Obeticholic acid (OCA), a potent agonist of the bile salt-activated nuclear receptor farnesoid X receptor (FXR), accelerates liver hypertrophy after portal vein embolization (PVE), but the mechanisms underlying this effect are incompletely understood. In a rabbit model of PVE, New Zealand White rabbits received OCA (10 mg/kg/day) or vehicle by oral gavage before and after embolization. We quantified systemic and hepatic bile salt pools, profiled FXR-regulated genes in ileum and liver, and related these parameters to volumetric and histological indices of regeneration. OCA shifted bile salt composition towards a more hydrophobic profile and improved homeostasis, with earlier normalization of serum total bile salts, reduced bile salt content in the non-embolized (hypertrophic) lobe, and lower circulating levels of the hepatotoxic bile salt lithocholic acid. Serum lithocholic acid strongly and inversely correlated with both caudal liver volume gain and hepatocyte proliferation. In the hypertrophic lobe, OCA markedly suppressed expression of CYP7A1, reduced circulating levels of the bile salt synthesis marker 7-alpha-hydroxy-4-cholesten-3-one, and increased expression of the basolateral bile salt exporter SLC51A/B, consistent with reduced bile salt synthesis and enhanced sinusoidal efflux. OCA also induced the mitotic entry regulator CDC25B. RNA sequencing identified ileal and hepatic signaling candidates, including C1q subunits, bone morphogenetic protein 3 (BMP3), and Indian hedgehog (IHH), which correlated with liver growth. These data indicate that FXR agonism by OCA promotes PVE-induced liver regeneration by improving bile salt homeostasis and modulating gut-liver growth signaling, supporting further evaluation of FXR agonists to enhance future liver remnant hypertrophy before major hepatectomy.

INTRODUCTION:Definitive assessment of resectability in perihilar cholangiocarcinoma (pCCA) often requires surgical exploration. Limited data exist on whether surgical exploration without resection affects the chance of receiving subsequent systemic therapy and survival. This nationwide analysis aims to address this question. METHODS:Patients diagnosed with non-metastatic pCCA between 2012 and 2023 were selected from the Netherlands Cancer Registry and categorized as resected, explored (surgical exploration without resection), or non-explored (non-metastatic tumours without exploration or resection). Overall survival data was stratified by systemic therapy use. RESULTS:The cohort included 2014 patients of which 490 patients (24.3 %) underwent resection, 258 patients (12.8 %) underwent surgical exploration without resection, and 1266 patients (62.9 %) were not explored. Overall, 90-day mortality following exploration was 19.5 %. Among explored patients, 38.0 % (98/258) received systemic therapy compared to 10.6 % (134/1266) of non-explored patients (p < 0.001). With systemic therapy, explored patients had a median overall survival (mOS) of 14.3 months (95 % CI 12.7-18.2) from diagnosis compared to 12.8 months (95 % CI 11.6-15.8) for non-explored patients (p = 0.350). With best supportive care, explored patients had a mOS of 8.1 months (95 % CI 6.5-10.3) compared to 3.2 months (95 % CI 2.8-3.7) for non-explored patients (p ≤ 0.001). CONCLUSION:Among patients with non-metastatic pCCA receiving systemic therapy, survival outcomes are comparable between those who undergo surgical exploration and those who do not. Despite a possible impact on quality of life, these findings suggest that surgical exploration does not hinder access to systemic therapy or negatively affect survival.

