Gut Microbiota and Modulation of Liver Damage in NAFLD

November 19, 2020 updated by: STEFANO GINANNI CORRADINI, University of Roma La Sapienza

Role and Pathogenetic Mechanisms of Intestinal Microbiota in Non-alcoholic Fatty Liver Disease Severity in Obese and Non-obese Subjects

Several experimental data suggest that gut-derived endotoxin and GM composition can act as a "second hit" or insult to convert hepatic SS to NASH and cause both local hepatic and systemic inflammation.This study's aim is to analyze microbiota diversity, providing information both on intestinal microbial composition and on the metabolic processes linked to them. In addition, we will correlate, for the first time, GM composition to hepatic and white adipose tissue gene expression patterns of interest and serum and fecal markers possibly related to impaired fat storage and inflammation. We aim to provide preliminary data to design future intervention studies with pre- or probiotics or bile acid derivatives to prevent/treat inflammation and fibrosis in NAFLD patients.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Non-alcoholic fatty liver disease (NAFLD) includes benign hepatic simple steatosis (SS) and the more severe steatohepatitis (NASH), which is characterized by inflammation and fibrosis potentially leading to cirrhosis and hepatocellular carcinoma. Current research is focused on what are the risk factors and determinants of NASH. NAFLD is associated with the metabolic syndrome, and the prevalence has been described to be up to 98% in morbidly obese individuals undergoing bariatric surgery. NAFLD in non-obese subjects have a different clinical profile than in obese individuals, being associated with insulin resistance (IR), differential distribution of visceral adipose tissue, recent increase in body weight and/or presence of overweight, intake of high cholesterol diet and genetic background.

Gut microbiota (GM) regulates fat metabolism in mice. In humans its alterations have been linked to diabetes, obesity, IR, atherosclerosis and inflammation, SS and NAFLD.

Several experimental data suggest that gut-derived endotoxin and GM composition can act as a "second hit" or insult to convert hepatic SS to NASH and cause both local hepatic and systemic inflammation. With regard to human studies, Muozaki et al. have recently showed, by using a polymerase chain reaction (PCR) TaqMan system approach, that obese patients with NASH, have a lower percentage of fecal Bacteroidetes (Bacteroidetes to total bacteria counts) compared to both SS and healthy controls and a higher percentage of C. coccoides compared to those with SS . In addition, Zhu et al. showed in pediatric subjects, by using a 16S ribosomal RNA detection method, an unique pattern of enterotypes in patients with NASH, in obese individuals with no sign of liver damage and in lean healthy controls. Finally, Wai-Sun Wong et al. showed, also using a 16S ribosomal RNA detection method, that a small group of Chinese NASH patients demonstrated fecal dysbiosis but not significant changes in biodiversity compared to healthy subjects. Finally, inflammation in patients with symptomatic atherosclerosis has been shown to be associated with lower levels of butyrate producing gut bacteria such as Roseburia.

Among the possible factors involved in determining NAFLD severity, serum bile acid (BA) concentration and its post-prandial variations have been recently linked to the regulation of body weight, liver fat and inflammation and glucose and lipid metabolism. These BA regulatory functions are mediated by their interaction with the farnesoid X receptor (FXR)and the G Protein-Coupled BA Receptor 1 (GPBAR1 or TGR5) at both hepatic and subcutaneous adipose tissue levels. No human study has been directed to investigating the mechanisms through which GM composition influences inflammation and fibrosis in both obese and non-obese patients with NAFLD.

Liver biopsy is clinically advisable during bariatric surgery, due to the high prevalence of NAFLD and NASH in morbidly obese patients. It has been previously suggested that the high prevalence of histologically proven NAFLD in patients with gallstones may also justify routine liver biopsy during cholecystectomy, even in non-obese subjects, to establish the diagnosis, stage, and possible therapy. The latter suggestion has been very recently reinforced by the evidence that, in humans, cholecystectomy may represent an independent risk factor for NAFLD detected at ultrasounds and by the experimental demonstration that cholecystectomy increases hepatic triglycerides content.

