Pathophysiology, prevention, treatment, and outcomes of intestinal failure-associated liver disease

Suppressor T helper type 17 cell responses in intestinal transplant recipients with allograft rejection

BACKGROUND

Intestinal transplant (ITx) rejection is associated with memory T helper type 17 cell (Th17) infiltration of grafted tissues. Modulation of Th17 effector cell response is facilitated by T regulatory (Treg) cells, but a phenotypic characterization of this process is lacking in the context of allograft rejection.

METHODS

Flow cytometry was performed to examine the expression of surface receptors, cytokines, and transcription factors in Th17 and Treg cells in ITx control (n = 34) and rejection patients (n = 23). To elucidate key pathways guiding the rejection biology, we utilized RNA sequencing (RNAseq) and assessed epigenetic stability through pyrosequencing of the Treg-specific demethylated region (TSDR).

RESULTS

We found that intestinal allograft rejection is characterized by Treg cellular infiltrates, which are polarized toward Th17-type chemokine receptor, ROR-γt transcription factor expression, and cytokine production. These Treg cell subsets have maintained epigenetic stability, as defined by FoxP3-TSDR methylation status, but displayed upregulation of functional Treg and purinergic signaling genes by RNAseq analysis such as CD39, in keeping with suppressor Th17 properties.

CONCLUSION

We show that ITx rejection is associated with increased polarized cells that express a Th17-like phenotype concurrent with regulatory purinergic markers.

Current Insights Regarding Intestinal Failure-Associated Liver Disease (IFALD): A Narrative Review

Intestinal failure-associated liver disease (IFALD) is a spectrum of liver disease including cholestasis, biliary cirrhosis, steatohepatitis, and gallbladder disease in patients with intestinal failure (IF). The prevalence of IFALD varies considerably, with ranges of 40-60% in the pediatric population, up to 85% in neonates, and between 15-40% in the adult population. IFALD has a complex and multifactorial etiology; the risk factors can be parenteral nutrition-related or patient-related. Because of this, the approach to managing IFALD is multidisciplinary and tailored to each patient based on the etiology. This review summarizes the current knowledge on the etiology and pathophysiology of IFALD and examines the latest evidence regarding preventative measures, diagnostic approaches, and treatment strategies for IFALD and its associated complications.

Interrupting tumor necrosis factor-alpha signaling prevents parenteral nutrition-associated cholestasis in mice

BACKGROUND

We have recently reported a mouse model of PN-associated cholestasis (PNAC) in which combining intestinal inflammation and PN infusion results in cholestasis, hepatic macrophage activation, and transcriptional suppression of canalicular bile acid, bilirubin and sterol transporters Abcb11, Abcc2 and Abcg5/8. The aim of this study was to examine the role of TNFα in promoting PNAC in mice.

METHODS

First, recombinant TNFα was administered to mice as well as in hepatocyte cell culture. Second, Tnfr1/2KO or wild-type (WT) mice were exposed to dextran sulfate sodium (DSS) for 4 days followed by soy-oil lipid emulsion-based PN infusion through a central venous catheter for 14 days (DSS-PN). Finally, WT/DSS-PN mice were also infused with infliximab at 10 mg/kg on days 3 and 10 of PN. PNAC was defined by increased serum aspartate aminotransferase, alanine aminotransferase, total bile acids, and bilirubin.

RESULTS

Intraperitoneal injection of TNFα into WT mice or TNFα treatment of Huh7 hepatocarcinoma cells and primary mouse hepatocytes suppressed messenger RNA (mRNA) transcription of bile (Abcb11, Abcc2]) and sterol transporters (Abcg5/8) and their regulators Nr1h3 and Nr1h4. DSS-PN mice with PNAC had increased hepatic TNFα mRNA expression and significant reduction of mRNA expression of Abcb11, Abcc2, Abcg5/8, Nr1h3, and Nr1h4. In contrast, PNAC development was prevented and mRNA expression normalized in both Tnfr1/2KO /DSS-PN mice and DSS-PN mice treated with infliximab.

CONCLUSIONS

TNFα is a key mediator in the pathogenesis of PNAC through suppression of hepatocyte Abcb11, Abcc2, and Abcg5/8. Pharmacologic targeting of TNFα as a therapeutic strategy for PNAC thus deserves further investigation.

