Intestinal failure-associated liver disease: causes, manifestations and therapies

Intestinal failure-associated liver disease: Current challenges in screening, diagnosis, and parenteral nutrition considerations

Intestinal failure-associated liver disease (IFALD) is a serious life-limiting complication that can occur throughout the clinical course of intestinal failure and its management by parenteral nutrition (PN). Despite this, there is a lack of a standardized definition for IFALD, which makes this insidious condition increasingly difficult to screen and diagnose in clinical practice. Attenuating the progression of liver disease before the onset of liver failure is key to improving morbidity and mortality in these patients. This requires timely detection and promptly addressing reversible factors. Although there are various noninvasive tools available to the clinician to detect early fibrosis or cirrhosis in various chronic liver disease states, these have not been validated in the patient population with IFALD. Such tools include biochemical composite scoring systems for fibrosis, transient elastography, and dynamic liver function tests. This review article aims to highlight the existing real need for an accurate, reproducible method to detect IFALD in its early stages. In addition, we also explore the role PN plays in the pathogenesis of this complex multifactorial condition. Various aspects of PN administration have been implicated in the etiology of IFALD, including the composition of the lipid component, nutrient excess and deficiency, and infusion timing. We aim to highlight the clinical relevance of these PN-associated factors in the development of IFALD and how these can be managed to mitigate the progression of IFALD.

Lactobacillus plantarum supplementation alleviates liver and intestinal injury in parenteral nutrition-fed piglets

OBJECTIVE

Long-term parenteral nutrition (PN) causes parenteral nutrition-associated liver disease (PNALD) for which therapeutic approaches are limited. This study aimed to investigate the effects of Lactobacillus plantarum CGMCC 1258 (LP) on liver and intestinal injury in the PN-fed neonatal piglets.

METHODS

The piglets received PN with or without oral LP for 14 days. The levels of liver enzymes and inflammatory markers were measured using biochemical kits and q-RT-PCR. Serum fibroblast growth factor 19 (FGF19) was detected using an enzyme-linked immunosorbent assay (ELISA). The bile acid profiles in the liver, serum, and intestinal contents were determined using ultraperformance liquid chromatography coupled with mass spectrometry (UPLC-MS). The composition of intestinal bacteria was analyzed with 16S rRNA gene amplicon sequencing.

RESULTS

LP supplementation was associated with improved markers of liver disease, inflammation, and oxidative stress in PN-fed piglets. Moreover, markers of intestinal injury and inflammation were alleviated by LP in PN-fed piglets. Mechanistically, LP increased the abundance of Lactobacillus in ileal contents and stimulated FGF19 expression in ileal mucosa. Subsequently, it increased the expression of small heterodimer partner (SHP) and inhibited cholesterol 7α-hydroxylase (CYP7A1) expression in the liver. Additionally, LP altered the systemic composition and metabolism of bile acids.

CONCLUSIONS

LP alleviated liver and intestinal injury in PN-fed neonatal piglets by altering the composition of intestinal bacteria and bile acids. This article is protected by copyright. All rights reserved.

Parenteral Nutrition and Oxidant Load in Neonates

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

New insights into intestinal failure-associated liver disease in adults: A comprehensive review of the literature

Intestinal failure-associated liver disease (IFALD) remains one of the most common and serious complications of parenteral nutrition (PN), causing a wide spectrum of hepatic manifestations from steatosis and mild cholestasis to portal hypertension and end-stage liver failure. The prevalence of IFALD depends on the diagnostic criteria and ranges from 4.3% to 65%. Moreover, many factors are shown to contribute to its development, including nutrient deficiencies, toxicity of PN, infections, and alterations of bile acid metabolism and gut microbiota. Prevention and management of IFALD aim at ameliorating or eliminating the risk factors associated with IFALD. The use of PN formulations with a lower ratio omega-6-to-omega-3 polyunsaturated fatty acids, cycle PN, optimization of enteral stimulation and prevention and early treatment of infections constitute the main therapeutic targets. However, failure of improvement and severe IFALD with end-stage liver failure should be considered as the indications of intestinal transplantation. The aim of this review is to provide an update of the epidemiology, pathophysiology, and diagnosis of IFALD in the adult population as well as to present a clinical approach of the therapeutic strategies of IFALD and present novel therapeutic targets.

