Periodic Reporting for period 1 - LIVER-X (Disentangling the early-life environmental determinants of pediatric LIVER injury: An eXposome-wide approach)
Reporting period: 2023-09-01 to 2025-08-31
Summary of the context and overall objectives of the project
The LIVER-X project investigates how the environment in early life—beginning in pregnancy and continuing through childhood—can influence the development of liver disease and metabolic dysfunction in children and adolescents. Chronic liver disease is a growing public health concern worldwide, with cases of Metabolic Dysfunction-Associated Fatty Liver Disease (MASLD) increasingly being diagnosed in children and adolescents. This form of liver injury is strongly linked to metabolic health issues, such as obesity and diabetes, and places a growing burden on healthcare systems. Alarmingly, the condition often starts without symptoms and may go undetected for years.
Traditionally, liver disease prevention strategies have focused on diet and physical activity. However, a growing body of research points to the role of environmental factors—including exposure to air pollution, toxic chemicals, and poor urban planning—as important contributors to liver and metabolic diseases. These exposures often occur simultaneously and may interact with genetic and lifestyle-related vulnerabilities. Yet, the long-term effects of these exposures during critical periods of development remain poorly understood.
LIVER-X addresses this knowledge gap by applying a novel, comprehensive approach known as the exposome—which refers to the totality of environmental exposures across an individual’s lifetime. The project uses existing data from large, well-established population cohorts. These datasets include thousands of children with information on chemical exposures (such as air pollutants, plasticizers, and heavy metals), lifestyle factors (such as diet and physical activity), genetic susceptibility, and objective liver health measurements, including blood biomarkers and MRI imaging.
The overall objective of LIVER-X is to identify which environmental exposures during early life most significantly increase the risk of pediatric metabolic dysfunction and liver injury—and to understand how these risks are modified by diet quality and genetic predisposition.
This research has the potential to produce a step change in how we think about liver health. By moving beyond single exposure-outcome studies, LIVER-X examines real-world, combined effects of multiple exposures, much like they occur in everyday life. This helps better reflect the complexity of modern urban environments.
The anticipated impact of the project includes:
- Scientific advancement: LIVER-X is among the first studies in Europe to use an exposome-wide approach to study pediatric liver disease. It applies cutting-edge statistical tools and combines environmental, genetic, and lifestyle data in novel ways.
- Public health relevance: The findings will help identify preventable environmental risk factors and inform early-life interventions aimed at reducing liver-related health issues across the population.
- Policy contribution: Results will support evidence-based environmental and urban planning policies, particularly in vulnerable communities where exposure to pollution and poor diets co-occur.
- Education and capacity building: The project includes training components for young scientists and public health professionals, as well as communication materials for broader audiences, including educators and policymakers.
By improving understanding of the environmental origins of liver disease, LIVER-X contributes to the wider European and global goals of reducing chronic disease burden, promoting child health, and achieving more sustainable and equitable living environments.
Traditionally, liver disease prevention strategies have focused on diet and physical activity. However, a growing body of research points to the role of environmental factors—including exposure to air pollution, toxic chemicals, and poor urban planning—as important contributors to liver and metabolic diseases. These exposures often occur simultaneously and may interact with genetic and lifestyle-related vulnerabilities. Yet, the long-term effects of these exposures during critical periods of development remain poorly understood.
LIVER-X addresses this knowledge gap by applying a novel, comprehensive approach known as the exposome—which refers to the totality of environmental exposures across an individual’s lifetime. The project uses existing data from large, well-established population cohorts. These datasets include thousands of children with information on chemical exposures (such as air pollutants, plasticizers, and heavy metals), lifestyle factors (such as diet and physical activity), genetic susceptibility, and objective liver health measurements, including blood biomarkers and MRI imaging.
The overall objective of LIVER-X is to identify which environmental exposures during early life most significantly increase the risk of pediatric metabolic dysfunction and liver injury—and to understand how these risks are modified by diet quality and genetic predisposition.
This research has the potential to produce a step change in how we think about liver health. By moving beyond single exposure-outcome studies, LIVER-X examines real-world, combined effects of multiple exposures, much like they occur in everyday life. This helps better reflect the complexity of modern urban environments.
The anticipated impact of the project includes:
- Scientific advancement: LIVER-X is among the first studies in Europe to use an exposome-wide approach to study pediatric liver disease. It applies cutting-edge statistical tools and combines environmental, genetic, and lifestyle data in novel ways.
