Short-chain fatty acids (SCFA), formed by microbial fermentation, are believed to be involved in the aetiology of obesity and diabetes. This study investigated the effects of colonic administration ...of physiologically relevant SCFA mixtures on human substrate and energy metabolism. In this randomized, double-blind, crossover study, twelve normoglycaemic men (BMI 25-35 kg/m
) underwent four investigational days, during which SCFA mixtures (200 mmol/L) high in either acetate (HA), propionate (HP), butyrate (HB) or placebo (PLA) were rectally administered during fasting and postprandial conditions (oral glucose load). Before and for two hours after colonic infusions, indirect calorimetry was performed and blood samples were collected. All three SCFA mixtures increased fasting fat oxidation (P < 0.01), whilst resting energy expenditure increased after HA and HP compared with PLA (P < 0.05). In addition, all three SCFA mixtures increased fasting and postprandial plasma peptide YY (PYY) concentrations, and attenuated fasting free glycerol concentrations versus PLA (P < 0.05). Colonic infusions of SCFA mixtures, in concentrations and ratios reached after fibre intake, increased fat oxidation, energy expenditure and PYY, and decreased lipolysis in overweight/obese men. Human intervention studies are warranted to investigate whether these effects translate into long-term benefits for body weight control and insulin sensitivity in the obese insulin resistant state.
Surgery for cholangiocarcinoma Cillo, Umberto; Fondevila, Constantino; Donadon, Matteo ...
Liver international,
20/May , Letnik:
39, Številka:
S1
Journal Article
Recenzirano
Odprti dostop
Surgical resection is the only potentially curative treatment for patients with cholangiocarcinoma. For both perihilar cholangiocarcinoma (pCCA) and intrahepatic cholangiocarcinoma (iCCA), 5‐year ...overall survival of about 30% has been reported in large series. This review addresses several challenges in surgical management of cholangiocarcinoma. The first challenge is diagnosis: a biopsy is typically avoided because of the risk of seeding metastases and the low yield of a brush of the bile duct. However, about 15% of patients with suspected pCCA are found to have a benign diagnosis after resection. The second challenge is staging; even with the best preoperative imaging, a substantial percentage of patients has occult metastatic disease detected at staging laparoscopy or early recurrence after resection. The third challenge is an adequate volume and function of the future liver remnant, which may require preoperative biliary drainage and portal vein embolization. The fourth challenge is a complete resection: a positive bile duct margin is not uncommon because the microscopic biliary extent of disease may be more extensive than perceived on imaging. The fifth challenge is the high post‐operative mortality that has decreased in very high volume Asian centres, but remains about 10% in many Western referral centres. The sixth challenge is that even after a complete resection most patients develop recurrent disease. Recent randomized controlled trials found conflicting results regarding the benefit of adjuvant chemotherapy. The final challenge is to determine which patients with cholangiocarcinoma should undergo liver transplantation rather than resection.
Environmental factors driving the development of type 1 diabetes (T1D) are still largely unknown. Both animal and human studies have shown an association between altered fecal microbiota composition, ...impaired production of short-chain fatty acids (SCFA) and T1D onset. However, observational evidence on SCFA and fecal and oral microbiota in adults with longstanding T1D vs healthy controls (HC) is lacking.
We included 53 T1D patients without complications or medication and 50 HC matched for age, sex and BMI. Oral and fecal microbiota, fecal and plasma SCFA levels, markers of intestinal inflammation (fecal IgA and calprotectin) and markers of low-grade systemic inflammation were measured.
Oral microbiota were markedly different in T1D (eg abundance of Streptococci) compared to HC. Fecal analysis showed decreased butyrate producing species in T1D and less butyryl-CoA transferase genes. Also, plasma levels of acetate and propionate were lower in T1D, with similar fecal SCFA. Finally, fecal strains Christensenella and Subdoligranulum correlated with glycemic control, inflammatory parameters and SCFA.
We conclude that T1D patients harbor a different amount of intestinal SCFA (butyrate) producers and different plasma acetate and propionate levels. Future research should disentangle cause and effect and whether supplementation of SCFA-producing bacteria or SCFA alone can have disease-modifying effects in T1D.
Background
Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in ...relation to survival, post‐operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas.
Methods
A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle radiation attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex‐specific cut‐offs were determined at the lower tertile for muscle radiation attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post‐operative complications (Dindo–Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox‐regression analysis and multivariable logistic regression analysis, respectively.
