Comparison between in vitro and in vivo models on bioavailability of lipid compounds

 The use of alternative methods in animal experimentation is now a necessity with regards to societal concerns about ethical approach to animal experimentation.

In this context, the EFSA Scientific Committee highlights the importance of minimizing tests on animals (in vivo tests) and of promoting alternative approaches, wherever possible. These alternatives include laboratory tests (in vitro) or tests performed by computer simulation (in silico). For example, it is recommended to replace or, when appropriate, to reduce the number of animals used in the experiments and to improve their well-being. The EU legislation on the protection of animals used for scientific purposes establishes guidelines for the ethical use of animals in experimental procedures (Directive 2010/63/EU). These are the “3Rs”: “Replacement (substitution and replacing animal models whenever possible), Reduction (reducing the number of animals in experiments) and refinement (optimizing the methodology applied to animals).

Studying the intestinal absorption of a compound and its metabolic fate in the organism is the result of different chemical, enzymatic and mechanical processes that occur simultaneously in the organism under the effect of complex regulatory pathways. In the case of studying the digestion of a compound, different approaches can be considered : in vivo, in vitro or in silico methods. However, in vitro or in silico models do not reproduce the biological complexity of the digestive tract and its metabolism. In a regulatory and societal context, it is important to know the advantages and limitations of the different models/approaches, in order to set up the best model that complete the study objectives, especially in projects dedicated to the evaluation of the absorption and metabolic fate of target molecules.

Through our research program, we defined different alternative methods to animal studies to follow the digestion and absorption of specific compounds. Also, a comparative study between in vitro and in vivo methods has been implemented to evaluate the intestinal absorption of nutrional molecules. The aim is to potentially identify an in vitro method that allows to all or a part of an approach on in vivo model.