Teduglutide-Stimulated Intestinal Adaptation Is Complemented and Synergistically Enhanced by Partial Enteral Nutrition in a Neonatal Piglet Model of Short Bowel Syndrome

A Digestive Cartridge Reduces Parenteral Nutrition Dependence and Increases Bowel Growth in a Piglet Short Bowel Model

OBJECTIVE

To determine whether the use of an immobilized lipase cartridge (ILC) to hydrolyze fats in enteral nutrition (EN) reduces parenteral nutrition (PN) dependence in a porcine model of short bowel syndrome with intestinal failure (SBS-IF).

BACKGROUND

SBS-IF occurs after intestinal loss resulting in malabsorption and PN dependence. Limited therapeutic options are available for achieving enteral autonomy.

METHODS

Eleven Yorkshire piglets underwent 75% jejunoileal resection and were randomized into control (n=6) and treatment (n = 5) groups. PN was initiated postoperatively and reduced as EN advanced if predefined clinical criteria were fulfilled. Animals were studied for 14 days and changes in PN/EN calories were assessed. Intestinal adaptation, absorption, and nutrition were evaluated at the end of the study (day 15). Comparisons between groups were performed using analysis of covariance adjusted for baseline.

RESULTS

ILC animals demonstrated a 19% greater reduction in PN calories ( P < 0.0001) and higher mean EN advancement (66% vs 47% of total calories, P < 0.0001) during the 14-day experiment. Treatment animals had increased intestinal length (19.5 vs 0.7%, P =0.03) and 1.9-fold higher crypt cell proliferation ( P =0.02) compared with controls. By day 15, ILC treatment resulted in higher plasma concentrations of glucagon-like peptide-2 ( P = 0.02), eicosapentaenoic acid ( P < 0.0001), docosahexaenoic acid ( P = 0.004), vitamin A ( P = 0.02), low-density lipoprotein ( P = 0.02), and high-density lipoprotein ( P = 0.04). There were no differences in liver enzymes or total bilirubin between the two groups.

CONCLUSIONS

ILC use in conjunction with enteral feeding reduced PN dependence, improved nutrient absorption, and increased bowel growth in a porcine SBS-IF model. These results support a potential role for the ILC in clinical SBS-IF.

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.

Total parenteral nutrition impairs glucose metabolism by modifying the gut microbiome

Total parenteral nutrition (TPN) can lead to complications, such as glucose metabolism disorders. While TPN is associated with impairments in intestinal function, the gut barrier and mucosal immunity, the relationship between the gut microbiome and TPN-related glucose metabolism disorders remains to be explored. In a cohort of 256 participants with type 2 intestinal failure, we show that parenteral nutrition providing >80% of total energy induces insulin resistance and a higher risk of complications. Using various male mouse models, we demonstrate that changes in Lactobacillaceae and indole-3-acetic acid (IAA) levels underlie these complications. Lactobacillaceae and IAA levels decrease in TPN-treated mice and participants, while their abundances in the latter are negatively correlated with insulin resistance and serum lipopolysaccharide levels. Furthermore, IAA activates the aryl hydrocarbon receptor and increases glucagon-like peptide-1 secretion through upregulation of Gcg expression and increased stem cell differentiation towards L cells. Finally, liraglutide, a glucagon-like peptide-1 receptor agonist, completely prevents TPN-induced glucose metabolism disorders in mice. Thus, TPN induces glucose metabolism disorders by altering the gut microbiota and its metabolites.

An in-line digestive cartridge increases enteral fat and vitamin absorption in a porcine model of short bowel syndrome

BACKGROUND & AIMS

Short bowel syndrome (SBS) occurs after intestinal loss resulting in parenteral nutrition dependence and micronutrient deficiencies, which may lead to life-limiting complications. ALC-078 is a cartridge containing immobilized lipase that connects in-line with enteral feeding sets and digests fats in enteral nutrition (EN). In this study, we evaluate the efficacy of ALC-078 to improve fat and nutrient absorption in a porcine SBS model.

METHODS

Fifteen male Yorkshire piglets were assessed. Animals were randomized to no intestinal resection (n = 5), 75% resection (n = 5), or 75% resection + ALC-078 (n = 5). After recovery, animals were treated for 14 days. Piglets received 60% of nutrition from continuous EN and 40% from chow. The degree of fat malabsorption was determined by the coefficient of fat absorption (CFA) following a 72-h stool collection. Body weight, fat-soluble vitamins, and nutritional markers were assessed.