Results
Low muscle radiation attenuation was associated with shorter survival in comparison with moderate and high muscle radiation attenuation median survival 10.8 (95% CI: 8.8–12.8) vs. 17.4 (95% CI: 14.7–20.1), and 18.5 (95% CI: 9.2–27.8) months, respectively; P < 0.008. Patient subgroups with high muscle radiation attenuation combined with either low visceral adipose tissue or age <70 years had longer survival than other subgroups (P = 0.011 and P = 0.001, respectively). Muscle radiation attenuation was inversely correlated with intermuscular adipose tissue (rp = −0.697, P < 0.001). High visceral adipose tissue was associated with an increased surgical site infection rate, OR: 2.4 (95% CI: 1.1–5.3; P = 0.027).
Conclusions
Low muscle radiation attenuation was associated with reduced survival, and high visceral adiposity was associated with an increase in surgical site infections. The strong correlation between muscle radiation attenuation and intermuscular adipose tissue suggests the presence of ectopic fat in muscle, warranting further investigation. CT image analysis could be implemented in pre‐operative risk assessment to assist in treatment decision‐making.
Summary Hepatic failure is a feared complication that accounts for up to 75% of mortality after extensive liver resection. Despite improved perioperative care, the increasing complexity and ...extensiveness of surgical interventions, in combination with an expanding number of resections in patients with compromised liver function, still results in an incidence of postresectional liver failure (PLF) of 1–9%. Preventive measures aim to enhance future remnant liver size and function. Numerous non-invasive techniques to assess liver function and predict remnant liver volume are being developed, along with introduction of novel surgical strategies that augment growth of the future remnant liver. Detection of PLF is often too late and treatment is primarily symptomatic. Current therapeutic research focuses on (bioartificial) liver function support and regenerative medicine. In this review we discuss the current state and new developments in prediction, prevention and management of PLF, in light of novel insights into the aetiology of this complex syndrome. Lay summary Liver failure is the main cause of death after partial liver resection for cancer, and is presumably caused by an insufficient quantity and function of the liver remnant. Detection of liver failure is often too late, and current treatment focuses on relieve of symptoms. New research initiatives explore artificial support of liver function and stimulation of regrowth of the remnant liver.
Summary
Bile salts are the water‐soluble end products of hepatic cholesterol catabolism that are released into the duodenum and solubilize lipids due to their amphipathic structure. Bile salts also ...act as endogenous ligands for dedicated nuclear receptors that exert a plethora of biological processes, mostly related to metabolism. Bile salts are actively reclaimed in the distal part of the small intestine, released into the portal system, and subsequently extracted by the liver. This enterohepatic cycle is critically dependent on dedicated bile salt transporters. In the intestinal lumen, bile salts exert direct antimicrobial activity based on their detergent property and shape the gut microbiota. Bile salt metabolism by gut microbiota serves as a mechanism to counteract this toxicity and generates bile salt species that are distinct from those of the host. Innate immune cells of the liver play an important role in the early recognition and effector response to invading microbes. Bile salts signal primarily via the membrane receptor TGR5 and the intracellular farnesoid‐x receptor, both present in innate immune cells. In this review, the interactions between bile salts, gut microbiota, and hepatic innate immunity are discussed.
Mass spectrometry imaging (MSI) simultaneously detects and identifies the spatial distribution of numerous molecules throughout tissues. Currently, MSI is limited to providing a static and ex vivo ...snapshot of highly dynamic systems in which molecules are constantly synthesized and consumed. Herein, we demonstrate an innovative MSI methodology to study dynamic molecular changes of amino acids within biological tissues by measuring the dilution and conversion of stable isotopes in a mouse model. We evaluate the method specifically on hepatocellular metabolism of the essential amino acid l‐phenylalanine, associated with liver diseases. Crucially, the method reveals the localized dynamics of l‐phenylalanine metabolism, including its in vivo hydroxylation to l‐tyrosine and co‐localization with other liver metabolites in a time course of samples from different animals. This method thus enables the dynamics of localized biochemical synthesis to be studied directly from biological tissues.
Imaging isotopes: A mass spectrometry imaging method using isotope labeling to study dynamic molecular changes of l‐phenylalanine (Phe) in mouse liver tissue was developed. Using this method, hydroxylation of Phe to l‐tyrosine (Tyr), as well as its co‐localization with other amino acids could be monitored. This study demonstrates the potential to spatially detect local molecular kinetics of amino acids in research and clinical applications.
