Failure and Potential Therapeutic Strategy Using Decanoic Acid

Pediatric intestinal failure (IF) is the reduction in gut function to 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. The overall goal in treating IF is to achieve intestinal adaptation; however, the underlying mechanisms have not been fully understood. In this study, by performing single-cell RNA sequencing in pediatric IF patients, we found that decreased Kruppel-Like Factor 4 (KLF4) may serve as the hub gene responsible for the functional deficit in mature enterocytes in IF patients, leading to the downregulation of solute carrier (SLC) family transporters (e.g., SLC7A9) and, consequently, nutrient malabsorption. We also found that inducible KLF4 was highly sensitive to the loss of certain enteral nutrients: in a rodent model of total parenteral nutrition mimicking the deprivation of enteral nutrition, the expression of KLF4 dramatically decreased only at the tip of the villus and not at the bottom of crypts. By using IF patient-derived intestinal organoids and Caco-2 cells as in vitro models, we demonstrated that the supplementation of decanoic acid (DA) could significantly induce the expression of KLF4 along with SLC6A4 and SLC7A9, suggesting that DA may function as a potential therapeutic strategy to promote cell maturation and functional improvement. In summary, this study provides new insights into the mechanism of intestinal adaptation depending on KLF4, and proposed potential strategies for nutritional management using DA.

Orally compensated short bowel patients are thin, potentially malnourished but rarely sarcopenic

BACKGROUND AND AIM

In short bowel syndrome, insufficient absorptive capacity of the remnant bowel may lead to metabolic and nutritional consequences including electrolyte disturbances, severe diarrhea and malnutrition. While intestinal failure requires parenteral nutrition, short bowel patients with intestinal insufficiency (SB/II) have achieved oral autonomy. The aim of this exploratory study was to assess the nutritional, muscular and functional status of orally compensated SB/II patients.

METHODS

28 orally compensated SB/II patients with a mean of 46 months after termination of parenteral nutrition and 56 age- and sex-matched healthy controls (HC) were compared regarding anthropometric parameters, body composition using bioelectrical impedance analysis, handgrip strength and gait speed, blood parameters as well as nutritional intake and physical activity using validated questionnaires. Malnutrition and sarcopenia were diagnosed according to the criteria of the GLIM or EWGSOP2.

RESULTS

SB/II patients had lower body mass index (BMI) and anthropometric parameters than HC but were within the normal weight range. The GLIM algorithm operationally diagnosed malnutrition in 39% (n = 11) of SB/II patients. Reduced skeletal muscle mass index and phase angle were rarely accompanied by a reduction of handgrip strength below cut-off values and the subsequent diagnosis of sarcopenia in SB/II patients (15%, n = 4). Compared to 11% of HC, 37% of SB/II patients had low physical activity level. Female SB/II patients had higher caloric and macronutrient intake. Caloric intake negatively correlated with body weight indicating compensatory hyperphagia in patients with lower body weight. Some of the SB/II patients showed signs of dehydration.

CONCLUSIONS

Orally compensated SB/II patients are thinner than HC but have mostly normal BMI. Malnutrition is frequently diagnosed but may be overestimated due to the underlying malabsorption and its interplay with hyperphagia. Muscle mass is often reduced but is rarely accompanied by functional impairment leading to sarcopenia diagnosis. Thus, SB/II patients long term after termination of parenteral support may be malnourished but usually do not develop sarcopenia.

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.

Short bowel syndrome: Complications and management

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

Definition, classification, and causes of short bowel syndrome

The term "short bowel syndrome (SBS)" defines "the clinical feature associated with a remaining small bowel in continuity of less than 200 cm from the ligament of Treitz" and is characterized by malabsorption, diarrhea, fatty stools, malnutrition, and dehydration. SBS is the primary pathophysiological mechanism of chronic intestinal failure (CIF), 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 (IVS) is required to maintain health and/or growth" in a metabolically stable patient. By contrast, the reduction of gut absorptive function that does not require IVS has been termed "intestinal insufficiency or deficiency" (II/ID). The classification of SBS can be categorized as follows: anatomical (anatomy and length of the residual bowel), evolutional (early, rehabilitative, and maintenance phases), pathophysiological (SBS with or without a colon in continuity), clinical (with II/ID or CIF), and severity of CIF (type and volume of the required IVS). Appropriate and homogeneous patient categorization is the mainstay of facilitating communication in clinical practice and in research.

Pediatric formulas: Categories, composition, and considerations

Formulas, liquid nutrition, may be consumed orally or via a feeding tube to provide partial or complete nutrition that a given individual could not obtain using natural food stuffs in their native form. A wide range of commercially available formulas exist, which may be used as sole-source nutrition or in conjunction with other foods. Physicians and dietitians must understand the nature of and indications for specific formulas to treat diseases, provide complete nutrition to patients, and avoid harm. Products vary in macronutrient and micronutrient content and calorie concentration among many other factors. They are formulated specifically for patients of specific ages, correlating to nutritional needs and medical diagnoses. Additionally, formula availability, insurance coverage, mode of consumption, physiologic tolerance, and caregiver preference influence formula selection. Caregivers may also make their own pediatric formulas. We review commercial and homemade pediatric formulas.