BACKGROUND & AIMS:Parenteral nutrition (PN) dependency in patients with intestinal failure (IF) can lead to complications including liver disease. Therefore, IF management strives to wean patients off PN. In adult IF, chronic cholestasis is predicted by the functional gut parameters citrulline (CIT) and enteroendocrine fibroblast growth factor 19 (FGF19), which inhibits hepatic bile salt synthesis. We investigated 1) whether CIT, FGF19 and a marker for enterocyte damage (urinary intestinal fatty acid-binding protein (I-FABP)) are associated with enteral autonomy within 60 days after intestinal surgery in neonates, and 2) the longitudinal patterns of CIT, FGF19, total bile salts and C4 (marker for bile salt synthesis) in subgroups of children on long-term PN (short bowel syndrome (SBS) and functional IF). METHODS:A prospective two-center cohort study, including 1) neonates with PN-need after intestinal surgery and 2) children (aged <18y) with >6 months PN-dependency. CIT, FGF19, and I-FABP were measured post-surgery in neonates. CIT, FGF19, total bile salts and C4 were assessed on inclusion in children with long-term PN-dependency. Associations were analyzed using Cox regression models. Longitudinal patterns were analyzed using linear mixed-effects models. RESULTS:Of 50 neonates, 52 % reached enteral autonomy. Residual small bowel length <75 cm (hazard ratio 0.23, p = 0.046), but not CIT, FGF19 or I-FABP concentrations, was negatively associated with 60-day enteral autonomy. Children with SBS (n = 20) had dysregulated bile salt synthesis with lower FGF19 (24.4 vs 108.8 pg/mL, p = 0.004) and higher C4 concentrations (110.3 vs 30.9 pg/mL, p = 0.024) than children with functional IF (n = 20). In children with long-term PN, CIT concentration significantly increased with decreasing PN-dependency and total bile salt concentration significantly increased with increasing PN-duration. CONCLUSION:Functional gut biomarkers provided no additional value in predicting enteral autonomy in neonates post-intestinal surgery over residual small bowel length. In children on long-term PN, enhanced bile salt synthesis was observed in those with SBS. CLINICAL TRIAL REGISTRATION:Overview of Medical research in the Netherlands (OMON) NL-OMON27840 (previously NTR6080), https://trialsearch.who.int/Trial2.aspx?TrialID=NL-OMON27840.

BACKGROUND AND AIMS:During bile acid (BA) intestinal transit, microbially amidated BAs (MABAs) are produced. This study investigated their cholephilic behavior and their presence in the bile of patients with hepatopancreatobiliary diseases. APPROACH AND RESULTS:Bile samples were collected during surgical or endoscopic procedures and analyzed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), with cholic acid (CA) and chenodeoxycholic acid (CDCA) chemically amidated with leucine (Leu), phenylalanine (Phe), or tyrosine (Tyr) as standards. Gut-to-bile transfer was investigated in cellular and animal models.MABAs (Leu>Phe>Tyr) were detected (<1 µM) in the bile of ≈50% of patients with hepatopancreatobiliary disorders. Their levels were positively correlated with total BA concentrations and inversely correlated with the proportion of major conjugated BAs, but not with age, fat-soluble vitamin levels, or disease outcomes. Oral gavage of D - and L -enantiomers of Tyr-CA in mice resulted in intestinal hydrolysis and limited access of L -Tyr-CA to the enterohepatic circulation. In rats, the intravenous injection of glycocholic acid (GCA) and MABAs resulted in similarly rapid biliary outputs. The time course of biliary secretion after infusing MABAs and GCA into the microbiota-free rat ileum in situ was also similar. Docking studies predicted the interaction of BA transporters and MABAs with binding energies comparable to those of taurocholic acid (TCA) and GCA. In cells expressing BA transporters, MABA uptake was efficient (NTCP>ASBT>OATP1B3) and inhibitable by TCA. CONCLUSIONS:Like major conjugated BAs, MABAs are transferred from the gut, where they are produced, to the bile of patients with hepatopancreatobiliary diseases, suggesting gut dysbiosis that favors species generating these compounds.

