Evaluation of pediatric patients for intestinal transplantation in the modern era.

OBJECTIVES: To review recent evaluations of pediatric patients with intestinal failure (IF) for intestinal transplantation (ITx), waiting list decisions, and outcomes of patients listed and not listed for ITx at our center. METHODS: Retrospective chart review of 97 patients evaluated for ITx from January 2014 to December 2021 including data from referring institutions and protocol laboratory testing, body imaging, endoscopy, and liver biopsy in selected cases. Survival analysis used Kaplan-Meier estimates and Cox proportional hazards regression. RESULTS: Patients were referred almost entirely from outside institutions, one-third because of intestinal failure-associated liver disease (IFALD), two-thirds because of repeated infective and non-IFALD complications under minimally successful intestinal rehabilitation, and a single patient because of lost central vein access. The majority had short bowel syndrome (SBS). Waiting list placement was offered to 67 (69%) patients, 40 of whom for IFALD. The IFALD group was generally younger and more likely to have SBS, have received more parenteral nutrition, have demonstrated more evidence of chronic inflammation and have inferior kidney function compared to those offered ITx for non-IFALD complications and those not listed. ITx was performed in 53 patients. Superior postevaluation survival was independently associated with higher serum creatinine (hazard ratio [HR] 15.410, p = 014), whereas inferior postevaluation survival was associated with ITx (HR 0.515, p = 0.035) and higher serum fibrinogen (HR 0.994, p = 0.005). CONCLUSIONS: Despite recent improvements in IF management, IFALD remains a prominent reason for ITx referral. Complications of IF inherent to ITx candidacy influence postevaluation and post-ITx survival.

Investigation of parenteral nutrition-induced hepatotoxicity using human liver spheroid co-cultures.

Parenteral nutrition (PN) is typically administered to individuals with gastrointestinal dysfunction, a contraindication for enteral feeding, and a need for nutritional therapy. When PN is the only energy source in patients, it is defined as total parenteral nutrition (TPN). TPN is a life-saving approach for different patient populations, both in infants and adults. However, despite numerous benefits, TPN can cause adverse effects, including metabolic disorders and liver injury. TPN-associated liver injury, known as intestinal failure-associated liver disease (IFALD), represents a significant problem affecting up to 90% of individuals receiving TPN. IFALD pathogenesis is complex, depending on the TPN components as well as on the patient's medical conditions. Despite numerous animal studies and clinical observations, the molecular mechanisms driving IFALD remain largely unknown. The present study was set up to elucidate the mechanisms underlying IFALD. For this purpose, human liver spheroid co-cultures were treated with a TPN mixture, followed by RNA sequencing analysis. Subsequently, following exposure to TPN and its single nutritional components, several key events of liver injury, including mitochondrial dysfunction, endoplasmic reticulum stress, oxidative stress, apoptosis, and lipid accumulation (steatosis), were studied using various techniques. It was found that prolonged exposure to TPN substantially changes the transcriptome profile of liver spheroids and affects multiple metabolic and signaling pathways contributing to liver injury. Moreover, TPN and its main components, especially lipid emulsion, induce changes in all key events measured and trigger steatosis.

Comparison of two formulations of intravenous lipid emulsions in pediatric intestinal failure.

PURPOSE: The effect of different types of lipid emulsion may guide therapy of patients with intestinal failure (IF) to limit morbidity such as intestinal failure-associated liver disease (IFALD). METHODS: A retrospective chart review of pediatric patients with IF who received soybean oil lipid emulsion (SL) or mixed oil lipid emulsion (ML) was performed. Data over 1 year were collected. RESULTS: Forty-five patients received SL and 34 received ML. There were no differences in the incidence (82 versus 74%, P = 0.35) or resolution (86 versus 92%, P = 0.5) of IFALD between the cohorts. The median dose of ML was higher compared to SL (2 versus 1 g/kg/day, P < 0.001). If resolved, IFALD resolved rapidly in the ML cohort compared to the SL cohort (67 versus 37 days, P = 0.01). Weight gain was higher in the ML compared to the SL cohort at resolution of IFALD or 1 year from diagnosis of IF (P = 0.009). CONCLUSION: The administration of ML did not alter the incidence or resolution of IFALD compared to SL in pediatric IF. There was rapid resolution of IFALD and enhanced weight gain in the ML cohort compared to SL in pediatric IF.