Inositol hexaphosphate promotes intestinal adaptation in short bowel syndrome via an HDAC3-mediated epigenetic pathway

Background

Short bowel syndrome (SBS) has high morbidity and mortality rates, and promoting intestinal adaptation of the residual intestine is a critical treatment. Dietary inositol hexaphosphate (IP6) plays an important role in maintaining intestinal homeostasis, but its effect on SBS remains unclear. This study aimed at investigating the effect of IP6 on SBS and clarified its underlying mechanism.

Methods

Forty male Sprague-Dawley rats (3-week-old) were randomly assigned into four groups (Sham, Sham + IP6, SBS, and SBS + IP6 groups). Rats were fed standard pelleted rat chow and underwent resection of 75% of the small intestine after 1 week of acclimation. They received 1 mL IP6 treatment (2 mg/g) or sterile water daily for 13 days by gavage. Intestinal length, levels of inositol 1,4,5-trisphosphate (IP3), histone deacetylase 3 (HDAC3) activity, and proliferation of intestinal epithelial cell-6 (IEC-6) were detected.

Results

IP6 treatment increased the length of the residual intestine in rats with SBS. Furthermore, IP6 treatment caused an increase in body weight, intestinal mucosal weight, and IEC proliferation, and a decrease in intestinal permeability. IP6 treatment led to higher levels of IP3 in feces and serum, and higher HDAC3 activity of the intestine. Interestingly, HDAC3 activity was positively correlated with the levels of IP3 in feces (r = 0.49, P = 0.01) and serum (r = 0.44, P = 0.03). Consistently, IP3 treatment promoted the proliferation of IEC-6 cells by increasing HDAC3 activity in vitro. IP3 regulated the Forkhead box O3 (FOXO3)/Cyclin D1 (CCND1) signaling pathway.

Conclusion

IP6 treatment promotes intestinal adaptation in rats with SBS. IP6 is metabolized to IP3 to increase HDAC3 activity to regulate the FOXO3/CCND1 signaling pathway and may represent a potential therapeutic approach for patients with SBS.

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.

The implication of gut microbiota in recovery from gastrointestinal surgery

Recovery from gastrointestinal (GI) surgery is often interrupted by the unpredictable occurrence of postoperative complications, including infections, anastomotic leak, GI dysmotility, malabsorption, cancer development, and cancer recurrence, in which the implication of gut microbiota is beginning to emerge. Gut microbiota can be imbalanced before surgery due to the underlying disease and its treatment. The immediate preparations for GI surgery, including fasting, mechanical bowel cleaning, and antibiotic intervention, disrupt gut microbiota. Surgical removal of GI segments also perturbs gut microbiota due to GI tract reconstruction and epithelial barrier destruction. In return, the altered gut microbiota contributes to the occurrence of postoperative complications. Therefore, understanding how to balance the gut microbiota during the perioperative period is important for surgeons. We aim to overview the current knowledge to investigate the role of gut microbiota in recovery from GI surgery, focusing on the crosstalk between gut microbiota and host in the pathogenesis of postoperative complications. A comprehensive understanding of the postoperative response of the GI tract to the altered gut microbiota provides valuable cues for surgeons to preserve the beneficial functions and suppress the adverse effects of gut microbiota, which will help to enhance recovery from GI surgery.

Self-Assembled Integrative Nutrient Carrier Platform Containing Green Tea Catechin for Short Bowel Syndrome Treatment

Extensive resection of the small intestine leads to the development of short bowel syndrome (SBS), which reduces the effective absorptive surface area of the intestine and predisposes patients to emaciation, malnutrition, and other severe symptoms. Herein, green tea catechin (-)-epigallocatechin gallate (EGCG) and ferrous ions (Fe²⁺ ) are utilized to construct a nutrient carrier platform that self-assembles with nutrients to form phenolic-based nutrient complexes (PNCs). PNCs effectively prolong the residence and absorption time of nutrients in the intestine. Further this platform is applied to integrate full nutrient formula, an enteral nutrition (EN) preparation containing a range of full nutrient components. In an SBS rat model, the prepared phenolic-based integrative nutrient complexes (PINCs) enhance nutritional status, improve anemia and immune function, as well as facilitate the growth of remaining intestinal villi and crypts, and maintain the integrity of the intestinal barrier. In addition, PINCs enable the modulation of gut microbial dysbiosis, enrich the abundance of beneficial bacteria, and have no toxic effects after the long-term ingestion. These results provide a proof of principle for the use of polyphenol-based nanocomplexes as EN preparation, offering a feasible strategy for both nutritional support and therapeutic perspectives for SBS treatment.

Dilemmas in feeding infants with intestinal failure: a neonatologist's perspective

Intestinal failure in neonatal and pediatric populations can be debilitating for patients and difficult to manage for clinicians. Management strategies include referral to an intestinal rehabilitation center, small volume trophic feeds to stimulate the intestine with cautious advancement of enteral nutrition using a standardized and evidence-based feeding protocol, and supplemental parenteral nutrition to optimize an infant's growth and nutrition. In this review, we discuss the causes of intestinal failure, parenteral nutrition strategies, enteral feeding initiation and advancement protocols, as well as the challenges in feeding an infant with intestinal failure.