RESULTS

Adverse events were similar across the three groups (P = 1.00). ALC-078-treated animals had similar weight gain compared to resected piglets. Resected animals had a lower CFA compared to unresected controls (79.3% vs. 95.2%, P = 0.01) while there was no significant difference in the ALC-078 animals (87.1% vs. 95.2%, P = 0.19). Between Study Days 1 and 15, ALC-078 animals had increased concentrations of vitamin D (12.2 vs. 8.7 ng/mL, P = 0.0006), and vitamin E (4.3 vs. 2.5 mg/L, P = 0.03). These markers did not significantly change in untreated resected animals.

CONCLUSION

ALC-078 increases the absorption of fat-soluble vitamins and may improve fat malabsorption. Future studies should determine whether ALC-078 can reduce PN dependence and if these findings translate to human patients with SBS.

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.

Durability of Linear Small-Intestinal Growth Following Treatment Discontinuation of Long-Acting Glucagon-Like Peptide 2 (GLP-2) Analogues

BACKGROUND

Short-bowel syndrome is the leading cause of pediatric intestinal failure, resulting in dependency on long-term parenteral nutrition (PN). To promote enteral autonomy in neonates, a key outcome may be intestinal growth in length. The purpose of this study was to determine if intestinal lengthening persists following discontinuation of treatment with 1 of 2 GLP-2 analogues with different pharmacokinetic profiles.

METHODS

Neonatal short-bowel piglets were assigned to saline control (S), 7-day treatment with teduglutide (T) (0.05 mg/kg twice daily), or 7-day treatment with apraglutide (A) (5 mg/kg twice weekly). Comparisons were made between day 7 and day 14 endpoints using analysis of variance. Data included small-intestine length, weight, histology, and quantitative polymerase chain reaction analysis of mucosal transcripts for peptide growth factors and their receptors, nutrient transporters, and tight-junction proteins.

RESULTS

Compared with control, 7 days of GLP-2 analogue treatment induced mucosal adaptation based on villus hyperplasia (P = .003), which was not durable 7 days after treatment cessation (day 14; P = .081). Treatment increased intestinal growth in length by day 7 (P = .005), which was maintained (by T) or further increased (by A) at day 14 (P < .001). No significant differences in mucosal transcripts were detected.

CONCLUSION

Unlike mucosal adaptation, intestinal growth appears to be a lasting outcome of treatment with long-acting GLP-2 analogues in a neonatal piglet short-bowel model. This has significant clinical implications for neonates, given their potential for intestinal growth. Intestinal lengthening varies between analogues with different half-lives; however, molecular mechanisms require further elucidation.

Cost-effectiveness of teduglutide in pediatric patients with short bowel syndrome: Markov modeling using traditional cost-effectiveness criteria

BACKGROUND

Teduglutide use in pediatric patients with short bowel syndrome can aid in the achievement of enteral autonomy, but with a price of >$400,000 per y.

OBJECTIVE

The current study evaluated the cost-effectiveness of using teduglutide in conjunction with offering intestinal transplantation in US pediatric patients with short bowel syndrome.

DESIGN

A Markov model was used to evaluate the costs (in US dollars) and effectiveness [in quality-adjusted life years (QALYs)] of using teduglutide compared with offering intestinal transplantation. Parameters were estimated from published data where available. The primary effect modeled was the probability of weaning from parenteral nutrition while on teduglutide. Sensitivity analyses were performed on all model parameters.

RESULTS

Compared with offering only intestinal transplantation, adding teduglutide cost ${\$}$124,353/QALY gained. Reducing the cost of the medication by 16% allowed the cost to reach the typical benchmark of ${\$}$100,000/QALY gained. Probabilistic sensitivity analysis favored transplantation without offering teduglutide in 68% of iterations at a ${\$}$100,000/QALY threshold. Never using teduglutide created an opportunity cost of over ${\$}$100,000 per patient.

CONCLUSIONS

At its current price, teduglutide does not provide a cost-effective addition to transplantation in the treatment of pediatric short bowel syndrome. Further work should look to identify cost-reducing strategies, including alternative dosing regimens.