A novel maladaptive unfolded protein response as a mechanism for small bowel resection-induced liver injury.

The unfolded protein response (UPR) is a complex adaptive signaling pathway activated by the accumulation of misfolded proteins in the endoplasmic reticulum (ER). ER stress (ERS) triggers a cascade of responses that converge upon C/EBP homologous protein (CHOP) to drive inflammation and apoptosis. Herein, we sought to determine whether liver injury and fibrosis after small bowel resection (SBR) were mediated by a maladaptive hepatic ERS/UPR. C57BL/6 mice underwent 50% proximal SBR or sham operation. Markers of liver injury and UPR/ERS pathways were analyzed. These were compared with experimental groups including dietary fat manipulation, tauroursodeoxycholic acid (TUDCA) treatment, distal SBR, and global CHOP knockout (KO). At 10 wk, proximal SBR had elevated alanine aminotransferase/aspartate aminotransferase (ALT/AST) (P < 0.005) and greater hepatic tumor necrosis factor-α (TNFα) (P = 0.001) and collagen type 1 α1 (COL1A1) (P = 0.02) than shams. SBR livers had increased CHOP and p-eIF2α, but were absent in activating transcription factor 4 (ATF4) protein expression. Low-fat diet (LFD), TUDCA, and distal SBR groups had decreased liver enzymes, inflammation, and fibrosis (P < 0.05). Importantly, they demonstrated reversal of hepatic UPR with diminished CHOP and robust ATF4 signal. CHOP KO-SBR had decreased ALT but not AST compared with wild-type (WT)-SBR (P = 0.01, P = 0.12). There were no differences in TNFα and COL1A1 (P = 0.09, P = 0.50). SBR-induced liver injury, fibrosis is associated with a novel hepatic UPR/ERS response characterized by increased CHOP and decreased ATF4. LFD, TUDCA, and ileocecal resection rescued the hepatic phenotype and reversed the UPR pattern. Global CHOP KO only partially attenuated liver injury. This underscores the significance of disruptions to the gut/liver axis after SBR and potentiates targets to mitigate the progression of intestinal failure-associated liver disease.NEW & NOTEWORTHY The unfolded protein response (UPR) is a complex signaling cascade that converges upon C/EBP-homologous protein (CHOP). Under conditions of chronic cellular stress, the UPR shifts from homeostatic to proapoptotic leading to inflammation and cell death. Here, we provide evidence that small bowel resection-induced liver injury and fibrosis are mediated by a maladaptive hepatic UPR. Low-fat diet, TUDCA treatment, and ileocecal resection rescued the hepatic phenotype and reversed the UPR pattern.

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.

Early detection of liver fibrosis with serum Mac-2 binding protein glycosylation-modified isomer (M2BPGi) during follow-up intestinal failure patients without intestinal failure-associated liver disease (IFALD).

PURPOSE: Mac-2 binding protein glycosylation-modified isomer (M2BPGi) is a new marker for hepatic fibrosis progression. We examined the relationship between serum M2BPGi levels and liver histological findings in intestinal failure (IF) patients without IF-associated liver disease (IFALD). METHODS: This study included IF patients without IFALD followed at our hospital. All patients underwent routine liver biopsies per protocol every 1-2 years. We examined M2BPGi levels and histological findings in relation to aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and AST/ALT ratio. Liver fibrosis was evaluated based on the METAVIR score. RESULTS: Total 18 liver biopsies out of eight patients were included. The median age was 11.5 years. Mean M2BPGi was 0.44 cutoff index (COI) in patients with F0 fibrosis, 0.78 COI in patients with F1 fibrosis and 1.63 COI in patients with F2 fibrosis. Mean M2BPGi was significantly higher in patients with F2 versus F1 or F0 fibrosis (P < 0.016 and P < 0.028, respectively). M2BPGi levels were more strongly correlated with fibrosis stage than with other conventional fibrosis markers. CONCLUSION: Serum M2BPGi is a novel marker of liver fibrosis in patients with IF. It is useful for follow-up prior to IFALD. Serum M2BPGi levels can support the interpretation of liver status.