Impaired FXR-CPT1a signaling contributes to parenteral nutrition-induced villus atrophy in short-bowel syndrome

Parenteral nutrition (PN)-induced villus atrophy is a major cause of intestinal failure (IF) for children suffering from short bowel syndrome (SBS), but the precise mechanism remains unclear. Herein, we report a pivotal role of farnesoid X receptor (FXR) signaling and fatty acid oxidation (FAO) in PN-induced villus atrophy. A total of 14 pediatric SBS patients receiving PN were enrolled in this study. Those patients with IF showed longer PN duration and significant intestinal villus atrophy, characterized by remarkably increased enterocyte apoptosis concomitant with impaired FXR signaling and decreased FAO genes including carnitine palmitoyltransferase 1a (CPT1a). Likewise, similar changes were found in an in vivo model of neonatal Bama piglets receiving 14-day PN, including villus atrophy and particularly disturbed FAO process responding to impaired FXR signaling. Finally, in order to consolidate the role of the FXR-CPT1a axis in modulating enterocyte apoptosis, patient-derived organoids (PDOs) were used as a mini-gut model in vitro. Consequently, pharmacological inhibition of FXR by tauro-β-muricholic acid (T-βMCA) evidently suppressed CPT1a expression leading to reduced mitochondrial FAO function and inducible apoptosis. In conclusion, impaired FXR/CPT1a axis and disturbed FAO may play a pivotal role in PN-induced villus atrophy, contributing to intestinal failure in SBS patients.

Nutritional Management of Intestinal Failure due to Short Bowel Syndrome in Children

BACKGROUND

The most common cause of intestinal failure (IF) in childhood remains short bowel syndrome (SBS), where bowel mass is significantly reduced due to a congenital atresia or resection and parenteral nutrition (PN) needed. Home PN has improved outcome and quality of life, but the long-term therapeutic goal is to achieve enteral autonomy whilst avoiding long term complications. This paper is aimed at discussing nutritional strategies available to clinicians caring for these patients.

METHODS

A literature search was performed from 1992 to 2022 using Pubmed, MEDLINE and Cochrane Database of Systematic Reviews, and recent guidelines were reviewed. In the absence of evidence, recommendations reflect the authors' expert opinion.

RESULTS

Consensus on the best possible way of feeding children with IF-SBS is lacking and practice varies widely between centres. Feeding should commence as soon as possible following surgery. Oral feeding is the preferred route and breast milk (BM) the first milk of choice in infants. Donor BM, standard preterm or term formula are alternatives in the absence of maternal BM. Extensively hydrolysed or amino acid-based feeds are used when these are not tolerated. Solids should be introduced as soon as clinically appropriate. Children are encouraged to eat by mouth and experience different tastes and textures to avoid oral aversion. Aggressive weaning of PN and tube (over-) feeding are now discouraged.

CONCLUSIONS

To date, uniform agreement on the optimal type of feed, timing of food introduction and feeding regime used is lacking and great difference in practice remains. There is need for more research to establish common treatment protocols.

Trans-anethole exerts protective effects on lipopolysaccharide-induced acute jejunal inflammation of broilers via repressing NF-κB signaling pathway

This study aimed to explore the effects of trans-anethole (TA) on lipopolysaccharide (LPS)-induced acute jejunal inflammation model of broilers. A total of 160 one-day-old broilers (male; Arbor Acres) were randomly allocated into four treatment groups with 8 replicates of 5 birds each. On d 20, the dose of 5 mg/kg body weight LPS solution and the equal amount of sterile saline were intraperitoneally injected into LPS-challenged and unchallenged broilers, respectively. Compared with the control group, LPS decreased (P < 0.05) the villus height (VH) and the ratio of villus height to crypt depth (VCR) but increased (P < 0.05) the crypt depth (CD), meanwhile, enhanced (P < 0.01) the levels of interleukin-6 (IL-6), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) but decreased (P < 0.01) the level of interleukin-10 (IL-10). The group supplemented with 600 mg/kg of TA had lower (P < 0.01) CD and higher (P < 0.01) VCR than the LPS group. TA increased (P < 0.01) the level of IL-10 and decreased (P < 0.01) the level of IL-1β. The mRNA expression levels of IL-6, nuclear factor kappa B (NF-κB), TNF-α were up-regulated (P < 0.05) and the levels of IL-10 and inhibitor of NF-κB alpha (IκBα) were down-regulated (P < 0.05) by LPS as compared with the control group. TA down-regulated (P < 0.05) the increased mRNA expression levels of genes caused by LPS, as well as up-regulated (P < 0.05) the levels of IL-10 and IκBα. Furthermore, LPS down-regulated (P < 0.05) and up-regulated (P < 0.05) the protein expression levels of IκBα and NF-κB p65, respectively. TA up-regulated (P < 0.05) the level of IκBα and down-regulated (P < 0.05) the level of NF-κB p65. The conclusion of this study is that TA could exert protective effect on the LPS-induced acute jejunal inflammation of broilers via repressing the activation of NF-κB and the 600 mg/kg is the optimal dose against LPS-induced acute jejunal inflammation of broilers.

Regional experience in the treatment of children with short bowel syndrome

Short bowel syndrome is a rare, chronic, debilitating, and potentially life-threatening condition in which loss of intestinal absorption capacity deprives children of the ability to absorb sufficient nutrients from the food they consumed. The authors describe regional experience of treating children with short bowel syndrome, which includes conservative and surgical approach, with an analysis of the leading causes, prognostic factors, timing of achieving intestinal autonomy, complications and catamnesis.

Purpose. The study aims at analyzing cases of short bowel syndrome in children in order to improve the provision of medical care for children in the Republic of Tatarstan and the nearest regions.

Material and methods. Single-center, retrospective study was conducted of 22 cases of children with short bowel syndrome who received treatment in the surgical department for young children in the State Autonomous Healthcare Institution Children’s Republican Clinical Hospital of the Ministry of Health of the Republic of Tatarstan for the period September 2014 till November 2021.