- Public health relevance: The findings will help identify preventable environmental risk factors and inform early-life interventions aimed at reducing liver-related health issues across the population.
- Policy contribution: Results will support evidence-based environmental and urban planning policies, particularly in vulnerable communities where exposure to pollution and poor diets co-occur.
- Education and capacity building: The project includes training components for young scientists and public health professionals, as well as communication materials for broader audiences, including educators and policymakers.
By improving understanding of the environmental origins of liver disease, LIVER-X contributes to the wider European and global goals of reducing chronic disease burden, promoting child health, and achieving more sustainable and equitable living environments.
Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far
The LIVER-X project aimed to disentangle the early-life environmental determinants of pediatric liver injury and metabolic dysfunction using an exposome-wide framework. Substantial progress has been achieved in securing, harmonizing, and analyzing large-scale data from European and US cohorts, which provide extensive information on prenatal and childhood exposures, liver biomarkers, imaging data, dietary indices, genetic variation, and covariates.
Data preparation and harmonization
Variables on liver function (ALT, AST, GGT, CK-18), MRI-derived hepatic fat fraction, dietary measures, genetic markers, and environmental exposures were harmonized following common protocols. Reproducible workflows were established for ensuring GDPR compliance and safeguarding sensitive child health data.
Methodological innovation
LIVER-X developed an exposome-wide association strategy that combines machine learning and mixture approaches to evaluate correlated exposures. This enabled simultaneous assessment of chemical pollutants (PFAS, pesticides, metals) and urban factors (air pollution, building density, green space). In parallel, multi-omics data integration (metabolomics, proteomics, transcriptomics, DNA methylation) uncovered molecular pathways linking exposures to early metabolic dysfunction. Polygenic risk scores (PRS) for MASLD and obesity are constructed and applied to examine gene–environment interactions. Diet quality is evaluated through validated tools (food-frequency questionnaires, NOVA classification of ultra-processed foods), enabling analyses of effect modification by lifestyle factors.
Scientific achievements
- Early-life environmental risk factors: LIVER-X provided strong evidence that prenatal and childhood exposures to persistent chemicals (e.g. PFAS, pesticides, metals) are linked with metabolic dysfunction and early signs of liver injury in children and adolescents.
- Role of diet and lifestyle: The project showed that poor diet quality, including low adherence to healthy dietary patterns and higher consumption of ultra-processed foods, are closely linked to adiposity and metabolic outcomes.
- Genetic susceptibility: Analyses incorporating polygenic risk scores demonstrate that children with higher inherited risk for obesity are more vulnerable to the detrimental effects of environmental exposures, highlighting opportunities for precision prevention.
- Molecular mechanisms and biomarkers: Multi-omics integration revealed pathways related to inflammation, insulin signaling, and lipid metabolism as mediators of early-life exposures, while epigenetic and microRNA analyses identified novel molecular biomarkers that may serve as early indicators of exposure-related liver and metabolic risk.
- Cross-cohort and methodological advances: By using large-scale data from European and US cohorts, LIVER-X applied innovative exposome-wide and mixture modeling approaches, setting a new standard for studying complex exposure–health relationships in child health research
Outcomes
The project has delivered the first comprehensive evidence that metabolic dysfunction including liver injury has developmental origins shaped by the interplay of environmental, and multi factors. The results highlight critical exposure windows (pregnancy and childhood), identify vulnerable groups, and provide mechanistic clues for early prevention.
Several publications were produced, including a landmark Nature Communications paper (the largest systems biology investigation of European children to date), alongside papers in JAMA Network Open, Clinical Epigenetics and others. Analytical pipelines and R code have been made available through open repositories (GitHub), ensuring reproducibility and re-use in future exposome and public health research.
Data preparation and harmonization
Variables on liver function (ALT, AST, GGT, CK-18), MRI-derived hepatic fat fraction, dietary measures, genetic markers, and environmental exposures were harmonized following common protocols. Reproducible workflows were established for ensuring GDPR compliance and safeguarding sensitive child health data.
Methodological innovation
LIVER-X developed an exposome-wide association strategy that combines machine learning and mixture approaches to evaluate correlated exposures. This enabled simultaneous assessment of chemical pollutants (PFAS, pesticides, metals) and urban factors (air pollution, building density, green space). In parallel, multi-omics data integration (metabolomics, proteomics, transcriptomics, DNA methylation) uncovered molecular pathways linking exposures to early metabolic dysfunction. Polygenic risk scores (PRS) for MASLD and obesity are constructed and applied to examine gene–environment interactions. Diet quality is evaluated through validated tools (food-frequency questionnaires, NOVA classification of ultra-processed foods), enabling analyses of effect modification by lifestyle factors.
