Differential Effects on Intestinal Adaptation Following Exogenous Glucagon‐Like Peptide 2 Therapy With and Without Enteral Nutrition in Neonatal Short Bowel Syndrome

Background: We aim to study the efficacy of exogenously administered glucagon‐like peptide 2 (GLP‐2) on intestinal adaptation in 2 preclinical models of neonatal short bowel syndrome (SBS) according to remnant intestinal anatomy, with and without ileum. Furthermore, we aim to determine if this adaptive effect was potentiated with enteral nutrition (EN). Methods: Neonatal piglets were block‐randomized to 75% mid‐intestinal (JI group, retains ileum) or distal‐intestinal (JC group, has no ileum) resection or no resection (sham control) and GLP‐2 treatment (11 nmol/kg/d) or saline control for 7 days. Piglets received nutrition support, either 100% parenteral nutrition (PN; 0% EN, n = 32 in total) or 80% PN + 40% EN (n = 28 in total). Adaptation was assessed by morphological and histological changes, as well as RT quantitative polymerase chain reaction of nutrient transporters and tight junctional proteins and fat absorption. Data are analyzed by 3‐way analysis of variance (ANOVA) and 2‐way ANOVA per EN level. Results: GLP‐2 treatment lengthened villi, deepened crypts, and improved intestinal weight in the remnant intestine of JC piglets. EN was a more potent adaptive stimulus for JI piglets. Small intestinal lengthening occurred only in the JI group, when given EN. There was no difference in total fat absorption and messenger RNA expression of nutrient transporters and tight junctional proteins. Conclusions: GLP‐2 administration augmented structural adaptation in JC piglets with distal intestinal resection. Given JI anatomy, further stimulation by GLP‐2 treatment over innate adaptation and stimulation by EN was modest and restricted to ileum. The differential effect of GLP‐2 in neonatal SBS, depending on remnant anatomy, has important implications for clinical translation and planning of clinical trials.     

Parenteral ω‐3 Fatty Acid Lipid Emulsions for Children With Intestinal Failure and Other Conditions

Background: There is growing interest in the use of ω‐3 fatty acid (n‐3FA) lipid emulsions to prevent complications associated with parenteral nutrition. The authors systematically reviewed the evidence on the benefits and safety of n‐3FA compared with standard lipid emulsions in children with intestinal disease, critical illness, trauma, or postoperative complications. Materials and Methods: The authors searched 4 bibliographic databases from their inception to March 2011, conference proceedings, trial registries, and reference lists. Two reviewers independently selected studies, assessed methodological quality, and rated the strength of the evidence. One reviewer extracted and a second reviewer verified data. The authors summarized findings qualitatively and conducted meta‐analysis when appropriate. Results: Five randomized controlled trials with unclear risk of bias and 3 high‐quality prospective cohort studies were included. The studies examined premature, low birth weight infants (n = 6) and children with heart disease (n = 1) or intestinal failure (n = 1). The strength of evidence was consistently low or very low across all lipid emulsion comparisons and outcomes. In young children, n‐3FA emulsions resulted in improvement in some biochemical outcomes of intestinal failure–associated liver disease but no difference in mortality. Few studies examined patient‐important outcomes, such as length of hospital and intensive care stay; need for transplantation, growth, and cognitive development; or the long‐term effects and potential harms associated with these therapies. Conclusions: Currently, there is a lack of sufficient high‐quality data to support the use of parenteral n‐3FA lipid emulsions in children. Future trials examining long‐term clinical outcomes and harms are needed.     

Colonic GLP‐2 is not Sufficient to Promote Jejunal Adaptation in a PN‐Dependent Rat Model of Human Short Bowel Syndrome