Intestinal failure-associated liver disease in the neonatal ICU: what we know and where we're going

PURPOSE OF REVIEW

Parenteral nutrition is an integral part of the care of infants in the neonatal ICU. However, prolonged use of parenteral nutrition can be associated with adverse outcomes, most notably parenteral nutrition-associated liver disease, now known as intestinal failure-associated liver disease (IFALD). This review highlights pertinent developments in the epidemiology of IFALD as it pertains to neonates and showcases recent advances in the pathophysiology, treatment, and outcomes of neonates with IFALD.

RECENT FINDINGS

The role of intravenous lipid emulsions in the pathogenesis, prevention, and treatment of IFALD remains a target for investigative studies. Recent data continues to support the use of fish-oil based intravenous lipids, but its use is limited due to concerns for essential fatty acid deficiency. Use of soy-based lipids and mixed lipids is not wrought with such concerns as these are often used at greater doses but their use is limited due to higher proinflammatory fatty acid content, increased phytosterols and decreased antioxidants, risk factors for the development of IFALD.

SUMMARY

Hepatic complications may limit the use of parenteral nutrition in the neonatal ICU. However, the pathophysiology of IFALD is continuing to be further elucidated and novel targets are being developed for the treatment of IFALD. As noninvasive disease monitoring strategies continue to be developed, early enteral nutrition ameliorates the risk of IFALD and should be considered when possible.

Milk Fat Globule Membrane Alleviates Short Bowel Syndrome-Associated Liver Injury in Rats Through Inhibiting Autophagy and NLRP3 Inflammasome Activation

Background

The milk fat globule membrane (MFGM), a tri-layer membrane structure surrounding the milk fat globule, has been shown to have immune-modulating properties. This study aimed to investigate the effects of MFGM supplementation in a rat model of short bowel syndrome (SBS) associated liver disease and its possible mechanisms.

Materials and Methods

Twenty one male Sprague-Dawley rats were randomly divided into three groups: Sham, SBS (underwent massive small bowel resection), and SBS+MFGM (SBS rats supplemented with 1.5 g/kg/d MFGM). Liver pathology, myeloperoxidase (MPO) staining, serum levels of aspartate aminotransferase (AST)/alanine aminotransferase (ALT), endotoxin concentration, protein expression of autophagy and nucleotide binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) pathway in the liver tissue were measured.

Results

Both SBS and SBS + MFGM groups had higher serum levels of ALT and liver endotoxin levels than the Sham group (P < 0.05), with no difference detected between each other. Compared with the SBS group, the SBS+MFGM group showed lower liver pathology scores of steatosis and inflammation, less MPO positive cells and reduced expressions of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, interleukin (IL)-1β(P < 0.05) in the liver. Additionally, the expression of Beclin-1 and microtubule-associated protein1 light chain 3(LC3) B, the fluorescence intensity of NLRP3 and LC3B in the SBS + MFGM group were lower than the SBS group (P < 0.05). The LC3B expression was positively correlated with the NLRP3 level.

Conclusion

Enteral supplementation of MFGM help to alleviate liver injury in SBS rats, which might be related to inhibition of aberrant activation of autophagy and NLRP3 inflammasome pathways.

Pharmacologic activation of hepatic farnesoid X receptor prevents parenteral nutrition-associated cholestasis in mice

BACKGROUND AND AIMS

Parenteral nutrition (PN)-associated cholestasis (PNAC) complicates the care of patients with intestinal failure. In PNAC, phytosterol containing PN synergizes with intestinal injury and IL-1β derived from activated hepatic macrophages to suppress hepatocyte farnesoid X receptor (FXR) signaling and promote PNAC. We hypothesized that pharmacological activation of FXR would prevent PNAC in a mouse model.

