scholarly journals Endotoxins and Non-Alcoholic Fatty Liver Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Takaomi Kessoku ◽  
Takashi Kobayashi ◽  
Kento Imajo ◽  
Kosuke Tanaka ◽  
Atsushi Yamamoto ◽  
...  

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It occurs with a prevalence of up to 25%, of which 10–20% cases progress to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. The histopathology of NASH is characterized by neutrophilic infiltration, and endotoxins from gram-negative rods have been postulated as a contributing factor. Elevations in endotoxin levels in the blood can be classified as intestinal and hepatic factors. In recent years, leaky gut syndrome, which is characterized by impaired intestinal barrier function, has become a significant issue. A leaky gut may prompt intestinal bacteria dysbiosis and increase the amount of endotoxin that enters the liver from the portal vein. These contribute to persistent chronic inflammation and progressive liver damage. In addition, hepatic factors suggest that liver damage can be induced by low-dose endotoxins, which does not occur in healthy individuals. In particular, increased expression of CD14, an endotoxin co-receptor in the liver, may result in leptin-induced endotoxin hyper-responsiveness in obese individuals. Thus, elevated blood endotoxin levels contribute to the progression of NASH. The current therapeutic targets for NASH treat steatosis and liver inflammation and fibrosis. While many clinical trials are underway, no studies have been performed on therapeutic agents that target the intestinal barrier. Recently, a randomized placebo-controlled trial examined the role of the intestinal barrier in patients with NAFLD. To our knowledge, this study was the first of its kind and study suggested that the intestinal barrier may be a novel target in the future treatment of NAFLD.

2021 ◽  
Vol 22 (15) ◽  
pp. 8161
Author(s):  
Takaomi Kessoku ◽  
Takashi Kobayashi ◽  
Kosuke Tanaka ◽  
Atsushi Yamamoto ◽  
Kota Takahashi ◽  
...  

The liver directly accepts blood from the gut and is, therefore, exposed to intestinal bacteria. Recent studies have demonstrated a relationship between gut bacteria and nonalcoholic fatty liver disease (NAFLD). Approximately 10%–20% of NAFLD patients develop nonalcoholic steatohepatitis (NASH), and endotoxins produced by Gram-negative bacilli may be involved in NAFLD pathogenesis. NAFLD hyperendotoxicemia has intestinal and hepatic factors. The intestinal factors include impaired intestinal barrier function (leaky gut syndrome) and dysbiosis due to increased abundance of ethanol-producing bacteria, which can change endogenous alcohol concentrations. The hepatic factors include hyperleptinemia, which is associated with an excessive response to endotoxins, leading to intrahepatic inflammation and fibrosis. Clinically, the relationship between gut bacteria and NAFLD has been targeted in some randomized controlled trials of probiotics and other agents, but the results have been inconsistent. A recent randomized, placebo-controlled study explored the utility of lubiprostone, a treatment for constipation, in restoring intestinal barrier function and improving the outcomes of NAFLD patients, marking a new phase in the development of novel therapies targeting the intestinal barrier. This review summarizes recent data from studies in animal models and randomized clinical trials on the role of the gut–liver axis in NAFLD pathogenesis and progression.


2016 ◽  
Vol 116 (10) ◽  
pp. 1682-1693 ◽  
Author(s):  
Cheng Jun Jin ◽  
Anna Janina Engstler ◽  
Cathrin Sellmann ◽  
Doreen Ziegenhardt ◽  
Marianne Landmann ◽  
...  