Background: Bowel resection may lead to short bowel syndrome (SBS), which often requires parenteral nutrition (PN) due to inadequate intestinal adaptation. The objective of this study was to determine the time course of adaptation and proglucagon system responses after bowel resection in a PN‐dependent rat model of SBS. Methods: Rats underwent jugular catheter placement and a 60% jejunoileal resection + cecectomy with jejunoileal anastomosis or transection control surgery. Rats were maintained exclusively with PN and killed at 4 hours to 12 days. A nonsurgical group served as baseline. Bowel growth and digestive capacity were assessed by mucosal mass, protein, DNA, histology, and sucrase activity. Plasma insulin‐like growth factor I (IGF‐I) and bioactive glucagon‐like peptide 2 (GLP‐2) were measured by radioimmunoassay. Results: Jejunum cellularity changed significantly over time with resection but not transection, peaking at days 3‐4 and declining by day 12. Jejunum sucrase‐specific activity decreased significantly with time after resection and transection. Colon crypt depth increased over time with resection but not transection, peaking at days 7‐12. Plasma bioactive GLP‐2 and colon proglucagon levels peaked from days 4‐7 after resection and then approached baseline. Plasma IGF‐I increased with resection through day 12. Jejunum and colon GLP‐2 receptor RNAs peaked by day 1 and then declined below baseline. Conclusions: After bowel resection resulting in SBS in the rat, peak proglucagon, plasma GLP‐2, and GLP‐2 receptor levels are insufficient to promote jejunal adaptation. The colon adapts with resection, expresses proglucagon, and should be preserved when possible in massive intestinal resection.     

Intravenous Fish Oil and Pediatric Intestinal Failure–Associated Liver Disease: Changes in Plasma Phytosterols,Cytokines, and Bile Acids and Erythrocyte Fatty Acids

Background: Soybean oil (SO) emulsions are associated with intestinal failure–associated liver disease (IFALD); fish oil (FO) emulsions are used to treat IFALD. SO and FO differ with respect to their fatty acid and phytosterol content. In children with IFALD whose SO was replaced with FO, we aimed to (1) quantify changes in erythrocyte fatty acids and plasma phytosterols, cytokines, and bile acids and (2) correlate these changes with direct bilirubin (DB). Design: This study enrolled IFALD children who received 6 months of FO. Blood samples were collected prior to FO, and after 2 weeks and 3 and 6 months of FO. The primary outcome was 3‐month vs baseline biomarker concentrations. Results: At study initiation, the median patient age was 3 months (interquartile range, 3–17 months), and mean ± standard deviation DB was 5.6 ± 0.7 mg/dL (n = 14). Cholestasis reversed in 79% of subjects. Eicosapentaenoic and docosahexaenoic acid was greater than baseline (P < .001, all time points). Linoleic and arachidonic acid and sitosterol and stigmasterol were less than baseline (P < .05, all time points). Three‐ and 6‐month interleukin‐8 (IL‐8) and total and conjugated bile acids were less than baseline (P < .05). Baseline IL‐8 was correlated with baseline DB (r = 0.71, P < .01). Early changes in stigmasterol and IL‐8 were correlated with later DB changes (r = 0.68 and 0.75, P < .05). Conclusion: Specific fat emulsion components may play a role in IFALD. Stigmasterol and IL‐8 may predict FO treatment response.     

3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropanoic acid (CMPF): A metabolite identified after consumption of fish oil and fish

3‐carboxy‐4‐methyl‐5‐propyl‐2‐furanpropanoic acid (CMPF) is a known metabolite of furan fatty acids and was first referred to as a urofuran fatty acid, as it was found in urine of humans and other species after consumption of furan fatty acids or foods containing furan fatty acids. More recently, CMPF has been identified as a highly prominent metabolite following the consumption of fish oil, fish oil fractions and diets rich in fish, and can be regarded as biomarker of oil‐rich fish or fish oil intakes. As furan fatty acids are known to occur in fish and fish oil (at a low level), it is possible that the CMPF in plasma arises from these furan fatty acids. On a structural basis, this is a likely explanation rather than the CMPF being an actual metabolite of long‐chain marine omega‐3 fatty acids. Recent studies in high fat‐fed mice given purified CMPF suggest that CMPF might contribute to the improved metabolic effects observed following consumption of long‐chain marine omega‐3 fatty acids but much is still to be known about the relationships between CMPF and health.     

Rapid Enrichment of Cell Phospholipids in Long‐Chain Polyunsaturated ω‐3 Fatty Acids After a Bolus Intravenous Injection of a Medium‐Chain Triacylglycerol

The present review aims at highlighting the use of a recently developed medium‐chain triacylglycerol:fish oil (MCT:FO) emulsion for the rapid and sustained enrichment of long‐chain polyunsaturated ω‐3 fatty acids in cell phospholipids. Preclinical in vitro, in vivo, and ex vivo experiments are briefly considered with emphasis on the changes in the fatty acid pattern of cell phospholipids in several organs, the partial correction of liver steatosis, and the cardiovascular modification of cationic and functional variables observed in ω‐3‐depleted rats examined 60–120 minutes after a bolus intravenous (IV) injection (1.0 mL) of the MCT:FO emulsion. The clinical findings collected in healthy male volunteers before or after the bolus IV injection (50.0 mL) of either the MCT:FO emulsion or a control medium‐chain triacylglycerol:long‐chain triacylglycerol emulsion are also reviewed, with emphasis on the rapid (within 60 minutes) and sustained (up to 2–3 days) enrichment of platelet and white blood cell phospholipids in long‐chain polyunsaturated ω‐3 fatty acids and hemostatic safety of the present procedure proposed as a tool for the rapid prevention or correction of metabolic and functional disturbances in humans with a relative deficiency in such ω‐3 fatty acids.     