APPROACH AND RESULTS

To induce PNAC, male C57BL/6 mice were subjected to intestinal injury (2% dextran sulfate sodium [DSS] for 4 days) followed by central venous catheterization and 14-day infusion of PN with or without the FXR agonist GW4064. Following sacrifice, hepatocellular injury, inflammation, and biliary and sterol transporter expression were determined. GW4064 (30 mg/kg/day) added to PN on days 4-14 prevented hepatic injury and cholestasis; reversed the suppressed mRNA expression of nuclear receptor subfamily 1, group H, member 4 (Nr1h4)/FXR, ATP-binding cassette subfamily B member 11 (Abcb11)/bile salt export pump, ATP-binding cassette subfamily C member 2 (Abcc2), ATP binding cassette subfamily B member 4(Abcb4), and ATP-binding cassette subfamily G members 5/8(Abcg5/8); and normalized serum bile acids. Chromatin immunoprecipitation of liver showed that GW4064 increased FXR binding to the Abcb11 promoter. Furthermore, GW4064 prevented DSS-PN-induced hepatic macrophage accumulation, hepatic expression of genes associated with macrophage recruitment and activation (ll-1b, C-C motif chemokine receptor 2, integrin subunit alpha M, lymphocyte antigen 6 complex locus C), and hepatic macrophage cytokine transcription in response to lipopolysaccharide in vitro. In primary mouse hepatocytes, GW4064 activated transcription of FXR canonical targets, irrespective of IL-1β exposure. Intestinal inflammation and ileal mRNAs (Nr1h4, Fgf15, and organic solute transporter alpha) were not different among groups, supporting a liver-specific effect of GW4064 in this model.

CONCLUSIONS

GW4064 prevents PNAC in mice through restoration of hepatic FXR signaling, resulting in increased expression of canalicular bile and of sterol and phospholipid transporters and suppression of macrophage recruitment and activation. These data support augmenting FXR activity as a therapeutic strategy to alleviate or prevent PNAC.

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.

Intestinal Failure-Associated Liver Disease in Neonates

Intestinal failure-associated liver disease (IFALD) is common in neonates who suffer from intestinal failure and rely on parenteral nutrition. The etiology is multifactorial, relating to the infant's underlying cause of intestinal failure and other infant factors such as prematurity. Management of the disease includes transitioning to enteral feedings as soon as is safe for the infant. In infants who continue to rely on parenteral nutrition, alternative lipid emulsions and other medications may be used. This article reviews the epidemiology and factors that contribute to IFALD in neonates, in addition to management strategies.

Current status of lipid emulsions in the prevention of intestinal failure-associated liver disease

PURPOSE OF REVIEW

The current review provides a summary of available lipid products and discusses current literature and the limitations to the use of various lipid products for treatment and prevention of intestinal failure-associated liver disease (IFALD) in pediatric patients dependent on parenteral nutrition.

RECENT FINDINGS

Improvements in markers of cholestasis and liver function have been seen with minimizing soybean lipid, fish oil lipid, and mixed fish oil-containing lipid emulsions. Soybean-based lipid products are thought to be the biggest contributor to development of IFALD. Mixed fish oil-containing lipid emulsions are most promising for minimizing and improving IFALD.

SUMMARY

Several types of lipid-based products are available for parenteral nutrition. Newer products like the mixed fish oil-containing-based lipid emulsions, that closely mimic the lipid composition provided by enteral feeding, may impact prevention and treatment of IFALD. Limitations exist in the current literature regarding mixed fish oil-containing-based emulsions, as many of the studies were designed to show efficacy with regard to growth, not prevention or treatment of IFALD. Based on available literature, it is reasonable to make some recommendations with regard to product selection for lipid provision.

A Comparison of Smoflipid® and Intralipid® in the Early Management of Infants with Intestinal Failure

PURPOSE

Cholestasis is problematic for infants with intestinal failure (IF). The soy-based lipid Intralipid® (IL) has been implicated. An alternative, Smoflipid® (SMOF), is increasingly used. However, its role in cholestasis prevention is unclear. This study compares the incidence and degree of cholestasis between infants with IF receiving SMOF or IL.

METHODS

Infants with IF receiving SMOF or IL during the first 8 weeks of parenteral nutrition (PN) support between 2014 and 2017 were reviewed. Clinical characteristics, cholestasis incidence (conjugated bilirubin (Cbili) >2 mg/dL for >2 weeks), and nutritional parameters were compared using Welch's t-test.

RESULTS

91% (21/23) of IL and 76% (16/21) of SMOF babies became cholestatic (p = 0.18). There was no significant difference in median peak Cbili, but SMOF babies normalized more quickly (p = 0.04). Median z-scores for weight were similar throughout the study. SMOF patients getting full PN had a lower incidence of cholestasis compared to IL patients (78% vs. 92%, p = 0.057), but those with cholestasis had similar peak Cbili, time to resolution, and growth.

CONCLUSION

Early use of Smoflipid® did not reduce the incidence of cholestasis compared to Intralipid® in infants with IF, but hyperbilirubinemia did resolve more quickly. SMOF may be most beneficial for infants tolerating no enteral nutrition.

