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Hire Dr. Julia H.

Netherlands

USD 100 /hr

Nutrition Scientist (PhD) | Registered Epidemiologist | Human Studies, Gut Microbiome & Cardiometabolic Health

Profile Summary

I am a Nutrition Scientist (PhD) and Registered Epidemiologist (The Netherlands Epidemiological Society), specialising in evidence-based evaluation of nutrition, phytochemicals, and gut microbiome interventions for human health. I completed my PhD at the Quadram Institute (UK), where I designed and led a human intervention study investigating the effects of dietary polyphenols on gut microbiome function and cardiometabolic risk markers. My work combined human study design, microbiome-related outcomes, and big data analyses, with a strong focus on translating mechanistic findings into clinically and commercially relevant insights. I hold an MSc in Nutritional Epidemiology & Public Health and a BSc in Nutrition and Health from Wageningen University, and I have conducted independent research projects in academic, industry, and non-profit settings, including NIZO (Netherlands), UCLA Neuroscience Department (USA), and international research organisations. As a consultant, I support organisations with: - Scientific literature reviews and evidence synthesis - Health claim substantiation and risk assessment - Human study design and protocol review - Interpretation of nutrition and microbiome data for decision-making - Translation of complex science into clear, defensible outputs I work with startups, research groups, and health-focused companies seeking rigorous, practical, and regulatory-aware scientific input.

Subject Matter Expertise

• ☆ Microbiology
• ☆ Microbiome Research
• ☆ Nutrition Science
• ☆ Public Health
• ☆ Epidemiology

Services

• Writing
• Research
• Consulting
• Data & AI

Writing Technical Writing, General Proofreading & Editing

Research Fact Checking, Scientific and Technical Research, Systematic Literature Review, Secondary Data Collection

Consulting Scientific and Technical Consulting

Data & AI Statistical Analysis, Data Visualization, Big Data Analytics, Data Processing, Data Insights

Work Experience

Colon Model Facility Manager (interim)

Quadram Institute

May 2023 - July 2023

Intern

NIZO Food Research BV

May 2020 - November 2020

Visiting Graduate Researcher

Jane and Terry Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles

January 2020 - November 2020

Education

PhD studentship: EDESIA Plants, Food and Health PhD programme

University of East Anglia

October 2021 - Present

MSc Nutritional Epidemiology and Public Health (Human Nutrition and Health)

Wageningen University

September 2019 - August 2021

BSc Nutrition and Health

Wageningen University

September 2016 - August 2019

Certifications

• Vereniging voor Epidemiologie logo Epidemiologist (cat. A)

  The Netherlands Epidemiological Society

  February 2022 - Present

Publications

DISSERTATION THESIS

Julia E. Haarhuis (2025). Effects of pomegranate polyphenols on the gut microbiota-dependent production of proatherogenic trimethylamine from L-carnitine . University of East Anglia Digital Repository.

JOURNAL ARTICLE

Julia E. Haarhuis, Priscilla Day‐Walsh, Emad Shehata, George M. Savva, Barbora Peck, Mark Philo, Paul A. Kroon (2025). A Pomegranate Polyphenol Extract Suppresses the Microbial Production of Proatherogenic Trimethylamine (TMA) in an In Vitro Human Colon Model . Molecular Nutrition & Food Research.

J. Haarhuis, P. Day-Walsh, E. Shehata, B. Nemeckova, S. Saha, P. Kroon (2024). A pomegranate extract inhibits the conversion of dietary L-carnitine to prothrombotic trimethylamine (TMA) by the gut microbiota . Proceedings of the Nutrition Society.

Julia E. Haarhuis(2022). Probiotics, prebiotics and postbiotics for better sleep quality: a narrative review . Beneficial Microbes. 13. (3). p. 169--182. Wageningen Academic Publishers