Diagnosis and management of secondary causes of steatohepatitis.

The term non-alcoholic fatty liver disease (NAFLD) was originally coined to describe hepatic fat deposition as part of the metabolic syndrome. However, a variety of rare hereditary liver and metabolic diseases, intestinal diseases, endocrine disorders and drugs may underlie, mimic, or aggravate NAFLD. In contrast to primary NAFLD, therapeutic interventions are available for many secondary causes of NAFLD. Accordingly, secondary causes of fatty liver disease should be considered during the diagnostic workup of patients with fatty liver disease, and treatment of the underlying disease should be started to halt disease progression. Common genetic variants in several genes involved in lipid handling and metabolism modulate the risk of progression from steatosis to fibrosis, cirrhosis and hepatocellular carcinoma development in NAFLD, alcohol-related liver disease and viral hepatitis. Hence, we speculate that genotyping of common risk variants for liver disease progression may be equally useful to gauge the likelihood of developing advanced liver disease in patients with secondary fatty liver disease.

Prediction, identification and progression of histopathological liver disease activity in children with intestinal failure.

BACKGROUND & AIMS: Diagnostic criteria, progression risk and optimal monitoring for intestinal failure (IF)-associated liver disease (IFALD) remain undefined. We assessed predictors, non-invasive markers and progression of histopathological liver disease in patients with IF. METHODS: In total, 77 children with IF and median age of 1.7 years underwent diagnostic liver biopsy, which was repeated in 48 patients after 2.9 years with simultaneous evaluation of liver biochemistry, liver stiffness, serum citrulline (a surrogate for viable enterocyte mass), spleen size, esophageal varices and clinical data. Patients were staged according to histopathological liver disease activity: active IFALD (cholestasis and/or inflammation), chronic IFALD (significant fibrosis and/or steatosis), or no IFALD (none of these features). RESULTS: Diagnostic liver biopsy revealed active, chronic or no IFALD in 48%, 21% and 31% of patients. Active IFALD was segregated by low serum citrulline, parenteral nutrition (PN) dependency and young age, while weaning off PN and older age predicted chronic IFALD. Although the liver histopathology in most patients either normalized (52%) or transformed to a less reactive (chronic) disease stage (23%), 19% of patients retained and 6.3% progressed to an active cholestatic/inflammatory IFALD phenotype. Decreased serum citrulline and PN-dependency also predicted active IFALD in follow-up biopsies. Increased median liver biochemistry values and liver stiffness only associated with active IFALD, which was accurately identified by gamma-glutamyltransferase (GGT), citrulline and liver stiffness, their combinations reaching diagnostic and follow-up AUROC values above 0.90. CONCLUSIONS: Active IFALD, essentially predicted by intestinal disruption and PN-dependency, was accurately detected by GGT, liver stiffness and citrulline, which together with recent advances in clinical management options, provides new avenues for monitoring and targeted liver protection in patients with IF. LAY SUMMARY: Liver disease is a common and critical complication in patients with intestinal failure, who require intravenous nutrition for survival due to severe intestinal dysfunction. We showed that both intravenous nutrition dependency and intestinal disruption essentially predicted development of active histopathological liver disease, which persisted in 25% of patients during long-term follow-up and could be accurately detected without the need for liver biopsy. Identification of the active and potentially progressive histopathology offers new possibilities for monitoring and targeted liver protection in patients with intestinal failure.