Results. The most common cause of intestinal resection in the study group were: congenital malformations in 7 children (32%), necrotizing enterocolitis in 5 children (23%), small intestine malrotation (Ladd’s bands) in 4 children (18%), mesenteric thrombosis in 4 (18%), Hirschsprung’s disease in 2 children (9%). By the end of the first year after diagnosis, intestine self-regulation was achieved in 17 children. The mortality rate was 9%. 

Bermúdez M, Campoy C. Impact of Total Parenteral Nutrition on Gut Microbiota in Pediatric Population Suffering Intestinal Disorders

Parenteral nutrition (PN) is a life-saving therapy providing nutritional support in patients with digestive tract complications, particularly in preterm neonates due to their gut immaturity during the first postnatal weeks. Despite this, PN can also result in several gastrointestinal complications that are the cause or consequence of gut mucosal atrophy and gut microbiota dysbiosis, which may further aggravate gastrointestinal disorders. Consequently, the use of PN presents many unique challenges, notably in terms of the potential role of the gut microbiota on the functional and clinical outcomes associated with the long-term use of PN. In this review, we synthesize the current evidence on the effects of PN on gut microbiome in infants and children suffering from diverse gastrointestinal diseases, including necrotizing enterocolitis (NEC), short bowel syndrome (SBS) and subsequent intestinal failure, liver disease and inflammatory bowel disease (IBD). Moreover, we discuss the potential use of pre-, pro- and/or synbiotics as promising therapeutic strategies to reduce the risk of severe gastrointestinal disorders and mortality. The findings discussed here highlight the need for more well-designed studies, and harmonize the methods and its interpretation, which are critical to better understand the role of the gut microbiota in PN-related diseases and the development of efficient and personalized approaches based on pro- and/or prebiotics.

Intestinal plasticity and metabolism as regulators of organismal energy homeostasis

The small intestine displays marked anatomical and functional plasticity that includes adaptive alterations in adult gut morphology, enteroendocrine cell profile and their hormone secretion, as well as nutrient utilization and storage. In this Perspective, we examine how shifts in dietary and environmental conditions bring about changes in gut size, and describe how the intestine adapts to changes in internal state, bowel resection and gastric bypass surgery. We highlight the critical importance of these intestinal remodelling processes in maintaining energy balance of the organism, and in protecting the metabolism of other organs. The intestinal resizing is supported by changes in the microbiota composition, and by activation of carbohydrate and fatty acid metabolism, which govern the intestinal stem cell proliferation, intestinal cell fate, as well as survivability of differentiated epithelial cells. The discovery that intestinal remodelling is part of the normal physiological adaptation to various triggers, and the potential for harnessing the reversible gut plasticity, in our view, holds extraordinary promise for developing therapeutic approaches against metabolic and inflammatory diseases.

Altered Bioavailability and Pharmacokinetics in Crohn's Disease: Capturing Systems Parameters for PBPK to Assist with Predicting the Fate of Orally Administered Drugs

Backgrond and Objective

Crohn’s disease (CD) is a chronic inflammatory bowel disease that affects a wide age range. Hence, CD patients receive a variety of drugs over their life beyond those used for CD itself. The changes to the integrity of the intestine and its drug metabolising enzymes and transporters (DMETs) can alter the oral bioavailability of drugs. However, there are other changes in systems parameters determining the fate of drugs in CD, and understanding these is essential for dose adjustment in patients with CD.

Methods

The current analysis gathered all the available clinical data on the kinetics of drugs in CD (by March 2021), focusing on orally administered small molecule drugs. A meta-analysis of the systems parameters affecting oral drug pharmacokinetics was conducted. The systems information gathered on intestine, liver and blood proteins and other physiological parameters was incorporated into a physiologically based pharmacokinetic (PBPK) platform to create a virtual population of CD patients, with a view for guiding dose adjustment in the absence of clinical data in CD.

Results

There were no uniform trends in the reported changes in reported oral bioavailability. The nature of the drug as well as the formulation affected the direction and magnitude of variation in kinetics in CD patients relative to healthy volunteers. Even for the same drug, the reported changes in exposure varied, possibly due to a lack of distinction between the activity states of CD. The highest alteration was seen with S-verapamil and midazolam, 8.7- and 5.3-fold greater exposure, respectively, in active CD patients relative to healthy volunteers. Only one report was available on liver DMETs in CD, and indicated reduced CYP3A4 activity. In a number of reports, mRNA expression of DMETs in the ileum and colon of CD patients was measured, focussing on P-glycoprotein (p-gp) transporter and CYP3A4 enzyme, and showed contradictory results. No data were available on protein expression in duodenum and jejunum despite their dominant role in oral drug absorption.

Conclusion

There are currently inadequate dedicated clinical or quantitative proteomic studies in CD to enable predictive PBPK models with high confidence and adequate verification. The PBPK models for CD with the available systems parameters were able to capture the major physiological influencers and the gaps to be filled by future research. Quantification of DMETs in the intestine and the liver in CD is warranted, alongside well-defined clinical drug disposition studies with a number of index drugs as biomarkers of changes in DMETs in these patients, to avoid large-scale dedicated studies for every drug to determine the effects of disease on the drug’s metabolism and disposition and the consequential safety and therapeutic concerns.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-022-01169-4.