BACKGROUND AND AIMS:The homozygous PiZ mutation (PIZZ genotype) constitutes the predominant cause of severe alpha-1 antitrypsin (AAT) deficiency and leads to liver disease via hepatocellular AAT aggregation. We systematically analysed the composition of AAT aggregates and studied the impact of bile acids. METHODS:AAT inclusions were isolated from livers of PiZ overexpressing mice and PIZZ humans via fluorescence-activated and immunomagnetic sorting (FACS/MACS), while insoluble proteins were obtained via Triton-X extraction. Inclusion composition was evaluated through mass-spectrometry (MS), immunoblotting and immunostaining. Hepatocytes with versus without AAT aggregates were obtained via microdissection. Serum bile acids were assessed in 57 PIZZ subjects and 19 controls. Mice were administered 2% cholic acid (CA)-supplemented chow for 7 days. RESULTS:MS identified the key endoplasmic reticulum chaperone 78 kDa glucose-regulated protein (GRP78) in FACS/MACS pulldowns. GRP78 was also enriched in insoluble fractions from PiZ mice versus wild types and detected in insoluble fractions/MACS isolates from PIZZ liver explants. In cultured cells/primary hepatocytes, PiZ overexpression was associated with increased GRP78 mRNA/protein levels. In human livers, hepatocytes with AAT aggregates had higher GRP78 levels than hepatocytes without. PIZZ subjects displayed higher serum bile acid levels than controls and the highest levels were seen in individuals with liver injury/fibrosis. In PiZ mice, CA-mediated bile acid challenge resulted in increased liver injury and translocation of GRP78 into the aggregates. CONCLUSIONS:Our results demonstrate that GRP78 is sequestered within AAT inclusions. Bile acid accumulation, as seen in PIZZ subjects with liver disease, may promote GRP78 segregation and thereby augment liver damage. TRIAL REGISTRATION:NCT02929940.

Ageing changes the impact of nutrition, whereby inflammation has been suggested to play a role in age-related disabilities such as diabetes and cardiovascular disease. The aim of this study was to investigate differences in postprandial bile-acid response and its effect on energy metabolism between young and elderly people. Nine young, healthy men and nine elderly, healthy men underwent a liquid mixed-meal test. Postprandial bile-acid levels, insulin, glucose, GLP-1, C4, FGF19 and lipids were measured. Appetite, body composition, energy expenditure and gut microbiome were also measured. The elderly population showed lower glycine conjugated CDCA and UDCA levels and higher abundances of Ruminiclostridium, Marvinbryantia and Catenibacterium, but lower food intake, decreased fat free mass and increased cholesterol levels. Aging is associated with changes in postprandial bile-acid composition and microbiome, diminished hunger and changes in body composition and lipid levels. Further studies are needed to determine if these changes may contribute to malnutrition and sarcopenia in elderly.

Background: Bile salts of hepatic and microbial origin mediate interorgan cross talk in the gut-liver axis. Here, we assessed whether the newly discovered class of microbial bile salt conjugates (MBSCs) activate the main host bile salt receptors (Takeda G protein-coupled receptor 5 [TGR5] and farnesoid X receptor [FXR]) and enter the human systemic and enterohepatic circulation. Methods: N-amidates of (chenodeoxy) cholic acid and leucine, tyrosine, and phenylalanine were synthesized. Receptor activation was studied in cell-free and cell-based assays. MBSCs were quantified in mesenteric and portal blood and bile of patients undergoing pancreatic surgery. Results: MBSCs were activating ligands of TGR5 as evidenced by recruitment of Gsα protein, activation of a cAMP-driven reporter, and diminution of lipopolysaccharide-induced cytokine release from macrophages. Intestine-enriched and liver-enriched FXR isoforms were both activated by MBSCs, provided that a bile salt importer was present. The affinity of MBSCs for TGR5 and FXR was not superior to host-derived bile salt conjugates. Individual MBSCs were generally not detected (ie, < 2.5 nmol/L) in human mesenteric or portal blood, but Leu-variant and Phe-variant were readily measurable in bile, where MBSCs comprised up to 213 ppm of biliary bile salts. Conclusions: MBSCs activate the cell surface receptor TGR5 and the transcription factor FXR and are substrates for intestinal (apical sodium-dependent bile acid transporter) and hepatic (Na+ taurocholate co-transporting protein) transporters. Their entry into the human circulation is, however, nonsubstantial. Given low systemic levels and a surplus of other equipotent bile salt species, the studied MBSCs are unlikely to have an impact on enterohepatic TGR5/FXR signaling in humans. The origin and function of biliary MBSCs remain to be determined.