Liver injury after small bowel resection is prevented in obesity-resistant 129S1/SvImJ mice.

Intestinal failure-associated liver disease is a major morbidity associated with short bowel syndrome. We sought to determine if the obesity-resistant mouse strain (129S1/SvImJ) conferred protection from liver injury after small bowel resection (SBR). Using a parenteral nutrition-independent model of resection-associated liver injury, C57BL/6J and 129S1/SvImJ mice underwent a 50% proximal SBR or sham operation. At postoperative week 10, hepatic steatosis, fibrosis, and cholestasis were assessed. Hepatic and systemic inflammatory pathways were evaluated using oxidative markers and abundance of tissue macrophages. Potential mechanisms of endotoxin resistance were also explored. Serum lipid levels were elevated in all mouse lines. Hepatic triglyceride levels were no different between mouse strains, but there was an increased accumulation of free fatty acids in the C57BL/6J mice. Histological and serum markers of hepatic fibrosis, steatosis, and cholestasis were significantly elevated in resected C57BL/6J SBR mice as well as oxidative stress markers and macrophage recruitment in both the liver and visceral white fat in C57BL/6J mice compared with sham controls and the 129S1/SvImJ mouse line. Serum endotoxin levels were significantly elevated in C57BL/6J mice with significant elevation of hepatic TLR4 and reduction in PPARα expression levels. Despite high levels of serum lipids, 129S1/SvImJ mice did not develop liver inflammation, fibrosis, or cholestasis after SBR, unlike C57BL/6J mice. These data suggest that the accumulation of hepatic free fatty acids as well as increased endotoxin-driven inflammatory pathways through PPARα and TLR4 contribute to the liver injury seen in C57BL/6J mice with short bowel syndrome.NEW & NOTEWORTHY Unlike C57BL/6 mice, the 129S1/SvImJ strain is resistant to liver inflammation and injury after small bowel resection. These disparate outcomes are likely due to the accumulation of hepatic free fatty acids as well as increased endotoxin-driven inflammatory pathways through PPARα and TLR4 in C57BL/6 mice with short bowel syndrome.

Fish Oil Emulsion Reduces Liver Injury and Liver Transplantation in Children with Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Study.

OBJECTIVE: To compare the aspartate aminotransferase to platelet ratio index, liver transplantation, and mortality rates between children with intestinal failure-associated liver disease who received fish oil lipid emulsion (FOLE) or soybean oil intravenous lipid emulsion (SOLE). STUDY DESIGN: In this multicenter integrated analysis, FOLE recipients (1 g/kg/d) (n = 189) were compared with historical controls administered SOLE (≤3 g/kg/d) (n = 73). RESULTS: Compared with SOLE, FOLE recipients had a higher direct bilirubin level at baseline (5.8 mg/dL vs 3.0 mg/dL; P < .0001). Among FOLE recipients, 65% experienced cholestasis resolution vs 16% of SOLE recipients (P < .0001). The aspartate aminotransferase to platelet ratio index scores improved in FOLE recipients (1.235 vs 0.810 and 0.758, P < .02) but worsened in SOLE recipients (0.540 vs 2.564 and 2.098; P ≤ .0003) when baseline scores were compared with cholestasis resolution and end of study, respectively. Liver transplantation was reduced in FOLE vs SOLE (4% vs 12%; P = .0245). The probability of liver transplantation in relation to baseline direct or conjugated bilirubin (DB) was lower in FOLE vs SOLE recipients (1% vs 9% at DB of 2 mg/dL; 8% vs 35% at DB of 12.87 mg/dL; P = .0022 for both). Death rates were similar (FOLE vs SOLE: 10% vs 14% at DB of 2 mg/dL; 17% vs 23% at a DB of 12.87 mg/dL; P = .36 for both). CONCLUSIONS: FOLE recipients experienced a higher rate of cholestasis resolution, lower aspartate aminotransferase to platelet ratio index, and fewer liver transplants compared with SOLE. This study demonstrates that FOLE may be the preferred parenteral lipid emulsion in children with intestinal failure-associated liver disease when DB reaches 2 mg/dL. TRIAL REGISTRATION: Clinicaltrials.gov: NCT00910104 and NCT00738101.