In the present research project we will study patients with histologically proven SS or with NASH. Liver biopsy will be performed during bariatric surgery (sleeve gastrectomy) or cholecystectomy in patients with preoperative evidence of NAFLD at ultrasounds. We will compare GM composition using, for the first time, the most accurate method available, that is metagenomic shotgun. This method allows to analyze microbiota diversity, providing information both on intestinal microbial composition and on the metabolic processes linked to them. In addition, we will correlate, for the first time, GM composition to hepatic and, only in the obese patients, also to white adipose tissue gene expression patterns of interest and serum and fecal markers possibly related to impaired fat storage and inflammation. We aim to provide preliminary data to design future intervention studies with pre- or probiotics or bile acid derivatives to prevent/treat inflammation and fibrosis in NAFLD patients.

Study Type

Observational

Enrollment (Actual)

44

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Italy
      • Rome, Italy, 00161
        • Stefano Ginanni Corradini

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

two groups of patients with morbid obesity undergoing sleeve gastrectomy will be enrolled. Grouping in patients with simple steatosis (SS) or non-alcoholic steatohepatitis (NASH) will be performed based on the histological diagnosis of the type of NAFLD obtained at operation. Two groups of non-obese patients undergoing cholecystectomy for gallstone disease will be enrolled. Grouping in patients with simple steatosis (SS) or non-alcoholic steatohepatitis (NASH) will be performed based on the histological diagnosis of the type of NAFLD obtained at operation.

Description

Inclusion Criteria:

  1. Male or female, equal or over 18 years old
  2. Eligible for Sleeve Gastrectomy for obesity with BMI 35-50 kg/m2
  3. Eligible for Cholecystectomy for symptomatic gallstones and bright liver at ultrasounds
  4. Alcohol consumption is less than 20 g/d

Exclusion Criteria:

  1. Having liver disease of other etiology
  2. Having advanced liver disease
  3. Having abnormal coagulation or other reason contraindicating a Liver Biopsy
  4. On regular intake of medications known to cause or exacerbate steatohepatitis or antibiotic, pre- or probiotics in the previous 3 months
  5. Use of vitamin E or fish oil supplements in the previous 2 months
  6. Alcohol consumption of more than 20 g/dl
  7. Inflammatory bowel diseases
  8. previous gastrointestinal surgery modifying the anatomy (prior to bariatric surgery)
  9. Pregnancy or lactating state

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Simple steatosis
We will run a cross-sectional observational study including two groups of human subjects: patients with simple steatosis (SS) or non-alcoholic steatohepatitis (NASH). Grouping in patients SS or NASH will be performed based on the histological diagnosis of the type of NAFLD obtained at operation (sleeve gastrectomy or cholecystectomy). BMI will be considered as a confounding variable to be statistically analyzed. Main hypothesis: GM can lead to liver inflammation in patients with liver fat accumulation.
Procedure: liver and white adipose tissue biopsies
Non-alcoholic steato-hepatitis
We will run a cross-sectional observational study including two groups of human subjects: patients with simple steatosis (SS) or non-alcoholic steatohepatitis (NASH). Grouping in patients SS or NASH will be performed based on the histological diagnosis of the type of NAFLD obtained at operation (sleeve gastrectomy or cholecystectomy). BMI will be considered as a confounding variable to be statistically analyzed. Main hypothesis: GM can lead to liver inflammation in patients with liver fat accumulation.
Procedure: liver and white adipose tissue biopsies