AbstractBackgroundCancer cachexia is a multifactorial metabolic syndrome characterized by systemic inflammation and ongoing skeletal muscle loss resulting in weakness, poor quality of life, and decreased survival. Whereas lipid accumulation in skeletal muscle is associated with cancer cachexia as well as the prognosis of cancer patients, surprisingly little is known about the nature of the lipids that accumulate in the muscle during cachexia, and whether this is related to inflammation. We aimed to identify the types and distributions of intramyocellular lipids in patients with and without cancer cachexia.MethodsRectus abdominis muscle biopsies were collected during surgery of patients with pancreatic ductal adenocarcinoma (n = 10 without cachexia, n = 20 cachectic without inflammation (CRP < 10 mg/L), n = 10 cachectic with inflammation (CRP ≥ 10 mg/L). L3‐CT scans were analysed to assess body composition based on validated thresholds in Hounsfield units (HU). Muscle sections were stained with Oil‐Red O and H&E to assess general lipid accumulation and atrophy. Untargeted lipidomic analyses were performed on laser‐microdissected myotubes using LC–MS/MS. The spatial distribution of intramyocellular lipids with differential abundance between groups was visualized by mass‐spectrometry imaging. Genes coding for inflammation markers and enzymes involved in de novo ceramide synthesis were studied by qPCR.ResultsMuscle radiation attenuation was lower in cachectic patients with inflammation (median 24.3 [18.6–30.8] HU) as compared with those without inflammation (34.2 [29.3–38.7] HU, P = 0.033) or no cachexia (37.4 [33.9–42.9] HU, P = 0.012). Accordingly, intramyocellular lipid content was lower in non‐cachectic patients (1.9 [1.6–2.1]%) as compared with those with cachexia with inflammation (5.5 [4.5–7.3]%, P = 0.002) or without inflammation (4.8 [2.6–6.0]%, P = 0.017). Intramyocellular lipid accumulation was associated with both local IL‐6 mRNA levels (rs = 0.57, P = 0.015) and systemic CRP levels (rs = 0.49, P = 0.024). Compared with non‐cachectic subjects, cachectic patients had a higher relative abundance of intramyocellular glycerophospholipids and a lower relative abundance of glycerolipids. Furthermore, increases in several intramyocellular lipids such as SM(d36:1), PC(34:1), and TG(48:1) were found in cachectic patients with inflammation and correlated with specific cachexia features. Altered intramyocellular lipid species such as PC(34:1), LPC(18:2), and TG(48:1) showed an uneven distribution in muscle sections of cachectic and non‐cachectic patients, with areas featuring abundance of these lipids next to areas almost devoid of them.ConclusionsIntramyocellular lipid accumulation in patients with cachexia is associated with both local and systemic inflammation, and characterized by changes in defined lipid species such as glycerolipids and glycerophospholipids.

