Parenteral Nutrition-associated Liver Disease Research Articles

The Use of Milk Bovine Extracellular Vesicles to Mitigate Gut-Liver Axis Dysfunction Under Pediatric Parenteral Nutrition

Parenteral Nutrition (PN) is a lifesaving strategy that provides intravenous nutrition in patients when enteral feeding is contraindicated, or access is insuffcient to prevent malnutrition. PN is used in low-birth-weight neonates whereprolonged use is associated with severe metabolic complications, including parenteral nutrition-associated liver disease (PNALD). PNALD is characterized by hepatitis, cholestasis, fibrosis, steatosis, and eventual organ failure. Elevated rates of PNALD in pediatric patients may be driven by liver immaturity, aberrant metabolic adaptation, and leaky gut barrier.To characterize the etiology of PNALD, we recently established a pediatric mouse model of PN. Using this model, we explored the intravenous use of bioactive milk components to augment hepatic immune response in pediatric mice without enteral milk intake. Extracellular vesicles (EVs) are involved in cell-to-cell communication, contain immune-augmenting microRNA, and are enriched in bovine milk. After isolating EVs from bovine milk and characterizing them, we explored EV use in vitro via M1 macrophage responses, showing TNF-alpha inhibition in the presence of LPS. Wethen hypothesized that EVs would protect the pediatric liver from hepatitis under PN feeding in vivo. Mouse pups were randomized to intravenous PN, PN + EV (1.39x109 particles/uL), or sham surgery control for 6 days. Flow cytometry showed PN elevated hepatic macrophages (CD11b+F4/80+), myeloid-derived suppressor cells (CD11b+GR1+) andreduced relative T cell populations compared with sham controls. PN+EV treatment restored hepatic immune profiles to patterns observed in sham controls. Spleen and liver cytokines also mirrored changes in hepatic flow results, where elevated proinflammatory IL-1 beta was induced with PN alone, but similar levels were found in sham and PN+EVanimals. MicroRNA sequencing showed the EV isolates contain 48% Let-7, a described myeloid suppressor microRNA. This data demonstrates that intravenous EV administration - or future synthetic microRNA - may provide a noveltherapeutic approach for patients requiring PN nutrition support, especially those with elevated risk of PNALD induced inflammation and organ dysfunction. Dairy Innovation Hub, UW-Madison. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Parenteral nutrition emulsion inhibits CYP3A4 in an iPSC derived liver organoids testing platform.

Parenteral nutrition (PN) is used for patients of varying ages with intestinal failure to supplement calories. Premature newborns with low birth weight are at a high risk for developing PN associated liver disease (PNALD) including steatosis, cholestasis, and gallbladder sludge/stones. To optimize nutrition regimens, models are required to predict PNALD. We have exploited induced pluripotent stem cell derived liver organoids to provide a testing platform for PNALD. Liver organoids mimic the developing liver and contain the different hepatic cell types. The organoids have an early postnatal maturity making them a suitable model for premature newborns. To mimic PN treatment we used medium supplemented with either clinoleic (80% olive oil/20% soybean oil) or intralipid (100% soybean oil) for 7 days. Homogenous HNF4a staining was found in all organoids and PN treatments caused accumulation of lipids in hepatocytes. Organoids exhibited a dose dependent decrease in CYP3A4 activity and expression of hepatocyte functional genes. The lipid emulsions did not affect overall organoid viability and glucose levels had no contributory effect to the observed results. Liver organoids could be utilized as a potential screening platform for the development of new, less hepatotoxic PN solutions. Both lipid treatments caused hepatic lipid accumulation, a significant decrease in CYP3A4 activity and a decrease in the RNA levels of both CYP3A4 and CYP1A2 in a dose dependent manner. The presence of high glucose had no additive effect, while Clinoleic at high dose, caused significant upregulation of interleukin 6 and TLR4 expression.

Lactobacillus johnsonii Attenuates Liver Steatosis and Bile Acid Dysregulation in Parenteral Nutrition-Fed Rats.