Approach to Intestinal Failure in Children.

PURPOSE OF REVIEW: Pediatric intestinal failure is a complex condition requiring specialized care to prevent potential complications. In this article, we review the available evidence supporting recent advances in care for children with intestinal failure. RECENT FINDINGS: Multidisciplinary intestinal rehabilitation teams utilize medical and surgical management techniques to help patients achieve enteral autonomy (EA) while preventing and treating the complications associated with intestinal failure. Recent advances in lipid management strategies, minimization of intestinal failure associated liver disease, prevention of central line-associated blood stream infections, and loss of access, as well as development of promising new hormone analogue therapy have allowed promotion of intestinal adaptation. These advances have decreased the need for intestinal transplant. There have been recent advances in the care of children with intestinal failure decreasing morbidity, mortality, and need for intestinal transplantation. The most promising new therapies involve replacement of enteroendocrine hormones.

What is the optimal lipid emulsion for preventing intestinal failure-associated liver disease following parenteral feeding in a rat model of short-bowel syndrome?

PURPOSE: Composite lipid emulsion (CLE) has been used for intestinal failure-associated liver disease (IFALD) to compensate for the disadvantages of soybean oil lipid emulsion (SOLE) or fish oil lipid emulsion (FOLE). However, the influence of its administration is unclear. We evaluated the effects of these emulsions on IFALD using a rat model of the short-bowel syndrome. METHODS: We performed jugular vein catheterization and 90% small bowel resection in Sprague-Dawley rats and divided them into four groups: control (C group), regular chow with intravenous administration of saline; and total parenteral nutrition co-infused with SOLE (SOLE group), CLE (CLE group) or FOLE (FOLE group). RESULTS: Histologically, obvious hepatic steatosis was observed in the SOLE and CLE groups but not the FOLE group. The liver injury grade of the steatosis and ballooning in the FOLE group was significantly better than in the SOLE group (p < 0.05). The TNF-α levels in the liver in the FOLE group were significantly lower than in the SOLE group (p < 0.05). Essential fatty acid deficiency (EFAD) was not observed in any group. CONCLUSION: Fish oil lipid emulsion attenuated hepatic steatosis without EFAD, while CLE induced moderate hepatic steatosis. The administration of CLE requires careful observation to prevent PN-induced hepatic steatosis.

Broad-spectrum antibiotics alter the microbiome, increase intestinal fxr, and decrease hepatic steatosis in zebrafish short bowel syndrome.

Short bowel syndrome (SBS) is associated with changes in the intestinal microbiome and marked local and systemic inflammation. There is also a late complication of SBS, intestinal failure associated liver disease (IFALD) in which hepatic steatosis progresses to cirrhosis. Most patients with SBS arrive at massive intestinal resection after a contaminating intraabdominal catastrophe and have a history of exposure to broad-spectrum antibiotics. We therefore investigated whether the administration of broad-spectrum antibiotics in conjunction with SBS in zebrafish (ZF) would replicate these systemic effects observed in humans to identify potentially druggable targets to aid in the management of SBS and resulting IFALD. In zebrafish with SBS, broad-spectrum antibiotics altered the microbiome, decreased inflammation, and reduced the development of hepatic steatosis. After two weeks of broad-spectrum antibiotics, these fish exhibited decreased alpha diversity, with less variation in microbial community composition between SBS and sham fish. Additionally, administration of broad-spectrum antibiotics was associated with decreased expression of intestinal toll-like receptor 4 (tlr4), increased expression of the intestinal gene encoding the Farnesoid X receptor (fxr), decreased expression of downstream hepatic cyp7a1, and decreased development of hepatic steatosis. SBS in zebrafish reproducibly results in increased epithelial surface area as occurs in human patients who demonstrate intestinal adaptation, but antibiotic administration in zebrafish with SBS reduced these gains with increased cell death in the intervillus pocket that contains stem/progenitor cells. These alternate states in SBS zebrafish might direct the development of future human therapies.NEW & NOTEWORTHY In a zebrafish model that replicates a common clinical scenario, systemic effects of the administration of broad-spectrum antibiotics in a zebrafish model of SBS identified two alternate states that led to the establishment of fat accumulation in the liver or its absence. Broad-spectrum antibiotics given to zebrafish with SBS over 2 wk altered the intestinal microbiome, decreased intestinal and hepatic inflammation, and decreased hepatic steatosis.