Scientific achievements
- Early-life environmental risk factors: LIVER-X provided strong evidence that prenatal and childhood exposures to persistent chemicals (e.g. PFAS, pesticides, metals) are linked with metabolic dysfunction and early signs of liver injury in children and adolescents.
- Role of diet and lifestyle: The project showed that poor diet quality, including low adherence to healthy dietary patterns and higher consumption of ultra-processed foods, are closely linked to adiposity and metabolic outcomes.
- Genetic susceptibility: Analyses incorporating polygenic risk scores demonstrate that children with higher inherited risk for obesity are more vulnerable to the detrimental effects of environmental exposures, highlighting opportunities for precision prevention.
- Molecular mechanisms and biomarkers: Multi-omics integration revealed pathways related to inflammation, insulin signaling, and lipid metabolism as mediators of early-life exposures, while epigenetic and microRNA analyses identified novel molecular biomarkers that may serve as early indicators of exposure-related liver and metabolic risk.
- Cross-cohort and methodological advances: By using large-scale data from European and US cohorts, LIVER-X applied innovative exposome-wide and mixture modeling approaches, setting a new standard for studying complex exposure–health relationships in child health research
Outcomes
The project has delivered the first comprehensive evidence that metabolic dysfunction including liver injury has developmental origins shaped by the interplay of environmental, and multi factors. The results highlight critical exposure windows (pregnancy and childhood), identify vulnerable groups, and provide mechanistic clues for early prevention.
Several publications were produced, including a landmark Nature Communications paper (the largest systems biology investigation of European children to date), alongside papers in JAMA Network Open, Clinical Epigenetics and others. Analytical pipelines and R code have been made available through open repositories (GitHub), ensuring reproducibility and re-use in future exposome and public health research.
Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)
LIVER-X has advanced the state of the art by moving beyond traditional single-exposure studies toward an exposome-wide framework for pediatric liver health and metabolic dysfunction. The project leveraged prenatal and childhood exposures, multi-omics, genetics, diet, and lifestyle into a unified analysis, across multiple large-scale population cohorts
Key advances beyond the state of the art include:
- Exposome modeling: Application of advanced mixture models and machine learning allowed simultaneous evaluation of multiple exposures, reflecting real-world conditions rather than isolated risk factors.
- Mechanistic depth: By combining molecular omics data with epidemiological analyses, the project identified biological pathways linking early-life exposures to inflammation, lipid metabolism, and insulin resistance—mechanistic evidence strengthening prevention strategies in child liver and metabolic health.
- Precision prevention: Demonstration of gene–environment interactions through polygenic risk scores highlighted vulnerable subgroups, paving the way for stratified prevention strategies.
- Biomarker discovery: Novel omics (microRNA and DNA methylation) signatures were identified as potential biomarkers of exposure-related metabolic dysfunction, providing tools for early detection and risk assessment.
- Methodological innovation: Development of harmonized protocols, and open-source pipelines sets methodological standards for exposome research in child health.
Together, these advances show that environmental hepatology—the study of how environmental factors contribute to liver disease—can be systematically investigated in children, establishing a new research frontier.
Potential Impacts
The findings of LIVER-X have important implications for public health, clinical research, and policy:
- Scientific and clinical impact: The project provides comprehensive evidence that liver injury and metabolic dysfunction originate in early life, influenced by environmental factors. This knowledge lays the groundwork for developing early screening tools and intervention strategies.
- Public health and prevention: By identifying vulnerable populations, LIVER-X supports interventions aimed at reducing harmful exposures during pregnancy and childhood, alongside promoting healthy diets and environments.
- Policy relevance: The results provide robust evidence for policymakers on the need to regulate hazardous chemicals (e.g. PFAS), and reduce pollution exposure in children’s environments. These findings align with EU priorities such as the European Green Deal, the Chemicals Strategy for Sustainability, and the Zero Pollution Action Plan.
- Capacity building and education: The project has trained early-career researchers in cutting-edge exposome methodologies and produced knowledge resources for wider dissemination to clinicians, educators, and the general public.
- Societal contribution: By linking environment, genetics, and lifestyle to child liver health, LIVER-X strengthens European leadership in exposome research and contributes to the UN Sustainable Development Goals (SDG 3 – Good Health and Wellbeing, SDG 11 – Sustainable Cities and Communities).