The Variable Response to Teduglutide in Pediatric Short Bowel Syndrome: A Single Country Real-Life Experience

OBJECTIVES

The glucagon-like peptide-2 analog Teduglutide has been shown to enhance intestinal absorption and decrease parenteral nutrition (PN) requirements in short bowel syndrome (SBS). As data in children is limited, we evaluated nationwide real-life experience and treatment outcome in children with SBS.

METHODS

Longitudinal data of children treated with Teduglutide for ≥3 months was collected. Data included demographic and medical background, anthropometrics, laboratory assessments and PN requirements. Treatment response was defined as >20% reduction in PN requirement.

RESULTS

The study included 13 patients [54% males, median (interquartile range {IQR}) age of 6 (4.7-7) years]. The most common SBS etiology was necrotizing enterocolitis (38%), and median (IQR) small bowel length was 20 (15-40) cm. Teduglutide treatment ranged between 3 and 51 months [median (IQR) of 18 (12-30) months], with 10 patients (77%) treated >1 year. Response to treatment was observed in 8 patients (62%), with a mean [±standard deviation (SD)] treatment duration of 5.9 (±3.2) months. Among responders, 2 patients were weaned off PN and additional 4 decreased PN needs by >40%. There was a median (IQR) reduction in PN volume/kg of 36% (15%-55%) and in PN energy/kg of 27% (6%-58%). Response was not associated with patients' background, and no correlation was found with bowel length or PN dependency at baseline.

CONCLUSIONS

Real-life response to Teduglutide is highly variable among children with SBS. While most patients did reach 20% reduction in PN, less achieved further significant reduction or enteral autonomy. No predictive factors of response to treatment were identified, and large multicenter studies are needed to elucidate predictive factors and long-term outcome.

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.

Lipid absorption and overall intestinal lymphatic transport are impaired following partial small bowel resection in mice

Short bowel syndrome (SBS) is associated with diminished levels of serum fats caused by unknown mechanisms. We have shown that mesenteric lymphatics remodel to a more primitive state one week after small bowel resection (SBR); therefore, this study focuses on the effect of chronic lymphatic remodeling and magnitude of resection on intestinal lipid uptake and transport. C57BL6 and Prox1 creER-Rosa26LSLTdTomato (lymphatic reporter) mice underwent 50% or 75% proximal SBR or sham operations. Functional transport of lipids and fecal fat content was measured and lymphatic vasculature was compared via imaging. There was a significant reduction in functional transport of cholesterol and triglyceride after SBR with increasing loss of bowel, mirrored by a progressive increase in fecal fat content. We also describe significant morphological changes in the lymphatic vasculature in both the lamina propria and mesentery. Intestinal lymphatic drainage assay in vivo demonstrated a marked reduction of systemic absorption after resection. Intestinal lymphatic vessels significantly remodel in the setting of chronic SBS. This remodeling may account at least in part for impaired intestinal uptake and transport of fat via the compromised lymphatic architecture. We believe that these changes may contribute to the development of intestinal failure associated liver disease (IFALD), a major morbidity in patients with SBS.

Impact of Pancreatic Enzymes on Enteral Fat and Nitrogen Absorption in Short Bowel Syndrome

OBJECTIVES

Patients with short bowel syndrome (SBS) can have a high morbidity rate. To minimize morbidity, enteral autonomy is the primary goal in clinical management of patients with SBS. This is often difficult to achieve because of significant malabsorption. To date, there are limited therapies that improve absorption in patients with SBS. The impact of pancreatic enzyme replacement treatment on enteral absorption has not been studied in this population and was the primary aim of this study.

SUBJECTS/METHODS

This was an interventional study in 11 subjects (6 pediatric subjects ages 4.0-17.9 years, 5 adult subjects 18-75 years) that compared enteral absorption in each subject before and after pancreatic enzyme medication (Creon). Coefficient of fat absorption (CFA) and coefficient of nitrogen absorption (CNA) were used as markers of enteral absorption of fat and protein, respectively.

RESULTS

There was no statistically significant mean change in CFA and CNA before and after pancreatic enzyme medication therapy. Six subjects demonstrated an increase in CFA and 8 subjects demonstrated an increase in CNA after the use of pancreatic enzyme medication therapy.

CONCLUSIONS

There was no statistically significant improvement in enteral fat and protein absorption in the cohort as a whole, though several subjects demonstrated an improvement. These results suggest that some patients with SBS may benefit from treatment with pancreatic enzymes. Further studies are needed to better evaluate the effect of pancreatic enzyme therapy on enteral absorption in subjects with SBS and to characterize factors that may predict a positive response.

Building gut from scratch - progress and update of intestinal tissue engineering

Short bowel syndrome (SBS), a condition defined by insufficient absorptive intestinal epithelium, is a rare disease, with an estimated prevalence up to 0.4 in 10,000 people. However, it has substantial morbidity and mortality for affected patients. The mainstay of treatment in SBS is supportive, in the form of intravenous parenteral nutrition, with the aim of achieving intestinal autonomy. The lack of a definitive curative therapy has led to attempts to harness innate developmental and regenerative mechanisms to engineer neo-intestine as an alternative approach to addressing this unmet clinical need. Exciting advances have been made in the field of intestinal tissue engineering (ITE) over the past decade, making a review in this field timely. In this Review, we discuss the latest advances in the components required to engineer intestinal grafts and summarize the progress of ITE. We also explore some key factors to consider and challenges to overcome when transitioning tissue-engineered intestine towards clinical translation, and provide the future outlook of ITE in therapeutic applications and beyond.