BACKGROUND:Extended liver resection is the only treatment option for perihilar cholangiocarcinoma (pCCA). Bile salts and the gut hormone FGF19, both promoters of liver regeneration (LR), have not been investigated in patients undergoing resection for pCCA. We aimed to evaluate the bile salt-FGF19 axis perioperatively in pCCA and study its effects on LR. METHODS:Plasma bile salts, FGF19, and C4 (bile salt synthesis marker) were assessed in patients with pCCA and controls (colorectal liver metastases), before and after resection on postoperative days (PODs) 1, 3, and 7. Hepatic bile salts were determined in intraoperative liver biopsies. RESULTS:Partial liver resection in pCCA elicited a sharp decline in bile salt and FGF19 plasma levels on POD 1 and remained low thereafter, unlike in controls, where bile salts rose gradually. Preoperatively, suppressed C4 in pCCA normalized postoperatively to levels similar to those in the controls. The remnant liver volume and postoperative bilirubin levels were negatively associated with postoperative C4 levels. Furthermore, patients who developed postoperative liver failure had nearly undetectable C4 levels on POD 7. Hepatic bile salts strongly predicted hyperbilirubinemia on POD 7 in both groups. Finally, postoperative bile salt levels on day 7 were an independent predictor of LR. CONCLUSIONS:Partial liver resection alters the bile salt-FGF19 axis, but its derailment is unrelated to LR in pCCA. Postoperative monitoring of circulating bile salts and their production may be useful for monitoring LR.

Cholangiocarcinoma (CCA), or bile duct cancer, is the second most common liver malignancy, with an increasing incidence in Western countries. The lack of effective treatments associated with the absence of early symptoms highlights the need to search for new therapeutic targets for CCA. Sulfatides (STs), a type of sulfoglycosphingolipids, have been found in the biliary tract, with increased levels in CCA and other types of cancer. STs are involved in protein trafficking and cell adhesion as part of the lipid rafts of the plasma membrane. We aimed to study the role of STs in CCA by the genetic targeting of GAL3ST1, an enzyme involved in ST synthesis. We used the CRISPR-Cas9 system to generate GAL3ST1-deficient TFK1 cells. GAL3ST1 KO cells showed lower proliferation and clonogenic activity and reduced glycolytic activity compared to TFK1 cells. Polarized TFK1 GAL3ST1 KO cells displayed increased transepithelial resistance and reduced permeability compared to TFK1 wt cells. The loss of GAL3ST1 showed a negative effect on growth in 30 out of 34 biliary tract cancer cell lines from the DepMap database. GAL3ST1 deficiency partially restored epithelial identity and barrier function and reduced proliferative activity in CCA cells. Sulfatide synthesis may provide a novel therapeutic target for CCA.

Purpose Cholangiocarcinoma (CCA) is a malignancy arising from the bile duct epithelium and has a poor outcome. Sulfatides are lipid components of lipid rafts, and are implicated in several cancer types. In the liver, sulfatides are specifically present in the bile ducts. Here, sulfatide abundance and composition were analyzed using mass spectrometry imaging in intrahepatic CCA (iCCA) tumor tissue, and correlated with tumor biology and clinical outcomes. Methods Sulfatides were analyzed in iCCA (n = 17), hepatocellular carcinoma (HCC, n = 10) and colorectal liver metastasis (CRLM, n = 10) tumor samples, as well as tumor-distal samples (control, n = 16) using mass spectrometry imaging. Levels of sulfatides as well as the relative amount in structural classes were compared between groups, and were correlated with clinical outcomes for iCCA patients. Results Sulfatide localization was limited to the respective tumor areas and the bile ducts. Sulfatide abundance was similar in iCCA and control tissue, while intensities were notably higher in CRLM in comparison with control (18-fold, P < 0.05) and HCC tissue (47-fold, P < 0.001). Considerable variation in sulfatide abundance was observed in iCCA tumors. A high ratio of unsaturated to saturated sulfatides was associated with reduced disease-free survival (10 vs. 20 months) in iCCA. The sulfatide pattern in HCC deviated from the other groups, with a higher relative abundance of odd- versus even-chain sulfatides. Conclusion Sulfatides were found in tumor tissue of patients with iCCA, with sulfatide abundance per pixel being similar to bile ducts. In this explorative study, sulfatide abundance was not related to overall survival of iCCA patients. A high ratio of unsaturated to saturated sulfatides was associated with earlier tumor recurrence in patients with iCCA.