Remnant Intestinal Length Defines Intestinal Adaptation and Hepatic Steatosis: Two Zebrafish Models.

BACKGROUND: Short bowel syndrome (SBS) is a condition that results from inadequate intestinal absorptive capacity, usually after the loss of functional intestine. We have previously developed a severe model of SBS in zebrafish that demonstrated increased intestinal adaptation (IA) and epithelial proliferation in SBS zebrafish. However, many children with SBS do not have this extreme intestinal loss. Therefore, in this study, we developed a variation of this model to evaluate the effects of increasing intestinal length on IA and the complications of SBS. MATERIALS AND METHODS: After Institutional Animal Care and Use Committee approval, adult male zebrafish were assigned to three groups: sham (n = 30), S1-SBS (n = 30), and S3-SBS (n = 30). Sham surgery included ventral laparotomy alone. S1-SBS surgery consisted of laparotomy with creation of a proximal stoma at S1 (jejunostomy equivalent) and ligation at S4. S3-SBS surgery had stoma creation at S3 (ileostomy equivalent) and the same ligation. Fish were harvested at 14 d. Markers of IA were measured from proximal intestinal segments, and the liver was analyzed for development of hepatic steatosis. RESULTS: At 14 d, S3-SBS fish lost less weight than S1-SBS and had increased markers of IA compared with sham fish, which were decreased compared with S1-SBS fish. S3-SBS fish had decreased proximal intestinal inflammation compared with S1-SBS fish. S1-SBS fish developed extensive hepatic steatosis. Although S3-SBS fish have increased hepatic steatosis compared with sham fish, it is decreased compared with S1-SBS. CONCLUSIONS: Longer remnant intestine decreases the extent of IA, inflammation, and hepatic steatosis in a zebrafish model of SBS.

Intravenous Lipid Emulsions in Infants: Is Balanced Better?

Parenteral nutrition (PN) is frequently required by extremely preterm infants due to gastrointestinal immaturity and complications of prematurity. Parenteral nutrition-associated cholestasis (PNAC) and intestinal failure-associated liver disease (IFALD) are common complications of prolonged PN. Plant-based intravenous lipid emulsions, containing proinflammatory omega-6 fatty acids and phytosterols, may contribute to these conditions as well as other comorbidities such as bronchopulmonary dysplasia and retinopathy of prematurity. Intravenous lipid emulsions containing animal-based fats, such as fish oil, contain fewer proinflammatory omega-6 fatty acids and more anti-inflammatory omega-3 fatty acids and antioxidants. SMOFlipid, recently Food and Drug Administration (FDA)-approved for adult use, is a blend of plant- and animal-based lipid emulsions with a favorable omega-6:omega-3 ratio that may prevent the development and progression of PNAC/IFALD in infants. Careful review of data supporting this alternative intravenous lipid emulsion is required prior to widespread use in neonatal intensive care.

The protective effect of fish oil lipid emulsions on intestinal failure-associated liver disease in a rat model of short-bowel syndrome.