Development and validation of an ambulatory piglet model for short bowel syndrome with ileo-colonic anastomosis

IMPACT STATEMENT

Short bowel syndrome is associated with significant comorbidities and mortality. This study is important as unlike current systems, it provides a validated piglet model which mirrors anatomical, histological, and serological characteristics observed in human SBS. This model can be used to advance knowledge into mechanistic pathways and therapeutic modalities to improve outcomes for SBS patients. This study is novel in that in addition to significant reduction in the remnant bowel and noted liver disease, we also developed a method to emulate ileocecal valve resection and described gut adaptive responses which has important clinical implications in humans.

Impaired Gut-Systemic Signaling Drives Total Parenteral Nutrition-Associated Injury

BACKGROUND

Total parenteral nutrition (TPN) provides all nutritional needs intravenously. Although lifesaving, enthusiasm is significantly tempered due to side effects of liver and gut injury, as well as lack of mechanistic understanding into drivers of TPN injury. We hypothesized that the state of luminal nutritional deprivation with TPN drives alterations in gut-systemic signaling, contributing to injury, and tested this hypothesis using our ambulatory TPN model.

METHODS

A total of 16 one-week-old piglets were allocated randomly to TPN (n = 8) or enteral nutrition (EN, n = 8) for 3 weeks. Liver, gut, and serum were analyzed. All tests were two-sided, with a significance level of 0.05.

RESULTS

TPN resulted in significant hyperbilirubinemia and cholestatic liver injury, p = 0.034. Hepatic inflammation (cluster of differentiation 3 (CD3) immunohistochemistry) was higher with TPN (p = 0.021). No significant differences in alanine aminotransferase (ALT) or bile ductular proliferation were noted. TPN resulted in reduction of muscularis mucosa thickness and marked gut atrophy. Median and interquartile range for gut mass was 0.46 (0.30-0.58) g/cm in EN, and 0.19 (0.11-0.29) g/cm in TPN (p = 0.024). Key gut-systemic signaling regulators, liver farnesoid X receptor (FXR; p = 0.021), liver constitutive androstane receptor (CAR; p = 0.014), gut FXR (p = 0.028), G-coupled bile acid receptor (TGR5) (p = 0.003), epidermal growth factor (EGF; p = 0.016), organic anion transporter (OAT; p = 0.028), Mitogen-activated protein kinases-1 (MAPK1) (p = 0.037), and sodium uptake transporter sodium glucose-linked transporter (SGLT-1; p = 0.010) were significantly downregulated in TPN animals, whereas liver cholesterol 7 alpha-hydroxylase (CyP7A1) was substantially higher with TPN (p = 0.011).

CONCLUSION

We report significant alterations in key hepatobiliary receptors driving gut-systemic signaling in a TPN piglet model. This presents a major advancement to our understanding of TPN-associated injury and suggests opportunities for strategic targeting of the gut-systemic axis, specifically, FXR, TGR5, and EGF in developing ameliorative strategies.

Hepatobiliary Complications of Chronic Intestinal Failure

Intestinal failure-associated liver disease is a multifactorial process that may occur in patients with chronic intestinal failure on long-term home parenteral nutrition. A very short gut, the lack of enteral feeding, recurrent sepsis, and parenteral overfeeding are major risk factors. Histologic changes include steatosis, steatohepatitis, cholestasis, fibrosis, and cirrhosis. Chronic cholestasis is common, but does not always progress to fibrosis and/or cirrhosis. Preventing harmful factors may dramatically decrease the risk of intestinal failure-associated liver disease. Advanced liver disease is an indication for intestinal and/or multivisceral transplantation. Biliary stone formation is frequent and mainly due to a lack of enteral feeding.