AbstractNon-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide with universally accepted treatments still lacking. Oral supplementation of sodium butyrate (SoB) has been suggested to attenuate liver damage of various aetiologies. Our study aimed to further delineate mechanisms involved in the SoB-dependent hepatic protection using a mouse model of fructose-induced NAFLD and in in vitro models. C57BL/6J mice were either pair-fed a fructose-enriched liquid diet ±0·6 g/kg body weight per d SoB or standard chow for 6 weeks. Markers of liver damage, intestinal barrier function, glucose metabolism, toll-like receptor-4 (TLR-4) and melatonin signalling were determined in mice. Differentiated human carcinoma colon-2 (Caco-2) and J774A.1 cells were used to determine molecular mechanisms involved in the effects of SoB. Despite having no effects on markers of intestinal barrier function and glucose metabolism or body weight gain, SoB supplementation significantly attenuated fructose-induced hepatic TAG accumulation and inflammation. The protective effects of SoB were associated with significantly lower expression of markers of the TLR-4-dependent signalling cascade, concentrations of inducible nitric oxide synthase (iNOS) protein and 4-hydroxynonenal protein adducts in liver. Treatment with SoB increased melatonin levels and expression of enzymes involved in melatonin synthesis in duodenal tissue and Caco-2 cells. Moreover, treatment with melatonin significantly attenuated lipopolysaccharide-induced expression of iNOS and nitrate levels in J774A.1 cells. Taken together, our results indicated that the protective effects of SoB on the development of fructose-induced NAFLD in mice are associated with an increased duodenal melatonin synthesis and attenuation of iNOS induction in liver.


2017 ◽  
Vol 26 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Ahmed Elgebaly ◽  
Ibrahim A. I. Radwan ◽  
Mohamed M. AboElnas ◽  
Hamza H. Ibrahim ◽  
Moutaz F. M. Eltoomy ◽  
...  

Background: Resveratrol is a potential treatment option for management of non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory, antioxidant properties, and calorie restriction-like effects. We aimed to synthesise evidence from published randomized clinical trials (RCTs) about the efficacy of resveratrol in the management of NAFLD.Methods: A computer literature search of PubMed, Scopus, Web of Science, and Cochrane Central was conducted using relevant keywords. Records were screened for eligible studies and data were extracted and synthesized using Review Manager Version 5.3 for windows. Subgroup analysis and sensitivity analysis were conducted.Results: Four RCTs (n=158 patients) were included in the final analysis. The overall effect estimates did not favor resveratrol group in terms of: serum ALT (MD -2.89, 95%CI [-15.66, 9.88], p=0.66), serum AST (MD -3.59, 95%CI [-13.82, 6.63], p=0.49), weight (MD -0.18, 95%CI [-0.92, 0.55], p=0.63), BMI (MD -0.10, 95 %CI [-0.43, 0.24], p=0.57), blood glucose level (MD -0.27, 95%CI [-0.55, 0.01], p=0.05), insulin level (MD -0.12, 95%CI [-0.69, 0.46], p=0.69), triglyceride level (MD 0.04, 95%CI [-0.45, 0.53], p=0.87), and LDL level (MD 0.21, 95%CI [-0.41, 0.83], p=0.51). Pooled studies were heterogeneous.Conclusion: Current evidence is insufficient to support the efficacy of resveratrol in the management of NAFLD. Resveratrol does not attenuate the degree of liver fibrosis or show a significant decrease in any of its parameters.Abbreviations: ALT: Alanine aminotransferase; AMPK: AMP-activated protein kinase; AST: Aspartate aminotransferase; BMI: Body mass index; CK-18: Cytokeratin-18; CRP: C-reactive protein; HC: Head circumference; HDL: High density lipoprotein; IL-6: Interleukin-6; LDL: Low density lipoprotein; MD: Mean difference; NAFLD: Non-alcoholic fatty liver disease; NASH: Non-alcoholic steatohepatitis; RCT: Randomized Controlled Trial; RR: Relative risk; SIRT1: Silent information regulation 2 homologue 1; TNF-α: Tumor necrosis factor α; WC: Waist circumference; WHR: Waist hip ratio.


2018 ◽  
Vol 1 (2) ◽  
pp. 24-28
Author(s):  
Tanita Suttichaimongkol

Non-alcoholic fatty liver disease (NAFLD) is a leading cause of death from liver cirrhosis, endstage liver disease, and hepatocellular carcinoma. It is also associated with increased cardiovasculardisease and cancer related mortality. While lifestyle modifications are the mainstay of treatment,only a proportion of patients are able to make due to difficult to achieve and maintain, and so moretreatment options are required such as pharmacotherapy. This review presents the drugs used inmanaging NAFLD and their pharmacologic targets. Therapies are currently directed towards improvingthe metabolic status of the liver, insulin resistance, cell oxidative stress, apoptosis, inflammation orfibrosis. Several agents are now in large clinical trials and within the next few years, the availability oftherapeutic options for NAFLD will be approved.     Keywords: nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, fibrosis, cirrhosis  


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