Parenteral nutrition (PN), a vital therapy for patients with intestinal failure, can lead to the development of parenteral nutrition-associated liver disease (PNALD). In this study, we aimed to investigate the role of Lactobacillus johnsonii (L. johnsonii) in a rat model of PNALD. Total parenteral nutrition (TPN)-fed rats were used to assess the role of L. johnsonii in liver steatosis, bile acid metabolism, gut microbiota, and hepatocyte apoptosis. We observed a depletion of L. johnsonii that was negatively correlated with the accumulation of glycochenodeoxycholic acid (GCDCA), a known apoptosis inducer, in rats subjected to TPN. L. johnsonii attenuated TPN-induced liver steatosis by inhibiting fatty acid synthesis and promoting fatty acid oxidation. TPN resulted in a decrease in bile acid synthesis and biliary bile secretion, which were partially restored by L. johnsonii treatment. The gut microbial profile revealed depletion of pathogenic bacteria in L. johnsonii-treated rats. L. johnsonii treatment reduced both hepatic GCDCA levels and hepatocyte apoptosis compared with the TPN group. In vitro, L. johnsonii treatment inhibited GCDCA-induced hepatocyte apoptosis via its bile salt hydrolase (BSH) activity. Our findings suggest that L. johnsonii protects against liver steatosis, bile acid dysregulation, and hepatocyte apoptosis in TPN-fed rats.

Complications and Outcomes of Nutritional Guidelines Implementation in Low Birth Weight Infants

Background: Necrotizing enterocolitis (NEC) is one of the most disastrous complications of premature infants. Using preterm feeding protocols can decrease NEC risk and improve feeding intolerance. Objective: To compare the rate of NEC and other comorbidities between low-birth-weight (LBW) infants that received a Bhumibol Adulyadej Hospital (BAH) standardized feeding protocol and those that underwent previous nutritional practice. Materials and Methods: A quasi-experimental study was conducted at neonatal intensive care unit (NICU) in BAH, Thailand. Participants were LBW newborns delivered at BAH between December 1, 2018 and March 31, 2020. The subjects were divided into the control group who underwent previous nutritional practice and the study group who were implemented with a new nutritional guideline. Primary outcome was NEC rate. Secondary outcomes were preterm complications such as neonatal sepsis, catheter-related bloodstream infection, parenteral nutrition-associated liver disease, osteopenia of prematurity, and intraventricular hemorrhage. Feeding achievement outcomes and growth outcome parameters were also evaluated. Results: Data were analyzed on 71 infants in the control group and 68 infants in the study group. The rate of NEC was not different between the two groups with 7% in the control versus 5.9% in the study (p=1.000). In addition, other preterm complications were not different between groups. However, the time to reaching full enteral feeding was shorter in the study group at 14 in the control versus 10 in the study (p<0.001). Day of life when the fortification start was significantly earlier in the study group at 15.5 in the control versus 12 in the study (p=0.008). Other feeding achievement outcomes also improved, which was evidenced by fewer parenteral nutrition (PN) days at 11.55 in the control versus 7.0 in the study (p=0.004) and shorter duration of indwelling central line at 9.5 in the control versus 7 in the study (p=0.001). Conclusion: Initiation of the new nutritional guideline produced a lower rate of NEC as compared to previous practice. Furthermore, the time to full enteral feeding, PN days, and central line days were decreased without increasing other preterm complications. Keywords: Low birth weight; Nutrition; Complication; NEC

Guidelines for parenteral nutrition in preterm infants: The American Society for Parenteral and Enteral Nutrition.