An Integrated Analysis of miRNA and Gene Expression Changes in Response to an Obesogenic Diet to Explore the Impact of Transgenerational Supplementation with Omega 3 Fatty Acids

Insulin resistance decreases the ability of insulin to inhibit hepatic gluconeogenesis, a key step in the development of metabolic syndrome. Metabolic alterations, fat accumulation, and fibrosis in the liver are closely related and contribute to the progression of comorbidities, such as hypertension, type 2 diabetes, or cancer. Omega 3 (n-3) polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), were identified as potent positive regulators of insulin sensitivity in vitro and in animal models. In the current study, we explored the effects of a transgenerational supplementation with EPA in mice exposed to an obesogenic diet on the regulation of microRNAs (miRNAs) and gene expression in the liver using high-throughput techniques. We implemented a comprehensive molecular systems biology approach, combining statistical tools, such as MicroRNA Master Regulator Analysis pipeline and Boolean modeling to integrate these biochemical processes. We demonstrated that EPA mediated molecular adaptations, leading to the inhibition of miR-34a-5p, a negative regulator of Irs2 as a master regulatory event leading to the inhibition of gluconeogenesis by insulin during the fasting–feeding transition. Omics data integration provided greater biological insight and a better understanding of the relationships between biological variables. Such an approach may be useful for deriving innovative data-driven hypotheses and for the discovery of molecular–biochemical mechanistic links.     

Rapid Incorporation of ω‐3 Fatty Acids Into Colonic Tissue After Oral Supplementation in Patients With Colorectal Cancer

Background: The purpose of the study was to examine whether a preoperative supplement with ω‐3 fatty acids (FAs) leads to their incorporation into colonic tissue in patients scheduled for colorectal cancer surgery. This would be of interest because ω‐3 FAs have potential beneficial (local) immunological effects that might benefit these patients. Methods: In a randomized, double‐blind, prospective, placebo‐controlled, single‐center intervention trial, patients referred for elective colorectal cancer surgery received either an ω‐3 FA–enriched oral nutrition supplement (ONS) (200 mL twice daily) providing 2.0 g of eicosapentaenoic acid (EPA) and 1.0 g of docosahexaenoic acid (DHA) per day or a standard ONS for 7 days before surgery. Tissue samples from healthy colonic tissue (mucosa and muscular layer) were obtained during surgery, and tissue fatty acid composition was analyzed by gas chromatography. Results: EPA was significantly higher in colonic mucosa (P = .001) and in the colonic muscular layer (P = .004) in the ω‐3 FA group compared with controls. Patients in the ω‐3 FA group also tended to have higher docosapentaenoic acid and DHA levels in colonic tissue. Conclusions: EPA is incorporated rapidly into colonic mucosa and colonic muscular layer in patients given 3 g of ω‐3 FA daily for 7 days before surgery for colorectal cancer. This may lead to potential beneficially effects on (local) immune function, which might benefit these patients.     

Glucagon‐Like Peptide 2 Stimulates Postresection Intestinal Adaptation in Preterm Pigs by Affecting Proteins Related to Protein,Carbohydrate, and Sulphur Metabolism