The liver is the primary organ involved in handling of bile salts, a class of amphipathic molecules with signaling activities as well as desired and detrimental detergent actions. To allow in-depth ...investigation of functions of bile salts in healthy and diseased liver, the spatial distribution of bile salt species within the liver needs to be studied. Therefore, the aim of our study was to determine hepatic bile salt distribution and identify specific lipid markers that define the structural elements of the liver. Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) was used to monitor the spatial distribution of bile salts and lipids in liver sections of rat, dog, and patients with unaffected and cholestatic parenchyma. MALDI-MSI in negative ion mode showed the local presence of a variety of bile salts, predominantly taurine-conjugates, as localized patches of varying sizes (representing the bile ducts) throughout the liver tissue. Specific molecular markers were identified for the connective tissue (phosphatidic acids, e.g., PA (18:0_18:1)-H
), the liver parenchyma (phosphatidylinositols, e.g., PI (18:0_20:4)-H
), and the bile ducts (hydroxylated-sulfatides, e.g., ST-OH (18:1_24:0)-H
). One of these sulfatides (at m/ z 906.6339) was found to be uniquely localized in a thin lining on the inside of the bile duct, colocalized with cytokeratins, and encased luminal bile salts. A similar distribution of the aforementioned sulfatide was observed, albeit in constricted ductular structures, in the liver of a patient with a mild clinical phenotype of primary sclerosing cholangitis (PSC). In contrast, sulfatides were virtually absent in the liver of patients with PSC and a severe clinical phenotype, with (atypical) cholanoids (e.g., the bile alcohol 5-cyprinolsulfate) abundant in the extra-ductular space and glyco(cheno)deoxycholic acid-3-sulfate localized to fibrotic connective tissue. The latter two molecular species were able to discriminate between healthy liver tissue ( n = 3) and tissue from PSC patients with a severe clinical phenotype ( n = 3). In conclusion, the distinct structural elements of the mammalian liver are characterized by specific classes of lipids. We propose that (hydroxylated-)sulfatides are specific molecular markers of the bile duct.
Pancreatic ductal adenocarcinoma (PDAC) and cholangiocarcinoma (CCA) are both deadly cancers and they share many biological features besides their close anatomical location. One of the main ...histological features is neurotropism, which results in frequent perineural invasion. The underlying mechanism of cancer cells favoring growth by and through the nerve fibers is not fully understood. In this review, we provide knowledge of these cancers with frequent perineural invasion. We discuss nerve fiber crosstalk with the main different components of the tumor microenvironment (TME), the immune cells, and the fibroblasts. Also, we discuss the crosstalk between the nerve fibers and the cancer. We highlight the shared signaling pathways of the mechanisms behind perineural invasion in PDAC and CCA. Hereby we have focussed on signaling neurotransmitters and neuropeptides which may be a target for future therapies. Furthermore, we have summarized retrospective results of the previous literature about nerve fibers in PDAC and CCA patients. We provide our point of view in the potential for nerve fibers to be used as powerful biomarker for prognosis, as a tool to stratify patients for therapy or as a target in a (combination) therapy. Taking the presence of nerves into account can potentially change the field of personalized care in these neurotropic cancers.
Human gut microbiota play an important role in maintaining human health. Dietary fibers, i.e. prebiotics, are fermented by human gut microbiota into the short-chain fatty acids (SCFAs) acetate, ...propionate, and butyrate. SCFAs promote fat oxidation and improve metabolic health. Therefore, the prebiotic inulin might be an effective dietary strategy to improve human metabolism. We aimed to investigate the acute metabolic effects of ingesting inulin compared with digestible carbohydrates and to trace inulin-derived SCFAs using stable isotope tracer methodology.
In a double-blind, randomized, placebo-controlled crossover design, 14 healthy, overweight to obese men consumed a high-fat milkshake containing A) 24 g inulin of which 0.5 g was U-13C-inulin (INU) or B) 24 g maltodextrin placebo (PLA), with a wash-out period of at least five days. Fat oxidation was measured via an open-circuit ventilated hood and blood samples were collected up to 7 h after ingestion. Plasma, breath, and fecal samples were collected, and appetite and satiety scores were assessed.
Fat oxidation increased in the early postprandial phase (0−3 h), and both plasma glucose and insulin were lower after INU ingestion compared with PLA (all P < 0.05). Plasma free fatty acids were higher in the early, and lower in the late postprandial period after INU ingestion. Inulin was fermented into SCFAs as indicated by higher plasma acetate concentrations after INU compared with PLA (P < 0.05). In addition, we found continuous increases in plasma 13C-SCFA enrichments (P < 0.05 from t = 120 onwards) and breath 13CO2 enrichments after INU intake. There were no effects on plasma triglycerides, free glycerol, satiety hormones GLP-1 and PYY, and appetite and satiety scores.
Ingestion of the prebiotic inulin improves fat oxidation and promotes SCFA production in overweight to obese men. Overall, replacing digestible carbohydrates with the fermentable inulin may favor human substrate metabolism.
The trial was registered at clinicaltrials.gov under number NCT02009670.
•Human gut microbiota ferments prebiotics, such as inulin, into short-chain fatty acids.•Short-chain fatty acids have positive effects on human metabolism.•Fat oxidation increased after inulin ingestion in human overweight to obese subjects.•13C-labeled inulin was microbially fermented into 13C-labeled short-chain fatty acids.•Replacing digestible carbohydrates with inulin may favor human substrate metabolism.
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