Einleitung Die 5-Jahres-Überlebensrate von hepato- und cholangiozellulären Karzinomen beträgt rund 15%, die von kolorektalen Lebermetastasen 40%. Da nur bei 10-20% der Patienten eine kurative Resektion möglich ist, ist eine optimale medikamentöse Therapie essenziell. Für die Entwicklung personalisierter Therapien fehlen häufig repräsentative in vitro Modelle. In dieser Studie wurde der Einfluss einer adäquate Strömungsbedingung auf die Zellviabilität untersucht. Hierfür wurde ein mikrofluidischer (MF) Chip entwickelt, in dem Precision-Cut Liver Slices (PCLS) kultiviert wurden

Purpose In the pre-clinical setting, hepatocellular bile salt accumulation impairs liver regeneration following partial hepatectomy. Here, we study the impact of cholestasis on portal vein embolization (PVE)-induced hypertrophy of the future liver remnant (FLR). Methods Patients were enrolled with perihilar cholangiocarcinoma (pCCA) or colorectal liver metastases (CRLM) undergoing PVE before a (extended) right hemihepatectomy. Volume of segments II/III was considered FLR and assessed on pre-embolization and post-embolization CT scans. The degree of hypertrophy (DH, percentual increase) and kinetic growth rate (KGR, percentage/week) were used to assess PVE-induced hypertrophy. Results A total of 50 patients (31 CRLM, 19 pCCA) were included. After PVE, the DH and KGR were similar in patients with CRLM and pCCA (5.2 [3.3–6.9] versus 5.7 [3.2–7.4] %, respectively, p = 0.960 for DH; 1.4 [0.9–2.5] versus 1.9 [1.0–2.4] %/week, respectively, p = 0.742 for KGR). Moreover, pCCA patients with or without hyperbilirubinemia had comparable DH (5.6 [3.0–7.5] versus 5.7 [2.4–7.0] %, respectively, p = 0.806) and KGR (1.7 [1.0–2.4] versus 1.9 [0.8–2.4] %/week, respectively, p = 1.000). For patients with pCCA, unilateral drainage in FLR induced a higher DH than bilateral drainage (6.7 [4.9–7.9] versus 2.7 [1.5–4.2] %, p = 0.012). C-reactive protein before PVE was negatively correlated with DH ( ρ = − 0.539, p = 0.038) and KGR ( ρ = − 0.532, p = 0.041) in patients with pCCA. Conclusions There was no influence of cholestasis on FLR hypertrophy in patients undergoing PVE. Bilateral drainage and inflammation appeared to be negatively associated with FLR hypertrophy. Further prospective studies with larger and more homogenous patient cohorts are desirable.

Cerebrotendinous xanthomatosis (CTX) is a rare inherited disease characterized by sterol 27-hydroxylase (CYP27A1) deficiency and, thus, a lack of bile acid synthesis with a marked accumulation of 7α-hydroxylated bile acid precursors. In addition to their renowned lipid-emulgating role, bile acids have been shown to stimulate secretion of the glucose-lowering and satiety-promoting gut hormone glucagon-like peptide 1 (GLP-1). In this paper, we examined postprandial bile acid, glucose, insulin, GLP-1 and fibroblast growth factor 19 (FGF19) plasma profiles in patients with CTX and matched healthy controls. Seven patients and seven age, gender and body mass index matched controls were included and subjected to a 4 h mixed meal test with regular blood sampling. CTX patients withdrew from chenodeoxycholic acid (CDCA) and statin therapy three weeks prior to the test. Postprandial levels of total bile acids were significantly lower in CTX patients and consisted of residual CDCA with low amounts of ursodeoxycholic acid (UDCA). The postprandial plasma glucose peak concentration occurred later in CTX patients compared to controls, and patients’ insulin levels remained elevated for a longer time. Postprandial GLP-1 levels were slightly higher in CTX subjects whereas postprandial FGF19 levels were lower in CTX subjects. This novel characterization of CTX patients reveals very low circulating bile acid levels and FGF19 levels, aberrant postprandial glucose and insulin profiles, and elevated postprandial GLP-1 responses.

