Development of an in vitro digestion and intestinal barrier model for a carnivorous teleost fish (DIGiFISH)

Project overview

Aquaculture is currently facing a major challenge: reducing dependence on fishmeal by developing sustainable alternative protein sources such as insects, algae, or agro-food by-products. However, evaluating the digestibility and physiological impact of these new ingredients in fish remains complex and often relies on costly in vivo experiments. The DIGiFISH project aims to develop innovative in vitro models of digestion and intestinal barrier for carnivorous teleost fish, using the European seabass (Dicentrarchus labrax) as a model species. The project will combine in vitro digestion models, intestinal cell culture systems, and host–pathogen interaction studies to better understand nutrient digestion and intestinal health in aquaculture species. In addition, the project will explore interactions between intestinal cells and the pathogen Vibrio harveyi, responsible for vibriosis, one of the most damaging bacterial diseases in marine aquaculture. These models will provide powerful tools for screening novel aquaculture feed ingredients and for studying emerging environmental issues such as microplastics and intestinal health.

Main objectives

The PhD candidate will:

• Develop a physiologically relevant in vitro gastrointestinal digestion model for European seabass
• Establish a fish intestinal barrier model using intestinal cell culture
• Evaluate the digestibility of alternative protein sources (algae, insect meals, protein hydrolysates)
• Study host-pathogen interactions with Vibrio harveyi
• Validate the models through collaborations with aquaculture research platforms

Research environment

The project will be carried out within the Sol4Health team of the BioEcoAgro joint research unit, across two sites in the Hauts-de-France region (Lille and Boulogne-sur-Mer). It will benefit from a dynamic interdisciplinary environment focusing on protein digestion, bioactive compounds, intestinal physiology, and marine microbiology.

The BioEcoAgro Joint Cross-Border Research Unit is a new structure which brings together around 400 researchers, technicians and PhD students from both sides of the Franco-Belgian border. Its ambition is to develop an international center of excellence in the field of biological engineering applied to agriculture, biotechnology, agri-food and the environment. Designed like a laboratory without walls bringing together researchers from INRAE, the University of Liège, the University of Lille and the University of Picardie Jules Verne, it focuses on the combination of (eco) systemic approaches and molecular for

• understanding the functioning of plants and ecosystems in natural or controlled environments and in the context of climate change
• decryption and control of the synthesis or the bioproduction of active biomolecules (specialized metabolites and polymers of plant origin, enzymes and secondary metabolites of microbial origin, active peptides from the hydrolysis of food proteins)
• biopreservation and food formulation.

The project will be carried out within the Sol4Health team of the BioEcoAgro joint research unit, across two sites in the Hauts-de-France region (Lille and Boulogne-sur-Mer). It will benefit from a dynamic interdisciplinary environment focusing on protein digestion, bioactive compounds, intestinal physiology, and marine microbiology.

We are looking for a highly motivated candidate with:

• Education

MSc (or equivalent) in biology, biotechnology, microbiology, biochemistry, aquaculture or food science

• Desired skills

Cell culture, Microbiology; Protein biochemistry; Enzymology; Molecular biology; Physiology; Gastrointestinal digestion models; Aquaculture nutrition and pathology

• Personal skills

Strong motivation for experimental research; Ability to work in an interdisciplinary team; Good English communication skills