Translational Advances in Pediatric Nutrition and Gastroenterology: New Insights from Pig Models

Pigs are increasingly important animals for modeling human pediatric nutrition and gastroenterology and complementing mechanistic studies in rodents. The comparative advantages in size and physiology of the neonatal pig have led to new translational and clinically relevant models of important diseases of the gastrointestinal tract and liver in premature infants. Studies in pigs have established the essential roles of prematurity, microbial colonization, and enteral nutrition in the pathogenesis of necrotizing enterocolitis. Studies in neonatal pigs have demonstrated the intestinal trophic effects of akey gut hormone, glucagon-like peptide 2 (GLP-2), and its role in the intestinal adaptation process and efficacy in the treatment of short bowel syndrome. Further, pigs have been instrumental in elucidating the physiology of parenteral nutrition-associated liver disease and the means by which phytosterols, fibroblast growth factor 19, and a new generation of lipid emulsions may modify disease. The premature pig will continue to be a valuable model in the development of optimal infant diets (donor human milk, colostrum), specific milk bioactives (arginine, growth factors), gut microbiota modifiers (pre-, pro-, and antibiotics), pharmaceutical drugs (GLP-2 analogs, FXR agonists), and novel diagnostic tools (near-infrared spectroscopy) to prevent and treat these pediatric diseases.

Comparing the Intestinotrophic Effects of 2 Glucagon-Like Peptide-2 Analogues in the Treatment of Short-Bowel Syndrome in Neonatal Piglets

BACKGROUND

In treating short-bowel syndrome (SBS), autonomy from parenteral nutrition (PN) relies upon intestinal adaptation, which can be augmented by glucagon-like peptide-2 (GLP-2) analogues. In neonatal piglets with SBS, we compared intestinal adaptation following treatment with 2 GLP-2 analogues: teduglutide (TED) and apraglutide (APRA) METHODS: Following 75% distal small-intestinal resection, piglets were allocated to 4 treatment groups: saline (CON: n = 8), twice weekly APRA (5 mg/kg/dose; n = 8), and TED once daily (TED, 0.05 mg/kg/dose; n = 8) or twice daily (TEDBID, 0.05 mg/kg/dose; n = 7). Pharmacokinetic (PK) studies were undertaken, and on day 7, small-intestinal length and weight were measured and jejunal tissue collected for histology.

RESULTS

PK profiles were different between the 2 analogues. To achieve a comparable exposure to APRA, TED requires twice daily injection (TEDBID). Compared with CON, APRA and TEDBID increased small-bowel length (cm) (CON: 141, APRA: 166, TED: 153, TEDBID: 165; P = .004), whereas APRA increased small-bowel weight (g) (CON: 26, APRA: 33, TED: 28, TEDBID: 31; P = .007) and villus height (mm) (CON: 0.59, APRA: 0.90, TED: 0.58, TEDBID: 0.74; P < .001).

CONCLUSION

APRA injected only twice during the 7 consecutive days demonstrated a superior intestinotrophic effect compared with TED injected once daily. Even at more comparable drug exposure, when TED was injected twice a day, APRA showed superior trophic activity at the mucosal level. This is highly relevant for the treatment of pediatric SBS, given the markedly lower dose frequency by subcutaneous injection of APRA.

Cost-effectiveness of teduglutide in adult patients with short bowel syndrome: Markov modeling using traditional cost-effectiveness criteria

BACKGROUND

Adults with short bowel syndrome have a high mortality and significant morbidity due to unsuccessful attempts at rehabilitation that necessitate chronic use of parenteral nutrition (PN). Teduglutide is a novel therapy that promotes intestinal adaptation to improve rehabilitation but with a price >$400,000/y.

OBJECTIVE

The current study evaluated the cost-effectiveness of using teduglutide in US adult patients with short bowel syndrome.

METHODS

A Markov model evaluated the costs (in US dollars) and effectiveness (in quality-adjusted life years, or QALYs) of treatment compared with no teduglutide use, with a presumed starting age of 40 y. Parameters were obtained from published data or estimation. The primary effect modeled was the increased likelihood of reduced PN days per week when using teduglutide, leading to greater quality of life and lower PN costs. Sensitivity analyses were performed on all model parameters.