PURPOSE: Pediatric patients with intestinal failure need long-term parenteral nutrition (PN), but this nutritional support causes liver dysfunction, such as intestinal failure-associated liver disease (IFALD). Several studies have shown that the lipid emulsion produced by soybean oil (SO) is associated with the occurrence of IFALD. In this study, we evaluated the effect of SO and fish oil (FO) lipid emulsion on hepatic steatosis. METHODS: Sprague-Dawley rats underwent jugular vein catheterization and were divided into three groups: sham operation with normal chow (Sham group), 80% small bowel resection (80% SBR) + TPN with SO lipid emulsion (SO group), and 80% SBR + TPN with FO lipid emulsion (FO group). All rats were euthanized and the serum biochemistry and hepatic histology analyzed. RESULTS: No significant differences in the serum liver or biliary enzymes were noted between the SO and FO groups. The pathological findings and NAFLD score in the FO group did not show steatosis and were significantly lower than in the SO group. An analysis of the fatty acids profile in the both the SO and FO groups did not indicate essential fatty acid deficiency (EFAD). CONCLUSION: FO lipid emulsion may have a protective role against steatosis of IFALD without EFAD.

Transient elastography and aspartate aminotransferase to platelet ratio predict liver injury in paediatric intestinal failure.

BACKGROUND & AIMS: We aimed to evaluate the value of AST to platelet ratio (APRI) and transient elastography (TE) as predictors of liver histopathology in children with intestinal failure (IF). METHODS: Altogether 93 liver biopsies from 57 children with parenteral nutrition (PN) duration ≥3 months were analysed. APRI measurement and TE (n = 46) were performed at the time of biopsy. RESULTS: IF was caused by short bowel syndrome in 75% of patients. At the time of liver biopsy, PN dependent patients (n = 42) were younger with longer PN duration compared to those weaned off PN (n = 51) (2.2 vs. 7.6 years, P < 0.001; 26 vs. 10.5 months, P = 0.043). Elevated transaminase or bilirubin levels were found in 51%, splenomegaly in 26%, and oesophageal varices in 3.5%. Histological fibrosis was present in 61% (Metavir stage F1; 27%, F2; 26%, F3-4; 9%), cholestasis in 25% and steatosis in 22% of biopsy specimens. TE was superior to APRI in prediction of any liver histopathology (fibrosis, cholestasis or steatosis) with areas under the receiving operating curve (AUROC) of 0.86 (95% CI 0.74-0.97) and 0.67 (95% CI 0.58-0.78) respectively. For prediction of ≥F1 and ≥F2 fibrosis, AUROC values for TE were 0.78 (95% CI 0.64-0.93) and 0.73 (95% CI 0.59-0.88), whereas APRI did not correlate with fibrosis stages. For detection of histological cholestasis, the AUROC for APRI was 0.77 (95% CI 0.64-0.89). CONCLUSIONS: Both TE and APRI are promising noninvasive methods for monitoring the development of IF-related liver histopathology. TE values reflected the degree of fibrosis better while APRI detected histological cholestasis more accurately.

Short bowel syndrome (SBS)-associated alterations within the gut-liver axis evolve early and persist long-term in the piglet model of short bowel syndrome.

BACKGROUND AND AIM: Short bowel syndrome (SBS) is primarily characterized by malabsorption and malnutrition, resulting from loss of intestinal absorptive area following massive small bowel resection (SBR). Bile acids and the gut microbiota are functionally linked within the gut-liver axis; however, SBS-associated disturbances within the gut-liver axis remain largely unexplored. The aim of this study was to characterize the evolution of bile acid alterations within the gut-liver axis at both short-term and long-term time points and to relate these changes to alterations in colonic bacterial composition. METHODS: Four-week-old piglets were assigned to 75% SBR, sham-operation or non-operation control groups. High throughput sequencing was employed to determine bacterial abundance in colonic content and ultra-performance liquid chromatography used to determine the bile acid concentration of gall bladder, portal serum, and fecal samples. RESULTS: Bile acid complexity and relative abundance are altered in the SBS piglet model at two weeks post-SBR, and these changes persisted at six weeks post-SBR. Our examination of the microbial profile revealed an early and persistent loss in bacteria belonging to the Clostridiales order. CONCLUSIONS: This study provides evidence of an early and persistent disturbance of the bile acid profile throughout the entero-hepatic circulation with an increase in the proportion of primary bile acids and a decrease in secondary bile acids following SBR. These changes were associated with a loss of bacteria belonging to the Clostridiales order consistent with a disturbance in the bile-microbial axis following SBR.