Rationale: Elderly people have lower insulin sensitivity and anabolic response compared with younger people. Elderly people are at risk for malnutrition and sarcopenia during illness. We examined the postprandial response to develop strategies that improve the anabolic response whilst minimizing unfavourable outcome Methods: 9 elderly and 9 young volunteers underwent a 6-hours liquid mixed meal test. Blood samples were collected every 30 minutes. Body composition was measured at the start of the MMT with BODPOD. Resting energy expenditure was measured with indirect calorimetry at baseline, at 150 and 270 minutes. At the end of the MMT, volunteers consumed an ad libitum lunch in which eating rate and appetite was measured using the Universal Eating Monitor. Results: Cholesterol levels were significantly higher in elderly volunteers(p<0.01). FGF19 levels tend to be higher at t=60 minutes in elderly volunteers(82.0 ± 34.7 pg/ml vs. 132.2 ± 76.7 pg/ml, p=0.092). GLP-1 levels tend to be higher at t=30 minutes in elderly volunteers (p=0.083), whereas at t=270 minutes levels tend to be higher in young volunteers(p=0.037). Fat mass was significantly higher in elderly volunteers(16.7 ± 4.8 kg vs. 8.3 ± 3.6 kg, p<0.001). Energy expenditure was higher in young volunteers at baseline, and t=150 minutes (baseline: 24.7 ± 1.4 kcal/kg/day vs. 22.0 ± 2.3 kcal/kg/day, p<0.01; t=150: 26.5 ± 1.8 kcal/kg/day vs. 22.7 ± 3.2 kcal/kg/day, p<0.01). A larger amount of food was consumed by the young volunteers at the ad libitum lunch test (844.1 ± 213.8 gram vs. 574.9 ± 245.0 gram, p<0.05). No differences in plasma glucose, insulin, total bile acid, triglycerides and HDL-levels were found. Conclusion: Aging impacts postprandial metabolism and anabolic response, whereby appetite decreases and fat mass increases. Dietary intervention studies may focus on retaining or improving the anabolic response. Disclosure of Interest: None declared

Background Cancer cachexia is a multifactorial syndrome characterized by body weight loss and systemic inflammation. The characterization of the inflammatory response in patients with cachexia is still limited. Lipocalin-2, a protein abundant in neutrophils, has recently been implicated in appetite suppression in preclinical models of pancreatic cancer cachexia. We hypothesized that lipocalin-2 levels could be associated with neutrophil activation and nutritional status of pancreatic ductal adenocarcinoma (PDAC) patients. Methods Plasma levels of neutrophil activation markers calprotectin, myeloperoxidase, elastase, and bactericidal/permeability-increasing protein (BPI) were compared between non-cachectic PDAC patients (n=13) and cachectic PDAC patients with high (≥26.9 ng/mL, n =34) or low (<26.9 ng/mL, n =34) circulating lipocalin-2 levels. Patients’ nutritional status was assessed by the patient-generated subjective global assessment (PG-SGA) and through body composition analysis using CT-scan slices at the L3 level. Results Circulating lipocalin-2 levels did not differ between cachectic and non-cachectic PDAC patients (median 26.7 (IQR 19.7-34.8) vs . 24.8 (16.6-29.4) ng/mL, p =0.141). Cachectic patients with high systemic lipocalin-2 levels had higher concentrations of calprotectin, myeloperoxidase, and elastase than non-cachectic patients or cachectic patients with low lipocalin-2 levels (calprotectin: 542.3 (355.8-724.9) vs . 457.5 (213.3-606.9), p =0.448 vs . 366.5 (294.5-478.5) ng/mL, p =0.009; myeloperoxidase: 30.3 (22.1-37.9) vs . 16.3 (12.0-27.5), p =0.021 vs . 20.2 (15.0-29.2) ng/mL, p =0.011; elastase: 137.1 (90.8-253.2) vs . 97.2 (28.8-215.7), p =0.410 vs . 95.0 (72.2-113.6) ng/mL, p =0.006; respectively). The CRP/albumin ratio was also higher in cachectic patients with high lipocalin-2 levels (2.3 (1.3-6.0) as compared to non-cachectic patients (1.0 (0.7-4.2), p =0.041). Lipocalin-2 concentrations correlated with those of calprotectin ( r s =0.36, p <0.001), myeloperoxidase ( r s =0.48, p <0.001), elastase ( r s =0.50, p <0.001), and BPI ( r s =0.22, p =0.048). Whereas no significant correlations with weight loss, BMI, or L3 skeletal muscle index were observed, lipocalin-2 concentrations were associated with subcutaneous adipose tissue index ( r s =-0.25, p =0.034). Moreover, lipocalin-2 tended to be elevated in severely malnourished patients compared with well-nourished patients (27.2 (20.3-37.2) vs . 19.9 (13.4-26.4) ng/mL, p =0.058). Conclusions These data suggest that lipocalin-2 levels are associated with neutrophil activation in patients with pancreatic cancer cachexia and that it may contribute to their poor nutritional status.