Parenteral nutrition (PN) is prescribed for preterm infants until nutrition needs are met via the enteral route, but unanswered questions remain regarding PN best practices in this population. An interdisciplinary committee was assembled to answer 12 questions concerning the provision of PN to preterm infants. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) process was used. Questions addressed parenteral macronutrient doses, lipid injectable emulsion (ILE) composition, and clinically relevant outcomes, including PNALD, early childhood growth, and neurodevelopment. Preterm infants with congenital gastrointestinal disorders or infants already diagnosed with necrotizing enterocolitis or PN-associated liver disease (PNALD) at study entry were excluded. The committee reviewed 2460 citations published between 2001 and 2023 and evaluated 57 clinical trials. For most questions, quality of evidence was very low. Most analyses yielded no significant differences between comparison groups. A multicomponent oil ILE was associated with a reduction in stage 3 or higher retinopathy of prematurity (ROP) compared to an ILE containing 100% soybean oil. For all other questions, expert opinion was provided. Most clinical outcomes were not significantly different between comparison groups when evaluating timing of PN initiation, amino acid dose, and ILE composition. Future clinical trials should standardize outcome definitions to permit statistical conflation of data, thereby permitting more evidence based recommendations in future guidelines. This guideline has been approved by the ASPEN 2022-2023 Board of Directors.

Targeted metabolomics unravels altered phenylalanine levels in piglets receiving total parenteral nutrition.

Parenteral nutrition, received by many patients with intestinal failure, can induce hepatobiliary complications, which is termed as parenteral nutrition-associated liver disease (PNALD). The spectrum of PNALD ranges from cholestasis and steatosis to fibrosis and cirrhosis. Although many factors contribute to the pathogenesis of PNALD, the underlying mechanisms remain unclear. In this study, we performed targeted metabolomics to characterize the metabolomic profile in neonatal piglets receiving total parenteral nutrition (TPN) or enteral nutrition (EN) for 1 or 2 weeks. Overall, the metabolomic signature of TPN groups differed from EN groups at both time points. Among the 20 acylcarnitines identified, a majority of them were significantly reduced in TPN groups. KEGG pathway analysis showed that phenylalanine metabolism-associated pathways were dysregulated accompanied by more progressive liver steatosis associated with TPN. Next, we evaluated phenylalanine catabolism and its association with fatty acid oxidation in piglets and rats with PNALD. We showed that the hepatic expression of phenylalanine-degrading enzyme phenylalanine hydroxylase (PAH) was reduced and systemic phenylalanine levels were increased in both animal models of PNALD. Moreover, carnitine palmitoyltransferase 1A, a central regulator of fatty acid oxidation, was downregulated and its expression was negatively correlated with phenylalanine levels in TPN-fed animals. To explore the effects of phenylalanine accumulation on lipid metabolism, we treated HepG2 cells with phenylalanine co-cultured with sodium palmitate or soybean oil emulsion to induce lipid accumulation. We found that phenylalanine treatment exacerbated lipid accumulation by inhibiting fatty acid oxidation without affecting fatty acid synthesis. In summary, our findings establish a pathogenic role of increased phenylalanine levels in driving liver steatosis, linking dysregulation of phenylalanine catabolism with lipid accumulation in the context of PNALD.

Proinflammatory mediators in lipid emulsions and parenteral-nutrition associated liver disease: Review of leading factors.

Lipid injectable emulsions have been in clinical use for over 60 years. The first product launched was Intralipid, which consisted of an emulsion of soybean oil in water for intravenous administration. It was a key source of essential fatty acids and an alternative source of energy for patients with gastrointestinal dysfunction requiring long-term parenteral nutrition. With clinical experience, a condition known as parenteral nutrition-associated liver disease (PNALD), or intestinal failure-associated liver disease (IFALD), was observed, with a focus on carbohydrate and fat energy. Modifying the daily doses and infusion rates had some salutary effects, but PNALD persisted. Subsequently, on closer inspection of the fatty acids profile and phytosterol concentrations, degradation products arising from chemical and physical stability issues of the available lipid injectable emulsions were implicated. Recently, the US Food and Drug Administration convened an online workshop entitled "The Role of Phytosterols in PNALD/IFALD," with an emphasis on (1) the multifactorial pathophysiology of PNALD/IFALD, (2) risk associated with phytosterols, and (3) regulatory history. The scope of this review includes the multifactorial pathophysiology of PNALD/IFALD as it relates to the pharmaceutical aspects of the various lipid injectable emulsions on the market, with respect to potential proinflammatory components, as well as physical and chemical stability issues that may also affect products' safe intravenous administration to patients.