Altered FXR signalling is associated with bile acid dysmetabolism in short bowel syndrome-associated liver disease.

BACKGROUND & AIMS: Despite the mortality associated with liver disease observed in patients with short bowel syndrome (SBS), mechanisms underlying the development of SBS-associated liver disease (SBS-ALD) are poorly understood. This study examines the impact of bacterially-mediated bile acid (BA) dysmetabolism on farnesoid X receptor (FXR) signalling pathways and clinical outcome in a piglet model of SBS-ALD. METHODS: 4-week old piglets underwent 75% small bowel resection (SBR) or sham operation. Liver histology and hepatic inflammatory gene expression were examined. Abundance of BA biotransforming bacteria was determined and metabolomic studies detailed the alterations in BA composition of stool, portal serum and bile samples. Gene expression of intestinal and hepatic FXR target genes and small heterodimer partner (SHP) transrepression targets were assessed. RESULTS: Histological evidence of SBS-ALD included liver bile duct proliferation, hepatocyte ballooning and fibrosis. Inflammatory gene expression was increased. Microbiota changes included a 10-fold decrease in Clostridium and a two-fold decrease in Bacteroides in SBS-ALD piglets. BA composition was altered and reflected a primary BA dominant composition. Intestinal and hepatic regulation of BA synthesis was characterised by a blunted intestinal FXR activation response and a failure of SHP to repress key hepatic targets. CONCLUSIONS: We propose a pathological scenario in which microbial dysbiosis following SBR results in significant BA dysmetabolism and consequent outcomes including steatorrhoea, persistent diarrhoea and liver damage. Furthermore alterations in BA composition may have contributed to the observed disturbance in FXR-mediated signalling pathways. These findings provide an insight into the complex mechanisms mediating the development of liver disease in patients with SBS.

Serum FGF21 increases with hepatic fat accumulation in pediatric onset intestinal failure.

BACKGROUND & AIMS: Previously, FGF21 has been related to glucose and lipid metabolism and liver steatosis. Our aim was to evaluate serum FGF21 levels in pediatric onset intestinal failure (IF). METHODS: Serum FGF21 was measured in 35 IF patients at median age of 7.8 years (range 0.2-27) and 59 matched healthy controls. Thirty patients underwent liver biopsy. RESULTS: Serum FGF21 levels were increased in patients compared to controls [229 pg/ml (21-20,345) vs. 133 pg/ml (7-1607), p=0.018]. Frequency of liver steatosis (60% vs. 50%, p=0.709) was similar during (6/10) and after (10/20) weaning off parenteral nutrition (PN). Patients with steatosis had markedly higher serum FGF21 concentration [626 pg/ml (21-20,345) vs. 108 pg/ml (32-568), p=0.002] and more advanced liver fibrosis [Metavir stage 1.6 (0-4) vs. 0.7 (0-3), p=0.020] without associated inflammation or Mallory body formation. Serum FGF21 levels reflected the degree of steatosis [FGF21 in grade 3 vs. grades 0-2, p<0.001; grade 1 vs. controls, p=0.002], and correlated with steatosis grade (r=0.589, p=0.001). Hepatic steatosis and serum FGF21 showed similar associations with duration of PN and remaining small bowel length (p<0.05 for all). In a multivariate regression model, liver steatosis grade (ß=0.630, p=0.001) predicted serum FGF21 concentration. CONCLUSIONS: In pediatric IF increased serum FGF21 levels reflect liver steatosis, while both are exclusively associated with duration of PN and extent of small intestinal resection. Liver steatosis is coupled with progression of fibrosis without accompanying inflammation. Serum FGF21 assay may be useful for diagnosing liver steatosis in IF patients.