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
gut microbiota composition
Time Frame: 12 months
In patients with simple steatosis SS vs those with NASH the gut microbiota composition is different even after BMI normalization
12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
In each patient group overall gut microbiota composition, and hepatic and (only in the obese patients submitted to bariatric surgery) adipose tissue mRNA expression of relevant lipid and inflammatory response pathways
Time Frame: 12 months
In each patient group [simple steatosis (SS) and NASH], overall gut microbiota composition, and hepatic and (only in patients submitted to bariatric surgery) adipose tissue messenger ribonucleic acid (mRNA) expression of relevant lipid and inflammatory response pathways: Acetyl-coenzyme A-carboxylase (ACC1), Fatty acid Synthase (FAS), Sterol regulatory element-binding protein (SREBP1c), apolipoprotein B (ApoB), farnesoid X receptor (FXR), Carbohydrate-responsive element-binding protein (ChREBP), TGR5, Sterol regulatory element-binding protein (SREBP2a), liver X receptor (LXR), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), low density lipoprotein receptor (LDLR) , Proprotein-convertase-subtilisin/kexin type 9 (PCSK9), tumor necrosis factor α (TNF-α), toll-like receptor 4 (TLR-4), NLRP3 (NOD-like receptor 3), c-Jun N-terminal kinase (JUN-K)
12 months
In each patient group overall gut microbiota composition, and hepatic and (only in the obese patients submitted to bariatric surgery) adipose tissue mRNA expression of relevant lipid and inflammatory response pathways
Time Frame: 12 months
In each patient group [simple steatosis (SS) and NASH], overall gut microbiota composition, and hepatic and (only in patients submitted to bariatric surgery) adipose tissue mRNA expression of relevant lipid and inflammatory response pathways: ACC1 (Acetyl-CoA carboxylase), FAS (Fatty acid Synthase), SREBP1c (Sterol regulatory element-binding protein), ApoB (apolipoprotein B), FXR (farnesoid X receptor), ChREBP (Carbohydrate-responsive element-binding protein), TGR5, SREBP2a (Sterol regulatory element-binding protein), LXR (liver X receptor), HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase), LDLR (low density lipoprotein receptor) , PCSK9 (Proprotein Convertase Subtilisin/Kexin type 9), TNF-α (tumor necrosis factor α), TLR-4 toll-like receptor 4), NLRP3 (NOD-like receptor 3), JUN-K (c-Jun N-terminal kinase)
12 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
In each group, overall gut microbiota composition, and serum fasting and (only in the obese patients) post-prandial bile acid levels, serum markers of inflammation and liver damage and white adipose tissue mRNA expression of relevant genes
Time Frame: 18 months
In each patient group [simple steatosis (SS) and NASH], overall gut microbiota composition, and serum fasting and (only in patients submitted to bariatric surgery) post-prandial bile acid levels.In each patient group [simple steatosis (SS) and NASH], overall gut microbiota composition, and serum markers of inflammation and liver damage (endotoxin, TNF-alfa, IL-6, aspartate aminotransferase (AST), alanine aminotransferase (ALT), cytokeratin 18.In each patient group [simple steatosis (SS) and NASH], overall gut microbiota composition and white adipose tissue mRNA expression of relevant genes chosen on the base of the mRNA expression results on liver specimens.
18 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Roma La Sapienza

Collaborators

Göteborg University

Investigators

  • Study Director: Stefano Ginnani Corradini, MD, PhD, Department of Translational and Precision Medicine, "Sapienza", University of Rome
  • Study Director: Fredrik Backhed, PhD, Wallenberg laboratoriet, Gotebörg, Sweden
  • Principal Investigator: Frida Leonetti, MD, PhD, University of Roma La Sapienza
  • Principal Investigator: Gianfranco Silecchia, MD, University of Roma La Sapienza
  • Principal Investigator: Francesco Gossetti, MD, University of Roma La Sapienza
  • Principal Investigator: Adriano De Santis, MD, University of Roma La Sapienza
  • Principal Investigator: Claudio Di Cristofano, MD, University of Roma La Sapienza

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 1, 2013

Primary Completion (Actual)

June 1, 2014

Study Completion (Actual)

October 1, 2017

Study Registration Dates

First Submitted

June 4, 2014

First Submitted That Met QC Criteria

June 4, 2014

First Posted (Estimate)

June 6, 2014

Study Record Updates

Last Update Posted (Actual)

November 20, 2020

Last Update Submitted That Met QC Criteria

November 19, 2020

Last Verified

November 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2943/14.11.2013

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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