LEVEL OF EVIDENCE

Level III Retrospective Comparative Treatment Study.

TYPE OF STUDY

Retrospective Review.

A Retrospective Analysis of the Effect of Combination of Pure Fish Oil with Third Generation Lipid Emulsion on Liver Function in Children on Long-Term Parenteral Nutrition

BACKGROUND

Deterioration of liver function, or intestinal failure-associated liver disease, is often observed in long-term parenterally fed children. Fish oil-based intravenous lipids have been reported to play a role in the prevention and treatment of intestinal failure associated liver disease.

METHODS

This retrospective analysis included 40 pediatric patients, (20 male and 20 female), median age 38 months (range 1.5-200 months) on long-term (≥1 month) parenteral nutrition who received the parenteral mixtures containing a combination of a third-generation lipid emulsion and pure fish oil because of laboratory liver function abnormalities. The total dose of fish oil from both emulsions for each patient exceeded 0.5 g/kg/day. Data from visits in an outpatient clinic were retrospectively analyzed using the Wilcoxon test, Mann-Whitney test, and Spearman correlation test.

RESULTS

The median time of therapy was 149 days (range 28-418 days). There was a decrease of median total and direct (conjugated) bilirubin concentration from 22.23 µmol/L (range 3.42-243 µmol/L) to 10.26 µmol/L (range 3.42-180.58 µmol/L; p < 0.005) and 8.55 (range 1.71-212.04 µmol/L) to 6.84 µmol/L (range 1.71-150.48 µmol/L; p < 0.007) respectively. A significant decrease in median alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase was also observed. In 11 patients bilirubin concentrations increased or remained unchanged. When compared to the patients who responded to the combination therapy, the patients who did not respond received parenteral nutrition for a longer time prior to the start of the therapy (51 vs. 30 months; p < 0.05).

CONCLUSIONS

The mixture of an intravenous lipid emulsion containing soybean oil, medium-chain triglycerides, olive oil, and fish oil with the addition of pure fish oil emulsion may be helpful in the treatment of liver complications in children on long-term parenteral nutrition.

Lipid emulsions for parenterally fed term and late preterm infants

BACKGROUND

Lipid emulsions (LE) form a vital component of infant nutrition for critically ill, late preterm or term infants, particularly for those with gastrointestinal failure. Conventionally used soybean oil-based LE (S-LE) have high polyunsaturated fatty acid (PUFA) content and phytosterols, which may contribute to adverse effects including parenteral nutrition-associated liver disease (PNALD).

OBJECTIVES

To compare the safety and efficacy of all LE for parenteral nutrition (PN) in term and late preterm infants (between 34 weeks' gestation and 36 weeks' and six days' gestation) with or without surgical conditions or PNALD within first six months of life, using all possible direct comparisons.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2018, Issue 5), MEDLINE (1946 to 18 June 2018), Embase (1974 to 18 June 2018), CINAHL (1982 to 18 June 2018), MIDRIS (1971 to 31 May 2018), conference proceedings, trial registries (ClinicalTrials.gov and the WHO's Trials Registry), and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised controlled studies in term and late preterm infants, with or without surgical conditions or PNALD.

DATA COLLECTION AND ANALYSIS

Data collection and analysis conformed to the methods of Cochrane Neonatal. We used the GRADE approach to assess the quality of evidence for important outcomes in addition to reporting the conventional statistical significance of results.