Incidence And Risk Factors Of Parenteral Nutrition-Associated Liver Disease In Surgical Infants With Very Low Birth Weight

Incidence And Risk Factors Of Parenteral Nutrition-Associated Liver Disease In Surgical Infants With Very Low Birth Weight

Association between congenital heart disease and parenteral nutrition-associated liver disease in neonates: A retrospective cohort study.

Infants receiving parenteral nutrition (PN) are at increased risk of PN-associated liver disease (PNALD), which can lead to hepatic fibrosis. Congenital heart disease (CHD) represents a risk factor for hepatic fibrosis, so this study sought to better understand whether infants with CHD were at elevated risk of PNALD when receiving long-term PN. This study includes a retrospective cohort of infants at a level IV neonatal intensive care unit from 2010 to 2020 who received long-term PN during the first 8 weeks of life. A time-varying Cox survival model was used to model risk of PNALD between infants with and without CHD, adjusted for demographics, surgical intervention, and PN exposure, using a 5000-iteration bootstrap estimation. Secondary analyses evaluated risk against discrete CHD diagnoses, and sensitivity analysis was performed on the magnitude and quantity of direct bilirubin laboratory measurements making up the PNALD definition. Neonates with CHD were found to be at higher risk for PNALD during or soon after long-term PN exposure. A pattern of increasing association strength with increasing bilirubin threshold suggests infants with CHD may also experience higher degrees of injury. This work offers a step in understanding how diagnoses can be factored into neonate PN prescription. Future work will explore modifications in lipid profiles and timing to mitigate risk in patients with CHD.

Necrotizing Enterocolitis: The Role of Hypoxia, Gut Microbiome, and Microbial Metabolites.

Necrotizing enterocolitis (NEC) is a life-threatening disease that predominantly affects very low birth weight preterm infants. Development of NEC in preterm infants is accompanied by high mortality. Surgical treatment of NEC can be complicated by short bowel syndrome, intestinal failure, parenteral nutrition-associated liver disease, and neurodevelopmental delay. Issues surrounding pathogenesis, prevention, and treatment of NEC remain unclear. This review summarizes data on prenatal risk factors for NEC, the role of pre-eclampsia, and intrauterine growth retardation in the pathogenesis of NEC. The role of hypoxia in NEC is discussed. Recent data on the role of the intestinal microbiome in the development of NEC, and features of the metabolome that can serve as potential biomarkers, are presented. The Pseudomonadota phylum is known to be associated with NEC in preterm neonates, and the role of other bacteria and their metabolites in NEC pathogenesis is also discussed. The most promising approaches for preventing and treating NEC are summarized.

Exclusive Fish Oil Lipid Emulsion Rescue Strategy Improves Cholestasis in Neonates on Partially Fish Oil-Based Lipid Emulsion: A Pilot Study.

Resolution of parenteral nutrition-associated liver disease has been identified in infants receiving SMOFlipid™ or a 100% fish oil lipid emulsion (FOLE). However, the effect of FOLE is unknown when the previous emulsion received is a mixed lipid emulsion containing fish oil. This observational pilot study reports data regarding the use of Omegaven™ after the diagnosis of cholestasis while receiving SMOFlipid™. We conducted a retrospective review of medical charts of neonates in which a partially fish oil-based lipid emulsion was replaced by a fish oil lipid emulsion at 1 g/kg/day due to cholestasis. Thirty-eight infants (92.1% preterm, being 44.7% born below 28 weeks' gestation), received FOLE. Birth weight was 1390 (743.0; 2298) grams. The age that cholestasis diagnosed was 15.0 (10.0; 24.8) days. The fish oil emulsion was administered for 38.5 (11.2; 51.8) days. In 73.7% (28/38) of the neonates, the cholestasis was resolved. In 34.2% (13/38), resolution happened before FOLE discontinuation. In addition, in the rest of the neonates (15) in whom cholestasis resolved, resolution occurred after FOLE discontinuation. Nine of the neonates died. In conclusion, the use of a 100% fish oil-based emulsion in neonates afflicted with cholestasis developed while on a partially fish oil-based emulsion is associated with a bilirubin decrease.