Background: Exogenous glucagon‐like peptide 2 (GLP‐2) stimulates intestinal adaptation after resection in animal models of pediatric short bowel syndrome (SBS). It is unknown whether the molecular mechanisms of such GLP‐2 effects are similar to those of postresection spontaneous adaptation. Using preterm pigs as a model, we hypothesized that GLP‐2 treatment would change the intestinal proteome within the first week after resection, relative to individuals not resected or resected without GLP‐2 treatment. Materials and Methods: Two‐day‐old preterm pigs were subjected to resection of 50% distal small intestine and fed total parenteral nutrition without (SBS) or with GLP‐2 infusion (3.5 µg/kg/h, SBS+GLP‐2) for 5 days. The proteome of the remnant proximal intestine was compared among the SBS, SBS+GLP‐2, and unresected pigs, through gel‐based proteomics. Results: Thirty‐two proteins with differential expression were identified. Ten of these proteins were affected by the resection alone (ie, SBS vs unresected pigs). Five of these resection‐responsive proteins and another 22 proteins were affected by GLP‐2 infusion (ie, SBS+GLP‐2 vs SBS or unresected pigs). Resection alone mainly affected cellular structural proteins, while the added GLP‐2 treatment affected proteins involved in protein processing and the metabolism of protein, carbohydrate, and sulphur. Conclusion: In the first days following resection, proteins affected by resection plus GLP‐2 treatment differed markedly from those affected by the spontaneous intestinal adaptation following resection alone. Whether more long‐term GLP‐2 treatment may affect the intestinal proteome following intestinal resection remains unknown.     

Longitudinal Bone Mineralization Assessment in Children Treated With Long‐Term Parenteral Nutrition for Severe Intestinal Failure

Background: Metabolic bone disease is common in children receiving home parenteral nutrition (HPN) for intestinal failure (IF). Long‐term evolution of bone mass in pediatric IF is poorly documented. The aims of this study were (1) to determine the prevalence of low bone mass (LBM) in children receiving HPN for IF, (2) to evaluate the evolution of total bone mineral content (TBMC) during HPN with dual‐energy x‐ray absorptiometry (DXA), and (3) to identify related factors. Methods: All children referred in our HPN center from 2004 to 2014 were eligible. Inclusion criteria were HPN dependence due to noninflammatory IF, at least 2 TBMC assessments, and HPN duration of at least 2 years at last DXA. TBMC was expressed in z score for ideal weight for height (WFH). LBM was defined by a TBMC WFH z score ≤–2 standard deviations (SD). Results: A total of 175 DXAs for 31 children were performed, mean of 5.6 ± 2.9 assessments per child. The median time between first and last DXA recorded was 6.2 years (0.7–16.6). At the first DXA, 14 children (45%) had a LBM. TBMC increased by +0.1 ± 0.04 SD per year of HPN (P = .012). The risk of LBM decreased with an odds ratio of 0.9 per year of HPN (95% confidence interval, 0.92–0.99; P = .018). Lean mass z score and calcium parenteral intakes were related to the TBMC improvement. Conclusion: LBM is common in pediatric IF, but bone status could improve during HPN in these children.     

ω‐3 Fatty Acids Reduce Chemotherapy‐Induced Hematological Toxicity by Bone Marrow Stimulation in Mice

Background: ω‐3 Fatty acids exert several benefits during chemotherapy, such as preventing intestinal mucosal damage and improving response to chemotherapy. However, little is known about the effect of ω‐3 fatty acids on chemotherapy‐induced hematological toxicities. Methods: Mice that had consumed either an ω‐3–rich or an ω–3‐poor diet for 2 weeks were intraperitoneally administered cisplatin. The resultant changes in blood cell count, bone marrow cell count, and cytokine levels in bone marrow supernatant were analyzed. The effect of ω‐3 fatty acids on human peripheral blood mononuclear cells (PBMCs) exposed to cisplatin was also examined. Results: Although peripheral blood cell counts decreased after cisplatin treatment in both groups of mice, the decrease in white blood cell count was significantly lower in mice that consumed the ω‐3–rich diet. The decrease in bone marrow cells after cisplatin treatment was also reduced in mice that consumed the ω‐3–rich diet. Levels of stem cell factor (SCF) and fibroblast growth factor 1 (FGF‐1) were significantly higher in bone marrow supernatants from mice that consumed the ω‐3–rich diet. The rate of apoptosis in PBMCs (after exposure to cisplatin) cultured in medium containing ω‐3 fatty acids was significantly lower than in PBMCs cultured in control medium. Conclusion: ω‐3–Rich diets reduced chemotherapy‐induced leukopenia in mice. This may be the result of increased numbers of bone marrow cells due to higher levels of SCF and FGF‐1 in the bone marrow.     