MAIN RESULTS

The review included nine randomised studies (n = 273). LE were classified in three broad groups: 1. all fish oil-containing LE including pure fish oil (F-LE) and multisource LE (e.g. medium-chain triglycerides (MCT)-olive-fish-soybean oil-LE (MOFS-LE), MCT-fish-soy oil-LE (MFS-LE) and olive-fish-soy-LE (OFS-LE)); 2. conventional pure S-LE; 3. alternative-LE (e.g. MCT-soy-LE (MS-LE), olive-soy-LE (OS-LE) and borage oil-based LE).We considered four broad comparisons: 1. all fish oil LE versus non-fish oil LE (6 studies; n = 182); 2. fish oil LE versus another fish oil LE (0 studies); 3. alternative-LE versus S-LE (3 studies; n = 91); 4. alternative-LE versus another alternative-LE (0 studies) in term and late preterm infants (0 studies), term and late preterm infants with surgical conditions (7 studies; n = 233) and term and late preterm infants with PNALD/cholestasis (2 studies; n = 40).PNALD/cholestasis was defined as conjugated bilirubin (Cbil) 2 mg/dL or greater and resolution of PNALD/cholestasis as Cbil less than 2 mg/dL. We put no restriction on timing of PNALD detection. There was heterogeneity in definitions and time points for detecting PNALD in the included studies.We found one study each in surgical infants and in infants with cholestasis, showing no evidence of difference in incidence or resolution of PNALD/cholestasis (Cbil cut-off: 2 mg/dL) with use of fish oil-containing LE compared to S-LE.We considered an outcome allowing for any definition of PNALD (different Cbil cut-off levels). In infants with surgical conditions and no pre-existing PNALD, meta-analysis showed no difference in the incidence of PNALD/cholestasis (any definition) with use of fish oil-containing LE compared to S-LE (typical risk ratio (RR) 1.20, 95% confidence interval (CI) 0.38 to 3.76; typical risk difference (RD) 0.03, 95% CI -0.14 to 0.20; 2 studies; n = 68; low-quality evidence). In infants with PNALD/cholestasis (any definition), use of fish oil-LEs was associated with significantly less cholestasis compared to the S-LE group (typical risk ratio (RR) 0.54, 95% confidence interval (CI) 0.32 to 0.91; typical risk difference (RD) -0.39, 95% CI -0.65 to -0.12; number needed to treat for additional beneficial outcome (NNTB) 3, 95% CI 2 to 9; 2 studies; n = 40; very low-quality evidence). This outcome had very low number of participants from two small studies with differences in study methodology and early termination in one study, which increased uncertainty about the effect estimates.One study in infants with cholestasis reported significantly better weight gain with a pure fish oil LE compared to a 10% S-LE (45 g/week, 95% CI 15.0 to 75.0; n = 16; very low-quality evidence). There were no significant differences in growth parameters in studies with surgical populations.For the secondary outcomes, in infants with cholestasis, one study (n = 24) reported significantly lower conjugated bilirubin levels but higher gamma glutamyl transferase levels with MOFS-LE (SMOFlipid) versus S-LE (Intralipid) and another study (n = 16), which was terminated early, reported significantly higher rates of rise in alanine aminotransferase (ALT) and conjugated bilirubin levels in the S-LE group compared to pure F-LE (Omegaven).In surgical infants, two studies each reported on hypertriglyceridaemia and Cbil levels with one study in each outcome showing significant benefit with use of a F-LE and the other study showing no difference between the groups. Meta-analysis was not performed for either of these outcomes as there were only two studies showing conflicting results with high heterogeneity between the studies.There was no evidence of differences in death, sepsis, alkaline phosphatase and ALT levels in infants with surgical conditions or cholestasis (very low-quality evidence).One study reported neurodevelopmental outcomes at six and 24 months in infants with surgical conditions (n = 11) with no evidence of difference with use of pure F-LE versus S-LE. Another study in infants with cholestasis (n = 16) reported no difference in head growth velocity between pure F-LE versus S-LE.GRADE quality of evidence ranged from low to very low as the included studies were small single-centre studies. Three of the six studies that contributed data to the review were terminated early for various reasons.

AUTHORS' CONCLUSIONS

Based on the current review, there is insufficient data from randomised studies to determine with any certainty, the potential benefit of any LE including fish oil-containing LEs over another LE, for prevention or resolution of PNALD/cholestasis or any other outcomes in term and late preterm infants with underlying surgical conditions or cholestasis. There were no studies in infants without surgical conditions or cholestasis.Further research is required to establish role of fish oil or lipids from other sources in LEs to improve PNALD/cholestasis, and other clinical outcomes in parenterally fed term and late preterm infants.