Analysis of Transition from Intravenous Iron Sucrose to Ferric Carboxymaltose Infusions in Pediatric Intestinal Failure Patients

BACKGROUND

Iron supplementation is required for pediatric patients with intestinal failure (IF). There is a paucity of literature on optimal iron formulation and outcomes in this patient population that requires ongoing supplementation. The aim of this study was to assess outcomes in pediatric patients with IF receiving iron sucrose (IS) versus ferric carboxymaltose (FCM) iron infusions.

METHODS

This was a single-center observational cohort study of pediatric patients with IF requiring ongoing intravenous iron supplementation. Patients were transitioned from IS to FCM as iron therapy. Longitudinal linear mixed-effects models and generalized estimating equations were used to compare outcomes including hematologic, iron, and growth parameters for 12 months treatment duration on each iron formulation. Adverse effects were descriptively summarized.

RESULTS

Twenty-three patients were included. Sixteen received IS and later switched to FCM, 5 received IS only, and 2 received FCM only. Most patients' etiology of IF was short bowel syndrome (FCM: 81%, IS: 83%). No differences were seen over time for iron, hematologic, and growth metrics between IS and FCM. The median number of infusions over 12 months for those taking IS was 15 (IQR = 13 - 26) and 2 for FCM (IQR = 1 - 2). Asymptomatic hypophosphatemia was noted in both groups. Similar central line associated blood steam infection rates were noted.

CONCLUSIONS

IS and FCM infusions both maintained hematologic and iron parameters with no significant difference noted between the two types of iron though the number of FCM infusions was significantly less. No significant adverse effects were noted.

CLINICAL RELEVANCY STATEMENT

Pediatric patients with intestinal failure dependent on parenteral nutrition require ongoing iron supplementation. Though there are a variety of iron formulations available, there is a paucity of literature on how iron should be administered in this patient population. Practice varies widely among different institutions. In this study, pediatric patients with intestinal failure were transitioned from iron sucrose to ferric carboxymaltose infusions, and laboratory and clinical outcomes were compared. We found that patients had comparable hematologic and iron parameters with significantly fewer infusions needed in the ferric carboxymaltose group. No significant adverse effects were noted in either group. This article is protected by copyright. All rights reserved.

Disease-modifying therapies in short bowel syndrome

Short bowel syndrome (SBS) is the main 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'. SBS is a rare disease requiring a multidisciplinary approach in specialized IF units. The aim of this review was to discuss the current pharmacological management of SBS-associated IF, since emerging treatments are currently modifying the natural evolution of these patients. Enterohormone therapy has become the first-choice treatment and may decrease the need for parenteral support and improve patients' quality of life.

Intestinal Continuity Alleviates Pediatric Intestinal Failure-Associated Liver Disease

Background

Type I short bowel syndrome (SBS) occurs after a critical reduction in the functional gut mass and resection of intestinal continuity after ileostomy or jejunostomy for necrotizing enterocolitis (NEC), intestinal atresia or other causes. SBS is often accompanied with intestinal failure-associated liver disease (IFALD) who requires long-term parenteral nutrition (PN). Our study aimed to observe the effect of intestinal continuity on the hepatic function of pediatric intestinal failure (IF) patients with type I SBS.

Methods

The pre-and post-anastomosis medical records of 35 pediatric patients with type I SBS from April 2013 to April 2019 were reviewed retrospectively. The average growth (cm/month) in the proximal and distal small bowel lengths was calculated as the growth in intestinal length (cm)/the duration (month) from enterostomy to anastomosis. The changes in hepatic function from enterostomy to anastomosis were evaluated by assessment of hepatic function before anastomosis for 6 weeks and after anastomosis for 4 weeks.

Results

The average growth in proximal intestinal length was 9.3 cm/month (±7.2) in neonates and 2.8 cm/month (1.3, 11.9) in infants and children, and in distal intestinal length was 1.5 cm/month (0, 2.7) in neonates and 0.4 cm/month (0, 1.4) in infants and children. The incidence of IFALD was 28.6% 1 month before anastomosis and 20.0% 1 month after anastomosis (p < 0.05).

Conclusion

In pediatric type I SBS with IFALD, restoration of intestinal continuity may alleviate liver injury. There was an intestinal compensatory effect on the growth in the intestinal length after resection, and better results were seen in neonates in terms of intestinal length growth.

First Registry of Adult Patients with Chronic Intestinal Failure due to Short Bowel Syndrome in Argentina, the RESTORE Project

BACKGROUND

Short-bowel syndrome (SBS) is considered a low prevalence disease. In Argentina, no registries are available on chronic intestinal failure (CIF) and SBS. This project was designed as the first national registry to report adult patients with this disease.

METHODS

A prospective multicenter observational registry was created including adult patients with CIF/SBS from 8/12 approved centers. Demographics, clinical characteristics, nutritional assessment, home-parenteral-nutrition (HPN) management plus complications, surgeries performed, medical treatment, overall survival, and freedom from HPN survival were analyzed.

