For the four objectives listed above, here we describe the work performed and main results.
Identification of gut-liver axis during development and progression of ALD
For this purpose, we used a study of 461 patients with ALD and a study of 148 healthy participants matched for age, gender and BMI (partly) with the ALD study. We mapped the microbiome taxonomy and transcription of microbial genes. We then correlated these measurements with histological liver lesions, and patient outcomes. This work has led os to identify specific changes to the microbiome during progression of ALD. First, we found that the microbiome diversity is stepwise reduced from a healthy gut microbiome to increasingly lower diversity in early and advanced ALD. Second, we found differences in certain microbial species between patients with severe ALD and healthy people or early ALD. One of these species where not only less abundant in ALD patients, its expression of genes (the bacterium’s activity) were also significantly altered.
Biomarkers for diagnosis, prognosis and monitoring in patients with excess use of alcohol
GALAXY’s biomarker work has been two-fold: First we validated best-in-class markers of liver fibrosis, liver inflammation, and the prediction of liver-related morbidity and mortality, because the existing markers had only been scarcely investigated in ALD. Second, we developed novel biomarkers based on omics technologies and on markers of collagen formation and degradation.
Until now, the GALAXY project has resulted in 13 scientific publications describing the diagnostic and prognostic accuracy of different biomarkers in ALD. We have several manuscripts in preparation describing the development of omics based biomarkers with high accuracy for diagnosis of fibrosis, inflammation and steatosis in ALD, and with excellent prognostic accuracy for all-cause mortality and occurrence of liver-related events.
Verify findings in animal models of ALD, and validate novel biomarkers in interventional study
GALAXY combined clinical studies in humans with investigations in animal models, for an in-depth understanding of the mechanisms driving chronic ALD. First, we developed an animal model that mimic human alcohol-related liver disease with fibrosis progression (PMID: 31188634). Next, we studied different aspects of disease progression in animals and human liver samples from cirrhosis patients and controls, to identify novel therapeutic targets. We explored the molecular mechanisms of how collagen accumulates in the liver as a result of alcohol-induced damage. These explorations included endocrine regulation by the Renin-Angiotensin-System, differences in the pattern by which different types of collagens accumulate in the liver, and the role of the innate immune system. Finally, we manipulated the gut-microbiome with Rifaximin, a gut-selective antibiotic, and compared its effects between our mouse models of ALD, and models of toxic and non-alcoholic fatty liver disease. Our data suggests different effects of rifaximin (RFX) depending on the etiology of liver disease.
We have measured our omics-based biomarkers and collagen biomarkers in two interventional studies – GAB-ALD and SYN-ALD – but not yet published results on the validation of biomarkers for monitoring the effect of treatment.
Evaluate interventions based on microbiome modulation to prevent progression of alcohol-related liver fibrosis
GAB-ALD and SYN-ALD tested the effect on ALD, when modulating the microbiome. Assessment of liver biopsies are the primary endpoint in both studies. Analysis of the microbiome, other omics, and biomarkers are currently under analysis.
In GAB-ALD we randomised 136 patients 1:1 to Rifaximin, or matching placebo. The protocol is published (DOI: 10.1186/s13063-018-2523-9). The study completed its last-patient-last-visit in Nov 2021. SYN-ALD randomised 56 patients with advanced ALD 1:1 to Fresubin or Profermin. Fresubin is a high-caloric liquid food for medical purposes. Profermin consists of fermented oat by Lactobacillus plantarum 299v, it is believed to improve the composition and activity of a dysbalanced microbiome. The study completed its last-patient-last-visit in Aug 2021, and we received results for the primary endpoint (attenuation of liver hepatic stellate cell activity) in Dec 2021.