Fibroblast growth factor 19 secretion and function in perinatal development.

Limited work has focused on fibroblast growth factor-19 (FGF19) secretion and function in the perinatal period. FGF19 is a potent growth factor that coordinates development of the brain, eye, inner ear, and skeletal system in the embryo, but after birth, FGF19 transitions to be an endocrine regulator of the classic pathway of hepatic bile acid synthesis. FGF19 has emerged as a mediator of metabolism and bile acid synthesis in aged animals and adults in the context of liver disease and metabolic dysfunction. FGF19 has also been shown to have systemic insulin-sensitizing and skeletal muscle hypertrophic effects when induced or supplemented at supraphysiological levels in adult rodent models. These effects could be beneficial to improve growth and nutritional outcomes in preterm infants, which are metabolically resistant to the anabolic effects of enteral nutrition. Existing clinical data on FGF19 secretion and function in the perinatal period in term and preterm infants has been equivocal. Studies in pigs show that FGF19 expression and secretion are upregulated with gestational age and point to molecular and endocrine factors that may be involved. Work focused on FGF19 in pediatric diseases suggests that augmentation of FGF19 secretion by activation of gut FXR signaling is associated with benefits in diseases such as short bowel syndrome, parenteral nutrition-associated liver disease, and biliary atresia. Future work should focus on characterization of FGF19 secretion and the mechanism underpinning the transition of FGF19 function as an embryological growth factor to metabolic and bile acid regulator.

Down regulation of NDUFS1 is involved in the progression of parenteral-nutrition-associated liver disease by increasing Oxidative stress

Parenteral nutrition (PN)-associated liver disease (PNALD) is a common and life-threatening complication of patients receiving PN. However, its definitive pathology remains unclear. Ubiquinone oxidoreductase core subunit S1 (NDUFS1), which is the largest core subunit of mitochondrial complex I, could alter the mitochondrial reactive oxygen species (ROS) formation. The purpose of this study was to investigate the role of NDUFS1 in the pathogenesis of PNALD and its underlying mechanism. We performed hepatic proteomics analysis of PNALD patients, and established a PNALD rat model to verify the role of oxidative stress, NDUFS1, pyrin inflammasome, and IL-1β in the progression of PNALD.Proteomics analysis revealed the NDUFS1 expression was decreased in PNALD patients, and the differentially espressed proteins were involved in mitochondrial respiratory chain complex Ⅰ. Treatment with MitoQ or overexpression of NDUFS1 can alleviate the progression of PNALD by reducing oxidative stress. The expression of pyrin, caspase-1, and IL-1β was increased in PN rats. Pharmacological antagonism of pyrin by colchicine can alleviate liver injury and hepatic steatosis.NDUFS1 prevents PNALD pathogenesis by regulating oxidative stress. Pyrin inflammasome and IL-1β may participate in the process of PNALD development by suppressing the transcription of MTTP and impairing the secretion of VLDL. Oxidative stress reduction may be employed as a strategy in the prevention and treatment of PNALD.

Early predictors of liver injury in patients on parenteral nutrition.

Parenteral nutrition-associated liver disease (PNALD) is diagnosed after at least 2 weeks of total parenteral nutrition (PN). However, its symptoms may occur early during PN. The aim of this study was to determine the early biochemical predictors of PNALD. This cross-sectional retrospective study included 160 patients on total parenteral nutrition. The clinical and laboratory data collected during parenteral nutrition were analyzed. Patients were assessed before the onset, on the 2nd, 7th and on the 14th day of PN according to the definition of PNALD and in search for predominant liver function tests findings. Out of 160 patients, 21 fulfilled the laboratory criteria of PNALD on the 14th day of PN. In the group of patients with PNALD, 14 met these criteria on the 7th day of PN. In multivariate logistic analyses the laboratory criteria of PNALD met on the 7th day of PN (OR=5637; 95%Cl: 1.162-33.578; p-value=.039) were found to be of predictive value for PNALD on the 14th day. In PNALD group the 1.5-fold elevation of GGTP activity above upper limit of norm was the most prominent laboratory finding during the fourteen-day course of PN. The percentage of patients with 1.5-fold increased activity of GGTP varied in time from 76.2% to 95.2% on the 2nd and 14th day of PN, respectively. PNALD may be predicted by liver function monitoring after seven days of PN.