RESULTS

Of the 61 enrolled patients, 56 with available follow up data were analyzed. At enrollment, the mean intestinal length was 59.5±47.3cms; the anatomy was: type 1 (n=41), type 2 (n=10), and type 3 (n=5). At the end of the interim analysis, anatomy changed to type 1 in 31, type 2 in 17, and type 3 in 8 patients. The overall mean time on HPN before enrollment was 33.5±56.2 months. Autologous gastrointestinal-reconstruction surgery was performed before enrollment on 21 patients, and afterward on 11. Nine patients (16.1%) were weaned-off HPN with standard medical-nutritional treatment; 12 patients received enterohormones, and 2 of them suspended HPN; 1 was considered a transplant candidate. In 23.7±14.5 months, 11 out of 56 patients discontinued HPN; Kaplan-Meier freedom from HPN survival was 28.9%. The number of cases collected represented 19.6 new adult CIF/SBS patients/year.

CONCLUSIONS

The RESTORE project allowed us to know the incidence, the current medical and surgical management of this pathology, as well as its outcome and complications related with the therapeutic approach currently available.

CLINICAL RELEVANCY STATEMENT

RESTORE is the first ongoing prospective, observational, epidemiological, multicenter registry of adult patients with chronic intestinal failure (CIF) due to short bowel syndrome (SBS) in Argentina. The interim analysis enabled an estimate of the incidence of adult CIF/SBS of 19.6 new adult CIF/SBS patients/year in our country and would serve for a better understanding of the current care provided, the manner to continue improving that condition, the current treatment outcomes, and a more accurate definition of the national needs. This article is protected by copyright. All rights reserved.

Autologous Intestinal Reconstruction Surgery in Short Bowel Syndrome: Which, When, and Why

Short bowel syndrome (SBS), secondary to any natural loss or after any extensive bowel resection for congenital malformations or acquired disease, is the most common cause of intestinal failure in children. Extensive introduction of parenteral nutrition (PN) has dramatically changed the outcome of these patients, allowing for long-term survival. The main goal in children with SBS remains to be increasing enteral tolerance and weaning from PN support. Post resection intestinal adaptation allows for achievement of enteral autonomy in a subset of these patients, but the inability to progress in enteral tolerance exposes others to long-term complications of PN. Autologous intestinal reconstruction surgery (AIRS) can facilitate the fulfilment of enteral autonomy, maximizing the absorptive potential of the remaining gut. All the different intestinal reconstruction techniques, from simple procedures like tapering, reversed segments, and colon interposition, to more complex lengthening procedures (LILT: longitudinal intestinal lengthening and tailoring, STEP: serial transverse enteroplasty, and SILT: spiral intestinal lengthening and tailoring) and techniques designed for peculiar problems like controlled intestinal tissue expansion or duodenal lengthening are presented. AIRS indications, clinical applications, and results reported in the literature are reviewed.

Jejunoileal mucosal growth in mice with a limited microbiome

Previous work demonstrated enhanced enterocyte proliferation and mucosal growth in gnotobiotic mice, suggesting that intestinal flora participate in mucosal homeostasis. Furthermore, broad-spectrum enteral antibiotics are known to induce near germ-free (GF) conditions in mice with conventional flora (CONV). We hypothesized that inducing near GF conditions with broad-spectrum enteral antibiotics would cause ordered small intestinal mucosal growth in CONV mice but would have no effect in GF mice with no inherent microbiome. C57BL/6J CONV and GF mice received either an antibiotic solution (Ampicillin, Ciprofloxacin, Metronidazole, Vancomycin, Meropenem) or a vehicle alone. After treatment, small intestinal villus height (VH), crypt depth (CD), mucosal surface area (MSA), crypt proliferation index (CPI), apoptosis, and villus and crypt cell types were assessed. Antibiotic-treated CONV (Abx-CONV) mice had taller villi, deeper crypts, increased CPI, increased apoptosis, and greater MSA compared to vehicle-treated CONV mice. Minor differences were noted in enterocyte and enterochromaffin cell proportions between groups, but goblet and Paneth cell proportions were unchanged in Abx-CONV mice compared to vehicle-treated CONV mice (p>0.05). Antibiotics caused no significant changes in VH or MSA in GF mice when compared to vehicle-treated GF mice (p>0.05). Enteral administration of broad-spectrum antibiotics to mice with a conventional microbiome stimulates ordered small intestinal mucosal growth. Mucosal growth was not seen in germ-free mice treated with antibiotics, implying that intestinal mucosal growth is associated with change in the microbiome in this model.

Etiologies and treatments of chronic intestinal failure-short bowel syndrome (SBS) in Japanese adults: a real-world observational study

Purpose

Short bowel syndrome (SBS) with intestinal failure (SBS-IF) requires long-term parenteral nutrition (PN). This study investigated the real-world etiologies of SBS, treatment patterns, and PN-related outcomes among adult patients with SBS-IF in Japan.

Methods

This retrospective, observational cohort study was based on data from April, 2008 to January, 2020 from one of the largest hospital-based claim databases in Japan. Analyzed patients were aged ≥ 16 years, had received continuous PN for ≥ 6 months, and had SBS or undergone SBS-related surgery with a diagnosis of a causative disease. The primary endpoint was PN weaning.

Results

We analyzed data for 393 patients. The most frequent causes of SBS-IF were ileus (31.8%), Crohn’s disease (20.1%), and mesenteric ischemia (16.0%). Of 144/393 (36.6%) patients who were weaned off their PN, 48 (33.3%) were subsequently restarted on PN. Of 276/393 (70.2%) patients whose PN was initiated in hospital, 156 (56.5%) transitioned to home management. The mean duration of initial PN was 450.4 and 675.5 days for patients who were able or unable to be weaned off PN, respectively. Sepsis (67.4%), catheter-related bloodstream infections (49.1%), and liver disorders (45.0%) were the most reported PN-related complications.