The Role of Parenteral Lipids in the Development of Hepatic Dysfunction and Hepatic Steatosis in a Mouse Model of Total Parenteral Nutrition

Parenteral nutrition-associated liver disease, a common and life-threating complication among people who require long-term parenteral nutrition, has been associated with abnormal liver function, cholestasis, steatosis and fibrosis. Intravenous soybean lipids may be associated with the development of liver disease. We therefore examined whether different doses of parenteral lipids would affect the development of liver disease, and further investigated the possible pathogenesis of it. C57BL/6J mice with a central catheter placed in the right jugular vein were divided into three groups. The control group received normal mouse chow with intravenous normal saline; The lipids group received parenteral nutrition solution (0.14 g lipids per day); the H-lipids group received parenteral nutrition solution with twice the amount of lipids (0.3 g lipids per day). Changes in body weight, serum biochemical parameters, liver histology and farnesoid X receptor gene expression in the liver were assessed. The values of serum direct bilirubin, total bilirubin and cholesterol were markedly increased in the H-lipids group at day 7. The predominant histologic finding in the H-lipids group was steatosis, and the steatosis score in the H-lipids group was much higher than in the other two groups at either day 5 or day 7. Hepatic expression of farnesoid X receptor mRNA decreased after 7 d of parenteral nutrition. High doses of parenteral lipids are more likely to develop liver disease in a mouse model of parenteral nutrition. Farnesoid X receptor may play a key role in the development of parenteral nutrition-associated liver disease.

Administration of antibiotics contributes to cholestasis in pediatric patients with intestinal failure via the alteration of FXR signaling

The link between antibiotic treatment and IF-associated liver disease (IFALD) is unclear. Here, we study the effect of antibiotic treatment on bile acid (BA) metabolism and investigate the involved mechanisms. The results showed that pediatric IF patients with cholestasis had a significantly lower abundance of BA-biotransforming bacteria than patients without cholestasis. In addition, the BA composition was altered in the serum, feces, and liver of pediatric IF patients with cholestasis, as reflected by the increased proportion of primary BAs. In the ileum, farnesoid X receptor (FXR) expression was reduced in patients with cholestasis. Correspondingly, the serum FGF19 levels decreased significantly in patients with cholestasis. In the liver, the expression of the rate-limiting enzyme in bile salt synthesis, cytochrome P450 7a1 (CYP7A1), increased noticeably in IF patients with cholestasis. In mice, we showed that oral antibiotics (gentamicin, GM or vancomycin, VCM) reduced colonic microbial diversity, with a decrease in both Gram-negative bacteria (GM affected Eubacterium and Bacteroides) and Gram-positive bacteria (VCM affected Clostridium, Bifidobacterium and Lactobacillus). Concomitantly, treatment with GM or VCM decreased secondary BAs in the colonic contents, with a simultaneous increase in primary BAs in plasma. Moreover, the changes in the colonic BA profile especially that of tauro-beta-muricholic acid (TβMCA), were predominantly associated with the inhibition of the FXR and further altered BA synthesis and transport. In conclusion, the administration of antibiotics significantly decreased the intestinal microbiota diversity and subsequently altered the BA composition. The alterations in BA composition contributed to cholestasis in IF patients by regulating FXR signaling.

Using antibiotics during intestinal failure in children may lead to the development of liver disease. Microbiota in the gut play vital roles in balancing the digestive system, including transforming bile acids (BAs) secreted by the liver into forms that help us digest food. Wai Cai and Ying Wang at Shanghai Jiao Tong University in China and co-workers examined samples from 46 children treated with antibiotics for intestinal failure. The patients who also had cholestasis – disrupted production and flow of bile – had far fewer BA-transforming bacteria in their gut than those without cholestasis. They also had altered expression of a crucial BA receptor protein. Experiments on mice showed that treatment with two different antibiotics reduced microbiota diversity, which in turn influenced BA receptor signaling and altered BA composition, contributing to cholestasis.

Significant Published Articles for Pharmacy Nutrition Support Practice in 2017

Purpose: The purpose of the article is to assist the pharmacist engaged in nutrition support therapy in staying current with pertinent literature. Methods: Several clinical pharmacists engaged in nutrition support therapy compiled a list of articles published in 2017 considered important to their clinical practice. The citation list was compiled into a spreadsheet where the author participants were asked to assess whether the article was considered important to nutrition support pharmacy practice. A culled list of publications was then identified whereby the majority (at least 5 out of 8 authors) considered the article to be of significance. Guideline and consensus articles from professional organizations, important to practice but not scored, were also included. Results: A total of 95 articles were identified; six from the primary literature were voted by the group to be of high importance. An additional 13 organizational guidelines, position, recommendation, or consensus papers were also identified. The top-ranked articles from the primary literature were reviewed. Conclusion: It is recommended that pharmacists engaged in nutrition support therapy be familiar with these articles as it pertains to their practice.