The gut and the liver are characterized by mutual interactions between both organs, the microbiome, diet and other environmental factors. The sum of these interactions is conceptualized as the gut–liver axis. In this Review we discuss the gut–liver axis, concentrating on the barriers formed by the enterohepatic tissues to restrict gut-derived microorganisms, microbial stimuli and dietary constituents. In addition, we discuss the establishment of barriers in the gut and liver during development and their cooperative function in the adult host. We detail the interplay between microbial and dietary metabolites, the intestinal epithelium, vascular endothelium, the immune system and the various host soluble factors, and how this interplay establishes a homeostatic balance in the healthy gut and liver. Finally, we highlight how this balance is disrupted in diseases of the gut and liver, outline the existing therapeutics and describe the cutting-edge discoveries that could lead to the development of novel treatment approaches.

Abstract Background Postprandial rise of plasma essential amino acids (EAAs) determines the anabolic effect of dietary protein. Disturbed gastrointestinal function could impair the anabolic response in critically ill patients. Aim was to investigate the postprandial EAA response in critically ill patients and its relation to small‐intestinal function. Methods Twenty‐one mechanically ventilated patients and 9 healthy controls received a bolus containing 100 ml of a formula feed (Ensure) and 2 g of 3‐O‐Methyl‐d‐glucose (3‐OMG) via postpyloric feeding tube. Fasting and postprandial plasma concentrations of EAAs, 3‐OMG, total bile salts, and the gut‐released hormone fibroblast growth factor 19 (FGF19) were measured over a 4‐hour period. Changes over time and between groups were assessed with linear mixed‐effects analysis. Early (0–60 minutes) and total postprandial responses are summarized as the incremental area under the curve (iAUC). Results At baseline, fasting EAA levels were similar in both groups: 1181 (1055–1276) vs 1150 (1065–1334) μmol·L−1, P = .87. The early postprandial rise in EAA was not apparent in critically ill patients compared with healthy controls (iAUC60, −4858 [−6859 to 2886] vs 5406 [3099–16,853] µmol·L−1·60 minutes; P = .039). Impaired EAA response did not correlate with impaired 3‐OMG response (Spearman ρ 0.32, P = .09). There was a limited increase in total bile salts but no relevant FGF19 response in either group. Conclusion Postprandial rise of EAA is blunted in critically ill patients and unrelated to glucose absorption measured with 3‐OMG. Future studies should aim to delineate governing mechanisms of macronutrient malabsorption.