Lipid emulsion rich in n–3 polyunsaturated fatty acids elicits a pro-resolution lipid mediator profile in mouse tissues and in human immune cells

Lipid emulsions are a key component of total parenteral nutrition (TPN) and are administered to patients who are unable to ingest their daily required calories orally. Lipid emulsions rich with n-6 (ω-6) PUFAs are known to cause parenteral nutrition-associated liver disease and have inflammatory side effects, whereas n-3 PUFA-rich emulsions have favourable clinical outcomes. The present study used targeted lipid mediator analysis to investigate the metabolism of a n-3 PUFA-rich lipid emulsion and a n-6 PUFA-rich lipid emulsion in a mouse model of TPN and in primary human monocyte-derived macrophages (MDMs) and CD4+ T cells. Mice given n-3 PUFA-based TPN for 7 d had a less proinflammatory lipid mediator profile compared with those receiving n-6 PUFA-based TPN. This was characterized by higher concentrations of specialized pro-resolving mediators (SPMs) and endocannabinoids, including resolvin D (RvD) 1, maresin (MaR) 1, MaR2, protectin D1 (PD1), protectin DX (PDX), and the endocannabinoids eicosapentaenoyl ethanolamide (EPEA) and docosahexaenoyl ethanolamide (DHEA) in the liver and RvD1, 17R-RvD1, RvD2, RvD3, RvD5, MaR1, MaR2, PD1, PDX, and EPEA and DHEA in the spleen. The spleen was identified as a source of high lipid mediator and SPM formation as lipid mediator concentrations were on average 25-fold higher than in the liver. Additionally, n-3 PUFA-treated primary human MDMs produced RvD5 and the endocannabinoids EPEA and DHEA, which was associated with an increased IL-10 secretion. In contrast, primary human CD4+ T cells showed only an increase in SPM precursors and an increase in the endocannabinoids EPEA and DHEA, which was associated with reduced cytokine expression. This demonstrates that lipid mediators, particularly SPMs and endocannabinoids from spleen, could play a key role in facilitating the favorable clinical outcomes associated with the use of n-3 PUFA-rich lipid emulsions in TPN.

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

Long-term parenteral nutrition (PN) causes PN-associated liver disease, 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 PN-fed neonatal piglets. 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 quantitative real-time polymerase chain reaction. Serum fibroblast growth factor 19 (FGF19) was detected using an enzyme-linked immunosorbent assay. The bile acid (BA) profiles in the liver, serum, and intestinal contents were determined using ultraperformance liquid chromatography coupled with mass spectrometry. The composition of intestinal bacteria was analyzed with 16S rRNA gene amplicon sequencing. 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 BAs. LP alleviated liver and intestinal injury in PN-fed neonatal piglets by altering the composition of intestinal bacteria and BAs.

Providing the Best Parenteral Nutrition before and after Surgery for NEC: Macro and Micronutrients Intakes.

Necrotizing enterocolitis (NEC) is the main gastrointestinal emergency of preterm infants for whom bowel rest and parenteral nutrition (PN) is essential. Despite the improvements in neonatal care, the incidence of NEC remains high (11% in preterm newborns with a birth weight <1500 g) and up to 20–50% of cases still require surgery. In this narrative review, we report how to optimize PN in severe NEC requiring surgery. PN should begin as soon as possible in the acute phase: close fluid monitoring is advocated to maintain volemia, however fluid overload and electrolytes abnormalities should be prevented. Macronutrients intake (protein, glucose, and lipids) should be adequately guaranteed and is essential in each phase of the disease. Composite lipid emulsion should be the first choice to reduce the risk of parenteral nutrition associated liver disease (PNALD). Vitamin and trace elements deficiency or overload are frequent in long-term PN, therefore careful monitoring should be planned starting from the recovery phase to adjust their parenteral intake. Neonatologists must be aware of the role of nutrition especially in patients requiring long-term PN to sustain growth, limiting possible adverse effects and long-term deficiencies.