Reversal of Parenteral Nutrition–Associated Liver Disease With a Fish Oil–Based Lipid Emulsion (Omegaven) in an Adult Dependent on Home Parenteral Nutrition

Patients with intestinal failure and short bowel syndrome usually require chronic parenteral nutrition (PN). PN is associated with risks, including infections, vascular thrombosis, and liver disease. PN‐associated liver disease (PNALD) can progress from steatosis to chronic hepatitis and ultimately to cirrhosis. The etiology of PNALD is not completely understood. Therapies for PNALD include carbohydrate or lipid calorie reduction, antibiotics, or the use of ursodeoxycholic acid. When these efforts fail, therapeutic options are limited and liver transplantation may be required. The transition from a soybean‐ to a fish oil–based lipid formulation, such as the ω‐3 parenteral lipid formulation (Omegaven), has shown a dramatic reversal of PNALD within the pediatric population. This is the first report of a PN‐dependent adult in the United States complicated by PNALD and hepatic failure who had improvement of liver disease with an ω‐3 fish oil–based parenteral formulation.     

ω‐3 Fatty Acids Prevent Hepatic Steatosis,Independent of PPAR‐α Activity,in a Murine Model of Parenteral Nutrition–Associated Liver Disease

Objectives: ω‐3 Fatty acids (FAs), natural ligands for the peroxisome proliferator‐activated receptor–α (PPAR‐α), attenuate parenteral nutrition–associated liver disease (PNALD). However, the mechanisms underlying the protective role of ω‐3 FAs are still unknown. The aim of this study was to determine the effects of ω‐3 FAs on hepatic triglyceride (TG) accumulation in a murine model of PNALD and to investigate the role of PPAR‐α and microsomal triglyceride transfer protein (MTP) in this experimental setting. Methods: 129S1/SvImJ wild‐type or 129S4/SvJaePparatm/Gonz/J PPAR‐α knockout mice were fed chow and water (controls); oral, fat‐free PN solution only (PN‐O); PN‐O plus intraperitoneal (IP) ω‐6 FA‐predominant supplements (PN–ω‐6); or PN‐O plus IP ω‐3 FA (PN–ω‐3). Control and PN‐O groups received sham IP injections of 0.9% NaCl. Hepatic histology, TG and cholesterol, MTP activity, and PPAR‐α messenger RNA were assessed after 19 days. Results: In all experimental groups, PN feeding increased hepatic TG and MTP activity compared with controls. Both PN‐O and PN–ω‐6 groups accumulated significantly greater amounts of TG when compared with PN–ω‐3 mice. Studies in PPAR‐α null animals showed that PN feeding increases hepatic TG as in wild‐type mice. PPAR‐α null mice in the PN‐O and PN–ω‐6 groups demonstrated variable degrees of hepatic steatosis, whereas no evidence of hepatic fat accumulation was found after 19 days of oral PN plus IP ω‐3 FAs. Conclusions: PN induces TG accumulation (steatosis) in wild‐type and PPAR‐α null mice. In PN‐fed wild‐type and PPAR‐α null mice given IP ω‐3 FAs, reduced hepatic TG accumulation and absent steatosis are found. Prevention of steatosis by ω‐3 FAs results from PPAR‐α–independent pathways.     

Increased Intestinal Absorption in the Era of Teduglutide and Its Impact on Management Strategies in Patients With Short Bowel Syndrome–Associated Intestinal Failure

Short bowel syndrome–associated intestinal failure (SBS‐IF) as a consequence of extensive surgical resection of the gastrointestinal (GI) tract results in a chronic reduction in intestinal absorption. The ensuing malabsorption of a conventional diet with associated diarrhea and weight loss results in a dependency on parenteral nutrition and/or intravenous fluids (PN/IV). A natural compensatory process of intestinal adaptation occurs in the years after bowel resection as the body responds to a lack of sufficient functional nutrient‐processing intestinal surface area. The adaptive process improves bowel function but is a highly variable process, yielding different levels of symptom control and PN/IV independence among patients. Intestinal rehabilitation is the strategy of maximizing the absorptive capacity of the remnant GI tract. The approaches for achieving this goal have been limited to dietary intervention, antidiarrheal and antisecretory medications, and surgical bowel reconstruction. A targeted pharmacotherapy has now been developed that improves intestinal absorption. Teduglutide is a human recombinant analogue of glucagon‐like peptide 2 that promotes the expansion of the intestinal surface area and increases the intestinal absorptive capacity. Enhanced absorption has been shown in clinical trials by a reduction in PN/IV requirements in patients with SBS‐IF. This article details the clinical considerations and best‐practice recommendations for intestinal rehabilitation, including optimization of fluids, electrolytes, and nutrients; the integration of teduglutide therapy; and approaches to PN/IV weaning.