Conclusions

Most patients with SBS-IF in Japan could not be weaned off PN and suffered life-threatening complications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00595-022-02469-9.

Evidence of glucose absorption in a neoformed intestine

Recent advances in the field of tissue regeneration are offering promising therapeutic options for the treatment of short bowel syndrome. This study aimed to evaluate the glucose absorptive capacity of a neoformed intestine obtained from a biological scaffold in a rodent model and the steadiness of the engrafted segment area. Twenty-four male Sprague–Dawley rats were used for this study. Under anesthesia, a patch of biological material (2.2 × 1.5 cm) was engrafted in the anti-mesenteric border of the small bowels of 12 rats. Twelve rats were sham-operated. Animals were studied at 4, 8, and 10 months postengraftment. Functional and histological analyses were performed. The functional analysis was performed using an 18F-FDG analog as a probe and the results were acquired with an optical imager. The intensity of the fluorescent signal emitted by the neointestine was comparable with that emitted by the native intestine in all animals and was visible after injection in the preserved mesentery. The mean intestinal volume at time of engraftment and after 10 months was 4.08 cm³ (95% CI [3.58–4.58]) and 3.26 cm³ (CI 95% [3.23–3.29]), respectively, with a mean shrinkage of 17.3% (range 10.6–23.8%), without any evidence of stenosis. Morphological analysis revealed the progression of the biological material toward a neoformed intestine similar to the native intestine, especially at 8 and 10 months. In a rodent model, we demonstrated that a neointestine, obtained from a biological scaffold showed glucose absorption and a durable increase in diameter.

Dietary excess regulates absorption and surface of gut epithelium through intestinal PPARα

Intestinal surface changes in size and function, but what propels these alterations and what are their metabolic consequences is unknown. Here we report that the food amount is a positive determinant of the gut surface area contributing to an increased absorptive function, reversible by reducing daily food. While several upregulated intestinal energetic pathways are dispensable, the intestinal PPARα is instead necessary for the genetic and environment overeating-induced increase of the gut absorptive capacity. In presence of dietary lipids, intestinal PPARα knock-out or its pharmacological antagonism suppress intestinal crypt expansion and shorten villi in mice and in human intestinal biopsies, diminishing the postprandial triglyceride transport and nutrient uptake. Intestinal PPARα ablation limits systemic lipid absorption and restricts lipid droplet expansion and PLIN2 levels, critical for droplet formation. This improves the lipid metabolism, and reduces body adiposity and liver steatosis, suggesting an alternative target for treating obesity.

Consideration of Intestinal Failure in Cases of De-Adaptation of Short Bowel Syndrome: A Case Report and Descriptive Review

Short bowel syndrome (SBS) causes malabsorption due to extensive intestinal resection. While intestinal function declines with age, little is known about the relationship between intestinal failure and ageing. For the first time in Japan, we report a case of de-adaptation of SBS thought to be due to ageing, in a 93-year-old woman who presented with electrolyte imbalance and malnutrition. She had undergone five surgical resections of the small intestine over the past 20 years. She had developed SBS once due to multiple surgeries, but due to compensatory function, the symptoms had abated. However, due to decreased intestinal function caused by ageing, it worsened and symptoms reappeared. A literature search for the period January 1990 to May 2021 in Ichushi a major journal in Japan, found that de-adaptation of SBS occurred in 23 previous cases, of which we were able to confirm the details in 17 cases, with no case reports on “de-adaptation of SBS”, demonstrating that the concept of “intestinal failure” has only recently begun to be used in routine practice. Therefore, we stress the importance of re-emphasizing the concept of ”intestinal failure” in everyday practice, as well as other organ-related conditions such as cardiac or renal failure, as this may lead to a better understanding of the pathogenesis of malnutrition and diarrhoea in elderly patients.

Trends in Pediatric Intestinal Failure: A Multicenter, Multinational Study

OBJECTIVES

To assess the natural history and outcomes of children with intestinal failure in a large, multicenter, geographically diverse contemporary cohort (2010-2015) from 6 pediatric intestinal failure programs.

STUDY DESIGN

Retrospective analysis of a multicenter intestinal failure cohort (n = 443). Competing-risk analysis was used to obtain cumulative incidence rates for the primary outcome (enteral autonomy, transplantation, or death). The χ² test and Cox proportional hazard regression were used for bivariate and multivariable analyses.

RESULTS

The study cohort comprised 443 patients (61.2% male). Primary etiologies included short bowel syndrome (SBS), 84.9%; dysmotility disorder, 7.2%; and mucosal enteropathy, 7.9%. Cumulative incidences for enteral autonomy, transplantation, and death at 6 years of follow-up were 53.0%, 16.7%, and 10.5%, respectively. Enteral autonomy was associated with SBS, ≥50% of small bowel length, presence of an ileocecal valve (ICV), absence of portal hypertension, and follow-up in a non-high-volume transplantation center. The composite outcome of transplantation/death was associated with persistent advanced cholestasis and hypoalbuminemia; age <1 year at diagnosis, ICV, and intact colon were protective.

CONCLUSIONS

The rates of death and transplantation in children with intestinal failure have decreased; however, the number of children achieving enteral autonomy has not changed significantly, and a larger proportion of patients remain parenteral nutrition dependent. New strategies to achieve enteral autonomy are needed to improve patient outcomes.