RESULTS

In the base scenario, teduglutide cost $949,910/QALY gained. In 1-way sensitivity analyses, only reducing teduglutide cost decreased the cost/QALY gained to below the typical threshold of $100,000/QALY gained. Specifically, teduglutide cost would need to be reduced by >65% for it to reach the threshold value. Probabilistic sensitivity analysis favored no teduglutide use in 80% of iterations at a $100,000/QALY threshold. However, teduglutide therapy was cost-saving in 13% of model iterations.

CONCLUSIONS

Teduglutide does not meet a traditional cost-effectiveness threshold as treatment for PN reduction in adult patients with short bowel syndrome compared with standard intestinal rehabilitation. Subpopulations that demonstrate maximum benefit could be cost-saving, and complete nonuse could lead to financial loss. Teduglutide becomes economically reasonable only if its cost is substantially reduced.

Amino Acids Influencing Intestinal Development and Health of the Piglets

Simple Summary

The health of piglets is an important issue in pig production. Nutritional support for intestinal development is a significant component of piglet care, and amino acids are essential for intestinal growth and development. For suckling piglets, the sows’ milk and the maternal environment shape the structure and support the function of the intestinal tract. The composition of milk affects intestinal morphology and the digestive, absorption and barrier function. After weaning, the optimal nutritional strategies of their diet are necessary to guarantee the piglets’ intestinal development and growth performance. Amino acids are the most important ingredient in piglet diets. The aim of this review is to collect and analyze the relationship between amino acid nutrition and intestinal development of piglets, and elucidate the impacts on piglet health.

Abstract

The amino acids and other components of diet provide nourishment for piglet intestinal development and maturation. However, early-weaned piglets struggle with tremendous stress, impairing normal intestinal health and leading to intestinal dysfunction and even death. The high prevalence worldwide of post-weaning diarrhoea syndrome (PWDS) in piglets has led to much interest in understanding the important role of nutrients in the establishment and maintenance of a functional intestinal tract. In particular, the impacts of amino acids on these functions must be considered. Amino acid levels greatly influence intestinal development in weaning piglets. The lack of amino acids can cause marked structural and functional changes in the intestine. Therefore, a comprehensive understanding of the functions of amino acids is necessary to optimize amino acid requirements of the developing intestinal tract to maximize piglet health and growth performance. This review summarizes the role of specific amino acids (arginine, glutamate, threonine, sulphur-containing amino acids (SCAAs), and branched-chain amino acids (BCAAs)) that have been proven to be beneficial for the intestinal health of weaned piglets.

Host-Gut Microbiota Crosstalk in Intestinal Adaptation

Short-bowel syndrome represents the most common cause of intestinal failure and occurs when the remaining intestine cannot support fluid and nutrient needs to sustain adequate physiology and development without the use of supplemental parenteral nutrition. After intestinal loss or damage, the remnant bowel undergoes multifactorial compensatory processes, termed adaptation, which are largely driven by intraluminal nutrient exposure. Previous studies have provided insight into the biological processes and mediators after resection, however, there still remains a gap in the knowledge of more comprehensive mechanisms that drive the adaptive responses in these patients. Recent data support the microbiota as a key mediator of gut homeostasis and a potential driver of metabolism and immunomodulation after intestinal loss. In this review, we summarize the emerging ideas related to host-microbiota interactions in the intestinal adaptation processes.

Synergy of glucagon-like peptide-2 and epidermal growth factor coadministration on intestinal adaptation in neonatal piglets with short bowel syndrome

Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) treatment enhance intestinal adaptation. To determine whether these growth factors exert synergistic effects on intestinal growth and function, GLP-2 and EGF-containing media (EGF-cm) were administered, alone and in combination, in neonatal piglet models of short bowel syndrome (SBS). Neonatal Landrace-Large White piglets were block randomized to 75% midintestinal [jejunoileal (JI) group] or distal intestinal [jejunocolic (JC) group] resection or sham control, with 7-day infusion of saline (control), intravenous human GLP-2 (11 nmol·kg^-1·day^-1) alone, enteral EGF-cm (80 μg·kg^-1·day^-1) alone, or GLP-2 and EGF-cm in combination. Adaptation was assessed by intestinal length, histopathology, Üssing chamber analysis, and real-time quantitative PCR of intestinal growth factors. Combined EGF-cm and GLP-2 treatment increased intestinal length in all three surgical models (P < 0.01). EGF-cm alone selectively increased bowel weight per length and jejunal villus height in the JI group only. The JC group demonstrated increased intestinal weight and villus height (P < 0.01) when given either GLP-2 alone or in combination with EGF-cm, with no effect of EGF-cm alone. Jejunal permeability of mannitol and polyethylene glycol decreased with combination therapy in both SBS groups (P < 0.05). No difference was observed in fat absorption or body weight gain. IGF-1 mRNA was differentially expressed in JI vs. JC piglets with treatment. Combined treatment with GLP-2 and EGF-cm induced intestinal lengthening and decreased permeability, in addition to the trophic effects of GLP-2 alone. Our findings demonstrate the benefits of novel combination GLP-2 and EGF treatment for neonatal SBS, especially in the JC model representing most human infants with SBS.NEW & NOTEWORTHY Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) are intestinotrophic, with demonstrated benefit in both animal models and human studies of short bowel syndrome (SBS). The current research shows that over and above known trophic effects, the combination of GLP-2 and EGF synergistically lengthens the bowel in neonatal piglet models of SBS. Most notable benefit occurred with resection of the terminal ileum, the common clinical anatomy seen in neonatal SBS and associated with least de novo lengthening postsurgery.

Improved capacity to evaluate changes in intestinal mucosal surface area using mathematical modeling

Quantification of intestinal mucosal growth typically relies on morphometric parameters, commonly villus height, as a surrogate for presumed changes in mucosal surface area (MSA). We hypothesized that using mathematical modeling based on multiple unique measurements would improve discrimination of the effects of interventions on MSA compared to standard measures. To determine the ability of mathematical modeling to resolve differences in MSA, a mouse model with enhanced serotonin (5HT) signaling known to stimulate mucosal growth was used. 5-HT signaling is potentiated by targeting the serotonin reuptake transporter (SERT) molecule. Selective serotonin reuptake inhibitor-treated wild-type (WT-SSRI), SERT-knockout (SERTKO), and wild-type C57Bl/6 (WT) mice were used. Distal ileal sections were H&E-stained. Villus height (VH), width (VW), crypt width (CW), and bowel diameter were used to calculate surface area enlargement factor (SEF) and MSA. VH alone for SERTKO and SSRI was significantly increased compared to WT, without a difference between SERTKO and WT-SSRI. VW and CW were significantly decreased for both SERTKO and WT-SSRI compared to WT, and VW for WT-SSRI was also decreased compared to SERTKO. These changes increased SEF and MSA for SERTKO and WT-SSRI compared to WT. Additionally, SEF and MSA were significantly increased for WT-SSRI compared to SERTKO. Mathematical modeling provides a valuable tool for differentiating changes in intestinal MSA. This more comprehensive assessment of surface area does not appear to correlate linearly with standard morphometric measures and represents a more comprehensive method for discriminating between therapies aimed at increasing functional intestinal mucosa.

Basic fibroblast growth factor eluting microspheres enhance distraction enterogenesis

PURPOSE

The purpose of this study was to determine if distraction enterogenesis using self-expanding polycaprolactone (PCL) springs is a potential therapy for short bowel syndrome. Sustained release basic fibroblast growth factor (bFGF) microspheres have been shown to induce angiogenesis and intestinal regeneration in tissue engineered scaffolds. We hypothesized that the provision of bFGF-loaded microspheres would increase angiogenesis and thereby enhance the process of enterogenesis.

METHODS

A 10-mm segment of rodent jejunum was isolated and an encapsulated PCL spring inserted. Blank or bFGF-loaded microspheres were delivered to the segment. After 4weeks, jejunal segments were assessed for lengthening, morphology, quantification of blood vessels, and ganglia.

RESULTS

Lengthened intestinal segments receiving bFGF microspheres demonstrated significantly increased microvascular density compared to those with blank microspheres. There were also significantly more submucosal and myenteric ganglia in the segments that received bFGF microspheres. Segments achieved similar lengthening and final muscular thickness in both blank and bFGF groups, but the bFGF microsphere caused a significant increase in luminal diameter of the jejunal segment.

CONCLUSION

Sustained release bFGF microspheres enhanced distraction enterogenesis through improved vascularity. The synergy of growth factors such as bFGF with distraction enterogenesis may yield improved results for the future treatment of patients with short bowel syndrome.