Exploitation and Future Uptake
The outputs of LIVER-X provide multiple opportunities for exploitation beyond academia:
- Research tools and resources: Analysis pipelines are openly available via GitHub, enabling re-use by other researchers
- Biomarkers for clinical translation: Identified multi-omics may be developed into diagnostic or prognostic biomarkers, pending further validation, to support early risk detection in pediatric populations.
- Precision prevention strategies: Polygenic risk scores and diet–exposure interaction findings can inform targeted prevention approaches in clinical and public health practice.
- Policy and regulatory uptake: Results are directly relevant to regulatory frameworks addressing environmental pollutants and food environments. Engagement with policymakers will facilitate translation into guidelines and standards.
- Capacity building: Workshops, and dissemination activities will continue to equip young researchers, healthcare professionals, and educators with skills to apply exposome science to real-world health challenges.
Future needs for uptake include:
- Validation of biomarkers and risk models in independent and diverse populations.
- Longitudinal follow-up into adolescence and adulthood to confirm long-term health trajectories.
- Collaboration with clinical partners for translational studies.
- Integration of findings into European and international policy dialogues on child health and environmental protection.
Key advances beyond the state of the art include:
- Exposome modeling: Application of advanced mixture models and machine learning allowed simultaneous evaluation of multiple exposures, reflecting real-world conditions rather than isolated risk factors.
- Mechanistic depth: By combining molecular omics data with epidemiological analyses, the project identified biological pathways linking early-life exposures to inflammation, lipid metabolism, and insulin resistance—mechanistic evidence strengthening prevention strategies in child liver and metabolic health.
- Precision prevention: Demonstration of gene–environment interactions through polygenic risk scores highlighted vulnerable subgroups, paving the way for stratified prevention strategies.
- Biomarker discovery: Novel omics (microRNA and DNA methylation) signatures were identified as potential biomarkers of exposure-related metabolic dysfunction, providing tools for early detection and risk assessment.
- Methodological innovation: Development of harmonized protocols, and open-source pipelines sets methodological standards for exposome research in child health.
Together, these advances show that environmental hepatology—the study of how environmental factors contribute to liver disease—can be systematically investigated in children, establishing a new research frontier.
Potential Impacts
The findings of LIVER-X have important implications for public health, clinical research, and policy:
- Scientific and clinical impact: The project provides comprehensive evidence that liver injury and metabolic dysfunction originate in early life, influenced by environmental factors. This knowledge lays the groundwork for developing early screening tools and intervention strategies.
- Public health and prevention: By identifying vulnerable populations, LIVER-X supports interventions aimed at reducing harmful exposures during pregnancy and childhood, alongside promoting healthy diets and environments.
- Policy relevance: The results provide robust evidence for policymakers on the need to regulate hazardous chemicals (e.g. PFAS), and reduce pollution exposure in children’s environments. These findings align with EU priorities such as the European Green Deal, the Chemicals Strategy for Sustainability, and the Zero Pollution Action Plan.
- Capacity building and education: The project has trained early-career researchers in cutting-edge exposome methodologies and produced knowledge resources for wider dissemination to clinicians, educators, and the general public.
- Societal contribution: By linking environment, genetics, and lifestyle to child liver health, LIVER-X strengthens European leadership in exposome research and contributes to the UN Sustainable Development Goals (SDG 3 – Good Health and Wellbeing, SDG 11 – Sustainable Cities and Communities).
Exploitation and Future Uptake
The outputs of LIVER-X provide multiple opportunities for exploitation beyond academia:
- Research tools and resources: Analysis pipelines are openly available via GitHub, enabling re-use by other researchers
- Biomarkers for clinical translation: Identified multi-omics may be developed into diagnostic or prognostic biomarkers, pending further validation, to support early risk detection in pediatric populations.
- Precision prevention strategies: Polygenic risk scores and diet–exposure interaction findings can inform targeted prevention approaches in clinical and public health practice.
- Policy and regulatory uptake: Results are directly relevant to regulatory frameworks addressing environmental pollutants and food environments. Engagement with policymakers will facilitate translation into guidelines and standards.
- Capacity building: Workshops, and dissemination activities will continue to equip young researchers, healthcare professionals, and educators with skills to apply exposome science to real-world health challenges.
Future needs for uptake include:
- Validation of biomarkers and risk models in independent and diverse populations.
- Longitudinal follow-up into adolescence and adulthood to confirm long-term health trajectories.
- Collaboration with clinical partners for translational studies.
- Integration of findings into European and international policy dialogues on child health and environmental protection.