Carbamazepine mitigates parenteral nutrition-associated liver disease in a novel ambulatory piglet model.

Parenteral nutrition (PN) remains a critical therapeutic option in patients who cannot tolerate enteral feeding. However, although lifesaving, PN is associated with significant side effects, including liver injury, the etiology of which is multifactorial. Carbamazepine (CBZ), an antiepileptic medication, is known to modulate hepatic fibrosis and hepatocellular injury in a variety of liver diseases. We hypothesized that CBZ could prevent PN-associated liver disease (PNALD), which we tested by using our novel ambulatory PN piglet model. Piglets were fitted with jugular catheters and infusion pumps for PN and randomized to enteral nutrition (n = 7), PN (n = 6), or PN with parenteral CBZ (n = 6) for 2 weeks. Serum and liver tissue were analyzed via light microscopy, quantification of serum liver injury markers, Ki67 and cytokeratin-7 indexing, and real-time quantitative polymerase chain reaction. PN-fed piglets in our model developed manifestations of PNALD-particularly, increased serum bilirubin, gamma-glutamyltransferase, liver cholestasis, and Ki67 expression compared with that of EN-fed animals (P < 0.03). CBZ therapy in PN-fed animals led to a significant reduction in these markers of injury (P < 0.05). Investigation into the mechanism of these therapeutic effects revealed increased expression of sterol regulatory element-binding protein 1 (SREBP-1), peroxisome proliferator-activated receptor alpha (PPAR-α), and fatty acid binding protein (FABP) in PN-fed animals receiving CBZ (P < 0.03). Further investigation revealed increased LC3 expression and decreased lysosomal-associated membrane protein (LAMP1) expression with CBZ (P < 0.03). CBZ administration mitigates PNALD severity, suggesting a novel therapeutic strategy targeting PN-associated side effects, and may present a paradigm change to current treatment options.

Beyond lipids: Novel mechanisms for parenteral nutrition-associated liver disease.

Parenteral nutrition (PN) is a therapy that delivers essential nutrients intravenously to patients who are unable to meet their nutrition requirements via standard enteral feeding. This methodology is often referred to as PN when accompanied by minimal or no enteral nutrition (EN). Although PN is lifesaving, significant complications can arise, such as intestinal failure-associated liver disease and gut-mucosal atrophy. The exact mechanism of injury remains ill defined. This review was designed to explore the available literature related to the drivers of injury mechanisms. The Farnesoid X receptor and fibroblast growth factor 19 signaling pathway seems to play an important role in gut-systemic signaling, and its alteration during PN provides insights into mechanistic links. Central line infections also play a key role in mediating PN-associated injury. Although lipid reduction strategies, as well as the use of multicomponent lipid emulsions and vitamin E, have shown promise, the cornerstone of preventing injury is the early establishment of EN.

Role of the Gut Microbiota in Parenteral Nutrition–Associated Liver Disease: From Current Knowledge to Future Opportunities

Parenteral nutrition–associated liver disease (PNALD) refers to a spectrum of conditions that can develop cholestasis, steatosis, fibrosis, and cirrhosis in the setting of parenteral nutrition (PN) use. Patient risk factors include short bowel syndrome, bacterial overgrowth and translocation, disturbance of hepatobiliary circulation, and lack of enteral feeding. A growing body of evidence suggests an intricate linkage between the gut microbiota and the pathogenesis of PNALD. In this review, we highlight current knowledge on the taxonomic and functional changes in the gut microbiota that might serve as noninvasive biomarkers. We also discuss the function of microbial metabolites and associated signaling pathways in the pathogenesis of PNALD. By providing the perspectives of microbiota-host interactions in PNALD for basic and translational research and summarizing current limitations of microbiota-based approaches, this review paves the path for developing novel and precise microbiota-based therapies in PNALD.